From: Damien Broderick (damienb@unimelb.edu.au)
Date: Wed Aug 27 2003 - 20:14:26 MDT
This is also an interesting Science Show piece on the big galactic hole.
http://www.abc.net.au/rn/science/ss/stories/s917636.htm
I was struck by one question (astro experts might care to comment):
>Well, this matter falls in and becomes very heated, starts to
> glow and we’re fortunate because the black hole at the
> galactic centre seems to be absorbing this matter but at a
> very low rate. The gas is there, it’s glowing but we can see
> all the way through and what that means is that this object in
> the middle casts a shadow, it absorbs all the light incident on
> it and it also bends light from behind it away from our line of
> sight, so light that would normally reach our eye from the
> gas behind it gets deflected, and as a result of these two
> effects, the fact that it absorbs the light and the fact that it
> bends the light, means that right in the middle there’s a
> significant shadow. And that shadow as it turns out, is big
> enough that we should be able to see it within the next few
> years.
But hang on... yeah, it bends light behind it *away* from us, but equally
it should bend some of the light coming at it sideways *toward* us, no?
more or less exactly compensating for what we'd see were it not there?
Damien Broderick
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