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No Stupid Questions@lemmy.worldEnglish · 2 days ago

How can we see other galaxies, and how do we know how many galaxies there are?

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How can we see other galaxies, and how do we know how many galaxies there are?

hokuspokus@piefed.social to

No Stupid Questions@lemmy.worldEnglish · 2 days ago

I’ve always wondered how astronomers can actually observe galaxies that are millions or even billions of light-years away. What exactly are we seeing when we look at them?

And when scientists say there are hundreds of billions, or possibly trillions, of galaxies in the observable universe, how do they know that if we obviously haven’t seen and counted every single one?

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litchralee@sh.itjust.works
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2 days ago
For folks that would like the cosmic distance ladder explained in video format, 3blue1brown sat down with Terence Tao: https://www.youtube.com/watch?v=YdOXS_9_P4U

Yes, it’s that Terence Tao, the famed mathematician.

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