Heinlein, Robert A – Expanded Universe

Mechanics”-the stickiest

subject in physical science. He tackled it his first year at Cambridge and has

continued tO unravel its paradoxes throughout his career; out of 123 publications

over the last 50 years the word quantum can be found 45 times in his titles.

Dirac remained at Cambridge-taught, thought, published. In 1932, the year

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before his Nobel prize, he received an honor rarer than that prize, one formerly

held by Newton: Lucasian professor of mathematics. Dirac kept it 37 years, until he

resigned from Cambridge. He accepted other posts during his Cantabrigian years:

member of the Institute for Advanced Study at Princeton, N.J., professor of the

Dublin Institute for Advanced Studies, visiting professorships here and there.

Intuitive mathematicians often burn out young. Not Dirac!-he is a

Michelangelo who started very young, never stopped, is still going strong.

Antimatter is not necessarily his contribution most esteemed by colleagues, but his

other major ones are so abstruse as to defy putting them into common words:

A mathematical attribute of particles dubbed “spin”; coinvention of the

Fermi-Dirac statistics; an abstract mathematical replacement for the “pellucid

aether” of classical mechanics. For centuries, ether was used and its “physical

reality” generally accepted either as “axiomatic” or “proved” through various

negative proofs. Both “axiom” and “negative proof” are treacherous; the 1887

Michelson-Morley experiment showed no physical reality behind the concept of ether,

and many variations of that experiment over many years gave the same null results.

So Einstein omitted ether from his treatments of relativity-while less

brilliant men ignored the observed facts and clung to classical ether for at least

40 years.

Dirac’s ether (circa 1950) is solely abstract mathematics, more useful

thereby than classical ether as it avoids the paradoxes of the earlier concepts.

Dirac has

consistently warned against treating mathematical equations as if they were pictures

of something that could be visualized in the way one may visualize the Taj Mahal or

a loaf of bread; his equations are rules concerning space-time events-not pictures.

(This may be the key to his extraordinary successes.) One more example must

represent a long list:

Dirac’s work on Georges Lemaltre’s “primeval egg”- later popularized as the “big

bang.”

Honors also are too many to list in full: fellow of the Royal Society, its

Royal Medal, its Copley Medal, honorary degrees (always refused), foreign associate

of the American Academy of Sciences, Oppenheimer Memorial Prize, and (most valued by

Dirac) Great Britain’s Order of Merit.

Dirac “retired” by accepting a research professorship at Florida State

University, where he is now working on gravitation theory. In 1937 he had theorized

that Newton’s “constant of gravitation” was in fact a decreasing variable . . . but

the amount of decrease he predicted was so small that it could not be verified in

1937.

Today the decrease can be measured. In July 1974 Thomas C. Van Flandern of

the U.S. Naval Observatory reported measurements showing a decrease in gravitation

of about a ten-billionth each year (1 per 1010 per annum). This amount seems

trivial, but it j~ very large in astronomical and geological time. If these findings

are confirmed and if they continue to support Dirac’s mathematical theory, he will

have upset physical science even more than he did in 1928 and 1930.

Here is an incomplete list of the sciences that would undergo radical

revision: physics from micro- through astro-, astronomy, geology, paleontology,

meteorology, chemistry, cosmology, cosmogony, geogony, ballistics. It is too early

to speculate about effects on the life sciences, but we exist inside this physical

world and gravitation is the most pervasive feature of our world.

Theory of biological evolution would certainly be affected. It is possible

that understanding gravitation could result in changes in engineering technology too

sweeping easily to be imagined.

Antimatter and You

Of cosmologies there is no end; astrophysicists enjoy “playing God.” It’s

safe fun, too, as the questions are so sweeping, the data so confusing, that any

cosmology is hard to prove or disprove. But since 1932 antimatter has been a

necessary datum. Many cosmologists feel that the universe (universes?) has as much

antimatter as matter-but they disagree over how to balance the two.

Some think that, on the average, every other star in our Milky Way galaxy is