„We see from Lenard's table that a cathode ray can travel through air at atmospheric pressure a distance of about half a centimetre before the brightness of the phosphorescence falls to about half its original value. Now the mean free path of the molecules of air at this pressure is about 10-5 cm., and if a molecule of air were projected it would lose half its momentum in a space comparable with the mean free path. Even if we suppose that it is not the same molecule that is carried, the effect of the obliquity of the collisions would reduce the momentum to half in a short multiple of that path. Thus, from Lenard's experiments on the absorption of the rays outside the tube, it follows on the hypothesis that the cathode rays are charged particles moving with high velocities, that the size of the carriers must be small compared with the dimensions of ordinary atoms or molecules. The assumption of a state of matter more finely subdivided than the atom of an element is a somewhat startling one; but a hypothesis that would involve somewhat similar consequences—viz. that the so-called elements are compounds of some primordial element—has been put forward from time to time by various chemists.“

—  Joseph John Thomson, Royal Institution Lecture (April 30, 1897) as quoted by Edmund Taylor Whittaker, A History of the Theories of Aether and Electricity from the Age of Descartes to the Close of the Nineteenth Century http://books.google.com/books?id=CGJDAAAAIAAJ (1910).
Publicidade

Citações relacionadas

Paul A. Samuelson photo
Charles Sanders Peirce photo
Publicidade
Aristarchus of Samos photo

„If you plot the movement of the molecule through time and space, those features governed by the higher properties of the plane as a whole make those controlled at the level of the molecule insignificant by comparison. The higher properties control the lower, not by direct intervention, but by supervention.“

—  Roger Wolcott Sperry American neuroscientist 1913 - 1994
Context: Science traditionally takes the reductionist approach, saying that the collective properties of molecules, or the fundamental units of whatever system you're talking about, are enough to account for all of the system's activity. But this standard approach leaves out one very important additional factor, and that's the spacing and timing of activity — its pattern or form. The components of any system are linked up in different ways, and these possible relationships, especially at the higher levels, are not completely covered by the physical laws for the elementary interactions between atoms and molecules. At some point, the higher properties of the whole begin to take over and govern the fate of its constituents. A simple way to illustrate this idea is to imagine a molecule in an airplane flying from L. A. to New York. The molecule may be jostled somewhat or held in position by its neighbors, but these lower-level actions are trivial compared to its movement as the plane flies across the continent. If you plot the movement of the molecule through time and space, those features governed by the higher properties of the plane as a whole make those controlled at the level of the molecule insignificant by comparison. The higher properties control the lower, not by direct intervention, but by supervention.

Jane Roberts photo
James K. Morrow photo
 Starhawk photo

„We are all longing to go home to some place we have never been — a place half-remembered and half-envisioned we can only catch glimpses of from time to time.“

—  Starhawk American author, activist and Neopagan 1951
Context: We are all longing to go home to some place we have never been — a place half-remembered and half-envisioned we can only catch glimpses of from time to time. Community. Somewhere, there are people to whom we can speak with passion without having the words catch in our throats. Somewhere a circle of hands will open to receive us, eyes will light up as we enter, voices will celebrate with us whenever we come into our own power. Community means strength that joins our strength to do the work that needs to be done. Arms to hold us when we falter. A circle of healing. A circle of friends. Someplace where we can be free. Ch. 6 : Building Community : Processes for Groups, p. 92

John Dewey photo
Herbert Spencer photo
James Jeans photo
Pierre Louis Maupertuis photo
Billie Piper photo

„People were dealing with CGI for the first time, so I think we were really unsure as to whether it would be a huge success or a big flop. … I thought the scripts were so good. It had a kind of domestic element which I'm not sure it ever had before. I think we were feeling quite confident about that. … In terms of whether it had a place in the world when it aired, I think everyone was quite unsure. I didn't know until it aired and people really seemed to like it.“

—  Billie Piper English singer, dancer and actress 1982
On her role in the 21st century revival of Doctor Who, as quoted in "'I've heard that before!': Chris Evans cracks ex-wife jokes with Billie Piper as she appears on his show with new husband Laurence Fox" in The Daily Mail Reporter (22 November 2013) http://www.dailymail.co.uk/tvshowbiz/article-2511885/Chris-Evans-cracks-ex-wife-jokes-Billie-Piper-appears-new-husband-Laurence-Fox.html

Arthur Koestler photo
James Jeans photo