Not to belittle the considerable scientific contributions made by the Hubble, but the precise age figures actually come primarily from the MAP satellite, which observed the cosmic microwave background. Speaking of which,
It’s customary to pick some convenient large object to use as a reference. Here on Earth, we usually use the Earth itself to set our reference frame. In the Solar System, we use the Sun. Well, the cosmic microwave background is just the ultimate “large object” to use as a reference. It’s still not inherently at rest (no more than anything else in the Universe can be), but it’s as good a standard as you’re going to find on a cosmological scale.
Although, in a sense, it’s also still a peculiarly local standard: We’re close to at rest relative to the CMB, but an observer a few billion lightyears away would see a slightly different CMB, and he’d find that he’s almost at rest relative to it.
Time dilation absolutely affects everything in the universe all the time. It’s just a matter of how much. And we can’t even tell how much. How fast is the earth traveling right now compared to the singularity starting point of the universe? We don’t know! Space and time are expanding together as a result of the big bang.
You can’t say, from the surface of the earth the universe is 13.370 Billion years old, because EVERYTHING is relative. The age comes from estimating the mass of the universe and using equations to wind everything backwards to the singularity. It has nothing to do with measuring " from the earth’s surface ". Everything is relative!
So, by the way, from our perspective, time could have passed on earth in a much different way than how we perceive it to pass in the universe. If we are travelling 99.99999999999% of C right now for example, our experience may be very different.
The OP states the world is 15 billion years old. I am not an astrophysicist, but I am willing to step out on a limb here in GQ and say that that number is probably incorrect. By a lot.
[/nitpick]
Caveat: “world” and “Earth” seems to be used interchangeably in the OP.
We are, relative to something very far away from us. That’s what makes your reasoning wrong. Everything is moving the same speed, barring local gravity effects.
But Katie revised her song to include a more accurate age of the universe! You can hear the revision in this excerpt from a TED talk by Michael Shermer.
Umm, I realize the original comment is over 2 years old and everything. That being said it was my understanding that Katie isn’t close, but neither are the guys who say we’re 13.7 billion light years from the edge. It’s at least 46 billion light years. http://en.wikipedia.org/wiki/Universe#History
I guess one of the astronomer dopers can confirm this but here’s a blog about it
That’s more or less true, but it’s complicated by the fact that, once you start looking at cosmological scales, there are multiple definitions of “distance”, which don’t all agree.
The rest of that piece explains the faster-than-light expansion of space itself. That’s fascinating but it doesn’t change the fact that the universe is 13.7 billion years old and everybody appears to agree with that number.
I think the figure I’ve been hearing lately is 13.6 billion years, after more data have come in, but still, less than a percent error in a cosmological measurement is damn impressive. When I started grad school, the best we could do was “Somewhere between 10 and 20 billion years”.
