TODAY IN SCIENCE HISTORY ®  •  TODAYINSCI ®
Celebrating 24 Years on the Web
Find science on or your birthday

Today in Science History - Quickie Quiz
Who said: “Truth is ever to be found in simplicity, and not in the multiplicity and confusion of things.”
more quiz questions >>
Home > Category Index for Science Quotations > Category Index T > Category: Temperature

Temperature Quotes (82 quotes)

…winds are produced by differences of air temperature, and hence density, between two regions of earth.
Lecture to the Accademia della Crusca. Quoted in Archana Srinivasan, Great Inventors (2007), 29.
Science quotes on:  |  Air (366)  |  Density (25)  |  Difference (355)  |  Earth (1076)  |  Produced (187)  |  Two (936)  |  Wind (141)

[John] Dalton was a man of regular habits. For fifty-seven years he walked out of Manchester every day; he measured the rainfall, the temperature—a singularly monotonous enterprise in this climate. Of all that mass of data, nothing whatever came. But of the one searching, almost childlike question about the weights that enter the construction of these simple molecules—out of that came modern atomic theory. That is the essence of science: ask an impertinent question, and you are on the way to the pertinent answer.
The Ascent of Man (1973), 153.
Science quotes on:  |  Answer (389)  |  Ask (420)  |  Atomic Theory (16)  |  Climate (102)  |  Construction (114)  |  John Dalton (25)  |  Data (162)  |  Enquiry (89)  |  Enter (145)  |  Enterprise (56)  |  Essence (85)  |  Habit (174)  |  Impertinence (4)  |  Impertinent (5)  |  Man (2252)  |  Manchester (6)  |  Mass (160)  |  Modern (402)  |  Molecule (185)  |  Nothing (1000)  |  Pertinent (4)  |  Question (649)  |  Regular (48)  |  Simple (426)  |  Theory (1015)  |  Walk (138)  |  Way (1214)  |  Weather (49)  |  Weight (140)  |  Whatever (234)  |  Year (963)

Question: If you were to pour a pound of molten lead and a pound of molten iron, each at the temperature of its melting point, upon two blocks of ice, which would melt the most ice, and why?
Answer: This question relates to diathermancy. Iron is said to be a diathermanous body (from dia, through, and thermo, I heat), meaning that it gets heated through and through, and accordingly contains a large quantity of real heat. Lead is said to be an athermanous body (from a, privative, and thermo, I heat), meaning that it gets heated secretly or in a latent manner. Hence the answer to this question depends on which will get the best of it, the real heat of the iron or the latent heat of the lead. Probably the iron will smite furthest into the ice, as molten iron is white and glowing, while melted lead is dull.
Genuine student answer* to an Acoustics, Light and Heat paper (1880), Science and Art Department, South Kensington, London, collected by Prof. Oliver Lodge. Quoted in Henry B. Wheatley, Literary Blunders (1893), 180-1, Question 14. (*From a collection in which Answers are not given verbatim et literatim, and some instances may combine several students' blunders.)
Science quotes on:  |  Answer (389)  |  Best (467)  |  Block (13)  |  Body (557)  |  Depend (238)  |  Dependence (46)  |  Dull (58)  |  Examination (102)  |  Heat (180)  |  Howler (15)  |  Ice (58)  |  Iron (99)  |  Large (398)  |  Latent (13)  |  Latent Heat (7)  |  Lead (391)  |  Manner (62)  |  Meaning (244)  |  Melting Point (3)  |  Molten (3)  |  Most (1728)  |  Point (584)  |  Pound (15)  |  Pour (9)  |  Quantity (136)  |  Question (649)  |  Secret (216)  |  Smite (4)  |  Through (846)  |  Two (936)  |  White (132)  |  Why (491)  |  Will (2350)

Question: State the relations existing between the pressure, temperature, and density of a given gas. How is it proved that when a gas expands its temperature is diminished?
Answer: Now the answer to the first part of this question is, that the square root of the pressure increases, the square root of the density decreases, and the absolute temperature remains about the same; but as to the last part of the question about a gas expanding when its temperature is diminished, I expect I am intended to say I don't believe a word of it, for a bladder in front of a fire expands, but its temperature is not at all diminished.
Genuine student answer* to an Acoustics, Light and Heat paper (1880), Science and Art Department, South Kensington, London, collected by Prof. Oliver Lodge. Quoted in Henry B. Wheatley, Literary Blunders (1893), 175, Question 1. (*From a collection in which Answers are not given verbatim et literatim, and some instances may combine several students' blunders.)
Science quotes on:  |  Absolute (153)  |  Answer (389)  |  Bladder (3)  |  Density (25)  |  Diminution (5)  |  Examination (102)  |  Existence (481)  |  Expand (56)  |  Expansion (43)  |  Expect (203)  |  Expectation (67)  |  Fire (203)  |  First (1302)  |  Gas (89)  |  Howler (15)  |  Increase (225)  |  Intention (46)  |  Last (425)  |  Pressure (69)  |  Proof (304)  |  Question (649)  |  Relation (166)  |  Remain (355)  |  Root (121)  |  Say (989)  |  Square (73)  |  Square Root (12)  |  State (505)  |  Word (650)

Question: Why do the inhabitants of cold climates eat fat? How would you find experimentally the relative quantities of heat given off when equal weights of sulphur, phosphorus, and carbon are thoroughly burned?
Answer: An inhabitant of cold climates (called Frigid Zoans) eats fat principally because he can't get no lean, also because he wants to rise is temperature. But if equal weights of sulphur phosphorus and carbon are burned in his neighbourhood he will give off eating quite so much. The relative quantities of eat given off will depend upon how much sulphur etc. is burnt and how near it is burned to him. If I knew these facts it would be an easy sum to find the answer.
Genuine student answer* to an Acoustics, Light and Heat paper (1880), Science and Art Department, South Kensington, London, collected by Prof. Oliver Lodge. Quoted in Henry B. Wheatley, Literary Blunders (1893), 183, Question 32. (*From a collection in which Answers are not given verbatim et literatim, and some instances may combine several students' blunders.)
Science quotes on:  |  Answer (389)  |  Burn (99)  |  Burning (49)  |  Call (781)  |  Carbon (68)  |  Climate (102)  |  Cold (115)  |  Depend (238)  |  Do (1905)  |  Easy (213)  |  Eat (108)  |  Eating (46)  |  Emission (20)  |  Equal (88)  |  Examination (102)  |  Experiment (736)  |  Fact (1257)  |  Facts (553)  |  Fat (11)  |  Find (1014)  |  Finding (34)  |  Heat (180)  |  Howler (15)  |  Inhabitant (50)  |  Knowledge (1647)  |  Lean (7)  |  Neighborhood (12)  |  Phosphorus (18)  |  Quantity (136)  |  Question (649)  |  Relative (42)  |  Rise (169)  |  Sulphur (19)  |  Sum (103)  |  Thoroughly (67)  |  Want (504)  |  Weight (140)  |  Why (491)  |  Will (2350)  |  Zone (5)

A nurse is to maintain the air within the room as fresh as the air without, without lowering the temperature.
In Notes on Nursing: What It Is and What It Is Not (1859), 10.
Science quotes on:  |  Air (366)  |  Fresh (69)  |  Maintain (105)  |  Nurse (33)  |  Room (42)

A single tree by itself is dependent upon all the adverse chances of shifting circumstances. The wind stunts it: the variations in temperature check its foliage: the rains denude its soil: its leaves are blown away and are lost for the purpose of fertilisation. You may obtain individual specimens of line trees either in exceptional circumstances, or where human cultivation had intervened. But in nature the normal way in which trees flourish is by their association in a forest. Each tree may lose something of its individual perfection of growth, but they mutually assist each other in preserving the conditions of survival. The soil is preserved and shaded; and the microbes necessary for its fertility are neither scorched, nor frozen, nor washed away. A forest is the triumph of the organisation of mutually dependent species.
In Science and the Modern World (1926), 296-7.
Science quotes on:  |  Assistance (23)  |  Association (49)  |  Chance (244)  |  Circumstance (139)  |  Circumstances (108)  |  Condition (362)  |  Cultivation (36)  |  Dependence (46)  |  Ecology (81)  |  Exceptional (19)  |  Fertility (23)  |  Flourish (34)  |  Foliage (6)  |  Forest (161)  |  Freezing (16)  |  Growth (200)  |  Human (1512)  |  Individual (420)  |  Lose (165)  |  Microbe (30)  |  Microbes (14)  |  Nature (2017)  |  Necessary (370)  |  Obtain (164)  |  Organization (120)  |  Other (2233)  |  Perfection (131)  |  Preservation (39)  |  Preserving (18)  |  Purpose (336)  |  Rain (70)  |  Shift (45)  |  Single (365)  |  Soil (98)  |  Something (718)  |  Species (435)  |  Specimen (32)  |  Stunt (7)  |  Survival (105)  |  Tree (269)  |  Triumph (76)  |  Variation (93)  |  Wash (23)  |  Way (1214)  |  Wind (141)

Adam, the first man, didn’t know anything about the nucleus but Dr. George Gamow, visiting professor from George Washington University, pretends he does. He says for example that the nucleus is 0.00000000000003 feet in diameter. Nobody believes it, but that doesn't make any difference to him.
He also says that the nuclear energy contained in a pound of lithium is enough to run the United States Navy for a period of three years. But to get this energy you would have to heat a mixture of lithium and hydrogen up to 50,000,000 degrees Fahrenheit. If one has a little stove of this temperature installed at Stanford, it would burn everything alive within a radius of 10,000 miles and broil all the fish in the Pacific Ocean.
If you could go as fast as nuclear particles generally do, it wouldn’t take you more than one ten-thousandth of a second to go to Miller's where you could meet Gamow and get more details.
'Gamow interviews Gamow' Stanford Daily, 25 Jun 1936. In Helge Kragh, Cosmology and Controversy: The Historica1 Development of Two Theories of the Universe (1996), 90.
Science quotes on:  |  Alive (97)  |  Burn (99)  |  Degree (277)  |  Detail (150)  |  Diameter (28)  |  Difference (355)  |  Do (1905)  |  Energy (373)  |  Enough (341)  |  Everything (489)  |  First (1302)  |  Fish (130)  |  Fusion (16)  |  Heat (180)  |  Hydrogen (80)  |  Know (1538)  |  Lithium (3)  |  Little (717)  |  Man (2252)  |  Mixture (44)  |  More (2558)  |  Nobody (103)  |  Nuclear (110)  |  Nuclear Energy (18)  |  Nuclear Power (16)  |  Nucleus (54)  |  Ocean (216)  |  Pacific Ocean (5)  |  Particle (200)  |  Period (200)  |  Professor (133)  |  Run (158)  |  Say (989)  |  State (505)  |  University (130)  |  Year (963)

All substances susceptible of decay, when in a moist state, and exposed to the air and light at the common temperature, undergo precisely the same change as they would if exposed to a red-heat, in a dry state, that is, they absorb oxygen,—they undergo combustion.
Justus von Liebig and John Gardner (ed.), Familiar Letters on Chemistry: Second Series. The Philosophical Principles and General Laws of the Science (1844), 183.
Science quotes on:  |  Absorb (54)  |  Air (366)  |  Change (639)  |  Combustion (22)  |  Decay (59)  |  Dry (65)  |  Expose (28)  |  Light (635)  |  Moist (13)  |  Oxygen (77)  |  Precisely (93)  |  Same (166)  |  Substance (253)  |  Undergo (18)

At terrestrial temperatures matter has complex properties which are likely to prove most difficult to unravel; but it is reasonable to hope that in the not too distant future we shall be competent to understand so simple a thing as a star.
The Internal Constitution of Stars, Cambridge. (1926, 1988), 393.
Science quotes on:  |  Complex (202)  |  Difficult (263)  |  Future (467)  |  Hope (321)  |  Matter (821)  |  Most (1728)  |  Prove (261)  |  Simple (426)  |  Star (460)  |  Terrestrial (62)  |  Thing (1914)  |  Understand (648)  |  Unravel (16)

At the planet’s very heart lies a solid rocky core, at least five times larger than Earth, seething with the appalling heat generated by the inexorable contraction of the stupendous mass of material pressing down to its centre. For more than four billion years Jupiter’s immense gravitational power has been squeezing the planet slowly, relentlessly, steadily, converting gravitational energy into heat, raising the temperature of that rocky core to thirty thousand degrees, spawning the heat flow that warms the planet from within. That hot, rocky core is the original protoplanet seed from the solar system’s primeval time, the nucleus around which those awesome layers of hydrogen and helium and ammonia, methane, sulphur compounds and water have wrapped themselves.
Ben Bova
Jupiter
Science quotes on:  |  Ammonia (15)  |  Appalling (10)  |  Awesome (15)  |  Billion (104)  |  Centre (31)  |  Compound (117)  |  Contraction (18)  |  Convert (22)  |  Core (20)  |  Degree (277)  |  Down (455)  |  Earth (1076)  |  Energy (373)  |  Five (16)  |  Flow (89)  |  Generate (16)  |  Gravitation (72)  |  Heart (243)  |  Heat (180)  |  Helium (11)  |  Hot (63)  |  Hydrogen (80)  |  Immense (89)  |  Inexorable (10)  |  Jupiter (28)  |  Large (398)  |  Layer (41)  |  Least (75)  |  Lie (370)  |  Mass (160)  |  Material (366)  |  Methane (9)  |  More (2558)  |  Nucleus (54)  |  Original (61)  |  Planet (402)  |  Power (771)  |  Press (21)  |  Primeval (15)  |  Raise (38)  |  Relentlessly (2)  |  Rocky (3)  |  Seed (97)  |  Seething (3)  |  Slowly (19)  |  Solar System (81)  |  Solar Systems (5)  |  Solid (119)  |  Spawn (2)  |  Squeeze (7)  |  Steadily (7)  |  Stupendous (13)  |  Sulphur (19)  |  System (545)  |  Themselves (433)  |  Thirty (6)  |  Thousand (340)  |  Time (1911)  |  Warm (74)  |  Water (503)  |  Wrap (7)  |  Year (963)

