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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."
As I'm sure everyone will be quick to point out, lightyears isn't a measure of time, rather of distance.
It is more accurate to say that the hubble could see images 13.3 billion years ago, and the Webb telescope may be able to see images 13.7 billion years ago.
13.5 billion light years ago? Maybe I am being stupid, but I always thought that a light year was a measurement of distance?
If it's any comfort, the concept of "now" over those distances is meaningless in the context of General Relativity.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
.03 is 3% but anyway
.1% improvement. .1% to .001% is a 10000% improvement.
Depends on how you look at it.
3 nines to 5 nines is
99.9% to 99.999% which is a
From the other end,
14-13.3 is 700M years after big bang
14-13.7 is 300M years after big bang
Better than 50% improvement (using Hubble as base)
Better than 100% improvement (using Webb as base)
The problem with percents is that they state one number and leave unstated the base for that number. Very little trickery is required to minimize or diminish importance without actually commiting falsehoods.
And if it doesn't work, we're all just going to sit down and have a good long cry together.
(I understand the logic, but I really like contingency plans...)
Also, you're perception of the past is wrong. If I'm a light-year away from something and see something happening, I can say that in my reference frame, that happened a year ago. Someone travelling at speeds approaching c might disagree, but that's another story.
And a light-year is a measure of distance. If you specify "the time it takes for light to travel a light-year" than you have a measure of time, but that was not what the original story poster wrote (although you could assume it since the telescopes are recieving light).