# [ExI] Can work be extracted from the expansion of the universe?

John Clark johnkclark at gmail.com
Wed Feb 28 17:15:46 UTC 2018

```For years physicists debated if gravitational waves were real, some said
they contained no energy and so were just a mathematical artifact of no
physical significance. But then in 1957 Richard Feynman came up with a
thought experiment that showed gravitational waves must contain energy and
thus must have real physical effects, the sticky bead argument. I could be
wrong but it sure seems to me it could also show that work can be extracted
from the expansion of the universe.

Feynman said place two beads on a sticky rigid rod, the beads can slide
freely but there is a small amount of friction between the beads and the
rod. If the rod is placed transversely to the direction of propagation of
the gravitational wave then atomic forces will hold the length of the rod
fixed, or almost fixed, but the proper distance between the two beads would
be free to oscillate. So the beads would have to rub against the rod, and
the friction from that would produce heat, and with heat you could run a
steam engine and get work out of it.

Why couldn’t the same argument also be used to show you could get work out
of the expansion of the universe? We already know that if local forces are
strong enough they can overcome the general expansion and acceleration of
the universe, that’s why the Andromeda galaxy is approaching the Milky Way,
the 2 galaxies are so close that the attraction is stronger than the
repulsion caused by the expansion of the universe. The atomic forces within
the rod should keep its length the same or almost the same just as it did
for gravitational waves, but the distance between the beads should increase
due to the expansion of the universe and if there is friction I don’t see
how heat could be avoided, but maybe I’m missing something, if so I hope
somebody can point it out. I’ve already asked several people and most say
no, you can’t get any work out but they can’t find and error in the thought
experiment.

I think it would work theoretically, it would be ridiculously impractical
to do now but perhaps not in the very distant future if the acceleration of
the universe is itself accelerating and we’re heading for the Big Rip. Most
think it will never happen but it depends on the ratio between the dark
energy pressure and its energy density. Physicist Robert R. Caldwell points
out that if this ratio is even slightly less than −1 then the Big Rip will
happen, its just a matter of when. For example, if the ratio is −1.5 then
the Big Rip will happen in 22 billion years, the Milky Way would be ripped
apart 60 million years before the Big Rip, the solar system would be ripped
apart 3 months before the Big Rip, in the last 2 or 3 minutes stars and
planets would be ripped apart and in the last few seconds even atoms would
come apart. And then protons and neutrons would be ripped into quarks.
Most think that would mean the end of any hope for a immortal life but
maybe not, subjective immortality might still be possible. In fact for
immortality to happen the Big Rip may be necessary.

By immortality I mean the ability to have an infinite number of new
thoughts, and that would require a infinite number of calculations, and
that would require a infinite amount of work. It might be possible to get
that much energy  before the Big Rip. Your computer would continually get
smaller as it was getting pulled apart but the energy available to run what
was still intact would keep getting larger because the heat from friction
would keep getting hotter and the cold sink of the external universe would
keep getting colder increasing the efficiency of the heat engine. If the
increase in speed of the remaining computer more than compensated for the
decrease in the number of processors then physical law may allow for a
infinite (and not just astronomical) number of calculations to be made
between now and The Big Rip.

John K Clark
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