Biological disciplines tend to guide research into certain channels. One consequence is that disciplines are apt to become parochial, or at least to develop blind spots, for example, to treat some questions as “interesting” and to dismiss others as “uninteresting.” As a consequence, readily accessible but unworked areas of genuine biological interest often lie in plain sight but untouched within one discipline while being heavily worked in another. For example, historically insect physiologists have paid relatively little attention to the behavioral and physiological control of body temperature and its energetic and ecological consequences, whereas many students of the comparative physiology of terrestrial vertebrates have been virtually fixated on that topic. For the past 10 years, several of my students and I have exploited this situation by taking the standard questions and techniques from comparative vertebrate physiology and applying them to insects. It is surprising that this pattern of innovation is not more deliberately employed.
In 'Scientific innovation and creativity: a zoologist’s point of view', American Zoologist (1982), 22, 233.
Science quotes on:  |  Accessible (27)  |  Apply (170)  |  Apt (9)  |  Area (33)  |  Attention (196)  |  Become (821)  |  Behavioral (6)  |  Being (1276)  |  Biological (137)  |  Blind (98)  |  Blind Spot (2)  |  Body (557)  |  Certain (557)  |  Channel (23)  |  Comparative (14)  |  Consequence (220)  |  Control (182)  |  Deliberately (6)  |  Develop (278)  |  Discipline (85)  |  Dismiss (12)  |  Ecological (7)  |  Employ (115)  |  Energetic (6)  |  Example (98)  |  Exploit (19)  |  Genuine (54)  |  Guide (107)  |  Heavily (14)  |  Historically (3)  |  Innovation (49)  |  Insect (89)  |  Interest (416)  |  Interesting (153)  |  Least (75)  |  Lie (370)  |  Little (717)  |  More (2558)  |  Often (109)  |  Other (2233)  |  Past (355)  |  Pattern (116)  |  Pay (45)  |  Physiological (64)  |  Physiologist (31)  |  Physiology (101)  |  Plain (34)  |  Question (649)  |  Readily (10)  |  Relatively (8)  |  Research (753)  |  Several (33)  |  Sight (135)  |  Situation (117)  |  Standard (64)  |  Student (317)  |  Surprise (91)  |  Technique (84)  |  Tend (124)  |  Terrestrial (62)  |  Topic (23)  |  Treat (38)  |  Uninteresting (9)  |  Untouched (5)  |  Unworked (2)  |  Vertebrate (22)  |  Virtually (6)  |  Work (1402)  |  Year (963)

By the end of the next century, the “greenhouse effect” may increase temperatures worldwide to levels that have not been reached for at least 100,000 years. And the effects on sea level and on agriculture and other human activities are likely to be so profound that we should be planning for them now.
In 'Temperatures Rise in the Global Greenhouse', New Scientist (15 May 1986), 110, No. 1508, 32.
Science quotes on:  |  Activity (218)  |  Agriculture (78)  |  Century (319)  |  Climate Change (76)  |  Effect (414)  |  End (603)  |  Greenhouse Effect (5)  |  Human (1512)  |  Increase (225)  |  Next (238)  |  Other (2233)  |  Plan (122)  |  Planning (21)  |  Profound (105)  |  Reach (286)  |  Sea (326)  |  Sea Level (5)  |  World (1850)  |  Worldwide (19)  |  Year (963)

Camels, unlike most animals, regulate their body temperatures at two different but stable states. During daytime in the desert, when it is unbearably hot, camels regulate close to 40°C, a close enough match to the air temperature to avoid having to cool by sweating precious water. At night the desert is cold, and even cold enough for frost; the camel would seriously lose heat if it tried to stay at 40°C, so it moves its regulation to a more suitable 34°C, which is warm.
In The Revenge of Gaia: Earth’s Climate Crisis & The Fate of Humanity (2006, 2007), 21.
Science quotes on:  |  Air (366)  |  Animal (651)  |  Avoid (123)  |  Camel (12)  |  Close (77)  |  Cold (115)  |  Cool (15)  |  Daytime (3)  |  Desert (59)  |  Different (595)  |  Frost (15)  |  Heat (180)  |  Hot (63)  |  Lose (165)  |  Match (30)  |  Move (223)  |  Night (133)  |  Precious (43)  |  Regulate (11)  |  Regulation (25)  |  Seriously (20)  |  Stable (32)  |  State (505)  |  Stay (26)  |  Suitable (10)  |  Sweat (17)  |  Try (296)  |  Unlike (9)  |  Warm (74)  |  Water (503)

Considering the difficulties represented by the lack of water, by extremes of temperature, by the full force of gravity unmitigated by the buoyancy of water, it must be understood that the spread to land of life forms that evolved to meet the conditions of the ocean represented the greatest single victory won by life over the inanimate environment.
(1965). In Isaac Asimov’s Book of Science and Nature Quotations (1988), 194.
Science quotes on:  |  Buoyancy (7)  |  Condition (362)  |  Difficulty (201)  |  Environment (239)  |  Evolution (635)  |  Extreme (78)  |  Force (497)  |  Form (976)  |  Gravity (140)  |  Greatest (330)  |  Inanimate (18)  |  Lack (127)  |  Land (131)  |  Life (1870)  |  Life Form (6)  |  Must (1525)  |  Ocean (216)  |  Represent (157)  |  Single (365)  |  Spread (86)  |  Understand (648)  |  Understood (155)  |  Victory (40)  |  Water (503)

Cosmology is a science which has only a few observable facts to work with. The discovery of the cosmic microwave background radiation added one—the present radiation temperature of the universe. This, however, was a significant increase in our knowledge since it requires a cosmology with a source for the radiation at an early epoch and is a new probe of that epoch. More sensitive measurements of the background radiation in the future will allow us to discover additional facts about the universe.
'Discovery of the Cosmic Microwave Background', in B. Bertotti (ed.) Modern Cosmology in Retrospect (1990), 304.
Science quotes on:  |  Background (44)  |  Background Radiation (3)  |  Cosmic (74)  |  Cosmology (26)  |  Discover (571)  |  Discovery (837)  |  Early (196)  |  Epoch (46)  |  Fact (1257)  |  Facts (553)  |  Future (467)  |  Increase (225)  |  Knowledge (1647)  |  Measurement (178)  |  Microwave (4)  |  More (2558)  |  New (1273)  |  Observable (21)  |  Observation (593)  |  Present (630)  |  Probe (12)  |  Radiation (48)  |  Require (229)  |  Significant (78)  |  Universe (900)  |  Will (2350)  |  Work (1402)

For if there is any truth in the dynamical theory of gases the different molecules in a gas at uniform temperature are moving with very different velocities. Put such a gas into a vessel with two compartments [A and B] and make a small hole in the wall about the right size to let one molecule through. Provide a lid or stopper for this hole and appoint a doorkeeper, very intelligent and exceedingly quick, with microscopic eyes but still an essentially finite being.
Whenever he sees a molecule of great velocity coming against the door from A into B he is to let it through, but if the molecule happens to be going slow he is to keep the door shut. He is also to let slow molecules pass from B to A but not fast ones ... In this way the temperature of B may be raised and that of A lowered without any expenditure of work, but only by the intelligent action of a mere guiding agent (like a pointsman on a railway with perfectly acting switches who should send the express along one line and the goods along another).
I do not see why even intelligence might not be dispensed with and the thing be made self-acting.
Moral The 2nd law of Thermodynamics has the same degree of truth as the statement that if you throw a tumblerful of water into the sea you cannot get the same tumblerful of water out again.
Letter to John William Strutt (6 Dec 1870). In P. M. Hannan (ed.), The Scientific Letters and Papers of James Clerk Maxwell (1995), Vol. 2, 582-3.
Science quotes on:  |  Action (342)  |  Against (332)  |  Agent (73)  |  Being (1276)  |  Coming (114)  |  Degree (277)  |  Different (595)  |  Do (1905)  |  Door (94)  |  Dynamical (15)  |  Exceedingly (28)  |  Expenditure (16)  |  Express (192)  |  Eye (440)  |  Finite (60)  |  Gas (89)  |  Good (906)  |  Great (1610)  |  Happen (282)  |  Intelligence (218)  |  Intelligent (108)  |  Law (913)  |  Maxwell�s Demon (2)  |  Microscopic (27)  |  Molecule (185)  |  Moral (203)  |  Pass (241)  |  Railway (19)  |  Right (473)  |  Sea (326)  |  See (1094)  |  Self (268)  |  Shut (41)  |  Slow (108)  |  Small (489)  |  Statement (148)  |  Still (614)  |  Theory (1015)  |  Thermodynamics (40)  |  Thing (1914)  |  Through (846)  |  Truth (1109)  |  Two (936)  |  Velocity (51)  |  Vessel (63)  |  Wall (71)  |  Water (503)  |  Way (1214)  |  Whenever (81)  |  Why (491)  |  Work (1402)

For terrestrial vertebrates, the climate in the usual meteorological sense of the term would appear to be a reasonable approximation of the conditions of temperature, humidity, radiation, and air movement in which terrestrial vertebrates live. But, in fact, it would be difficult to find any other lay assumption about ecology and natural history which has less general validity. … Most vertebrates are much smaller than man and his domestic animals, and the universe of these small creatures is one of cracks and crevices, holes in logs, dense underbrush, tunnels, and nests—a world where distances are measured in yards rather than miles and where the difference between sunshine and shadow may be the difference between life and death. Actually, climate in the usual sense of the term is little more than a crude index to the physical conditions in which most terrestrial animals live.
From 'Interaction of physiology and behavior under natural conditions', collected in R.I. Bowman (ed.), The Galapagos (1966), 40.
Science quotes on:  |  Actually (27)  |  Air (366)  |  Animal (651)  |  Appear (122)  |  Approximation (32)  |  Assumption (96)  |  Climate (102)  |  Condition (362)  |  Crack (15)  |  Creature (242)  |  Crude (32)  |  Death (406)  |  Dense (5)  |  Difference (355)  |  Difficult (263)  |  Distance (171)  |  Domestic (27)  |  Ecology (81)  |  Fact (1257)  |  Find (1014)  |  General (521)  |  History (716)  |  Hole (17)  |  Humidity (3)  |  Index (5)  |  Less (105)  |  Lie (370)  |  Life (1870)  |  Little (717)  |  Live (650)  |  Log (7)  |  Man (2252)  |  Measure (241)  |  Mile (43)  |  More (2558)  |  Most (1728)  |  Movement (162)  |  Natural (810)  |  Natural History (77)  |  Nest (26)  |  Other (2233)  |  Physical (518)  |  Radiation (48)  |  Reasonable (29)  |  Sense (785)  |  Shadow (73)  |  Small (489)  |  Sunshine (12)  |  Term (357)  |  Terrestrial (62)  |  Tunnel (13)  |  Underbrush (2)  |  Universe (900)  |  Validity (50)  |  Vertebrate (22)  |  World (1850)  |  Yard (10)

From a certain temperature on, the molecules 'condense' without attractive forces; that is, they accumulate at zero velocity. The theory is pretty, but is there some truth in it.
Letter to Ehrenfest (Dec 1924). Quoted in Abraham Pais, Roger Penrose, Subtle Is the Lord: The Science and the Life of Albert Einstein (2005), 432.
Science quotes on:  |  Attractive (25)  |  Certain (557)  |  Force (497)  |  Molecule (185)  |  Theory (1015)  |  Truth (1109)  |  Velocity (51)  |  Zero (38)

Global nuclear war could have a major impact on climate—manifested by significant surface darkening over many weeks, subfreezing land temperatures persisting for up to several months, large perturbations in global circulation patterns, and dramatic changes in local weather and precipitation rates—a harsh “nuclear winter” in any season. [Co-author with Carl Sagan]
In 'Nuclear Winter: Global Consequences of Multiple Nuclear Explosions', Science (1983), 222, 1290.
Science quotes on:  |  Author (175)  |  Change (639)  |  Circulation (27)  |  Climate (102)  |  Climate Change (76)  |  Dark (145)  |  Dramatic (19)  |  Freezing (16)  |  Global (39)  |  Harsh (9)  |  Impact (45)  |  Large (398)  |  Major (88)  |  Month (91)  |  Nuclear (110)  |  Nuclear Winter (3)  |  Pattern (116)  |  Persisting (2)  |  Perturbation (7)  |  Precipitation (7)  |  Carl Sagan (120)  |  Season (47)  |  Significant (78)  |  Surface (223)  |  War (233)  |  Weather (49)  |  Week (73)  |  Winter (46)

Harvard Law: Under the most rigorously controlled conditions of pressure, temperature, humidity, and other variables, the organism will do as it damn well pleases.
Anonymous
The Coevolution Quarterly, Nos. 8-12 (1975), 138.
Science quotes on:  |  Condition (362)  |  Control (182)  |  Do (1905)  |  Harvard (7)  |  Humidity (3)  |  Law (913)  |  Most (1728)  |  Murphy�s Law (4)  |  Organism (231)  |  Other (2233)  |  Please (68)  |  Pressure (69)  |  Rigour (21)  |  Variable (37)  |  Will (2350)

Heat energy of uniform temperature [is] the ultimate fate of all energy. The power of sunlight and coal, electric power, water power, winds and tides do the work of the world, and in the end all unite to hasten the merry molecular dance.
Matter and Energy (1911), 140.
Science quotes on:  |  Coal (64)  |  Dance (35)  |  Do (1905)  |  Electric (76)  |  Electricity (168)  |  End (603)  |  Energy (373)  |  Entropy (46)  |  Fate (76)  |  Haste (6)  |  Hasten (13)  |  Heat (180)  |  Merry (3)  |  Molecule (185)  |  Power (771)  |  Solar Power (10)  |  Sunlight (29)  |  Thermodynamics (40)  |  Tidal Power (4)  |  Tide (37)  |  Ultimate (152)  |  Uniform (20)  |  Unite (43)  |  Water (503)  |  Water Power (6)  |  Wind (141)  |  Wind Power (10)  |  Work (1402)  |  World (1850)

Heat may be considered, either in respect of its quantity, or of its intensity. Thus two lbs. of water, equally heated, must contain double the quantity that one of them does, though the thermometer applied to them separately, or together, stands at precisely the same point, because it requires double the time to heat two lbs. as it does to heat one.
In Alexander Law, Notes of Black's Lectures, vol. 1, 5. Cited in Charles Coulston Gillispie, Dictionary of Scientific Biography: Volumes 1-2 (1981), 178.
Science quotes on:  |  Applied (176)  |  Consider (428)  |  Equally (129)  |  Heat (180)  |  Intensity (34)  |  Must (1525)  |  Point (584)  |  Precisely (93)  |  Quantity (136)  |  Require (229)  |  Respect (212)  |  Stand (284)  |  Thermometer (11)  |  Time (1911)  |  Together (392)  |  Two (936)  |  Water (503)

I have found that a measurable period of time elapses before the stimulus applied to the iliac plexus of the frog is transmitted to the insertion of the crural nerve into the gastrocnemius muscle by a brief electric current. In large frogs, in which the nerves were from 50-60 mm. in length, and which were preserved at a temperature of 2-6° C, although the temperature of the observation chanber was between 11° and 150° C, the elapsed time was 0.0014 to 0.0020 of a second.
'Vorläufiger Bericht über die Fortpflanzungsgeschwindigkeit der Nervenreizung' (1850). Trans. Edwin Clarke and C. D. O'Malley, The Human Brain and Spinal Cord (1968), 207.
Science quotes on:  |  Applied (176)  |  Brief (37)  |  Current (122)  |  Electric (76)  |  Frog (44)  |  Large (398)  |  Muscle (47)  |  Nerve (82)  |  Observation (593)  |  Period (200)  |  Stimulus (30)  |  Time (1911)

