WEBVTT

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Galaxies through time.

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[MUSIC PLAYING]

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Telescopes allow us
to see very far away.

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And also to see light that
was emitted long ago, which

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is like looking back in time.

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By viewing the universe at
different distances and eras

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we have evidence that
galaxies change over time.

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They grow, collide and
merge with each other,

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and form new stars.

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The most distant, earliest
galaxies we have seen

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tend to be smaller
and less structured

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than those in the
nearby universe.

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How did galaxies evolve
over billions of years?

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From the early universe to
the era of our own Milky Way,

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how can we learn about the
forces that drive this change?

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Using images of many
different galaxies

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throughout the history of
the universe astronomers

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can assemble something
like a galactic flipbook.

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Patterns emerge.

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Some eras were big for mergers
and new star formations,

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while during others astronomers
see trends for growth

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into larger galaxies with
supermassive black holes

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at their centers.

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Together, these images
provide an outline

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of the average galaxy story.

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However, the opening
chapters are still blank.

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This is because the
universe is expanding.

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And as space itself
stretches, so

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does the wavelength of the
light from the first galaxies.

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Putting them beyond the
detection of our most powerful

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telescopes.

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The story of the
universe and its galaxies

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is like other stories, if
you miss the beginning you

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lose a lot of understanding.

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Seeing the light of
the first galaxies

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provides a more complete
picture of galaxy evolution.

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NASA's James Webb
Space Telescope

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was specially designed to detect
the ancient, stretched light

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from the first galaxies.

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Webb will fill in
the blank pages

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in the flip book
of galactic history

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and examine the middle
eras in new detail.

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Providing essential insight into
some of our biggest questions.

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How does the universe work?

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And how did we get here?

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