Celebrating 19 Years on the Web
TODAY IN SCIENCE HISTORY ®
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 I > Category: Irreversibility

Irreversibility Quotes (4 quotes)

Evolution in the biosphere is therefore a necessarily irreversible process defining a direction in time; a direction which is the same as that enjoined by the law of increasing entropy, that is to say, the second law of thermodynamics. This is far more than a mere comparison: the second law is founded upon considerations identical to those which establish the irreversibility of evolution. Indeed, it is legitimate to view the irreversibility of evolution as an expression of the second law in the biosphere.
In Jacques Monod and Austryn Wainhouse (trans.), Chance and Necessity: An Essay on the Natural Philosophy of Modern Biology (1971), 123.
Science quotes on:  |  Biosphere (13)  |  Comparison (102)  |  Consideration (139)  |  Direction (175)  |  Entropy (44)  |  Evolution (590)  |  Expression (175)  |  Identical (53)  |  Indeed (324)  |  Irreversible (12)  |  Law (894)  |  Legitimate (25)  |  More (2559)  |  Necessarily (135)  |  Process (423)  |  Say (984)  |  Second Law Of Thermodynamics (14)  |  Thermodynamics (40)  |  Time (1877)  |  View (488)

In a sense cosmology contains all subjects because it is the story of everything, including biology, psychology and human history. In that single sense it can be said to contain an explanation also of time's arrow. But this is not what is meant by those who advocate the cosmological explanation of irreversibility. They imply that in some way the time arrow of cosmology imposes its sense on the thermodynamic arrow. I wish to disagree with this view. The explanation assumes that the universe is expanding. While this is current orthodoxy, there is no certainty about it. The red-shifts might be due to quite different causes. For example, when light passes through the expanding clouds of gas it will be red-shifted. A large number of such clouds might one day be invoked to explain these red shifts. It seems an odd procedure to attempt to 'explain' everyday occurrences, such as the diffusion of milk into coffee, by means of theories of the universe which are themselves less firmly established than the phenomena to be explained. Most people believe in explaining one set of things in terms of others about which they are more certain, and the explanation of normal irreversible phenomena in terms of the cosmological expansion is not in this category.
'Thermodynamics, Cosmology) and the Physical Constants', in J. T. Fraser (ed.), The Study of Time III (1973), 117-8.
Science quotes on:  |   (2863)  |  Advocate (18)  |  All (4108)  |  Arrow (20)  |  Attempt (251)  |  Biology (216)  |  Category (18)  |  Cause (541)  |  Certain (550)  |  Certainty (174)  |  Cloud (104)  |  Coffee (19)  |  Cosmological (11)  |  Cosmology (25)  |  Current (118)  |  Different (577)  |  Diffusion (13)  |  Due (141)  |  Everyday (32)  |  Everything (476)  |  Expansion (41)  |  Explain (322)  |  Explanation (234)  |  Gas (83)  |  History (673)  |  Human (1468)  |  Irreversible (12)  |  Large (394)  |  Light (607)  |  Mean (809)  |  Means (579)  |  Milk (22)  |  More (2559)  |  Most (1731)  |  Number (699)  |  Occurrence (53)  |  Orthodoxy (9)  |  Other (2236)  |  People (1005)  |  Procedure (41)  |  Psychology (154)  |  Red-Shift (4)  |  Sense (770)  |  Set (394)  |  Shift (44)  |  Single (353)  |  Story (118)  |  Subject (521)  |  Term (349)  |  Terms (184)  |  Themselves (433)  |  Thermodynamics (40)  |  Thing (1915)  |  Through (849)  |  Time (1877)  |  Universe (857)  |  View (488)  |  Way (1217)  |  Will (2355)  |  Wish (212)

It has been suggested that thermodynamic irreversibility is due to cosmological expansion.
'Thermodynamics, Cosmology, and the Physical Constants', in J. T. Fraser (ed.), The Study of Time III (1973), 117-8.
Science quotes on:  |  Cosmological (11)  |  Cosmology (25)  |  Due (141)  |  Expansion (41)  |  Thermodynamics (40)

Perhaps the majority of paleontologists of the present time, who believe in orthogenesis, the irreversibility of evolution and the polyphyletic origin families, will assume that a short molar must keep on getting shorter, that it can never get longer and then again grow relatively shorter and therefore that Propliopithecus with its extremely short third molar and Dryopithecus its long m3 are alike excluded from ancestry of the Gorilla, in which the is a slight retrogression in length of m3. After many years reflection and constant study of the evolution of the vertebrates however, I conclude that 'orthogenesis' should mean solely that structures and races evolve in a certain direction, or toward a certain goal, only until the direction of evolution shifts toward some other goal. I believe that the 'irreversibility of evolution' means only that past changes irreversibly limit and condition future possibilities, and that, as a matter of experience, if an organ is once lost the same (homogenous) organ can be regained, although nature is fertile in substituting imitations. But this not mean, in my judgement, that if one tooth is smaller than its fellows it will in all cases continue to grow smaller.
'Studies on the Evolution of the Primates’, Bulletin of the American Museum of Natural History, 1916, 35, 307.
Science quotes on:  |  Alike (60)  |  All (4108)  |  Ancestry (12)  |  Certain (550)  |  Change (593)  |  Conclude (65)  |  Condition (356)  |  Constant (144)  |  Continue (165)  |  Direction (175)  |  Evolution (590)  |  Experience (467)  |  Fellow (88)  |  Fertile (29)  |  Future (429)  |  Goal (145)  |  Gorilla (18)  |  Grow (238)  |  Limit (280)  |  Long (790)  |  Majority (66)  |  Matter (798)  |  Mean (809)  |  Means (579)  |  Must (1526)  |  Nature (1926)  |  Never (1087)  |  Organ (115)  |  Origin (239)  |  Other (2236)  |  Paleontologist (19)  |  Past (337)  |  Present (619)  |  Race (268)  |  Reflection (90)  |  Retrogression (6)  |  Shift (44)  |  Short (197)  |  Structure (344)  |  Study (653)  |  Time (1877)  |  Tooth (29)  |  Vertebrate (20)  |  Will (2355)  |  Year (933)


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 Einstein • Isaac Newton • Lord Kelvin • Charles Darwin • Srinivasa Ramanujan • Carl Sagan • Florence Nightingale • Thomas Edison • Aristotle • Marie Curie • Benjamin Franklin • Winston Churchill • Galileo Galilei • Sigmund Freud • Robert Bunsen • Louis Pasteur • Theodore Roosevelt • Abraham Lincoln • Ronald Reagan • Leonardo DaVinci • Michio Kaku • Karl Popper • Johann Goethe • Robert Oppenheimer • Charles Kettering  ... (more people)

Quotations about: • Atomic  Bomb • Biology • Chemistry • Deforestation • Engineering • Anatomy • Astronomy • Bacteria • Biochemistry • Botany • Conservation • Dinosaur • Environment • Fractal • Genetics • Geology • History of Science • Invention • Jupiter • Knowledge • Love • Mathematics • Measurement • Medicine • Natural Resource • Organic Chemistry • Physics • Physician • Quantum Theory • Research • Science and Art • Teacher • Technology • Universe • Volcano • Virus • Wind Power • Women Scientists • X-Rays • Youth • Zoology  ... (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 |

- 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



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