Re: opposite of relativistic time contraction

Tim Little wrote:
> On 2008-03-14, Ben Crowell <crowell07@[EMAIL PROTECTED]
>
wrote:
>> Suppose we have an intelligent species with control over godlike
>> amounts of matter and energy.
> [...]
>> For instance, maybe this observer wants to be able to play chess, and
>> have 10x more time to think about his moves than he otherwise
>> would have. Is this possible?
> 
> It should be: I think the ergosphere of a suitably spinning Kerr black
> hole might have the required property (but too lazy to check).
> Certainly something just short of a Tipler cylinder should suffice.

The WP article on Tipler cylinders was helpful. I was actually hoping
to find a method for time un-contraction that *wouldn't* also be a
technology for closed timelike curves. CTCs definitely allow some
spectacular types of computation (
http://www.sciam.com/article.cfm?id=the-limits-of-quantum-computers
), but I find it hard enough to write an interesting human drama when
there are gods onstage, without having to also deal with the drama-
killing implications of infinite "do-overs" when something goes
wrong :-) It seems that you may be able to make a (finite-length) Tipler
cylinder iff you have a stockpile of negative mass. That's bad for my
purposes, because I'd been thinking that a negative-mass black hole
would be a technology for time un-contraction *without* CTCs. But
I dunno, maybe it's plausible that even if you have access to some
negative mass, making a Tipler cylinder is still just a very difficult
thing to do. There might also be good reasons why you wouldn't want
a Tipler cylinder in your neighborhood.

On the same topic of what you can do if you have access to exotic
matter, one possible solution to accelerating a black hole might be
to give it a magnetic monopole charge, and then accelerate it using
magnetic fields. I'm not sure if I'm getting tripped up on systems of
units and coupling constants and so on, but if my estimate is correct,
you can produce the 100g acceleration on the black hole while
exposing the passenger to fields of only ~10-100 kT. Although these
are big fields, they're not as obviously incompatible with the existence
of matter as the ~10^13 V/m electric fields that would be needed to
produce these accelerations. I can imagine ****elding the passenger
against a 10 kT field using a magnetically permeable material, and
reducing the field down to, say, 10 T, which is the kind of field
used in the famous levitating frog experiment. OTOH, you can't use
a Faraday cage to ****eld against an electric field of 10^13 V/m,
since the Faraday cage itself would go up in a puff of plasma.