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Asked by 07yousafj to Hywel on 25 Jun 2010 in Categories: General.
Question: in space, is it likie behind 1000 years so they can see the people that was here 1000 years ago?
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Hywel Vaughan answered on 25 Jun 2010:
Not far off in the concept Yousaf!
The distance between our planet and the next closest solar system (Alpha Centauri) is 4.22 light years. A light year is the distance that light travels (at the speed of light of course!) in one year – about the same as 5,878,630,000,000 miles.If we are talking only 4.22 light years, it means that the light leaving our solar system doesn’t reach theirs until 4.22 years later, so what they are seeing is 4.22 years old!
If we are talking further and greater distances, then yes, the light they see could be 1000years old, and vice versa. A lot of the stars we see in the night sky were there millions of years ago, and the light is only just reaching us – we are essentially looking back in time.
It is the same when you look at our sun – it takes the light about 8 minutes to reach the Earth after leaving the sun, so what we see is actually 8 minutes ago…
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Comments
07hubbardc commented on :
i dont get this question
Keith commented on :
The idea is that if you look at something 1000 light years away, you’re not seeing something that it happen, now because the light has been travelling for 1000 years to reach us.
Instead, you’re seeing something that happened 1000 years ago. So, looking at the stars is very much looking back in time.