Harry Veeder wrote:
Gotta love those probabilities.
With them you can save relativity from obscurity.
Harry
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Professor Resolves Einstein's Twin Paradox
Science Daily <http://www.sciencedaily.com/> — Subhash Kak, Delaune
Distinguished Professor of Electrical and Computer Engineering at LSU,
Specializing in relativity, which is a branch of physics? Tensor
calculus doesn't see a lot of use in CS/EE departments, FWIW.
recently resolved the twin paradox, known as one of the most enduring
puzzles of modern-day physics.
First suggested by Albert Einstein more than 100 years ago, the paradox
deals with the effects of time in the context of travel at near the speed of
light. Einstein originally used the example of two clocks -- one motionless,
one in transit. He stated that, due to the laws of physics, clocks being
transported near the speed of light would move more slowly than clocks that
remained stationary. In more recent times, the paradox has been described
using the analogy of twins. If one twin is placed on a space shuttle and
travels near the speed of light while the remaining twin remains earthbound,
the unmoved twin would have aged dramatically compared to his interstellar
sibling, according to the paradox.
This is not a paradox, and the "paradoxical" nature of the problem was
in fact resolved something on the order of a century ago. The traveling
twin accelerates; the stay-at-home twin does not; thus, the symmetry is
broken.
The paths "close" -- the twins meet again -- which can't happen unless
at least one of the twins accelerates.
Invoking Mach's principle to try to "resolve" this seems kind of silly,
since the "paradox" (which is not a paradox, anyway) exists in the SR
model of the world even when there are just two items in the model: two
clocks. You don't need to bring in the fixed stars to state the
problem, nor to resolve it. What's more, if you start with a planet
that's in motion with respect to the "fixed stars" and a "traveler" who
stops relative to the "fixed stars", you find find yourself back where
you started -- Mach's principle is kind of useless in general, IMHO, in
that it never really explains anything, even when it seems to.
"If the twin aboard the spaceship went to the nearest star, which is 4.45
light years away at 86 percent of the speed of light, when he returned, he
would have aged 5 years. But the earthbound twin would have aged more than
10 years!" said Kak.
The fact that time slows down on moving objects has been documented and
verified over the years through repeated experimentation. But, in the
previous scenario, the paradox is that the earthbound twin is the one who
would be considered to be in motion -- in relation to the sibling -- and
therefore should be the one aging more slowly. Einstein and other scientists
have attempted to resolve this problem before, but none of the formulas they
presented proved satisfactory.
This is false.
Kak's findings were published online in the International Journal of
Theoretical Science, and will appear in the upcoming print version of the
publication. "I solved the paradox by incorporating a new principle within
the relativity framework that defines motion not in relation to individual
objects, such as the two twins with respect to each other, but in relation
to distant stars," said Kak. Using probabilistic relationships, Kak's
solution assumes that the universe has the same general properties no matter
where one might be within it.
The implications of this resolution will be widespread, generally enhancing
the scientific community's comprehension of relativity.
I doubt that a whole lot.
It may eventually
even have some impact on quantum communications and computers, potentially
making it possible to design more efficient and reliable communication
systems for space applications.
Note: This story has been adapted from a news release issued by Louisiana
State University.
