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Home > Category Index for Science Quotations > Category Index R > Category: Radioactivity

Radioactivity Quotes (21 quotes)

Beta decay was... like a dear old friend. There would always be a special place in my heart reserved especially for it.

I came into the room, which was half dark, and presently spotted Lord Kelvin in the audience and realised that I was in for trouble at the last part of my speech dealing with the age of the earth, where my views conflicted with his. To my relief, Kelvin fell fast asleep, but as I came to the important point, I saw the old bird sit up, open an eye and cock a baleful glance at me! Then a sudden inspiration came, and I said Lord Kelvin had limited the age of the earth, provided no new source (of energy) was discovered. That prophetic utterance refers to what we are now considering tonight, radium! Behold! the old boy beamed upon me.
Speech at the Royal Institution (1904). Quoted in Arthur S. Eve, Rutherford (1939), 107.
Science quotes on:  |  Age Of The Earth (10)  |  Baron William Thomson Kelvin (23)  |  Radium (13)

I have satisfied myself that the [cosmic] rays are not generated by the formation of new matter in space, a process which would be like water running up a hill. Nor do they come to any appreciable amount from the stars. According to my investigations the sun emits a radiation of such penetrative power that it is virtually impossible to absorb it in lead or other substances. ... This ray, which I call the primary solar ray, gives rise to a secondary radiation by impact against the cosmic dust scattered through space. It is the secondary radiation which now is commonly called the cosmic ray, and comes, of course, equally from all directions in space. [The article continues: The phenomena of radioactivity are not the result of forces within the radioactive substances but are caused by this ray emitted by the sun. If radium could be screened effectively against this ray it would cease to be radioactive, he said.]
Quoted in 'Tesla, 75, Predicts New Power Source', New York Times (5 Jul 1931), Section 2, 1.
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I will insist particularly upon the following fact, which seems to me quite important and beyond the phenomena which one could expect to observe: The same [double sulfate of uranium and potassium] crystalline crusts, arranged the same way [as reported to the French academy on 24 Feb 1896] with respect to the photographic plates, in the same conditions and through the same screens, but sheltered from the excitation of incident rays and kept in darkness, still produce the same photographic images ... [when kept from 26 Feb 1896] in the darkness of a bureau drawer. ... I developed the photographic plates on the 1st of March, expecting to find the images very weak. Instead the silhouettes appeared with great intensity.
It is important to observe that it appears this phenomenon must not be attributed to the luminous radiation emitted by phosphorescence ... One hypothesis which presents itself to the mind naturally enough would be to suppose that these rays, whose effects have a great similarity to the effects produced by the rays studied by M. Lenard and M. Röntgen, are invisible rays ...
[Having eliminated phosphorescence as a cause, he has further revealed the effect of the as yet unknown radioactivity.]
Read at French Academy of Science (2 Mar 1896). In Comptes Rendus (1896), 122, 501. As translated by Carmen Giunta on the Classic Chemistry web site.
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It is probable that all heavy matter possesses—latent and bound up with the structure of the atom—a similar quantity of energy to that possessed by radium. If it could be tapped and controlled, what an agent it would be in shaping the world's destiny! The man who puts his hand on the lever by which a parsimonious nature regulates so jealously the output of this store of energy would possess a weapon by which he could destroy the Earth if he chose.
A prescient remark on atomic energy after the discovery of radioactivity, but decades before the harnessing of nuclear fission in an atomic bomb became a reality.
Lecture to the Corps of Royal Engineers, Britain (19040. In Rodney P. Carlisle, Scientific American Inventions and Discoveries (2004), 373.
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It was my good fortune to be linked with Mme. Curie through twenty years of sublime and unclouded friendship. I came to admire her human grandeur to an ever growing degree. Her strength, her purity of will, her austerity toward herself, her objectivity, her incorruptible judgement— all these were of a kind seldom found joined in a single individual... The greatest scientific deed of her life—proving the existence of radioactive elements and isolating them—owes its accomplishment not merely to bold intuition but to a devotion and tenacity in execution under the most extreme hardships imaginable, such as the history of experimental science has not often witnessed.
Out of My Later Years (1950), 227-8.
Science quotes on:  |  Marie Curie (28)