I suppose that I tend to be optimistic about the future of physics. And nothing makes me more optimistic than the discovery of broken symmetries. In the seventh book of the Republic, Plato describes prisoners who are chained in a cave and can see only shadows that things outside cast on the cave wall. When released from the cave at first their eyes hurt, and for a while they think that the shadows they saw in the cave are more real than the objects they now see. But eventually their vision clears, and they can understand how beautiful the real world is. We are in such a cave, imprisoned by the limitations on the sorts of experiments we can do. In particular, we can study matter only at relatively low temperatures, where symmetries are likely to be spontaneously broken, so that nature does not appear very simple or unified. We have not been able to get out of this cave, but by looking long and hard at the shadows on the cave wall, we can at least make out the shapes of symmetries, which though broken, are exact principles governing all phenomena, expressions of the beauty of the world outside.
In Nobel Lecture (8 Dec 1989), 'Conceptual Foundations of the Unified Theory of Weak and Electromagnetic Interactions.' Nobel Lectures: Physics 1971-1980 (1992), 556.
Science quotes on:  |  Beautiful (271)  |  Beauty (313)  |  Book (413)  |  Broken (56)  |  Cast (69)  |  Cave (17)  |  Describe (132)  |  Discovery (837)  |  Do (1905)  |  Eventually (64)  |  Experiment (736)  |  Expression (181)  |  Eye (440)  |  First (1302)  |  Future (467)  |  Governing (20)  |  Hard (246)  |  Limitation (52)  |  Long (778)  |  Looking (191)  |  Low (86)  |  Matter (821)  |  More (2558)  |  Nature (2017)  |  Nothing (1000)  |  Object (438)  |  Outside (141)  |  Phenomenon (334)  |  Physic (515)  |  Physics (564)  |  Plato (80)  |  Principle (530)  |  Prisoner (8)  |  Reality (274)  |  Republic (16)  |  Saw (160)  |  See (1094)  |  Shadow (73)  |  Shape (77)  |  Simple (426)  |  Study (701)  |  Suppose (158)  |  Symmetry (44)  |  Tend (124)  |  Thing (1914)  |  Think (1122)  |  Understand (648)  |  Understanding (527)  |  Vision (127)  |  Wall (71)  |  World (1850)

I think it is a sad reflection on our civilization that while we can and do measure the temperature in the atmosphere of Venus we do not know what goes on inside our soufflés.
[Remark made while demonstrating the progress of cooking a Soufflé à la Chartreuse, demonstrating its progress with thermocouples and chart recorders.]
Friday Evening Discourse at the Royal Institution, ‘The Physicist in the Kitchen’. In Proceedings of the Royal Institution (1969), 42/199, 451–67. Cited in article on Kurti by Ralph G. Scurlock in Oxford Dictionary of National Biography.
Science quotes on:  |  Atmosphere (117)  |  Chemistry (376)  |  Civilization (220)  |  Cooking (12)  |  Do (1905)  |  Know (1538)  |  Measure (241)  |  Progress (492)  |  Reaction (106)  |  Reflection (93)  |  Sadness (36)  |  Think (1122)  |  Venus (21)

I think it would be a very rash presumption to think that nowhere else in the cosmos has nature repeated the strange experiment which she has performed on earth—that the whole purpose of creation has been staked on this one planet alone. It is probable that dotted through the cosmos there are other suns which provide the energy for life to attendant planets. It is apparent, however, that planets with just the right conditions of temperature, oxygen, water and atmosphere necessary for life are found rarely.
But uncommon as a habitable planet may be, non-terrestrial life exists, has existed and will continue to exist. In the absence of information, we can only surmise that the chance that it surpasses our own is as good as that it falls below our level.
As quoted by H. Gordon Garbedian in 'Ten Great Riddles That Call For Solution by Scientists', New York Times (5 Oct 1930), XX4. Garbedian gave no citation to a source for Shapley’s words. However, part of this quote is very similar to that of Sir Arthur Eddington: “It would indeed be rash to assume that nowhere else has Nature repeated the strange experiment which she has performed on the earth,” from 'Man’s Place in the Universe', Harper’s Magazine (Oct 1928), 157 573.
Science quotes on:  |  Absence (21)  |  Alone (324)  |  Apparent (85)  |  Atmosphere (117)  |  Chance (244)  |  Condition (362)  |  Continue (179)  |  Cosmos (64)  |  Creation (350)  |  Earth (1076)  |  Energy (373)  |  Exist (458)  |  Existence (481)  |  Experiment (736)  |  Extraterrestrial Life (20)  |  Fall (243)  |  Good (906)  |  Habitable (3)  |  Information (173)  |  Life (1870)  |  Nature (2017)  |  Necessary (370)  |  Necessity (197)  |  Nowhere (28)  |  Other (2233)  |  Oxygen (77)  |  Perform (123)  |  Performing (3)  |  Planet (402)  |  Presumption (15)  |  Purpose (336)  |  Rare (94)  |  Rash (15)  |  Repeat (44)  |  Right (473)  |  Stake (20)  |  Strange (160)  |  Sun (407)  |  Surmise (7)  |  Surpass (33)  |  Terrestrial (62)  |  Think (1122)  |  Through (846)  |  Uncommon (14)  |  Water (503)  |  Whole (756)  |  Will (2350)

In despair, I offer your readers their choice of the following definitions of entropy. My authorities are such books and journals as I have by me at the moment.
(a) Entropy is that portion of the intrinsic energy of a system which cannot be converted into work by even a perfect heat engine.—Clausius.
(b) Entropy is that portion of the intrinsic energy which can be converted into work by a perfect engine.—Maxwell, following Tait.
(c) Entropy is that portion of the intrinsic energy which is not converted into work by our imperfect engines.—Swinburne.
(d) Entropy (in a volume of gas) is that which remains constant when heat neither enters nor leaves the gas.—W. Robinson.
(e) Entropy may be called the ‘thermal weight’, temperature being called the ‘thermal height.’—Ibid.
(f) Entropy is one of the factors of heat, temperature being the other.—Engineering.
I set up these bald statement as so many Aunt Sallys, for any one to shy at.
[Lamenting a list of confused interpretations of the meaning of entropy, being hotly debated in journals at the time.]
In The Electrician (9 Jan 1903).
Science quotes on:  |  Being (1276)  |  Book (413)  |  Call (781)  |  Choice (114)  |  Rudolf Clausius (9)  |  Constant (148)  |  Converted (2)  |  Definition (238)  |  Despair (40)  |  Energy (373)  |  Engine (99)  |  Engineering (188)  |  Enter (145)  |  Entropy (46)  |  Factor (47)  |  Gas (89)  |  Heat (180)  |  Heat Engine (4)  |  Height (33)  |  Imperfect (46)  |  Interpretation (89)  |  Intrinsic (18)  |  Journal (31)  |  Leave (138)  |  Maxwell (42)  |  James Clerk Maxwell (91)  |  Meaning (244)  |  Moment (260)  |  Offer (142)  |  Other (2233)  |  Perfect (223)  |  Portion (86)  |  Remain (355)  |  Set (400)  |  Shy (5)  |  Statement (148)  |  System (545)  |  Peter Guthrie Tait (11)  |  Thermal (15)  |  Time (1911)  |  Weight (140)  |  Work (1402)

In fact, the thickness of the Earth's atmosphere, compared with the size of the Earth, is in about the same ratio as the thickness of a coat of shellac on a schoolroom globe is to the diameter of the globe. That's the air that nurtures us and almost all other life on Earth, that protects us from deadly ultraviolet light from the sun, that through the greenhouse effect brings the surface temperature above the freezing point. (Without the greenhouse effect, the entire Earth would plunge below the freezing point of water and we'd all be dead.) Now that atmosphere, so thin and fragile, is under assault by our technology. We are pumping all kinds of stuff into it. You know about the concern that chlorofluorocarbons are depleting the ozone layer; and that carbon dioxide and methane and other greenhouse gases are producing global warming, a steady trend amidst fluctuations produced by volcanic eruptions and other sources. Who knows what other challenges we are posing to this vulnerable layer of air that we haven't been wise enough to foresee?
In 'Wonder and Skepticism', Skeptical Enquirer (Jan-Feb 1995), 19, No. 1.
Science quotes on:  |  Air (366)  |  Assault (12)  |  Atmosphere (117)  |  Carbon (68)  |  Carbon Dioxide (25)  |  Challenge (91)  |  Concern (239)  |  Deadly (21)  |  Death (406)  |  Diameter (28)  |  Earth (1076)  |  Effect (414)  |  Enough (341)  |  Eruption (10)  |  Fact (1257)  |  Fluctuation (15)  |  Foresee (22)  |  Fragile (26)  |  Freezing (16)  |  Freezing Point (3)  |  Global (39)  |  Global Warming (29)  |  Globe (51)  |  Greenhouse Effect (5)  |  Greenhouse Gas (4)  |  Kind (564)  |  Know (1538)  |  Layer (41)  |  Life (1870)  |  Light (635)  |  Methane (9)  |  Nurture (17)  |  Other (2233)  |  Ozone (7)  |  Plunge (11)  |  Point (584)  |  Produced (187)  |  Protect (65)  |  Pump (9)  |  Ratio (41)  |  School (227)  |  Source (101)  |  Steady (45)  |  Stuff (24)  |  Sun (407)  |  Surface (223)  |  Technology (281)  |  Thickness (5)  |  Thin (18)  |  Through (846)  |  Trend (23)  |  Ultraviolet (2)  |  Volcano (46)  |  Vulnerability (5)  |  Warming (24)  |  Water (503)  |  Wisdom (235)  |  Wise (143)

In the beginning there was an explosion. Not an explosion like those familiar on earth, starting from a definite center and spreading out to engulf more and more of the circumambient air, but an explosion which occurred simultaneously everywhere, filling all space from the beginning, with every particle of matter rushing apart from every other particle. ‘All space’ in this context may mean either all of an infinite universe, or all of a finite universe which curves back on itself like the surface of a sphere. Neither possibility is easy to comprehend, but this will not get in our way; it matters hardly at all in the early universe whether space is finite or infinite. At about one-hundredth of a second, the earliest time about which we can speak with any confidence, the temperature of the universe was about a hundred thousand million (1011) degrees Centigrade. This is much hotter than in the center of even the hottest star, so hot, in fact, that none of the components of ordinary matter, molecules, or atoms, or even the nuclei of atoms, could have held together. Instead, the matter rushing apart in this explosion consisted of various types of the so-called elementary particles, which are the subject of modern high­energy nuclear physics.
The First Three Minutes: A Modern View of the Origin of the Universe (1977), 5.
Science quotes on:  |  Air (366)  |  Atom (381)  |  Atomic Bomb (115)  |  Back (395)  |  Beginning (312)  |  Call (781)  |  Component (51)  |  Comprehension (69)  |  Confidence (75)  |  Consist (223)  |  Context (31)  |  Curve (49)  |  Definite (114)  |  Degree (277)  |  Early (196)  |  Earth (1076)  |  Easy (213)  |  Elementary (98)  |  Energy (373)  |  Everywhere (98)  |  Explosion (51)  |  Fact (1257)  |  Finite (60)  |  High (370)  |  Hot (63)  |  Hottest (2)  |  Hundred (240)  |  Infinite (243)  |  Matter (821)  |  Mean (810)  |  Million (124)  |  Modern (402)  |  Molecule (185)  |  More (2558)  |  Nuclear (110)  |  Nuclear Physics (6)  |  Nucleus (54)  |  Ordinary (167)  |  Other (2233)  |  Particle (200)  |  Particle Physics (13)  |  Physic (515)  |  Physics (564)  |  Possibility (172)  |  So-Called (71)  |  Space (523)  |  Speak (240)  |  Sphere (118)  |  Star (460)  |  Subject (543)  |  Surface (223)  |  Thousand (340)  |  Time (1911)  |  Together (392)  |  Type (171)  |  Universe (900)  |  Various (205)  |  Way (1214)  |  Will (2350)

In the early days of dealing with climate change, I wouldn’t go out on a limb one way or another, because I don’t have the qualifications there. But I do have the qualifications to measure the scientific community and see what the consensus is about climate change. I remember the moment when I suddenly thought it was incontrovertible. There was a lecture given by a distinguished American expert in atmospheric science and he showed a series of graphs about the temperature changes in the upper atmosphere. He plotted time against population growth and industrialisation. It was incontrovertible, and once you think it’s really totally incontrovertible, then you have a responsibility to say so.
From interview with Brian Cox and Robert Ince, in 'A Life Measured in Heartbeats', New Statesman (21 Dec 2012), 141, No. 5138, 32.
Science quotes on:  |  Against (332)  |  Atmosphere (117)  |  Change (639)  |  Climate (102)  |  Climate Change (76)  |  Community (111)  |  Consensus (8)  |  Distinguish (168)  |  Distinguished (84)  |  Do (1905)  |  Early (196)  |  Expert (67)  |  Graph (8)  |  Growth (200)  |  Incontrovertible (8)  |  Industrialisation (4)  |  Lecture (111)  |  Measure (241)  |  Moment (260)  |  Population (115)  |  Population Growth (9)  |  Qualification (15)  |  Remember (189)  |  Responsibility (71)  |  Say (989)  |  Scientific (955)  |  See (1094)  |  Series (153)  |  Show (353)  |  Suddenly (91)  |  Think (1122)  |  Thought (995)  |  Time (1911)  |  Way (1214)

In Winter, [the Antarctic] is perhaps the dreariest of places. Our base, Little America, lay in a bowl of ice, near the edge of the Ross Ice Barrier. The temperature fell as low as 72 degrees below zero. One could actually hear one's breath freeze.
In 'Hoover Presents Special Medal to Byrd...', New York Times (21 Jun 1930), 1.
Science quotes on:  |  America (143)  |  Antarctic (7)  |  Barrier (34)  |  Base (120)  |  Bowl (4)  |  Breath (61)  |  Coldness (2)  |  Degree (277)  |  Dreariness (3)  |  Edge (51)  |  Freezing (16)  |  Hear (144)  |  Hearing (50)  |  Ice (58)  |  Little (717)  |  Low (86)  |  Winter (46)  |  Zero (38)

It is impossible for a self-acting machine, unaided by any external agency, to convey heat from one body to another at a higher temperature.
In 'On the Dynamical Theory of Heat, with Numerical Results Deduced from Mr Joule's Equivalent of a Thermal Unit, and M. Regnault's Observations on Steam' (1851). In Mathematical and Physical Papers (1882), Vol. 1, 181.
Science quotes on:  |  Body (557)  |  Heat (180)  |  Impossible (263)  |  Machine (271)  |  Self (268)

