How do they know the universe is expanding when all the evidence pointing to that fact is millions or even billions of years old.
LURCH said:The best answer is to switch your statement from "millions or billions", to "millions and billions". Truth is, all the evidence we have shows the same story; redshift. We see redshift in objects billions of lightyears away, and in objects just a few million lightyears away. So, if our interprtation of the data (that redshift means expansion) is correct, then we can see that the universe was expanding several billion years ago, that it was still expanding a couple hundred million years ago, and yet still expanding 10 0r 20 million years ago. From this, we can conclude with considerable certainty that this condition still persists (simlpy by assuming that what the whole universe has done for the past several billion years, it did not cease to do just before we looked).
Lunatic said:It's not expanding, the space in between the objects that we can identify is increasing
That's not really the issue though, the point i was trying to to raise is, if the evidence we are relying on is millions AND billions of years out of date how can it be used as evidence for what could be happening to the universe today. a lot of things can happen in a few million years much more in a billion.Lunatic said:It's not expanding, the space in between the objects that we can identify is increasing
ukmicky said:The evidence of expansion is at best millions of years out of date and wouldn't stand up in court.