Like taxes, radioactivity has long been with us and in increasing amounts; it is not to be hated and feared, but accepted and controlled. Radiation is dangerous, let there be no mistake about that—but the modern world abounds in dangerous substances and situations too numerous to mention. ... Consider radiation as something to be treated with respect, avoided when practicable, and accepted when inevitable.
Recommending the same view towards radiation as the risks of automobile travel.
While in the Office of Naval Research. In Must we Hide? (1949), 44.
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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.
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One of the most striking results of modern investigation has been the way in which several different and quite independent lines of evidence indicate that a very great event occurred about two thousand million years ago. The radio-active evidence for the age of meteorites; and the estimated time for the tidal evolution of the Moon's orbit (though this is much rougher), all agree in their testimony, and, what is far more important, the red-shift in the nebulae indicates that this date is fundamental, not merely in the history of our system, but in that of the material universe as a whole.
The Solar System and its Origin (1935), 137.
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Some months ago we discovered that certain light elements emit positrons under the action of alpha particles. Our latest experiments have shown a very striking fact: when an aluminium foil is irradiated on a polonium preparation [alpha ray emitter], the emission of positrons does not cease immediately when the active preparation is removed: the foil remains radioactive and the emission of radiation decays exponentially as for an ordinary radio-element. We observed the same phenomenon with boron and magnesium.
[Co-author with Irène Joliot-Curie. This one-page paper reported their discovery of artificial radioactivity for which they were awarded the 1935 Nobel Prize for Chemistry.]
Letter to the Editor, 'Artificial Production of a New Kind of Radio-Element'(10 Jan 1934) published in Nature (1934), 133, 201-2. Cited in Mauro Dardo, Nobel Laureates and Twentieth-Century Physics (2004), 187.
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The age of the earth was thus increased from a mere score of millions [of years] to a thousand millions and more, and the geologist who had before been bankrupt in time now found himself suddenly transformed into a capitalist with more millions in the bank than he knew how to dispose of ... More cautious people, like myself, too cautious, perhaps, are anxious first of all to make sure that the new [radioactive] clock is not as much too fast as Lord Kelvin's was too slow.
1921 British Association for the Advancement of Science symposium on 'The Age of the Earth'. In Nature (1921), 108, 282.
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The incomplete knowledge of a system must be an essential part of every formulation in quantum theory. Quantum theoretical laws must be of a statistical kind. To give an example: we know that the radium atom emits alpha-radiation. Quantum theory can give us an indication of the probability that the alpha-particle will leave the nucleus in unit time, but it cannot predict at what precise point in time the emission will occur, for this is uncertain in principle.
The Physicist's Conception of Nature (1958), 41.
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The radiation of radium was “contagious”—Contagious like a persistent scent or a disease. It was impossible for an object, a plant, an animal or a person to be left near a tube of radium without immediately acquiring a notable “activity” which a sensitive apparatus could detect.
Eve Curie
In Eve Curie, Madame Curie: a Biography by Eve Curie (1937, 2007), 196.
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The various reasons which we have enumerated lead us to believe that the new radio-active substance contains a new element which we propose to give the name of radium.
Marie Curie, Pierre Curie and Gustave Bémont, 'Sur une Nouvelle Substance Fortement Radio-Active, Contenue dans las Pechblende', (On a new, strongly radio-active substance, contained in pitchblende), Comptes Rendus (1898). 127, 1217. In Joseph E. Harmon and Alan G. Gross (editors), The Scientific Literature (2007), 151.
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Though much new light is shed by ... studies in radioactivity, the nucleus of the atom, with its hoard of energy, thus continues to present us with a fascinating mystery. ... Our assault on atoms has broken down the outer fortifications. We feel that we know the fundamental rules according to which the outer part of the atom is built. The appearance and properties of the electron atmosphere are rather familiar. Yet that inner citadel, the atomic nucleus, remains unconquered, and we have reason to believe that within this citadel is secreted a great treasure. Its capture may form the main objective of the physicists’ next great drive.