It is the destiny of wine to be drunk, and it is the destiny of glucose to be oxidized. But it was not oxidized immediately: its drinker kept it in his liver for more than a week, well curled up and tranquil, as a reserve aliment for a sudden effort; an effort that he was forced to make the following Sunday, pursuing a bolting horse. Farewell to the hexagonal structure: in the space of a few instants the skein was unwound and became glucose again, and this was dragged by the bloodstream all the way to a minute muscle fiber in the thigh, and here brutally split into two molecules of lactic acid, the grim harbinger of fatigue: only later, some minutes after, the panting of the lungs was able to supply the oxygen necessary to quietly oxidize the latter. So a new molecule of carbon dioxide returned to the atmosphere, and a parcel of the energy that the sun had handed to the vine-shoot passed from the state of chemical energy to that of mechanical energy, and thereafter settled down in the slothful condition of heat, warming up imperceptibly the air moved by the running and the blood of the runner. 'Such is life,' although rarely is it described in this manner: an inserting itself, a drawing off to its advantage, a parasitizing of the downward course of energy, from its noble solar form to the degraded one of low-temperature heat. In this downward course, which leads to equilibrium and thus death, life draws a bend and nests in it.
The Periodic Table (1975), trans. Raymond Rosenthal (1984), 192-3.
Science quotes on:  |  Acid (83)  |  Advantage (144)  |  Air (366)  |  Alcohol (22)  |  Atmosphere (117)  |  Blood (144)  |  Carbon (68)  |  Carbon Dioxide (25)  |  Chemical (303)  |  Chemical Energy (3)  |  Condition (362)  |  Conservation Of Energy (30)  |  Course (413)  |  Death (406)  |  Destiny (54)  |  Down (455)  |  Draw (140)  |  Drawing (56)  |  Drunk (10)  |  Effort (243)  |  Energy (373)  |  Equilibrium (34)  |  Fatigue (13)  |  Fiber (16)  |  Form (976)  |  Glucose (2)  |  Heat (180)  |  Horse (78)  |  Immediately (115)  |  Instant (46)  |  Lactic Acid (2)  |  Lead (391)  |  Life (1870)  |  Liver (22)  |  Low (86)  |  Lung (37)  |  Mechanical (145)  |  Minute (129)  |  Molecule (185)  |  More (2558)  |  Muscle (47)  |  Necessary (370)  |  Nest (26)  |  New (1273)  |  Noble (93)  |  Oxidation (8)  |  Oxygen (77)  |  Pass (241)  |  Plant (320)  |  Pursuing (27)  |  Reserve (26)  |  Return (133)  |  Running (61)  |  Settled (34)  |  Space (523)  |  State (505)  |  Structure (365)  |  Sudden (70)  |  Sun (407)  |  Supply (100)  |  Two (936)  |  Warming (24)  |  Way (1214)  |  Week (73)  |  Wine (39)

It then came into my mind what that most careful observer of natural phenomena [Amontons] had written about the correction of the barometer; for he had observed that the height of the column of mercury in the barometer was a little (though sensibly enough) altered by the varying temperature of the mercury. From this I gathered that a thermometer might be perhaps constructed with mercury.
From 'Experimenta circa gradum caloris liquorum nonnullorum ebullientium instituta', Philosophical Transactions (1724), 33, 1, as translated in William Francis Magie, A Source Book in Physics (1935), 131.
Science quotes on:  |  Alter (64)  |  Altered (32)  |  Guillaume Amontons (3)  |  Barometer (7)  |  Careful (28)  |  Column (15)  |  Construct (129)  |  Correction (42)  |  Enough (341)  |  Gather (76)  |  Height (33)  |  Invention (400)  |  Little (717)  |  Mercury (54)  |  Mind (1377)  |  Most (1728)  |  Natural (810)  |  Observe (179)  |  Observed (149)  |  Observer (48)  |  Phenomenon (334)  |  Thermometer (11)  |  Vary (27)

It will be noticed that the fundamental theorem proved above bears some remarkable resemblances to the second law of thermodynamics. Both are properties of populations, or aggregates, true irrespective of the nature of the units which compose them; both are statistical laws; each requires the constant increase of a measurable quantity, in the one case the entropy of a physical system and in the other the fitness, measured by m, of a biological population. As in the physical world we can conceive the theoretical systems in which dissipative forces are wholly absent, and in which the entropy consequently remains constant, so we can conceive, though we need not expect to find, biological populations in which the genetic variance is absolutely zero, and in which fitness does not increase. Professor Eddington has recently remarked that “The law that entropy always increases—the second law of thermodynamics—holds, I think, the supreme position among the laws of nature.” It is not a little instructive that so similar a law should hold the supreme position among the biological sciences. While it is possible that both may ultimately be absorbed by some more general principle, for the present we should note that the laws as they stand present profound differences—-(1) The systems considered in thermodynamics are permanent; species on the contrary are liable to extinction, although biological improvement must be expected to occur up to the end of their existence. (2) Fitness, although measured by a uniform method, is qualitatively different for every different organism, whereas entropy, like temperature, is taken to have the same meaning for all physical systems. (3) Fitness may be increased or decreased by changes in the environment, without reacting quantitatively upon that environment. (4) Entropy changes are exceptional in the physical world in being irreversible, while irreversible evolutionary changes form no exception among biological phenomena. Finally, (5) entropy changes lead to a progressive disorganization of the physical world, at least from the human standpoint of the utilization of energy, while evolutionary changes are generally recognized as producing progressively higher organization in the organic world.
The Genetical Theory of Natural Selection (1930), 36.
Science quotes on:  |  Absorb (54)  |  Aggregate (24)  |  Bear (162)  |  Being (1276)  |  Biological (137)  |  Both (496)  |  Change (639)  |  Conceive (100)  |  Consider (428)  |  Constant (148)  |  Contrary (143)  |  Difference (355)  |  Different (595)  |  Sir Arthur Stanley Eddington (135)  |  End (603)  |  Energy (373)  |  Entropy (46)  |  Environment (239)  |  Exception (74)  |  Exceptional (19)  |  Existence (481)  |  Expect (203)  |  Extinction (80)  |  Find (1014)  |  Force (497)  |  Form (976)  |  Fundamental (264)  |  General (521)  |  Genetic (110)  |  Human (1512)  |  Improvement (117)  |  Increase (225)  |  Irreversible (12)  |  Law (913)  |  Lead (391)  |  Little (717)  |  Meaning (244)  |  Method (531)  |  More (2558)  |  Must (1525)  |  Natural Selection (98)  |  Nature (2017)  |  Occur (151)  |  Organic (161)  |  Organism (231)  |  Organization (120)  |  Other (2233)  |  Permanent (67)  |  Physical (518)  |  Physical World (30)  |  Population (115)  |  Possible (560)  |  Present (630)  |  Principle (530)  |  Professor (133)  |  Profound (105)  |  Quantity (136)  |  Remain (355)  |  Require (229)  |  Resemblance (39)  |  Second Law Of Thermodynamics (14)  |  Species (435)  |  Stand (284)  |  Standpoint (28)  |  Statistics (170)  |  Supreme (73)  |  System (545)  |  Theorem (116)  |  Thermodynamics (40)  |  Think (1122)  |  Ultimately (56)  |  Utilization (16)  |  Variance (12)  |  Wholly (88)  |  Will (2350)  |  World (1850)  |  Zero (38)

Let us now recapitulate all that has been said, and let us conclude that by hermetically sealing the vials, one is not always sure to prevent the birth of the animals in the infusions, boiled or done at room temperature, if the air inside has not felt the ravages of fire. If, on the contrary, this air has been powerfully heated, it will never allow the animals to be born, unless new air penetrates from outside into the vials. This means that it is indispensable for the production of the animals that they be provided with air which has not felt the action of fire. And as it would not be easy to prove that there were no tiny eggs disseminated and floating in the volume of air that the vials contain, it seems to me that suspicion regarding these eggs continues, and that trial by fire has not entirely done away with fears of their existence in the infusions. The partisans of the theory of ovaries will always have these fears and will not easily suffer anyone's undertaking to demolish them.
Nouvelles Recherches sur les Découvertes Microscopiques, et la Génération des Corps Organisés (1769), 134-5. Quoted in Jacques Roger, The Life Sciences in Eighteenth-Century French Thought, ed. Keith R. Benson and trans. Robert Ellrich (1997), 510-1.
Science quotes on:  |  Action (342)  |  Air (366)  |  Animal (651)  |  Birth (154)  |  Boil (24)  |  Conclude (66)  |  Conclusion (266)  |  Continue (179)  |  Contrary (143)  |  Demolish (8)  |  Demolition (4)  |  Dissemination (3)  |  Ease (40)  |  Easy (213)  |  Egg (71)  |  Existence (481)  |  Fear (212)  |  Fire (203)  |  Float (31)  |  Heat (180)  |  Hermetic (2)  |  Infusion (4)  |  Mean (810)  |  Means (587)  |  Never (1089)  |  New (1273)  |  Outside (141)  |  Ovary (2)  |  Partisan (5)  |  Penetrate (68)  |  Pentration (2)  |  Prevent (98)  |  Prevention (37)  |  Production (190)  |  Proof (304)  |  Prove (261)  |  Provision (17)  |  Ravage (7)  |  Recapitulation (6)  |  Seal (19)  |  Suffer (43)  |  Suspicion (36)  |  Theory (1015)  |  Tiny (74)  |  Trial (59)  |  Undertaking (17)  |  Vial (4)  |  Will (2350)

Life can be thought of as water kept at the right temperature in the right atmosphere in the right light for a long enough period of time.
You and The Universe (1958), 145.
Science quotes on:  |  Atmosphere (117)  |  Enough (341)  |  Life (1870)  |  Light (635)  |  Long (778)  |  Period (200)  |  Right (473)  |  Thought (995)  |  Time (1911)  |  Water (503)

Man must at all costs overcome the Earth’s gravity and have, in reserve, the space at least of the Solar System. All kinds of danger wait for him on the Earth… We are talking of disaster that can destroy the whole of mankind or a large part of it… For instance, a cloud of bolides [meteors] or a small planet a few dozen kilometers in diameter could fall on the Earth, with such an impact that the solid, liquid or gaseous blast produced by it could wipe off the face of the Earth all traces of man and his buildings. The rise of temperature accompanying it could alone scorch or kill all living beings… We are further compelled to take up the struggle against gravity, and for the utilization of celestial space and all its wealth, because of the overpopulation of our planet. Numerous other terrible dangers await mankind on the Earth, all of which suggest that man should look for a way into the Cosmos. We have said a great deal about the advantages of migration into space, but not all can be said or even imagined.
Science quotes on:  |  Advantage (144)  |  Against (332)  |  Alone (324)  |  Being (1276)  |  Blast (13)  |  Building (158)  |  Celestial (53)  |  Cloud (111)  |  Cosmos (64)  |  Cost (94)  |  Danger (127)  |  Deal (192)  |  Destroy (189)  |  Diameter (28)  |  Disaster (58)  |  Earth (1076)  |  Face (214)  |  Fall (243)  |  Gravity (140)  |  Great (1610)  |  Impact (45)  |  Kill (100)  |  Kilometer (10)  |  Kind (564)  |  Large (398)  |  Liquid (50)  |  Living (492)  |  Look (584)  |  Man (2252)  |  Mankind (356)  |  Meteor (19)  |  Migration (12)  |  Must (1525)  |  Numerous (70)  |  Other (2233)  |  Overcome (40)  |  Overpopulation (6)  |  Planet (402)  |  Produced (187)  |  Reserve (26)  |  Rise (169)  |  Small (489)  |  Solar System (81)  |  Solid (119)  |  Space (523)  |  Struggle (111)  |  System (545)  |  Talking (76)  |  Terrible (41)  |  Trace (109)  |  Utilization (16)  |  Way (1214)  |  Wealth (100)  |  Whole (756)

Mathematical analysis is as extensive as nature itself; it defines all perceptible relations, measures times, spaces, forces, temperatures; this difficult science is formed slowly, but it preserves every principle which it has once acquired; it grows and strengthens itself incessantly in the midst of the many variations and errors of the human mind.
From Théorie Analytique de la Chaleur (1822), Discours Préliminaire, xiv, (Theory of Heat, Introduction), as translated by Alexander Freeman in The Analytical Theory of Heat (1878), 7. From the original French, “L’analyse mathématique est aussi étendue que la nature elle-même; elle définit tous les rapports sensibles, mesure les temps y les espaces, les forces, les températures; cette science difficile se forme avec lenteur, mais elle conserve tous les principes quelle a une fois acquis; elle s’accroît et s’affermit sans cesse au milieu de tant de variations et d’erreurs de l’esprit humain.”
Science quotes on:  |  Acquired (77)  |  Analysis (244)  |  Define (53)  |  Difficult (263)  |  Error (339)  |  Extensive (34)  |  Force (497)  |  Form (976)  |  Formed (5)  |  Grow (247)  |  Human (1512)  |  Human Mind (133)  |  Incessantly (3)  |  Mathematical Analysis (23)  |  Measure (241)  |  Midst (8)  |  Mind (1377)  |  Nature (2017)  |  Nature Of Mathematics (80)  |  Perceptible (7)  |  Preserve (91)  |  Principle (530)  |  Relation (166)  |  Slowly (19)  |  Space (523)  |  Strengthen (25)  |  Time (1911)  |  Variation (93)

My experiments proved that the radiation of uranium compounds ... is an atomic property of the element of uranium. Its intensity is proportional to the quantity of uranium contained in the compound, and depends neither on conditions of chemical combination, nor on external circumstances, such as light or temperature.
... The radiation of thorium has an intensity of the same order as that of uranium, and is, as in the case of uranium, an atomic property of the element.
It was necessary at this point to find a new term to define this new property of matter manifested by the elements of uranium and thorium. I proposed the word radioactivity which has since become generally adopted; the radioactive elements have been called radio elements.
In Pierre Curie, with the Autobiographical Notes of Marie Curie, trans. Charlotte and Vernon Kellogg (1923), 96. Also in reprint (2012) 45-46.
Science quotes on:  |  Become (821)  |  Call (781)  |  Chemical (303)  |  Circumstance (139)  |  Circumstances (108)  |  Combination (150)  |  Compound (117)  |  Condition (362)  |  Depend (238)  |  Element (322)  |  Experiment (736)  |  Find (1014)  |  Intensity (34)  |  Light (635)  |  Matter (821)  |  Necessary (370)  |  New (1273)  |  Nomencalture (4)  |  Order (638)  |  Point (584)  |  Property (177)  |  Quantity (136)  |  Radiation (48)  |  Radio (60)  |  Radioactive (24)  |  Radioactivity (33)  |  Term (357)  |  Thorium (5)  |  Uranium (21)  |  Word (650)

My observations of the young physicists who seem to be most like me and the friends I describe in this book tell me that they feel as we would if we had been chained to those same oars. Our young counterparts aren’t going into nuclear or particle physics (they tell me it’s too unattractive); they are going into condensed-matter physics, low-temperature physics, or astrophysics, where important work can still be done in teams smaller than ten and where everyone can feel that he has made an important contribution to the success of the experiment that every other member of the collaboration is aware of. Most of us do physics because it’s fun and because we gain a certain respect in the eyes of those who know what we’ve done. Both of those rewards seem to me to be missing in the huge collaborations that now infest the world of particle physics.
Alvarez: Adventures of a Physicist (1987), 198.
Science quotes on:  |  Astrophysics (15)  |  Book (413)  |  Both (496)  |  Certain (557)  |  Collaboration (16)  |  Contribution (93)  |  Counterpart (11)  |  Describe (132)  |  Do (1905)  |  Experiment (736)  |  Eye (440)  |  Feel (371)  |  Friend (180)  |  Gain (146)  |  Know (1538)  |  Low (86)  |  Matter (821)  |  Men Of Science (147)  |  Missing (21)  |  Most (1728)  |  Nuclear (110)  |  Nuclear Physics (6)  |  Observation (593)  |  Other (2233)  |  Particle (200)  |  Particle Physics (13)  |  Physic (515)  |  Physicist (270)  |  Physics (564)  |  Research (753)  |  Respect (212)  |  Reward (72)  |  Still (614)  |  Success (327)  |  Team (17)  |  Tell (344)  |  Work (1402)  |  World (1850)  |  Young (253)

