How old is the universe? Scientists have attempted to come up with estimates that are believed to constitute a rather good idea of its age. However, a scientist suggests that the real answer might depend on your location in the universe: this means that those on a planet other than ours might have a different answer because of the fact that light takes different amounts of time to travel to different areas.
Various indicators seem to point at the time when the Big Bang might have happened: around 13.8 billion years ago. On the other hand, given that we see galaxies as they were when light first touched them and not as they are right now, the calculation will not be exact. However, fortunately, on a 13.8-billion-years scale, the difference would not be as consequential. This might not be the same for other planets though.
The difference could be significant on other planets. Astrophysicist Ethan Siegel states that planets travelling at nearly the speed of light will perceive the universe differently. The planets would be much younger than everything else: if one were travelling at 99 % the speed of light since the universe was 1 billion years of age, it would have lived through 1.8 billion years rather 13.8 billion. This implies that those on such planets would have different figures as to the age of the universe, regardless of the real age thereof.
“So the Universe should appear the same for almost all observers anywhere, with the same amount of time having passed and the Universe having the same large-scale properties pretty much everywhere,” says Siegel. “But for a few select observers - the ones who’ve spent some significant time moving close to the speed of light relative to the CMB’s [cosmic background radiation] rest frame – the Universe will be quite bizarre. As soon as they slow down relative to the CMB and come to rest, they’ll find themselves as young ones in a strangely old Universe.”
We do not know whether such planets exist. However, the theory provides new insight as to how speed and light in combination affect how we view time.