• Question: When you look at a star is it like looking into the past because its so far away?

    Asked by jessica606 to Alan, Murray, Sarah on 25 Mar 2011.
    • Photo: Murray Collins

      Murray Collins answered on 24 Mar 2011:


      Yes. The light we actually see on earth was actually emitted some time ago. Even the light from our own sun takes several minutes to reach us here on earth. Light travels *extremely* quickly. However, the universe is so hugely enormous that it can take even light many many years to cross space. That’s why astrophysicist talk about light-years to measure distance in the universe, as it becomes meaningless to talk about piddling little human-scale units like metres!

      By looking at the distant reaches of the universe we can start to look a really long way back in time, which is amazing. The hubble telescope’s deep-space field has revealed a fascinating window into the history of the universe, as you can literally look back in time. That really is utterly staggering.

      http://hubblesite.org/newscenter/archive/releases/1996/01

    • Photo: Sarah Thomas

      Sarah Thomas answered on 25 Mar 2011:


      Yeah I think you are right in a way because it takes so long for light to travel all that distance, so yeah it kind of it like looking into the past…

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