Nature prefers the more probable states to the less probable because in nature processes take place in the direction of greater probability. Heat goes from a body at higher temperature to a body at lower temperature because the state of equal temperature distribution is more probable than a state of unequal temperature distribution.
'The Atomic Theory of Matter', third lecture at Columbia University (1909), in Max Planck and A. P. Wills (trans.), Eight Lectures on Theoretical Physics (1915), 44.
Science quotes on:  |  Body (557)  |  Direction (185)  |  Distribution (51)  |  Equal (88)  |  Greater (288)  |  Heat (180)  |  Higher (37)  |  Less (105)  |  Lower (11)  |  More (2558)  |  Nature (2017)  |  Preference (28)  |  Probability (135)  |  Process (439)  |  Second Law Of Thermodynamics (14)  |  State (505)  |  Unequal (12)

Of all regions of the earth none invites speculation more than that which lies beneath our feet, and in none is speculation more dangerous; yet, apart from speculation, it is little that we can say regarding the constitution of the interior of the earth. We know, with sufficient accuracy for most purposes, its size and shape: we know that its mean density is about 5½ times that of water, that the density must increase towards the centre, and that the temperature must be high, but beyond these facts little can be said to be known. Many theories of the earth have been propounded at different times: the central substance of the earth has been supposed to be fiery, fluid, solid, and gaseous in turn, till geologists have turned in despair from the subject, and become inclined to confine their attention to the outermost crust of the earth, leaving its centre as a playground for mathematicians.
'The Constitution of the Interior of the Earth, as Revealed by Earthquakes', Quarterly Journal of the Geological Society (1906), 62, 456.
Science quotes on:  |  Accuracy (81)  |  Attention (196)  |  Become (821)  |  Beneath (68)  |  Beyond (316)  |  Central (81)  |  Constitution (78)  |  Crust (43)  |  Dangerous (108)  |  Density (25)  |  Despair (40)  |  Different (595)  |  Earth (1076)  |  Fact (1257)  |  Facts (553)  |  Fluid (54)  |  Geologist (82)  |  High (370)  |  Inclined (41)  |  Increase (225)  |  Interior (35)  |  Know (1538)  |  Known (453)  |  Lie (370)  |  Little (717)  |  Mathematics (1395)  |  Mean (810)  |  More (2558)  |  Most (1728)  |  Must (1525)  |  Playground (6)  |  Purpose (336)  |  Say (989)  |  Solid (119)  |  Speculation (137)  |  Subject (543)  |  Substance (253)  |  Sufficient (133)  |  Theory (1015)  |  Time (1911)  |  Turn (454)  |  Water (503)

One of my inventions was a large thermometer made of an iron rod, … The expansion and contraction of this rod was multiplied by a series of levers … so that the slightest change in the length of the rod was instantly shown on a dial about three feet wide multiplied about thirty-two thousand times. The zero-point was gained by packing the rod in wet snow. The scale was so large that … the temperature read while we were ploughing in the field below the house.
From The Story of My Boyhood and Youth (1913), 258-259. One of the inventions made while growing up on his father’s farm, before he left the year after he was 21.
Science quotes on:  |  Change (639)  |  Contraction (18)  |  Dial (9)  |  Expansion (43)  |  Field (378)  |  Gain (146)  |  House (143)  |  Instantly (20)  |  Invention (400)  |  Iron (99)  |  Large (398)  |  Lever (13)  |  Melting Point (3)  |  Multiply (40)  |  Ploughing (3)  |  Point (584)  |  Read (308)  |  Rod (6)  |  Scale (122)  |  Series (153)  |  Snow (39)  |  Thermometer (11)  |  Thousand (340)  |  Time (1911)  |  Two (936)  |  Wide (97)  |  Zero (38)

Our atom of carbon enters the leaf, colliding with other innumerable (but here useless) molecules of nitrogen and oxygen. It adheres to a large and complicated molecule that activates it, and simultaneously receives the decisive message from the sky, in the flashing form of a packet of solar light; in an instant, like an insect caught by a spider, it is separated from its oxygen, combined with hydrogen and (one thinks) phosphorus, and finally inserted in a chain, whether long or short does not matter, but it is the chain of life. All this happens swiftly, in silence, at the temperature and pressure of the atmosphere, and gratis: dear colleagues, when we learn to do likewise we will be sicut Deus [like God], and we will have also solved the problem of hunger in the world.
Levi Primo and Raymond Rosenthal (trans.), The Periodic Table (1975, 1984), 227-228. In this final section of his book, Levi imagines the life of a carbon atom. He calls this his first “literary dream”. It came to him at Auschwitz.
Science quotes on:  |  Activate (3)  |  Activation (6)  |  Adherence (2)  |  Atmosphere (117)  |  Atom (381)  |  Carbon (68)  |  Catch (34)  |  Chain (51)  |  Colleague (51)  |  Collision (16)  |  Combination (150)  |  Complicated (117)  |  Decisive (25)  |  Do (1905)  |  Enter (145)  |  Flash (49)  |  Form (976)  |  God (776)  |  Gratis (2)  |  Happen (282)  |  Happening (59)  |  Hunger (23)  |  Hydrogen (80)  |  Innumerable (56)  |  Insect (89)  |  Insertion (2)  |  Instant (46)  |  Large (398)  |  Leaf (73)  |  Learn (672)  |  Learning (291)  |  Life (1870)  |  Light (635)  |  Likewise (2)  |  Long (778)  |  Matter (821)  |  Message (53)  |  Molecule (185)  |  Nitrogen (32)  |  Other (2233)  |  Oxygen (77)  |  Packet (3)  |  Phosphorus (18)  |  Photon (11)  |  Photosynthesis (21)  |  Pressure (69)  |  Problem (731)  |  Receive (117)  |  Separation (60)  |  Short (200)  |  Silence (62)  |  Simultaneity (3)  |  Sky (174)  |  Solar (8)  |  Solution (282)  |  Spider (14)  |  Sun (407)  |  Swiftness (5)  |  Think (1122)  |  Uselessness (22)  |  Will (2350)  |  World (1850)

People have noted with admiration how the progress of scientific enquiry is like the growth of a coral reef; each generation of little toilers building a sure foundation on which their successors may build yet further. The simile is apt in many ways, and in one way in particular that is worth considering. When we see how industrious and how prolific are the coral insects, our chief astonishment should be, not how vast are the structures they have built, but how few and scattered. Why is not every coast lined with coral? Why is the abyss if ocean not bridged with it. The answer is that coral only lives under certain limitations; it can only thrive at certain depths, in water of certain temperatures and salinities; outside these limits it languishes and dies. Science is like coral in this. Scientific investigators can only work in certain spots of the ocean of Being, where they are at home, and all outside is unknown to them...
Scientific Method: An Inquiry into the Character and Validy of Natural Law (1923), 195. Quoted in Wilson Gee, Social science research methods (1950), 182.
Science quotes on:  |  Abyss (30)  |  Admiration (61)  |  Answer (389)  |  Astonishment (30)  |  Being (1276)  |  Build (211)  |  Building (158)  |  Certain (557)  |  Chief (99)  |  Coral Reef (15)  |  Depth (97)  |  Enquiry (89)  |  Foundation (177)  |  Generation (256)  |  Growth (200)  |  Home (184)  |  Industrious (12)  |  Insect (89)  |  Investigator (71)  |  Limit (294)  |  Limitation (52)  |  Little (717)  |  Live (650)  |  Ocean (216)  |  Outside (141)  |  People (1031)  |  Progress (492)  |  Research (753)  |  Scientific (955)  |  See (1094)  |  Simile (8)  |  Structure (365)  |  Successor (16)  |  Thrive (22)  |  Unknown (195)  |  Vast (188)  |  Water (503)  |  Way (1214)  |  Why (491)  |  Work (1402)  |  Worth (172)

Sarcastic Science, she would like to know,
In her complacent ministry of fear,
How we propose to get away from here
When she has made things so we have to go
Or be wiped out. Will she be asked to show
Us how by rocket we may hope to steer
To some star off there, say, a half light-year
Through temperature of absolute zero?
Why wait for Science to supply the how
When any amateur can tell it now?
The way to go away should be the same
As fifty million years ago we came—
If anyone remembers how that was
I have a theory, but it hardly does.
'Why Wait for Science?' In Edward Connery Latham (ed.), The Poetry of Robert Frost: The Collected Poems, Complete and Unabridged (1979), 395.
Science quotes on:  |  Absolute (153)  |  Ask (420)  |  Fear (212)  |  Hope (321)  |  Know (1538)  |  Light (635)  |  Remember (189)  |  Rocket (52)  |  Say (989)  |  Show (353)  |  Space Flight (26)  |  Star (460)  |  Supply (100)  |  Tell (344)  |  Theory (1015)  |  Thing (1914)  |  Through (846)  |  Way (1214)  |  Why (491)  |  Will (2350)  |  Year (963)  |  Zero (38)

Sex is the best form of fusion at room temperature.
Anonymous
Saying.
Science quotes on:  |  Best (467)  |  Form (976)  |  Fusion (16)  |  Research (753)  |  Sex (68)

So many of the properties of matter, especially when in the gaseous form, can be deduced from the hypothesis that their minute parts are in rapid motion, the velocity increasing with the temperature, that the precise nature of this motion becomes a subject of rational curiosity. Daniel Bernoulli, Herapath, Joule, Kronig, Clausius, &c., have shewn that the relations between pressure, temperature and density in a perfect gas can be explained by supposing the particles move with uniform velocity in straight lines, striking against the sides of the containing vessel and thus producing pressure. (1860)
In W.D. Niven (ed.) 'Illustrations of the Dynamical Theory of Gases,' The Scientific Papers of James Clerk Maxwell, Vol 1, 377. Quoted in John David Anderson, Jr., Hypersonic and High Temperature Gas Dynamics (2000), 468.
Science quotes on:  |  Against (332)  |  Become (821)  |  Daniel Bernoulli (5)  |  Rudolf Clausius (9)  |  Curiosity (138)  |  Density (25)  |  Explain (334)  |  Form (976)  |  Gas (89)  |  Hypothesis (314)  |  Kinetic Theory (7)  |  Matter (821)  |  Minute (129)  |  Motion (320)  |  Move (223)  |  Nature (2017)  |  Particle (200)  |  Perfect (223)  |  Precise (71)  |  Pressure (69)  |  Properties Of Matter (7)  |  Rational (95)  |  Side (236)  |  Straight (75)  |  Straight Line (34)  |  Striking (48)  |  Subject (543)  |  Velocity (51)  |  Vessel (63)

Suppose [an] imaginary physicist, the student of Niels Bohr, is shown an experiment in which a virus particle enters a bacterial cell and 20 minutes later the bacterial cell is lysed and 100 virus particles are liberated. He will say: “How come, one particle has become 100 particles of the same kind in 20 minutes? That is very interesting. Let us find out how it happens! How does the particle get in to the bacterium? How does it multiply? Does it multiply like a bacterium, growing and dividing, or does it multiply by an entirely different mechanism ? Does it have to be inside the bacterium to do this multiplying, or can we squash the bacterium and have the multiplication go on as before? Is this multiplying a trick of organic chemistry which the organic chemists have not yet discovered ? Let us find out. This is so simple a phenomenon that the answers cannot be hard to find. In a few months we will know. All we have to do is to study how conditions will influence the multiplication. We will do a few experiments at different temperatures, in different media, with different viruses, and we will know. Perhaps we may have to break into the bacteria at intermediate stages between infection and lysis. Anyhow, the experiments only take a few hours each, so the whole problem can not take long to solve.”
[Eight years later] he has not got anywhere in solving the problem he set out to solve. But [he may say to you] “Well, I made a slight mistake. I could not do it in a few months. Perhaps it will take a few decades, and perhaps it will take the help of a few dozen other people. But listen to what I have found, perhaps you will be interested to join me.”
From 'Experiments with Bacterial Viruses (Bacteriophages)', Harvey Lecture (1946), 41, 161-162. As cited in Robert Olby, The Path of the Double Helix: The Discovery of DNA (1974, 1994), 237.
Science quotes on:  |  Answer (389)  |  Bacteria (50)  |  Become (821)  |  Break (109)  |  Chemist (169)  |  Chemistry (376)  |  Condition (362)  |  Decade (66)  |  Different (595)  |  Discover (571)  |  Divide (77)  |  Do (1905)  |  Enter (145)  |  Experiment (736)  |  Find (1014)  |  Grow (247)  |  Growing (99)  |  Happen (282)  |  Hard (246)  |  Hour (192)  |  Infection (27)  |  Influence (231)  |  Interest (416)  |  Interesting (153)  |  Intermediate (38)  |  Kind (564)  |  Know (1538)  |  Listen (81)  |  Long (778)  |  Lysis (4)  |  Mechanism (102)  |  Media (14)  |  Minute (129)  |  Mistake (180)  |  Month (91)  |  Multiplication (46)  |  Multiply (40)  |  Organic (161)  |  Organic Chemistry (41)  |  Other (2233)  |  Particle (200)  |  People (1031)  |  Phenomenon (334)  |  Physicist (270)  |  Problem (731)  |  Say (989)  |  Set (400)  |  Simple (426)  |  Solve (145)  |  Squash (4)  |  Stage (152)  |  Student (317)  |  Study (701)  |  Suppose (158)  |  Trick (36)  |  Virus (32)  |  Whole (756)  |  Will (2350)  |  Year (963)

Suppose you were given a watch, a tube to sight with and a string, and then asked to determine the distance to the nearest star. Or you were asked the chemical composition, pressure or temperature of the Sun. A hundred or more years ago, these questions seemed impossible. Now astronomers are answering them all the time, and they believe their answers. Why? Because there are many parallel ways and tests, and they all give the same answers.
As quoted in John Noble Wilford, 'Sizing up the Cosmos: An Astronomers Quest', New York Times (12 Mar 1991), C10.
Science quotes on:  |  All The Time (4)  |  Answer (389)  |  Ask (420)  |  Astronomer (97)  |  Belief (615)  |  Chemical (303)  |  Composition (86)  |  Determine (152)  |  Distance (171)  |  Hundred (240)  |  Impossible (263)  |  More (2558)  |  Parallel (46)  |  Pressure (69)  |  Question (649)  |  Seem (150)  |  Sight (135)  |  Star (460)  |  String (22)  |  Sun (407)  |  Suppose (158)  |  Test (221)  |  Time (1911)  |  Tube (6)  |  Watch (118)  |  Way (1214)  |  Why (491)  |  Year (963)

