Hubble vs. Webb - How Far Back Will They See?

Roland Piquepaille writes "According to Forbes, reporting in "Peering Back At The Universe's Past," space telescopes are really acting as time machines. They can watch objects which are so far from us that light has taken billions of years before reaching their mirrors. The Hubble telescope is able to look at events that took place 13.3 billion light-years ago. But the James E. Webb space telescope, currently under construction, and scheduled to be launched in 2011, will be able to see even further and catch phenomena which happened 13.5 billion light-years ago. The astronomers think the Webb telescope might even be able to see up to 13.7 billion light-years ago, when our universe was just 200 or 300 million years old. We are used to see fantastic images from Hubble, without paying too much attention to the characteristics of the telescope itself. So here is a thorough comparison between the two space telescopes."

Comments

Time Distance?

[CGP314]

light-years ago

Wouldn't that just be years ago? A light-year is a measure of distance, not time. It's like saying 'I can see three inches into the past.' The only reason I can think of to say this is if you also want to indicate how far away the event was when it happened.


-Colin

A light year ago ?

[xquark]

A light year is a measure of distance not time,
saying 13 billion light years ago is like saying
something like 100 km ago, it doesn't make sense
all you gotta say is 13 billion years ago, also
you should note that its been proven that the
general speed of light is actually decreasing,
so you can't really make an exact or near exact
estimation about the time period for which something
that occurred many thousands of light years away
occurred.

Arash Partow
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