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Science

sakabatou

(46,165 posts)

4. A light year is also a measure of time.

Reply to Silent3 (Reply #2)

Wed Jun 13, 2012, 05:07 PM

Jun 2012

The Sun is about 8 light-minutes away, therefore, we are seeing 8 minutes into the past when we look at the Sun from the Earth. The star Proxima Centauri is about 4.2 light years away. The light we see is 4.2 years into the star's past.

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'Oldest galaxy' discovered using Hawaii telescope [View all] Judi Lynn Jun 2012 OP

I'm going to have to see the long-form. n/t Bolo Boffin Jun 2012 #1

That's "12.91bn light years AWAY", not AGO. Silent3 Jun 2012 #2

A light year is also a measure of time. sakabatou Jun 2012 #4

Light years relate fairly directly to time... Silent3 Jun 2012 #5

Yes, it's still a mesure of length. sakabatou Jun 2012 #6

We substitute time for distance all the time depending on the context. laconicsax Jun 2012 #7

Yes, but you still know someone screwed up when they say... Silent3 Jun 2012 #8

Ah, but even then, the rationalizations have been made: laconicsax Jun 2012 #9

Wow... galaxies formed pretty early after the Big Bang sakabatou Jun 2012 #3