Take the living human brain endowed with mind and thought. …. The physicist brings his tools and commences systematic exploration. All that he discovers is a collection of atoms and electrons and fields of force arranged in space and time, apparently similar to those found in inorganic objects. He may trace other physical characteristics, energy, temperature, entropy. None of these is identical with thought. … How can this collection of ordinary atoms be a thinking machine? … The Victorian physicist felt that he knew just what he was talking about when he used such terms as matter and atoms. … But now we realize that science has nothing to say as to the intrinsic nature of the atom. The physical atom is, like everything else in physics, a schedule of pointer readings.
From a Gifford Lecture, University of Edinburgh (1927), published in 'Pointer Readings: Limits of Physical Knowledge', The Nature of the Physical World (1929), 258-259.
Science quotes on:  |  Atom (381)  |  Brain (281)  |  Characteristic (154)  |  Collection (68)  |  Discover (571)  |  Electron (96)  |  Endowed (52)  |  Energy (373)  |  Entropy (46)  |  Everything (489)  |  Exploration (161)  |  Field (378)  |  Force (497)  |  Human (1512)  |  Identical (55)  |  Inorganic (14)  |  Intrinsic (18)  |  Life (1870)  |  Living (492)  |  Machine (271)  |  Matter (821)  |  Measurement (178)  |  Mind (1377)  |  Nature (2017)  |  Nothing (1000)  |  Object (438)  |  Ordinary (167)  |  Other (2233)  |  Physic (515)  |  Physical (518)  |  Physicist (270)  |  Physics (564)  |  Pointer (6)  |  Reading (136)  |  Realize (157)  |  Say (989)  |  Space (523)  |  Space And Time (38)  |  Systematic (58)  |  Talking (76)  |  Term (357)  |  Terms (184)  |  Thinking (425)  |  Thought (995)  |  Time (1911)  |  Time And Space (39)  |  Tool (129)  |  Trace (109)  |  Victorian (6)

The ‘Doctrine of Uniformity’ in Geology, as held by many of the most eminent of British Geologists, assumes that the earth’s surface and upper crust have been nearly as they are at present in temperature, and other physical qualities, during millions of millions of years. But the heat which we know, by observation, to be now conducted out of the earth yearly is so great, that if this action has been going on with any approach to uniformity for 20,000 million years, the amount of heat lost out of the earth would have been about as much as would heat, by 100 Cent., a quantity of ordinary surface rock of 100 times the earth’s bulk. This would be more than enough to melt a mass of surface rock equal in bulk to the whole earth. No hypothesis as to chemical action, internal fluidity, effects of pressure at great depth, or possible character of substances in the interior of the earth, possessing the smallest vestige of probability, can justify the supposition that the earth’s upper crust has remained nearly as it is, while from the whole, or from any part, of the earth, so great a quantity of heat has been lost.
In 'The “Doctrine of Uniformity” in Geology Briefly Refuted' (1866), Popular Lectures and Addresses (1891), Vol. 2, 6-7.
Science quotes on:  |  Action (342)  |  Amount (153)  |  Approach (112)  |  British (42)  |  Bulk (24)  |  Character (259)  |  Chemical (303)  |  Conduct (70)  |  Crust (43)  |  Depth (97)  |  Earth (1076)  |  Effect (414)  |  Enough (341)  |  Geologist (82)  |  Geology (240)  |  Great (1610)  |  Heat (180)  |  Hypothesis (314)  |  Interior (35)  |  Internal (69)  |  Know (1538)  |  Mass (160)  |  More (2558)  |  Most (1728)  |  Nearly (137)  |  Observation (593)  |  Ordinary (167)  |  Other (2233)  |  Physical (518)  |  Possible (560)  |  Present (630)  |  Pressure (69)  |  Probability (135)  |  Quantity (136)  |  Remain (355)  |  Rock (176)  |  Substance (253)  |  Supposition (50)  |  Surface (223)  |  Time (1911)  |  Uniformity (38)  |  Vestige (11)  |  Whole (756)  |  Year (963)

The automatic computing engine now being designed at N.P.L. [National Physics Laboratory] is atypical large scale electronic digital computing machine. In a single lecture it will not be possible to give much technical detail of this machine, and most of what I shall say will apply equally to any other machine of this type now being planned. From the point of view of the mathematician the property of being digital should be of greater interest than that of being electronic. That it is electronic is certainly important because these machines owe their high speed to this, and without the speed it is doubtful if financial support for their construction would be forthcoming. But this is virtually all that there is to be said on that subject. That the machine is digital however has more subtle significance. It means firstly that numbers are represented by sequences of digits which can be as long as one wishes. One can therefore work to any desired degree of accuracy. This accuracy is not obtained by more careful machining of parts, control of temperature variations, and such means, but by a slight increase in the amount of equipment in the machine.
Lecture to the London Mathematical Society, 20 February 1947. Quoted in B. E. Carpenter and R. W. Doran (eds.), A. M. Turing's Ace Report of 1946 and Other Papers (1986), 106.
Science quotes on:  |  Accuracy (81)  |  Amount (153)  |  Apply (170)  |  Atypical (2)  |  Automatic (16)  |  Being (1276)  |  Certainly (185)  |  Computer (131)  |  Construction (114)  |  Control (182)  |  Degree (277)  |  Design (203)  |  Designed (2)  |  Desired (5)  |  Detail (150)  |  Digital (10)  |  Doubtful (30)  |  Electronics (21)  |  Engine (99)  |  Engineering (188)  |  Equally (129)  |  Equipment (45)  |  Greater (288)  |  High (370)  |  Increase (225)  |  Interest (416)  |  Laboratory (214)  |  Large (398)  |  Lecture (111)  |  Long (778)  |  Machine (271)  |  Mathematician (407)  |  Mean (810)  |  Means (587)  |  More (2558)  |  Most (1728)  |  Number (710)  |  Obtain (164)  |  Other (2233)  |  Owe (71)  |  Physic (515)  |  Physics (564)  |  Point (584)  |  Point Of View (85)  |  Possible (560)  |  Property (177)  |  Represent (157)  |  Say (989)  |  Scale (122)  |  Sequence (68)  |  Significance (114)  |  Single (365)  |  Speed (66)  |  Subject (543)  |  Support (151)  |  Technology (281)  |  Type (171)  |  Variation (93)  |  View (496)  |  Will (2350)  |  Work (1402)

The cause of rain is now, I consider, no longer an object of doubt. If two masses of air of unequal temperatures, by the ordinary currents of the winds, are intermixed, when saturated with vapour, a precipitation ensues. If the masses are under saturation, then less precipitation takes place, or none at all, according to the degree. Also, the warmer the air, the greater is the quantity of vapour precipitated in like circumstances. ... Hence the reason why rains are heavier in summer than in winter, and in warm countries than in cold.
Memoirs of the Literary and Philosophical Society of Manchester (1819), 3, 507. Quoted in George Drysdale Dempsey and Daniel Kinnear Clark, On the Drainage of Lands, Towns, & Buildings (1887), 246.
Science quotes on:  |  According (236)  |  Air (366)  |  Cause (561)  |  Circumstance (139)  |  Circumstances (108)  |  Cold (115)  |  Consider (428)  |  Current (122)  |  Degree (277)  |  Doubt (314)  |  Greater (288)  |  Intermix (3)  |  Mixture (44)  |  Object (438)  |  Ordinary (167)  |  Precipitation (7)  |  Quantity (136)  |  Rain (70)  |  Reason (766)  |  Saturation (9)  |  Summer (56)  |  Two (936)  |  Unequal (12)  |  Vapour (16)  |  Warm (74)  |  Warmth (21)  |  Why (491)  |  Wind (141)  |  Winter (46)

The difference between the long-term average of the graph and the ice age, 12,000 years ago, is just over 3°C. The IPCC 2001 report suggests that the line of the hockey stick graph might rise a further 5°C during this century. This is about twice as much as the temperature change from the ice age to pre-industrial times.
In The Revenge of Gaia: Earth’s Climate Crisis & The Fate of Humanity (2006, 2007), 67.
Science quotes on:  |  Average (89)  |  Century (319)  |  Change (639)  |  Difference (355)  |  Graph (8)  |  Ice Age (10)  |  Line (100)  |  Long-Term (11)  |  Report (42)  |  Rise (169)  |  Suggest (38)  |  Time (1911)  |  Twice (20)  |  Year (963)

The earth in its rapid motion round the sun possesses a degree of living force so vast that, if turned into the equivalent of heat, its temperature would be rendered at least one thousand times greater than that of red-hot iron, and the globe on which we tread would in all probability be rendered equal in brightness to the sun itself.
'On Matter, Living Force, and Heat' (1847). In The Scientific Papers of James Prescott Joule (1884), Vol. 1, 271.
Science quotes on:  |  Brightness (12)  |  Degree (277)  |  Earth (1076)  |  Equivalent (46)  |  Force (497)  |  Greater (288)  |  Heat (180)  |  Hot (63)  |  Iron (99)  |  Living (492)  |  Motion (320)  |  Orbit (85)  |  Probability (135)  |  Render (96)  |  Sun (407)  |  Thousand (340)  |  Time (1911)  |  Tread (17)  |  Turn (454)  |  Vast (188)

The epoch of intense cold which preceded the present creation has been only a temporary oscillation of the earth’s temperature, more important than the century-long phases of cooling undergone by the Alpine valleys. It was associated with the disappearance of the animals of the diluvial epoch of the geologists, as still demonstrated by the Siberian mammoths; it preceded the uplifting of the Alps and the appearance of the present-day living organisms, as demonstrated by the moraines and the existence of fishes in our lakes. Consequently, there is complete separation between the present creation and the preceding ones, and if living species are sometimes almost identical to those buried inside the earth, we nevertheless cannot assume that the former are direct descendants of the latter or, in other words, that they represent identical species.
From Discours de Neuchâtel (1837), as translated by Albert V. Carozzi in Studies on Glaciers: Preceded by the Discourse of Neuchâtel (1967), lviii.
Science quotes on:  |  Alp (9)  |  Alps (9)  |  Animal (651)  |  Appearance (145)  |  Century (319)  |  Cold (115)  |  Complete (209)  |  Cooling (10)  |  Creation (350)  |  Descendant (18)  |  Direct (228)  |  Disappearance (28)  |  Earth (1076)  |  Epoch (46)  |  Evolution (635)  |  Existence (481)  |  Extinction (80)  |  Former (138)  |  Geologist (82)  |  Geology (240)  |  Ice Age (10)  |  Identical (55)  |  Lake (36)  |  Living (492)  |  Long (778)  |  Mammoth (9)  |  More (2558)  |  Nevertheless (90)  |  Organism (231)  |  Oscillation (13)  |  Other (2233)  |  Phase (37)  |  Present (630)  |  Represent (157)  |  Separation (60)  |  Species (435)  |  Still (614)  |  Temporary (24)  |  Valley (37)  |  Word (650)

The experiment left no doubt that, as far as accuracy of measurement went, the resistance disappeared. At the same time, however, something unexpected occurred. The disappearance did not take place gradually but abruptly. From 1/500 the resistance at 4.2K, it could be established that the resistance had become less than a thousand-millionth part of that at normal temperature. Thus the mercury at 4.2K has entered a new state, which, owing to its particular electrical properties, can be called the state of superconductivity.
'Investigations into the Properties of Substances at low Temperatures, which have led, amongst other Things, to the Preparation of Liquid Helium', Nobel Lecture (11 Dec 1913). In Nobel Lectures in Physics 1901-1921 (1967), 333.
Science quotes on:  |  Accuracy (81)  |  Become (821)  |  Call (781)  |  Disappear (84)  |  Disappearance (28)  |  Doubt (314)  |  Electrical (57)  |  Electricity (168)  |  Enter (145)  |  Experiment (736)  |  Gradually (102)  |  Measurement (178)  |  Mercury (54)  |  New (1273)  |  Owing (39)  |  Resistance (41)  |  Something (718)  |  State (505)  |  Thousand (340)  |  Time (1911)  |  Unexpected (55)

The history of thermodynamics is a story of people and concepts. The cast of characters is large. At least ten scientists played major roles in creating thermodynamics, and their work spanned more than a century. The list of concepts, on the other hand, is surprisingly small; there are just three leading concepts in thermodynamics: energy, entropy, and absolute temperature.
In Great Physicists (2001), 93.
Science quotes on:  |  Absolute (153)  |  Cast (69)  |  Century (319)  |  Character (259)  |  Concept (242)  |  Create (245)  |  Energy (373)  |  Entropy (46)  |  History (716)  |  Large (398)  |  Leading (17)  |  Major (88)  |  More (2558)  |  Other (2233)  |  People (1031)  |  Role (86)  |  Scientist (881)  |  Small (489)  |  Span (5)  |  Story (122)  |  Thermodynamics (40)  |  Work (1402)

The importance of rice will grow in the coming decades because of potential changes in temperature, precipitation, and sea-level rise, as a result of global warming. Rice grows under a wide range of latitudes and altitudes and can become the anchor of food security in a world confronted with the challenge of climate change.
In 'Science and Shaping the Future of Rice', collected in Pramod K. Aggarwal et al. (eds.), 206 International Rice Congress: Science, Technology, and Trade for Peace and Prosperity (2007), 4.
Science quotes on:  |  Altitude (5)  |  Anchor (10)  |  Become (821)  |  Challenge (91)  |  Change (639)  |  Climate (102)  |  Climate Change (76)  |  Coming (114)  |  Confront (18)  |  Decade (66)  |  Food (213)  |  Food Security (7)  |  Global (39)  |  Global Warming (29)  |  Grow (247)  |  Importance (299)  |  Latitude (6)  |  Potential (75)  |  Precipitation (7)  |  Range (104)  |  Result (700)  |  Rice (5)  |  Rise (169)  |  Sea (326)  |  Sea Level (5)  |  Security (51)  |  Warming (24)  |  Wide (97)  |  Will (2350)  |  World (1850)

The production of motion in the steam engine always occurs in circumstances which it is necessary to recognize, namely when the equilibrium of caloric is restored, or (to express this differently) when caloric passes from the body at one temperature to another body at a lower temperature.
'Réflexions sur la Puissance Motrice du Feu et sur les Machines Propres a Développer cette Puissance' (1824). Trans. Robert Fox, Reflexions on the Motive Power of Fire (1986), 64.
Science quotes on:  |  Body (557)  |  Circumstance (139)  |  Circumstances (108)  |  Engine (99)  |  Equilibrium (34)  |  Express (192)  |  Heat (180)  |  Motion (320)  |  Necessary (370)  |  Occur (151)  |  Production (190)  |  Recognize (136)  |  Steam (81)  |  Steam Engine (47)  |  Thermodynamics (40)

The sun is a mass of incandescent gas, a gigantic nuclear furnace,
Where hydrogen is built into helium at a temperature of millions of degrees.
Yo ho, it’s hot, the sun is not a place where we could live.
But here on earth there’d be no life without the light it gives.
We need its light, we need its heat, we need its energy.
Without the sun, without a doubt, there’d be no you and me.
Hy Zaret
From song 'Why Does the Sun Shine? (The Sun Is A Mass Of Incandescent Gas)' on LP record album Space Songs (1961), in the series Ballads for the Age of Science. Music by Louis Singer, and sung by Tom Glazer. Also recorded by the group They Might Be Giants (1998) who followed up with 'Why Does The Sun Really Shine? (The Sun is a Miasma of Incandescent Plasma)' on CD album Here Comes Science (2009), which corrects several scientific inaccuracies in the lyrics
Science quotes on:  |  Built (7)  |  Degree (277)  |  Doubt (314)  |  Earth (1076)  |  Energy (373)  |  Furnace (13)  |  Gas (89)  |  Gigantic (40)  |  Heat (180)  |  Helium (11)  |  Hot (63)  |  Hydrogen (80)  |  Incandescent (7)  |  Life (1870)  |  Light (635)  |  Live (650)  |  Mass (160)  |  Million (124)  |  Need (320)  |  Nuclear (110)  |  Sun (407)

