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[ HUBBLE SCIENCE ]

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[ EINSTEIN RINGS // OPTICAL ILLUSIONS ]

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An Einstein Ring is a very cool feature
of gravitational lensing

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where a background galaxy
gets stretched out into a full ring

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around the foreground lens.

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The Molten Ring is a really interesting case
where it's one of the largest galaxies

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that forms a near complete Einstein ring,

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The Molten Ring, you have a very large cluster of galaxies

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that has magnified this background galaxy.

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Einstein's theory of general relativity
is really sort of what

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predicted these Einstein rings
in the first place.

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He created this whole machinery
for how gravity is supposed to work.

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Matter would tell spacetime how to curve

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and spacetime
would tell matter how to move.

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And then as you have light moving
through this curved spacetime,

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that those equations led to the prediction
that this light would almost move on

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what seems like curved paths and caused
the phenomenon of gravitational lensing,

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which is where this light gets
essentially bent

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and distorted by a foreground lens,
like a galaxy cluster,

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and creates these stretched out
images that are magnified of these

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distant galaxies that we see.

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It's definitely
a bit of an optical illusion.

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So if you were to take
the gravitational lens completely away,

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then these background galaxies
would just look like,

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you know, the normal everyday galaxies
that we see at these distances.

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And it'd be a lot harder to to pick apart
what's going on in

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their inner workings.

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So the gravitational lensing effect,
it is kind of like

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looking at a funhouse mirror
and it makes the background object appear

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a little bit bigger,
a little bit distorted,

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you know, just like you go to a funhouse
and you see,

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you know, your head looks gigantic,
your body looks tiny.

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It's a similar effect, but we can use it
for science as opposed to just,

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you know, looking at ourselves and saying,
oh, wow, that's kind of funny.

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The Hubble Space Telescope
has definitely taken the clearest images

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of the Einstein rings

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and they've really, you know,
verified this part of Einstein's theory of

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general relativity.

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They've really shown us a lot more
about how gravitational lensing works

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and really sort of push
the limits of what we can learn

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about these distant galaxies
with gravitational lensing.

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