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[Music]

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one of the hubble space telescope's

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major achievements was the confirmation

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that galaxies have

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in their core

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at least for a time were kind of a

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mythical idea you know a mathematical

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possibility coming from the physics but

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it was not clear decades ago whether we

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could actually observe a black hole

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because kind of by definition black

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holes are not viewable the light cannot

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escape

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so the question is could you observe

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effects of black holes to determine that

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they are there

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now the way hubble has detected this is

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by looking not at the black hole which

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is really impossible to see what we see

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is material right around the black hole

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particularly this galaxy called m87

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which has a spectacular ejected jet

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and often we see material orbiting that

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inner black hole like gas

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and orbiting very fast so we can use the

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instruments on hubble to discern whether

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material on one side of the black hole

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is moving away from us and the material

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on the other side is moving toward us as

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you might expect if the material is

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orbiting

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since that time hubble has followed up

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with many other galaxies and seen

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evidence for supermassive black holes so

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we now believe that most and maybe all

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galaxies have some kind of supermassive

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black hole in the center

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people did not dream that that would be

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true it wasn't that long ago that people

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thought there were no black holes then

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we thought well we don't imagine how

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they could exist so there probably

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aren't any and now we are forced into

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understanding how come there are so many