The Universe is Pretty Big

Psiolent writes "According to a recent article on Space.com, the universe is pretty big (156 billion light years across, to be more precise). Some recent research examining 'primordial radiation imprinted on the cosmos' has led to this conclusion, as well as a few others. This finding is particularly interesting considering the universe is only 13.7 billion years old (which would mean the universe has been expanding faster than light travels), but the article does a good job addressing this seeming paradox."

Comments

That's a minimum....

[Rob Carr]

the universe is pretty big (156 billion light years across, to be more precise)

It's worth pointing out that the156 billion lyrs number is a minimum size for the universe. There's nothing in the data that tells us it's only this large.

It also doesn't tell us anything about the shape of the universe. Recent studies of the microwave background have proposed that the universe has a soccer ball or even a Picard (no relation to the TV character) shape. Neither of these have been ruled out, but the minimum size for either of these shapes in our region of space would be 156 billion lyrs. This new result doesn't even tell us if there is a boundary (no, don't ask me what happens at the edge, I don't know) or if the universe "wraps" like the Asteroids game.

Re: Excerpt from the Weekly World News ?!?!?

[Corvus9]

The frame of reference is given in the quote; "us". That is, Earth. According to the Big Bang model, the universe expanded from a point. Since every place was once at that same point, every place has an equal claim to be the "center of the universe". Picking Earth is just as valid as picking any other place.

There's another good reason to pick Earth as the center; if the universe is 13.7 billion years old then there is no way that anything - light, gravity, particles, aliens - from farther than 13.7 billion light years has reached us. We are at the centre of a 13.7 billion light year sphere containing everything which we can possibly observe.

Not only does this not rule out the possibility of light which hasn't reached us yet, it is defined by it. This observable universe, which some have called "the cosmos", expands by 1 light year every year, as light further out has time to reach us. The entire universe could well be much larger than this; we can only theorize.

By the way, the observable universe is very symmetrical in every direction, so we can consider ourselves to be at the centre even in a literal geometric sense of the word.