Subject: NOVA Online/Einstein Revealed/Genius (Levenson Essay)
Date: Mon, 22 Jan 2001 11:24:38 -0800
There is a parlor game physics
students play: Who was the
greater genius? Galileo or
Kepler? (Galileo) Maxwell or
Bohr? (Maxwell, but it's closer
than you might think). Hawking or
Heisenberg? (A no-brainer,
whatever the best-seller lists
might say. It's Heisenberg). But
there are two figures who are
simply off the charts. Isaac
Newton is one. The other is
Albert Einstein. If pressed,
physicists give Newton pride of
place, but it is a photo finish
-- and no one else is in the
race.
Newton's claim is obvious. He
created modern physics. His
system described the behavior of
the entire cosmos -- and while
others before him had invented
grand schemes, Newton's was
different. His theories were
mathematical, making specific
predictions to be confirmed by
experiments in the real world.
Little wonder that those after
Newton called him lucky -- "for
there is only one universe to
discover, and he discovered it. "
But what of Einstein? Well,
Einstein felt compelled to
apologize to Newton. "Newton,
forgive me;" Einstein wrote in
his Autobiographical Notes. "You
found the only way which, in your
age, was just about possible for
a man of highest thought and
creative power." Forgive him? For
what? For replacing Newton's
system with his own -- and, like
Newton, for putting his mark on
virtually every branch of
physics.
That's the difference. Young
physicists who play the "who's
smarter" game are really asking,
"how will I measure up?" Is there
a shot to match -- if not
Maxwell, then perhaps Lorentz?
But Einstein? Don't go there.
Match this:
* In 1905, Einstein is 26, a
patent examiner, working on
physics on his own. After hours,
he creates the Special Theory of
Relativity, in which he
demonstrates that measurements
of time and distance vary
systematically as anything moves
relative to anything else. Which
means that Newton was wrong.
Space and time are not absolute
-- and the relativistic universe
we inhabit is not the one Newton
"discovered."
That's pretty good -- but one
idea, however spectacular, does
not make a demi-god. But now add
the rest of what Einstein did in
1905:
* In March, Einstein creates the
quantum theory of light, the
idea that light exists as tiny
packets, or particles, that we
now call photons. Alongside Max
Planck's work on quanta of heat,
and Niels Bohr's later work on
quanta of matter, Einstein's
work anchors the most shocking
idea in twentieth century
physics: we live in a quantum
universe, one built out of tiny,
discrete chunks of energy and
matter.
* Next, in April and May,
Einstein publishes two papers.
In one he invents a new method
of counting and determining the
size of the atoms or molecules
in a given space and in the
other he explains the phenomenon
of Brownian motion. The net
result is a proof that atoms
actually exist -- still an issue
at that time -- and the end to a
millennia-old debate on the
fundamental nature of the
chemical elements.
* And then, in June, Einstein
completes special relativity --
which adds a twist to the story:
Einstein's March paper treated
light as particles, but special
relativity sees light as a
continuous field of waves.
Alice's Red Queen can accept
many impossible things before
breakfast, but it takes a
supremely confident mind to do
so. Einstein, age 26, sees light
as wave and particle, picking
the attribute he needs to
confront each problem in turn.
Now that's tough.
* And of course, Einstein isn't
finished. Later in 1905 comes an
extension of special relativity
in which Einstein proves that
energy and matter are linked in
the most famous relationship in
physics: E=mc2. (The energy
content of a body is equal to
the mass of the body times the
speed of light squared). At
first, even Einstein does not
grasp the full implications of
his formula, but even then he
suggests that the heat produced
by radium could mark the
conversion of tiny amounts of
the mass of the radium salts
into energy.
In sum -- an amazing outburst:
Einstein's 1905 still evokes awe.
Historians call it the annus
mirabilis, the miracle year.
Einstein ranges from the smallest
scale to the largest (for special
relativity is embodied in all
motion throughout the universe),
through fundamental problems
about the nature of energy,
matter, motion, time and
space--all the while putting in
forty hours a week at the patent
office.
And that alone would have been
enough to secure Einstein's
reputation. But it is what comes
next that is almost more
remarkable. After 1905, Einstein
achieves what no one since has
equaled: a twenty year run at the
cutting edge of physics. For all
the miracles of his miracle year,
his best work is still to come:
* In 1907, he confronts the
problem of gravitation -- the
same problem that Newton
confronted, and solved --
almost. Einstein begins his work
with one crucial insight:
gravity and acceleration are
equivalent, two facets of the
same phenomenon. Where this
"principle of equivalence" will
lead remains obscure, but to
Einstein, it offers the first
hint of a theory that could
supplant Newton's.
