Tag Archives: black holes

Hawking radiation precludes singularity formation?

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Laura Mersini-Houghton at the University of North Carolina and Harald Pfeiffer of the University of Toronto have published a paper suggesting that as a collapsing star emits Hawking radiation, it must also shed mass at a rate that would necessarily prevent it from achieving the density necessary to form a singularity. This doesn’t mean they are claiming black holes don’t exist, they’re saying that if Hawking radiation is real (and so far it’s entirely theoretical) a black hole singularity cannot be formed by the implosion of a star.

Of course if a mass is high enough to create an information paradox, would we ever be able to tell if that mass is a point singularity or not? I don’t know, but the non-mathematical parts of the paper are surprisingly readable.

A big week in science…

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I didn’t believe in black holes until very recently. But my friends and relatives in the space telescope biz kept seeing things I couldn’t explain any other way, so despite my deep misgivings about Stephen Hawking’s attempts to explain how such things must work, and despite Einstein’s suspicions that their predicted existence was really simply a place where physics formulae break down (a “mathematical singularity” not necessarily corresponding to any real object), I eventually gave in.

So, now that I’ve grudgingly admitted black holes really do seem to exist, Hawking publishes a paper saying “The absence of event horizons mean that there are no black holes – in the sense of regimes from which light can’t escape to infinity. There are however apparent horizons which persist for a period of time. This suggests that black holes should be redefined as metastable bound states of the gravitational field.” Arrgh! Now I have to find time to read more physics.

A more interesting and less aggravating scientific announcement was that physicists at Amherst have created a magnetic monopole! Their synthetic monopole exists at the particle level, but proving submicroscopic monopoles can exist is the first step towards finding out if larger monopoles can exist (most physicists say they can’t) and quite possibly a major step towards finding out if they occur in nature (most physicists say they can).

Finally and most importantly, a team of scientists working in the USA and Japan announced a breakthrough in stem-cell creation that potentially obviates all the kerfuffle about existing medical markets for aborted fetus cells.