# Magnetic Crunch

Loren Booda
Assume the universe, after an eventful life doubling our current age, has coalesced all matter into pulsars each with magnetic field of 1014 Gauss. Given the number of pulsars in this observable universe to be 1022, initially distributed homogeneously, at what radius would the expanding (H0=65 km s-1 Mpc-1) universe outstrip the average magnetic attraction between pulsars? In this scenario, might the universe lose its homogeneity over time, or form "magnetic galactic" cores within the forementioned radius?

Greetings !
Originally posted by Loren Booda
Assume the universe, after an eventful life doubling our current age, has coalesced all matter into pulsars...

Why would it do that ?!

"Does dice play God ?"

Live long and prosper.

Loren Booda
drag-

Pulsars are one quite probable end state for stars in our universe, and have an extremely dense quantum magnetic field.

Even more probable is the nuclear equilibrium that stars evolve eventually into pure iron. (Many pulsars have a 1/2 mile crust of iron!) Remember that purely iron stars would have not nearly as strong ferromagnetic field as pulsars, but would themselves make an interesting substitution into the originally proposed problem.

Greetings !

Hmm...
Iron it is, of course.
However, as I heard (unless the Big Rip or something
happens before that), by the time that much of the
Universe becomes iron the CMBR is going to be
extremely low up the spectrum (with hardly much
other radiation) and except some huge BH's that
survive we'll just have iron spread all over.
Then again, maybe it does follow from it...
Anyway, aren't the distances going to be too great
to really effect each other ?

"Does dice play God ?"

Live long and prosper.

Loren Booda
drag-

Remember that ferromagnetic dipoles have in general a much stronger mutual attraction than do their corresponding gravitational masses.

Greetings !

Hmm... Well, I guess your possibility
is certainly possible. But, of course that it
depends upon the way the Universe will evolve.
If the expansion is indeed accelerated all the
time then this probably won't be the case.
I think your enitial question is also complicated
by the fact that you need a reliable estimate
about when such pulsars may form.
(Even if you consider no real changes in the
Universe across such a large time scale as tens
of billions of years. And, of course, even now we
know that H0 is growing.)

"Does dice play God ?"

Live long and prosper.

Loren Booda
drag-

My concern that you raise is whether the cosmological constant/quintessence is great enough always to negate any significant effect by magnetism. Remember that smaller-scale "magnetic galaxies" may still, if temporarily, form under outward acceleration as "gravitational galaxies" formed in Hubble-expansion environment.

Greetings !
Originally posted by Loren Booda
drag-

My concern that you raise is whether the cosmological constant/quintessence is great enough always to negate any significant effect by magnetism. Remember that smaller-scale "magnetic galaxies" may still, if temporarily, form under outward acceleration as "gravitational galaxies" formed in Hubble-expansion environment.
Well, since we have no exact answers from
cosmology estimates for such time scales
are a great problem.
BTW, are you suggesting that magnetic fields can
"pull" space itself back together ?

Live long and prosper.

Loren Booda
drag
BTW, are you suggesting that magnetic fields can
"pull" space itself back together
Good point. Indirectly, the magnetic interaction affects spacetime by accelerating relatively the masses involved.