* Before anyone else, Einstein
recognizes the essential dualism
in nature, the co-existence of
particles and waves at the level
of quanta. In 1911 he declares
resolving the quantum issue to
be the central problem of
physics.
* Even the minor works resonate.
For example, in 1910, Einstein
answers a basic question: "Why
is the sky blue?" His paper on
the phenomenon called critical
opalescence solves the problem
by examining the cumulative
effect of the scattering of
light by individual molecules in
the atmosphere.
* Then in 1915, Einstein
completes the General Theory of
Relativity--the product of eight
years of work on the problem of
gravity. In general relativity
Einstein shows that matter and
energy--all the "stuff" in the
universe--actually mold the
shape of space and the flow of
time. What we feel as the
"force" of gravity is simply the
sensation of following the
shortest path we can through
curved, four-dimensional
space-time. It is a radical
vision: space is no longer the
box the universe comes in;
instead, space and time, matter
and energy are, as Einstein
proves, locked together in the
most intimate embrace.
* In 1917, Einstein publishes a
paper which uses general
relativity to model the behavior
of an entire universe. General
relativity has spawned some of
the weirdest, and most important
results in modern astronomy (see
Alan Lightman's article on this
website), but Einstein's paper
is the starting point, the first
in the modern field of
cosmology--the study of the
behavior of the universe as a
whole. (It is also the paper in
which Einstein makes what he
would call his worst
blunder--inventing a
"cosmological constant" to keep
his universe static. When
Einstein learned of Edwin
Hubble's observations that the
universe is expanding, he
promptly jettisoned the
constant.)
* Returning to the quantum, by
1919, six years before the
invention of quantum mechanics
and the uncertainty principle
Einstein recognizes that there
might be a problem with the
classical notion of cause and
effect. Given the peculiar, dual
nature of quanta as both waves
and particles, it might be
impossible, he warns, to
definitively tie effects to
their causes.
* Yet as late as 1924 and 1925,
Einstein still makes significant
contributions to the development
of quantum theory. His last work
on the theory builds on ideas
developed by Satyendra Nath
Bose, and predicts a new state
of matter (to add to the list of
solid, liquid, and gas) called a
Bose-Einstein condensate. The
condensate was finally created
at exceptionally low
temperatures only last year.
In sum: Einstein is famous for
his distaste for modern quantum
theory --largely because its
probabilistic nature forbids a
complete description of cause and
effect. But still, he recognizes
many of the fundamental
implications of the idea of the
quantum long before the rest of
the physics community does.
After the quantum mechanical
revolution of 1925 through 1927,
Einstein spends the bulk of his
remaining scientific career
searching for a deeper theory to
subsume quantum mechanics and
eliminate its probabilities and
uncertainties. It is the end, as
far as his contemporaries
believe, of Einstein's active
participation in science. He
generates pages of equations,
geometrical descriptions of
fields extending through many
dimensions that could unify all
the known forces of nature. None
of the theories work out. It is a
waste of time...and yet
Contemporary theoretical physics
is dominated by what are known as
"String theories." They are
multi-dimensional. (Some versions
include as many as 26 dimensions,
with fifteen or sixteen curled up
in a tiny ball.) They are
geometrical -- the interactions
of one multi-dimensional shape
with another produces the effects
we call forces, just as the
"force" of gravity in general
relativity is what we feel as we
move through the curves of
four-dimensional space-time. And
they unify, no doubt about it: in
the math, at least, all of nature
from quantum mechanics to gravity
emerges from the equations of
string theory.
As it stands, string theories are
unproved, and perhaps unprovable,
as they involve interactions at
energy levels far beyond any we
can handle. But they are
beautiful, to those versed enough
in the language of mathematics to
follow them. And in their beauty
(and perhaps in their
impenetrability) they are the
heirs to Einstein's primitive,
first attempts to produce a
unified field theory.
Between 1905 to 1925, Einstein
transformed humankind's
understanding of nature on every
scale, from the smallest to that
of the cosmos as a whole. Now,
nearly a century after he began
to make his mark, we are still
exploring Einstein's universe.
The problems he could not solve
remain the ones that define the
cutting edge, the most
tantalizing and compelling.
You can't touch that. Who's
smarter? No one since Newton
comes close.
Thomas Levenson is a Boston-based
independent film maker and
author. He is a producer of
NOVA's Einstein Revealed, and
author of several books. The
latest is Measure for Measure: A
Musical History of Science, with
Einstein in Berlin to follow,
scheduled for publication in
1998.