The thermal agency by which mechanical effect may be obtained is the transference of heat from one body to another at a lower temperature.
'Réflexions sur la puissance motrice du feu' (1824) translated by R.H. Thurston in Reflections on the Motive Power of Fire, and on Machines Fitted to Develop that Power (1890), 139.
Science quotes on:  |  Agency (14)  |  Body (557)  |  Effect (414)  |  Heat (180)  |  Mechanical (145)  |  Mechanics (137)  |  Obtain (164)  |  Thermal (15)  |  Transfer (21)

The vacuum-apparatus requires that its manipulators constantly handle considerable amounts of mercury. Mercury is a strong poison, particularly dangerous because of its liquid form and noticeable volatility even at room temperature. Its poisonous character has been rather lost sight of during the present generation. My co-workers and myself found from personal experience-confirmed on many sides when published—that protracted stay in an atmosphere charged with only 1/100 of the amount of mercury required for its saturation, sufficed to induce chronic mercury poisoning. This first reveals itself as an affection of the nerves, causing headaches, numbness, mental lassitude, depression, and loss of memory; such are very disturbing to one engaged in intellectual occupations.
Hydrides of Boron and Silicon (1933), 203.
Science quotes on:  |  Affection (44)  |  Amount (153)  |  Apparatus (70)  |  Atmosphere (117)  |  Character (259)  |  Confirm (58)  |  Considerable (75)  |  Dangerous (108)  |  Depression (26)  |  Disturbance (34)  |  Engagement (9)  |  Experience (494)  |  First (1302)  |  Form (976)  |  Generation (256)  |  Handle (29)  |  Handling (7)  |  Headache (5)  |  Induce (24)  |  Intellect (251)  |  Intellectual (258)  |  Lassitude (4)  |  Liquid (50)  |  Loss (117)  |  Manipulator (5)  |  Memory (144)  |  Mental (179)  |  Mercury (54)  |  Mind (1377)  |  Myself (211)  |  Nerve (82)  |  Occupation (51)  |  Poison (46)  |  Present (630)  |  Require (229)  |  Required (108)  |  Reveal (152)  |  Saturation (9)  |  Side (236)  |  Sight (135)  |  Strong (182)  |  Vacuum (41)  |  Volatility (3)  |  Worker (34)

The whole theory of the motive power of heat is founded on the two following propositions, due respectively to Joule, and to Carnot and Clausius.
PROP. I. Joule).—When equal quantities of mechanical effect are produced by any means whatever from purely thermal sources, or lost in purely thermal effects, equal quantities of heat are put out of existence or are generated.
PROP. II. (Carnot and Clausius).—If an engine be such that, when it is worked backwards, the physical and mechanical agencies in every part of its motions are all reversed, it produces as much mechanical effect as can be produced by any thermo-dynamic engine, with the same temperatures of source and refrigerator, from a given quantity of heat.
In 'On the Dynamical Theory of Heat, with Numerical Results Deduced from Mr Joule's Equivalent of a Thermal Unit, and M. Regnault's Observations on Steam' (1851). In Mathematical and Physical Papers (1882), Vol. 1, 178.
Science quotes on:  |  Backwards (18)  |  Due (143)  |  Effect (414)  |  Engine (99)  |  Existence (481)  |  Heat (180)  |  Mean (810)  |  Means (587)  |  Mechanical (145)  |  Motion (320)  |  Motive (62)  |  Physical (518)  |  Power (771)  |  Produced (187)  |  Proposition (126)  |  Purely (111)  |  Quantity (136)  |  Refrigerator (8)  |  Respectively (13)  |  Theory (1015)  |  Thermal (15)  |  Two (936)  |  Whatever (234)  |  Whole (756)  |  Work (1402)

There are no physicists in the hottest parts of hell, because the existence of a ‘‘hottest part’’ implies a temperature difference, and any marginally competent physicist would immediately use this to run a heat engine and make some other part of hell comfortably cool. This is obviously impossible.
…...
Science quotes on:  |  Competent (20)  |  Cool (15)  |  Difference (355)  |  Engine (99)  |  Existence (481)  |  Heat (180)  |  Heat Engine (4)  |  Hell (32)  |  Hot (63)  |  Immediately (115)  |  Imply (20)  |  Impossible (263)  |  Obviously (11)  |  Other (2233)  |  Part (235)  |  Physicist (270)  |  Run (158)  |  Use (771)

There could not be a language more universal and more simple, more exempt from errors and obscurities, that is to say, more worthy of expressing the invariable relations of natural objects. Considered from this point of view, it is coextensive with nature itself; it defines all the sensible relations, measures the times, the spaces, the forces, the temperatures; this difficult science is formed slowly, but it retains all the principles it has once acquired. It grows and becomes more certain without limit in the midst of so many errors of the human mind.
From Théorie Analytique de la Chaleur, Discours Préliminaire (Theory of Heat, Introduction), quoted as translated in F.R. Moulton, 'The Influence of Astronomy on Mathematics', Science (10 Mar 1911), N.S. Vol. 33, No. 845, 359.
Science quotes on:  |  Acquired (77)  |  Become (821)  |  Certain (557)  |  Consider (428)  |  Considered (12)  |  Definition (238)  |  Difficult (263)  |  Error (339)  |  Exempt (3)  |  Force (497)  |  Form (976)  |  Grow (247)  |  Human (1512)  |  Human Mind (133)  |  Invariable (6)  |  Language (308)  |  Limit (294)  |  Measure (241)  |  Mind (1377)  |  More (2558)  |  Natural (810)  |  Nature (2017)  |  Nature Of Mathematics (80)  |  Object (438)  |  Obscurity (28)  |  Point (584)  |  Point Of View (85)  |  Principle (530)  |  Relation (166)  |  Retain (57)  |  Say (989)  |  Sensible (28)  |  Simple (426)  |  Slowly (19)  |  Space (523)  |  Time (1911)  |  Universal (198)  |  View (496)

There exists for every liquid a temperature at which no amount of pressure is sufficient to retain it in the liquid form.
[These words are NOT by Thomas Andrews. See below.]
This is NOT a quote by Andrews. It is only included here to provide this caution, because at least one book attributes it incorrectly to Andrews, as in John Daintith, Biographical Encyclopedia of Scientists (3rd. ed., 2008), 19. Webmaster has determined that these words are those of William Allen Miller, in Elements of Chemistry (1855), Vol. 1, 257. In the article on Thomas Andrews in Charles Coulston Gillespie (ed.), Dictionary of Scientific Biography (1970), Vol. 1, 161, the later, third edition (1863) of Miller's textbook is named as the first printed account of Andrews' work. (Andrews had furnished his experimental results to Miller by letter.) After stating Miller's description of Andrews' results, the article in DSB refers ambiguously to “his” summary and gives the quote above. No quotation marks are present in Miller's book. Specifically, in fact, the words in the summary are by Miller. This is seen in the original textbook, because Miller prefaced the quote with “From these experiments it is obvious that...” and is summarizing the related work of several scientists, not just Andrews. Miller described the earlier experiments of those other researchers in the immediately preceding pages. It is clear that the quote does not come from Andrews when comparing Miller's first edition (1855), which had not yet included the work by Andrews. Thus, the same summary words (as quoted above) in the earliest edition refer to the experiments of only the other researchers, not including Andrews. Furthermore, the quote is not present in the Bakerian Lecture by Andrews on his work, later published in Philosophical Transactions of the Royal Society (1869). Webmaster speculates Daintith's book was written relying on a misreading of the ambiguous sentence in DSB.
Science quotes on:  |  Amount (153)  |  Exist (458)  |  Existence (481)  |  Form (976)  |  Liquid (50)  |  Pressure (69)  |  Retain (57)  |  Retention (5)  |  See (1094)  |  Sufficient (133)  |  Word (650)

Time out of mind—or, rather, ever since Nicolas Le Fèvre … pointed out that chemistry was the art of separations as well as of transmutations—it has been recognized that, with every increase of temperature, or dissociating power, bodies were separated from each other.
In The Chemistry of the Sun (1887), x.
Science quotes on:  |  Art (680)  |  Body (557)  |  Chemistry (376)  |  Dissociate (2)  |  Increase (225)  |  Mind (1377)  |  Point (584)  |  Power (771)  |  Recognize (136)  |  Separate (151)  |  Separation (60)  |  Time (1911)  |  Transmutation (24)

To make still bigger telescopes will be useless, for the light absorption and temperature variations of the earth’s atmosphere are what now limits the ability to see fine detail. If bigger telescopes are to be built, it will have to be for use in an airless observatory, perhaps an observatory on the moon.
(1965). In Isaac Asimov’s Book of Science and Nature Quotations (1988), 284.
Science quotes on:  |  Ability (162)  |  Absorption (13)  |  Airless (3)  |  Atmosphere (117)  |  Big (55)  |  Build (211)  |  Detail (150)  |  Earth (1076)  |  Fine (37)  |  Light (635)  |  Limit (294)  |  Moon (252)  |  Observatory (18)  |  See (1094)  |  Still (614)  |  Telescope (106)  |  Use (771)  |  Useless (38)  |  Variation (93)  |  Will (2350)

To pick a hole–say in the 2nd law of Ωcs, that if two things are in contact the hotter cannot take heat from the colder without external agency.
Now let A & B be two vessels divided by a diaphragm and let them contain elastic molecules in a state of agitation which strike each other and the sides. Let the number of particles be equal in A & B but let those in A have equal velocities, if oblique collisions occur between them their velocities will become unequal & I have shown that there will be velocities of all magnitudes in A and the same in B only the sum of the squares of the velocities is greater in A than in B.
When a molecule is reflected from the fixed diaphragm CD no work is lost or gained.
If the molecule instead of being reflected were allowed to go through a hole in CD no work would be lost or gained, only its energy would be transferred from the one vessel to the other.
Now conceive a finite being who knows the paths and velocities of all the molecules by simple inspection but who can do no work, except to open and close a hole in the diaphragm, by means of a slide without mass.
Let him first observe the molecules in A and when lie sees one coming the square of whose velocity is less than the mean sq. vel. of the molecules in B let him open a hole & let it go into B. Next let him watch for a molecule in B the square of whose velocity is greater than the mean sq. vel. in A and when it comes to the hole let him draw and slide & let it go into A, keeping the slide shut for all other molecules.
Then the number of molecules in A & B are the same as at first but the energy in A is increased and that in B diminished that is the hot system has got hotter and the cold colder & yet no work has been done, only the intelligence of a very observant and neat fingered being has been employed. Or in short if heat is the motion of finite portions of matter and if we can apply tools to such portions of matter so as to deal with them separately then we can take advantage of the different motion of different portions to restore a uniformly hot system to unequal temperatures or to motions of large masses. Only we can't, not being clever enough.
Letter to Peter Guthrie Tait (11 Dec 1867). In P. M. Harman (ed.), The Scientific Letters and Papers of James Clerk Maxwell (1995), Vol. 2, 331-2.
Science quotes on:  |  Advantage (144)  |  Agitation (10)  |  Apply (170)  |  Become (821)  |  Being (1276)  |  Clever (41)  |  Cold (115)  |  Collision (16)  |  Coming (114)  |  Conceive (100)  |  Contact (66)  |  Deal (192)  |  Different (595)  |  Divided (50)  |  Do (1905)  |  Draw (140)  |  Employ (115)  |  Energy (373)  |  Enough (341)  |  Finite (60)  |  First (1302)  |  Gain (146)  |  Greater (288)  |  Heat (180)  |  Hot (63)  |  Intelligence (218)  |  Know (1538)  |  Large (398)  |  Law (913)  |  Lie (370)  |  Magnitude (88)  |  Mass (160)  |  Matter (821)  |  Maxwell�s Demon (2)  |  Mean (810)  |  Means (587)  |  Molecule (185)  |  Motion (320)  |  Next (238)  |  Number (710)  |  Observe (179)  |  Occur (151)  |  Open (277)  |  Other (2233)  |  Particle (200)  |  Path (159)  |  Portion (86)  |  Say (989)  |  See (1094)  |  Short (200)  |  Shut (41)  |  Side (236)  |  Simple (426)  |  Square (73)  |  State (505)  |  Strike (72)  |  Sum (103)  |  System (545)  |  Thermodynamics (40)  |  Thing (1914)  |  Through (846)  |  Tool (129)  |  Two (936)  |  Unequal (12)  |  Velocity (51)  |  Vessel (63)  |  Watch (118)  |  Will (2350)  |  Work (1402)

To take one of the simplest cases of the dissipation of energy, the conduction of heat through a solid—consider a bar of metal warmer at one end than the other and left to itself. To avoid all needless complication, of taking loss or gain of heat into account, imagine the bar to be varnished with a substance impermeable to heat. For the sake of definiteness, imagine the bar to be first given with one half of it at one uniform temperature, and the other half of it at another uniform temperature. Instantly a diffusing of heat commences, and the distribution of temperature becomes continuously less and less unequal, tending to perfect uniformity, but never in any finite time attaining perfectly to this ultimate condition. This process of diffusion could be perfectly prevented by an army of Maxwell’s ‘intelligent demons’* stationed at the surface, or interface as we may call it with Prof. James Thomson, separating the hot from the cold part of the bar.
* The definition of a ‘demon’, according to the use of this word by Maxwell, is an intelligent being endowed with free will, and fine enough tactile and perceptive organisation to give him the faculty of observing and influencing individual molecules of matter.
In 'The Kinetic Theory of the Dissipation of Energy', Nature (1874), 9, 442.
Science quotes on:  |  According (236)  |  Account (195)  |  Army (35)  |  Avoid (123)  |  Become (821)  |  Being (1276)  |  Call (781)  |  Cold (115)  |  Complication (30)  |  Condition (362)  |  Conduction (8)  |  Consider (428)  |  Definition (238)  |  Diffusion (13)  |  Distribution (51)  |  End (603)  |  Endowed (52)  |  Energy (373)  |  Enough (341)  |  Finite (60)  |  First (1302)  |  Free (239)  |  Free Will (15)  |  Gain (146)  |  Heat (180)  |  Hot (63)  |  Imagine (176)  |  Individual (420)  |  Instantly (20)  |  Intelligent (108)  |  Loss (117)  |  Matter (821)  |  Maxwell (42)  |  Metal (88)  |  Molecule (185)  |  Never (1089)  |  Other (2233)  |  Perceptive (3)  |  Perfect (223)  |  Prevent (98)  |  Process (439)  |  Sake (61)  |  Solid (119)  |  Station (30)  |  Substance (253)  |  Surface (223)  |  Through (846)  |  Time (1911)  |  Ultimate (152)  |  Unequal (12)  |  Uniformity (38)  |  Use (771)  |  Varnish (2)  |  Will (2350)  |  Word (650)

