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Yuzzit
  • 21/07/2023
Description AT Dailymotion Multi Sharing
Transcription
00:00 identified tens of thousands of galaxies.
00:03 To get a full understanding of the history and development of galaxies
00:06 over the vast stretch of the Universe's history,
00:09 we need to be able to pin down their distances more precisely
00:13 to fix them in cosmic time.
00:16 As these galaxies are so far away,
00:18 the light waves we see from them today
00:20 started their journey up to about 13 billion years ago.
00:24 And because the Universe has been expanding since the Big Bang,
00:28 back then the Universe was less than one-seventh of its current size.
00:33 During the billions of years of the light's journey,
00:38 its wavelength has been stretched as the fabric of space has expanded.