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General Science => General Science => Topic started by: nismo1 on 17/03/2011 14:47:59

Title: Can telescopes view the same object in space at different points in time?
Post by: nismo1 on 17/03/2011 14:47:59
Dear Naked Scientist and forum goers
I've been fascinated in science and astronomy for a while now but this question has always been in the back of my mind.  I don't remember it being mention yet so here goes..
I've been told that telescopes are like time machines eg. The further it penetrates space, the further back in time it can observe.  I know this is simplifying the process a bit, but if this is true, is it possible then to view the same object e.g a relatively nearby supernova, magnify the telescope to go further back to a time where the the same supernova was still an unexploded star and observe it in this state?
Thanks in advance and keep up the great work!
Title: Can telescopes view the same object in space at different points in time?
Post by: imatfaal on 17/03/2011 15:12:02
Nismo - nice idea, but no.  Light travels at three hundred million metres per second - regardless of the magnification we use (in fact regardless of almost everything). All magnification does is gather more light and focus so that we may see more clearly; it doesn't change how long the light takes to get here.  You are quite right in saying that the view through a telescope of a distant object is a view of that object in the past - unfortunately the only way we could change this is to move closer. 

Although magnification might appear to make us closer to the object we are looking at - this is not in fact the case.  Magnification takes a large area of light and focusses it down to a small area thus allowing us to see things that with the naked eye would be too faint.
Title: Can telescopes view the same object in space at different points in time?
Post by: neilep on 17/03/2011 16:35:46
Excellent question nismo1 ( i was going to ask the very same too !)...and excellent answer imatfaal.

Title: Can telescopes view the same object in space at different points in time?
Post by: nismo1 on 17/03/2011 21:48:19
Thank you so much imatfaal for that answer.  I think I just got a bit carried away with the idea and imagery of a telescope moving closer to an object the more it is magnified but thank you for setting me straight!!