Wednesday, August 26, 2015

BLACK HOLES


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One of today's PBS headlines was: "How a global network of telescopes may give us first glimpse of a black hole."

This struck me as being a stupendous feat, because I had always thought of a black hole as being a region where gravity s so strong that nothing can escape from it... even light. And I can only see an object when light strikes it and then rebounds and strikes my eyes. So, you can probably understand my confusion. Probably.

Indeed, a Google search for black hole brings up: A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can't see black holes.

But the report byRebecca Jacobson goes on to say that even though black holes are vital to our understanding of the universe, no one has ever seen one -- yet. To change this, a team of scientists in northern Chile, is using a network of telescopes around the globe to capture an image of a black hole for the first time to prove Einstein’s Theory of General Relativity. 

video

Predicted appearance of non-rotating black hole with toroidal ring of ionized matter, such as has been proposed as a model for Sagittarius A*. The asymmetry is due to the Doppler effect resulting from the enormous orbital speed needed for centrifugal balance of the very strong gravitational attraction of the hole.


Notice that the above is the "predicted appearance."

I imagine it would look more like this
(black hole is tiny dot in center)

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