#light-travel-time

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OMG science
fromBig Think
6 hours ago

Ask Ethan: Is the Universe the same age everywhere?

Light from distant sources reaches observers after long travel times, so the Universe’s apparent age depends on the observer’s location and frame of reference.
fromwww.scientificamerican.com
2 months ago

Could aliens in another galaxy see dinosaurs on Earth?

For example, reader David Erickson had this on his mind: If there were aliens 66 million light-years from Earth, how big a telescope would they need to see dinosaurs? Ha! I love this question. I've thought of it myself but never worked out the mathexcept to think, Probably pretty big, which turns out to dramatically underestimate the actual answer.
Science
Science
fromBig Think
5 months ago

How far back in time can the naked eye see?

Observing distant astronomical objects means seeing them as they were in the past, from milliseconds to billions of years ago.
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