Saturday, October 06, 2007

Strange science time

I mentioned recently that it seems that the creation of "naked singularities" (without the cloak of a black hole event horizon) at the Large Hadron Collider is considered a possibility. It seems that their creation via the same astrophysical process of gravitational collapse that leads to black holes is still being considered too.

This recent paper looks at the possibility that may account for some of the most powerfully energetic events in the universe. Here's some extracts:
Impulsive cosmic events combine two main puzzling features, namely an extremely short time of emission (order of a second) and a very high energy fluence. The main challenge therefore is to find a unique mechanism which allows at once for both properties.

The most impressive examples of the above type of events are the Gamma Ray Bursts. The total energy emitted can be as high as 1054 ergs, mostly concentrated in a pulse as short as a second. This amount of energy appears much more stunning if we think to it as being the energy emitted in a second-long pulse by 1010 galaxies each made of 1011 Sun-like stars, each emitting at a rate of ∼ 1033 ergs/sec., concentrated in a region probably smaller than a galactic core!
OK, I knew Gamma Ray Bursts were powerful, but that just sounds ridiculous. I wonder how far away from one you have to be in order to stand any chance of survival?

The paper goes on to explain that naked singularities comprise a Cosmic Time Machine, which, if I understand it correctly, can beam out huge amounts of energy from the the past and future. The author believes that these may account for some (all?) Gamma Ray Bursts.

Still, there seems to be a limit on how long the burst can last (luckily!):
Evidently the longer a naked singularity lasts as such the more luminous will be the burst because longer is the future development which will be ”compressed” by the time inversion and therefore more are the photons which will contribute to the prompt emission. This mechanism may lead to undesirable bursts of infinite intensity! Naked singularities however appear to prevent this circumstance. It is well established that a naked singularity decays to a black hole.
For the possibility of naked singularities being created right here on Earth, maybe late next year at the LHC, go see the paper extracted at my previous post here.

I presume that astrophysical naked singularities may be very, very different from the ones formed at the LHC, but as I said in my last post, it would be nice to see the possible consequences of having then in Europe clearly addressed.

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