R
rowan999
Guest
Hi, I often see references to images captured from observatories which are 'looking back in time' billions of years, or even to the beginnings of the universe itself.<br />I am just wondering how these images are obtained. I assume the light, X-rays, etc are still travelling through the universe from those events and finally reach our shores at this, much later, point in time. Is this correct? If so, it doesn't seem to completely explain it for me.<br />Here is an aticle describing how the Chandra Observatory has revealed 12 billion year old images from when the universe was very young ::<br /><br />http://www.abc.net.au/science/news/stories/s259759.htm<br /><br />It describes using a 500,000 second long exposure and including imagery from the Hubble as well.<br /><br />What is being captured in a general sense?<br />How is any sort of data emmission from the beginning of the universe still traveling around inside of it?<br />Or is it from the other side of the universe coming back across? Or is that completely ridiculous? <img src="/images/icons/smile.gif" /><br />How can any sort of meaningful view be put together, wouldn't vast amounts of the information have been blocked by various instersteller bodies over the course of the journey?<br />Are there special regions of the 'sky' where these images can only be collected?<br />Is the massive receiving power of these telescopes and methods required to sift out the information because it is so weak?<br />How can this information be explicitly extracted from the spectrum of other information that must also be falling to earth from the same areas (ie: 5 billion year old signals, 1 billion, 1 million, yesterdays...)?<br /><br />Is there some kind of simple idea behind this science, or is it actually very complicated?<br /><br /><br />Your input is appreciated, or if there is a good site somewhere with the info I'm after, please let me know.<br />(I did some sea