On Sun, 22 Aug 1999, John Clark wrote:
>
> Tipler found a solution in General Relativity that shows that an
> infinitely long, extremely dense cylinder made of Neutronium (the stuff of
> Neutron Stars)
Aha, I'll invoke the "Use of Magic Physics" warning when people use terms like "infinitely long", "infinitely dense", "negative mass", etc.!!! Only half :-).
> 2) The very rapid rotation would cause the cylinder to fly apart. This is
> much more than just an Engineering difficulty, no known force in Physics
> would be strong enough to hold the cylinder together, not even the strong
> nuclear force.
John, interestingly enough there is a concept called "momentum transfer" that has shown up in some astroengineering articles I've reviewed for the Dyson shell work. It is used in the recently mentioned "The Saga of the Cuckoo" as well. If your Neutronium "cylinder" were surrounded by a large number of particle accelerators whose beam emissions were perpendicular to the axis of rotation, and the force of the beams striking the outside wall of the cylinder were high enough, it would be impossible for the cylinder to "fly apart". I suppose if you angled the beams slightly, they could impart some of the force required to rotate the cylinder at high velocity.
Now, the thought question for you (since you know more physics than I), is what happens when a beam of protons (or I suppose neutrons if you want really high density beams) hits a neutronium cylinder?
Can neutrons interact in any way so as to produce photons? [It seems kind of strange since there are no electrons involved.]
Do some strange interactions occur so that neutrinos/antineutrinos get produced? [Since presumably those are the only things that can radiate "out" through the incoming mass streams.]
A related question would appear to be -- since a mass density above a certain level will generate a black hole, will an energy density equivalent to that mass density (by e=mc^2) do the same thing?
Thought questions for the day...
Robert