'Assault on Atoms' (Read 23 Apr 1931 at Symposium—The Changing World) Proceedings of the American Philosophical Society (1931), 70, No. 3, 229.
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Thus the radio elements formed strange and cruel families in which each member was created by spontaneous transformation of the mother substance: radium was a “descendant” of uranium, polonium a descendant of radium.
Eve Curie
In Eve Curie, Madame Curie: a Biography by Eve Curie (1937, 2007), 197.
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We believe the substance we have extracted from pitch-blende contains a metal not yet observed, related to bismuth by its analytical properties. If the existence of this new metal is confirmed we propose to call it polonium, from the name of the original country of one of us.
Proceedings of the Academy of Science (18 July 1898). In Eve Curie, Madame Curie (1937, 2007), 161.
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We don't know what we are talking about. Many of us believed that string theory was a very dramatic break with our previous notions of quantum theory. But now we learn that string theory, well, is not that much of a break. The state of physics today is like it was when we were mystified by radioactivity. They were missing something absolutely fundamental. We are missing perhaps something as profound as they were back then.
Closing address to the 23rd Solvay Conference in Physics, Brussels, Belgium (Dec 2005). Quoted in Ashok Sengupta, Chaos, Nonlinearity, Complexity: The Dynamical Paradigm of Nature (2006), vii. Cite in Alfred B. Bortz, Physics: Decade by Decade (2007), 206.
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When one studies strongly radioactive substances special precautions must be taken if one wishes to be able to take delicate measurements. The various objects used in a chemical laboratory and those used in a chemical laboratory, and those which serve for experiments in physics, become radioactive in a short time and act upon photographic plates through black paper. Dust, the air of the room, and one's clothes all become radioactive.
Notebook entry. In Eve Curie, Madame Curie: a Biography by Eve Curie (1937, 2007), 196.
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With an interest almost amounting to anxiety, geologists will watch the development of researches which may result in timing the strata and the phases of evolutionary advance; and may even-going still further back—give us reason to see in the discrepancy between denudative and radioactive methods, glimpses of past aeons, beyond that day of regeneration which at once ushered in our era of life, and, for all that went before, was 'a sleep and a forgetting'.
John Joly
Radioactivity and Geology (1909), 250-1.
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[Concerning] phosphorescent bodies, and in particular to uranium salts whose phosphorescence has a very brief duration. With the double sulfate of uranium and potassium ... I was able to perform the following experiment: One wraps a Lumière photographic plate with a bromide emulsion in two sheets of very thick black paper, such that the plate does not become clouded upon being exposed to the sun for a day. One places on the sheet of paper, on the outside, a slab of the phosphorescent substance, and one exposes the whole to the sun for several hours. When one then develops the photographic plate, one recognizes that the silhouette of the phosphorescent substance appears in black on the negative. If one places between the phosphorescent substance and the paper a piece of money or a metal screen pierced with a cut-out design, one sees the image of these objects appear on the negative. One can repeat the same experiments placing a thin pane of glass between the phosphorescent substance and the paper, which excludes the possibility of chemical action due to vapors which might emanate from the substance when heated by the sun's rays. One must conclude from these experiments that the phosphorescent substance in question emits rays which pass through the opaque paper and reduces silver salts.
[Although the sun is irrelevant, and he misinterprets the role of phosphorescence, he has discovered the effect of radioactivity.]
Read at French Academy of Science (24 Feb 1896). In Comptes Rendus (1896), 122, 420. As translated by Carmen Giunta on the Classic Chemistry web site.
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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
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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
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Giordano Bruno
JJ Thomson
Thomas Kuhn
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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
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Rene Descartes
Francis Crick
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Michael Faraday
Srinivasa Ramanujan
Francis Bacon
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- 10 -
Aristotle
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
Charles Darwin
Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton