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• Radioactivity is shown to be accompanied by chemical changes in which new types of matter are being continually produced. ... The conclusion is drawn that these chemical changes must be sub-atomic in character.
  • "The Cause and Nature of Radioactivity" in Philosophical Magazine (September 1902)

• All science is either physics or stamp collecting.
  • As quoted in Rutherford at Manchester (1962) by J. B. Birks
  • Unsourced variant: That which is not measurable is not science. That which is not physics is stamp collecting.
  • "Physics is the only real science. The rest are just stamp collecting." (Unsourced)
    • "That which is not measurable is not science." is also attributed to Lord Kelvin

• 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 heat] was discovered. That prophetic utterance referred to what we are now considering tonight, radium! Behold! The old boy beamed upon me.
  • As quoted in "Rutherford's Timebomb" in The New Zealand (15 May 2004)

• If you can't explain your physics to a barmaid it is probably not very good physics.
  • As quoted in Journal of Advertising Research (March-April 1998)
  • Variant: A theory that you can't explain to a bartender is probably no damn good.
  • As quoted in The Language of God (2006) by Francis Collins, p.60

• We've got no money, so we've got to think.
  • As quoted in Quips, Quotes, and Quanta by Anton Z. Capri, page 65.