To-day, science has withdrawn into realms that are hardly understanded of the people. Biology means very largely histology, the study of the cell by difficult and elaborate microscopical processes. Chemistry has passed from the mixing of simple substances with ascertained reactions, to an experimentation of these processes under varying conditions of temperature, pressure, and electrification—all requiring complicated apparatus and the most delicate measurement and manipulation. Similarly, physics has outgrown the old formulas of gravity, magnetism, and pressure; has discarded the molecule and atom for the ion, and may in its recent generalizations be followed only by an expert in the higher, not to say the transcendental mathematics.
Anonymous
‘Exit the Amateur Scientist.’ Editorial, The Nation, 23 August 1906, 83, 160.
Science quotes on:  |  Apparatus (70)  |  Ascertain (41)  |  Atom (381)  |  Biology (232)  |  Chemistry (376)  |  Complicated (117)  |  Condition (362)  |  Delicate (45)  |  Difficult (263)  |  Discard (32)  |  Elaborate (31)  |  Expert (67)  |  Follow (389)  |  Formula (102)  |  Generalization (61)  |  Gravity (140)  |  Histology (4)  |  Ion (21)  |  Magnetism (43)  |  Manipulation (19)  |  Mathematics (1395)  |  Mean (810)  |  Means (587)  |  Measurement (178)  |  Molecule (185)  |  Most (1728)  |  Old (499)  |  Pass (241)  |  People (1031)  |  Physic (515)  |  Physics (564)  |  Pressure (69)  |  Reaction (106)  |  Realm (87)  |  Recent (78)  |  Research (753)  |  Say (989)  |  Simple (426)  |  Study (701)  |  Substance (253)  |  Transcendental (11)  |  Understand (648)

Unconscious, perhaps, of the remote tendency of his own labours, he [Joseph Black] undermined that doctrine of material heat, which he seemed to support. For, by his advocacy of latent heat, he taught that its movements constantly battle, not only some of our senses, but all of them; and that, while our feelings make us believe that heat is lost, our intellect makes us believe that it is not lost. Here, we have apparent destructability, and real indestructibility. To assert that a body received heat without its temperature rising, was to make the understanding correct the touch, and defy its dictates. It was a bold and beautiful paradox, which required courage as well as insight to broach, and the reception of which marks an epoch in the human mind, because it was an immense step towards idealizing matter into force.
History of Civilization in England (1861), Vol. 2, 494.
Science quotes on:  |  Apparent (85)  |  Assert (69)  |  Beautiful (271)  |  Joseph Black (14)  |  Body (557)  |  Bold (22)  |  Courage (82)  |  Defy (11)  |  Epoch (46)  |  Feeling (259)  |  Feelings (52)  |  Force (497)  |  Heat (180)  |  Human (1512)  |  Human Mind (133)  |  Immense (89)  |  Insight (107)  |  Intellect (251)  |  Labor (200)  |  Latent Heat (7)  |  Material (366)  |  Matter (821)  |  Mind (1377)  |  Movement (162)  |  Paradox (54)  |  Reception (16)  |  Remote (86)  |  Required (108)  |  Rising (44)  |  Sense (785)  |  Step (234)  |  Support (151)  |  Tendency (110)  |  Touch (146)  |  Understanding (527)

We only have to look around us to see how complexity ... and psychic “temperature” are still rising: and rising no longer on the scale of the individual but now on that of the planet. This indication is so familiar to us that we cannot but recognize the objective, experiential, reality of a directionally controlled transformation of the Noosphere “as a whole.”
In Teilhard de Chardin and René Hague (trans.), The Heart of Matter (1950, 1978), 38. His term Noosphere refers to the collective sphere of human consciousness.
Science quotes on:  |  Complexity (121)  |  Controlled (3)  |  Familiar (47)  |  Indication (33)  |  Individual (420)  |  Look (584)  |  Objective (96)  |  Planet (402)  |  Psychic (15)  |  Reality (274)  |  Recognize (136)  |  Rising (44)  |  Scale (122)  |  See (1094)  |  Still (614)  |  Transformation (72)  |  Whole (756)

What is there about fire that's so lovely? ... It's perpetual motion; the thing man wanted to invent but never did. Or almost perpetual motion. ... What is fire? It's a mystery. Scientists give us gobbledegook about friction and molecules. But they don't really know.
[Fahrenheit 451 refers to the temperature at which book paper burns. In the short novel of this title 'firemen' burn books forbidden by the totalitaran regime.]
Fahrenheit 451 (1953, 1996), 115.
Science quotes on:  |  Book (413)  |  Burn (99)  |  Fire (203)  |  Forbidden (18)  |  Friction (14)  |  Invention (400)  |  Know (1538)  |  Man (2252)  |  Molecule (185)  |  Motion (320)  |  Mystery (188)  |  Never (1089)  |  Novel (35)  |  Paper (192)  |  Perpetual (59)  |  Perpetual Motion (14)  |  Scientist (881)  |  Short (200)  |  Thing (1914)  |  Want (504)

While no one can ascribe a single weather event to climate change with any degree of scientific certainty, higher maximum temperatures are one of the most predictable impacts of accelerated global warming, and the parallels—between global climate change and global terrorism—are becoming increasingly obvious.
In 'Global Warming is Now a Weapon of Mass Destruction', The Guardian (28 Jul 2003).
Science quotes on:  |  Accelerate (11)  |  Becoming (96)  |  Certainty (180)  |  Change (639)  |  Climate (102)  |  Climate Change (76)  |  Degree (277)  |  Event (222)  |  Global (39)  |  Global Warming (29)  |  Impact (45)  |  Maximum (16)  |  Most (1728)  |  Obvious (128)  |  Parallel (46)  |  Predictable (10)  |  Scientific (955)  |  Single (365)  |  Terrorism (3)  |  Warming (24)  |  Weather (49)

While working with staphylococcus variants a number of culture-plates were set aside on the laboratory bench and examined from time to time. In the examinations these plates were necessarily exposed to the air and they became contaminated with various micro-organisms. It was noticed that around a large colony of a contaminating mould the staphylococcus colonies became transparent and were obviously undergoing lysis. Subcultures of this mould were made and experiments conducted with a view to ascertaining something of the properties of the bacteriolytic substance which had evidently been formed in the mould culture and which had diffused into the surrounding medium. It was found that broth in which the mould had been grown at room temperature for one or two weeks had acquired marked inhibitory, bacteriocidal and bacteriolytic properties to many of the more common pathogenic bacteria.
'On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. Influenzae', British Journal of Experimental Pathology, 1929, 10, 226.
Science quotes on:  |  Acquired (77)  |  Air (366)  |  Bacteria (50)  |  Bacteriology (5)  |  Bench (8)  |  Common (447)  |  Conduct (70)  |  Culture (157)  |  Discovery (837)  |  Evidently (26)  |  Examination (102)  |  Experiment (736)  |  Exposed (33)  |  Form (976)  |  Laboratory (214)  |  Large (398)  |  Lysis (4)  |  Marked (55)  |  Micro-Organism (3)  |  More (2558)  |  Necessarily (137)  |  Number (710)  |  Organism (231)  |  Penicillin (18)  |  Set (400)  |  Something (718)  |  Staphylococcus (2)  |  Substance (253)  |  Time (1911)  |  Transparent (16)  |  Two (936)  |  Variant (9)  |  Various (205)  |  View (496)  |  Week (73)

Who does not know Maxwell’s dynamic theory of gases? At first there is the majestic development of the variations of velocities, then enter from one side the equations of condition and from the other the equations of central motions, higher and higher surges the chaos of formulas, suddenly four words burst forth: “Put n = 5.” The evil demon V disappears like the sudden ceasing of the basso parts in music, which hitherto wildly permeated the piece; what before seemed beyond control is now ordered as by magic. There is no time to state why this or that substitution was made, he who cannot feel the reason may as well lay the book aside; Maxwell is no program-musician who explains the notes of his composition. Forthwith the formulas yield obediently result after result, until the temperature-equilibrium of a heavy gas is reached as a surprising final climax and the curtain drops.
In Ceremonial Speech (15 Nov 1887) celebrating the 301st anniversary of the Karl-Franzens-University Graz. Published as Gustav Robert Kirchhoff: Festrede zur Feier des 301. Gründungstages der Karl-Franzens-Universität zu Graz (1888), 29-30, as translated in Robert Édouard Moritz, Memorabilia Mathematica; Or, The Philomath’s Quotation-book (1914), 187. From the original German, “Wer kennt nicht seine dynamische Gastheorie? – Zuerst entwickeln sich majestätisch die Variationen der Geschwindigkeiten, dann setzen von der einen Seite die Zustands-Gleichungen, von der anderen die Gleichungen der Centralbewegung ein, immer höher wogt das Chaos der Formeln; plötzlich ertönen die vier Worte: „Put n=5.“Der böse Dämon V verschwindet, wie in der Musik eine wilde, bisher alles unterwühlende Figur der Bässe plötzlich verstummt; wie mit einem Zauberschlage ordnet sich, was früher unbezwingbar schien. Da ist keine Zeit zu sagen, warum diese oder jene Substitution gemacht wird; wer das nicht fühlt, lege das Buch weg; Maxwell ist kein Programmmusiker, der über die Noten deren Erklärung setzen muss. Gefügig speien nun die Formeln Resultat auf Resultat aus, bis überraschend als Schlusseffect noch das Wärme-Gleichgewicht eines schweren Gases gewonnen wird und der Vorhang sinkt.” A condensed alternate translation also appears on the Ludwig Boltzmann Quotes page of this website.
Science quotes on:  |  Bass (2)  |  Beyond (316)  |  Book (413)  |  Burst (41)  |  Cease (81)  |  Central (81)  |  Chaos (99)  |  Composition (86)  |  Condition (362)  |  Control (182)  |  Curtain (4)  |  Demon (8)  |  Development (441)  |  Disappear (84)  |  Drop (77)  |  Dynamic (16)  |  Enter (145)  |  Equation (138)  |  Equilibrium (34)  |  Evil (122)  |  Explain (334)  |  Feel (371)  |  Final (121)  |  First (1302)  |  Formula (102)  |  Gas (89)  |  Heavy (24)  |  Higher (37)  |  Know (1538)  |  Magic (92)  |  Majestic (17)  |  Mathematics As A Fine Art (23)  |  Maxwell (42)  |  James Clerk Maxwell (91)  |  Motion (320)  |  Music (133)  |  Musician (23)  |  Note (39)  |  Obedient (9)  |  Order (638)  |  Other (2233)  |  Permeate (3)  |  Program (57)  |  Reach (286)  |  Reason (766)  |  Result (700)  |  Side (236)  |  State (505)  |  Substitution (16)  |  Sudden (70)  |  Suddenly (91)  |  Surge (2)  |  Surprise (91)  |  Theory (1015)  |  Time (1911)  |  Variation (93)  |  Velocity (51)  |  Why (491)  |  Wild (96)  |  Word (650)  |  Yield (86)

You can swim (uncomfortably) in water at a temperature slightly above freezing; a tiny drop in temperature—or a miracle—allows you to walk on water.
Co-authored with Bruce A. Albrecht.
Craig F. Bohren and Bruce A. Albrecht. In Michael Dudley Sturge , Statistical and Thermal Physics (2003), 273.
Science quotes on:  |  Author (175)  |  Drop (77)  |  Freezing (16)  |  Miracle (85)  |  Swim (32)  |  Tiny (74)  |  Walk (138)  |  Water (503)


Carl Sagan Thumbnail In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) -- Carl Sagan
Quotations by:Albert EinsteinIsaac NewtonLord KelvinCharles DarwinSrinivasa RamanujanCarl SaganFlorence NightingaleThomas EdisonAristotleMarie CurieBenjamin FranklinWinston ChurchillGalileo GalileiSigmund FreudRobert BunsenLouis PasteurTheodore RooseveltAbraham LincolnRonald ReaganLeonardo DaVinciMichio KakuKarl PopperJohann GoetheRobert OppenheimerCharles Kettering  ... (more people)

Quotations about:Atomic  BombBiologyChemistryDeforestationEngineeringAnatomyAstronomyBacteriaBiochemistryBotanyConservationDinosaurEnvironmentFractalGeneticsGeologyHistory of ScienceInventionJupiterKnowledgeLoveMathematicsMeasurementMedicineNatural ResourceOrganic ChemistryPhysicsPhysicianQuantum TheoryResearchScience and ArtTeacherTechnologyUniverseVolcanoVirusWind PowerWomen ScientistsX-RaysYouthZoology  ... (more topics)
Sitewide search within all Today In Science History pages:
Visit our Science and Scientist Quotations index for more Science Quotes from archaeologists, biologists, chemists, geologists, inventors and inventions, mathematicians, physicists, pioneers in medicine, science events and technology.

Names index: | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

Categories index: | 1 | 2 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Thank you for sharing.
- 100 -
Sophie Germain
Gertrude Elion
Ernest Rutherford
James Chadwick
Marcel Proust
William Harvey
Johann Goethe
John Keynes
Carl Gauss
Paul Feyerabend
- 90 -
Antoine Lavoisier
Lise Meitner
Charles Babbage
Ibn Khaldun
Euclid
Ralph Emerson
Robert Bunsen
Frederick Banting
Andre Ampere
Winston Churchill
- 80 -
John Locke
Bronislaw Malinowski
Bible
Thomas Huxley
Alessandro Volta
Erwin Schrodinger
Wilhelm Roentgen
Louis Pasteur
Bertrand Russell
Jean Lamarck
- 70 -
Samuel Morse
John Wheeler
Nicolaus Copernicus
Robert Fulton
Pierre Laplace
Humphry Davy
Thomas Edison
Lord Kelvin
Theodore Roosevelt
Carolus Linnaeus
- 60 -
Francis Galton
Linus Pauling
Immanuel Kant
Martin Fischer
Robert Boyle
Karl Popper
Paul Dirac
Avicenna
James Watson
William Shakespeare
- 50 -
Stephen Hawking
Niels Bohr
Nikola Tesla
Rachel Carson
Max Planck
Henry Adams
Richard Dawkins
Werner Heisenberg
Alfred Wegener
John Dalton
- 40 -
Pierre Fermat
Edward Wilson
Johannes Kepler
Gustave Eiffel
Giordano Bruno
JJ Thomson
Thomas Kuhn
Leonardo DaVinci
Archimedes
David Hume
- 30 -
Andreas Vesalius
Rudolf Virchow
Richard Feynman
James Hutton
Alexander Fleming
Emile Durkheim
Benjamin Franklin
Robert Oppenheimer
Robert Hooke
Charles Kettering
- 20 -
Carl Sagan
James Maxwell
Marie Curie
Rene Descartes
Francis Crick
Hippocrates
Michael Faraday
Srinivasa Ramanujan
Francis Bacon
Galileo Galilei
- 10 -
Aristotle
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
Charles Darwin
Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton


by Ian Ellis
who invites your feedback
Thank you for sharing.
Today in Science History
Sign up for Newsletter
with quiz, quotes and more.