<p>Hello, and welcome to Space.com! </p><p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That is if the information is correct. - (NASA summarizes existing data to indicate a constant of). - (if spacetime is assumed to be flat). - I could pick other possible discrepencies. - (The galaxies at the edge of what the Hubble can see appear to be younger). - What if they are not, but much older. One small error in all these calculations can throw everything out of perspective. Which would have serious affects on other calculations.Look at the evidence. As we look out into Space in any direction, We see galaxy after Galaxy, after Galaxy. The evidence supports it just goes on & on & on. Just get in a earoplane and fly along the equator and do not stop till you find the edge of the Earth. Where do you stop. To me the evidence suggests it is thousands of billions years old. There must be a point when light is unable to carry on travelling. If I was to shine a 1oo watt light bulb at the moon. I know it would not reach there.How far would I have to be to be able to notice it was just about visible? Has anyone taken this into account or does light go on forever being visible no matter how far away you are? <br /> Posted by Gary_Peck</DIV></p><p>It sounds to me that the main reason you doubt the generally accepted age of the Universe is because there could be more galaxies beyond our current observable horizon, correct? (Our current observable horizon means the limit of our observational abilities.)</p><p>If that is so, then you are definitely oversimplifying the way that age is calculated. It is not merely a matter of seeing how far we can look and then assuming that to be the edge. In fact, the most distant galaxies that we can presently observe are quite a bit *younger* than the Universe, so astronomers expect the universe to go on a fair bit past that. I'm not an astrophysicist, so I can't really explain it very well, but as I understand it, the number is based on the maximum age it could be given currently observed expansion, the light speed limit, and so on.</p><p>Now, it could indeed be that the calculations are based on some wrong assumptions, or that there is a hitherto unknown error in the data. That's okay. The generally accepted age of the universe is not considered an absolute fact. (Absolute facts are vanishingly rare in science, as it happens.) Rather, it is considered the best estimate that anybody's come up with so far. It is expected that the value will be refined, and perhaps completely replaced as new information becomes available. That's how science works. ;-)</p><p>But for scientists to change their mind about the age of the Universe, they need something more than a hunch. In this case, they'll need some fairly persuasive evidence that some of the basic assumptions underlying the estimate are wrong, and that's not a simple thing. For instance, one of the assumptions is that light speed is an absolute limit, and so far that particular assumption has stood up remarkably well to testing. It would take something extraordinary to surpass it. </p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>