13.7b,age of universe?

Question

If the universe currantly assumed to be 13.7 billion years old.
and galaxies have just been discovered 13.2b light years away.

If this is the case," the big bang "(start of the universe) must have been alot longer than, 13.7billion years ago.
since matter suposenly cant travel faster than light, the matter exploded would take at least 13.2b years to reach its target, and development of the galaxy would add more time, then the light to get back here? It doesnt make sense. Maybe you can enlighten me?

Answer 1

Well, the equipment we are using, along with the math, is still subject to errors.

We may not be taking something else into consideration

Answer 2

You are suffering from a common misconception about the Big Bang. The Big Bang was NOT an explosion that happened somewhere in space, sending galaxies in all directions. It was not an explosion at all.

Space is uniformly filled with galaxies everywhere, and always has been. There are no void places or any center to it. The distances between the galaxies are increasing, however, because space itself is expanding between them. In other words, more real estate is constantly being created. The universe remains uniformly filled with stuff, but the distances between things continue to expand.

So if there's more real estate today, there was less yesterday. In fact, there was a time when there was very little space at all, and because the same amount of matter had to fit in a smaller space, it was hotter.

So the "Big Bang" wasn't a bang at all; it was just the hot state of the early universe. It was hot and dense everywhere, so everywhere you look 13.7 billion light years away you will see that hot dense state (the Cosmic Microwave Background). You will also see galaxies everywhere in every direction, so long as you're not looking so far away that galaxies haven't formed yet, since they too form everywhere in space.

Answer 3

The Big Bang Theory is based on the idea that space itself is constantly expanding. At the moment of the bang, the universe was very, very small. As time went on, space expanded, carry the matter that would eventually form galaxies with it. The most distant galaxies did not need to first travel 13 billion light years before sending light back to Earth. They started out on the edge of the universe, but back then the universe was much, much smaller and the edges closer together. The current estimates about the age of our universe are based on the distance of the most distant visible objects.

Answer 4

I understand your confusion. So lets see if I can help (it took me a while to get it).

13.7 billion years ago the Big Bang occured, causing rapid expansion of the universe (called cosmic inflation).
But it was still hot and extremely dense, and it took 380,000 years to cool enough so that neutral hydrogen could form (which was the start of the so-called Dark Ages when visible light was not free to travel since hydrogen absorbs visible light).

Light travels at a finite speed, and so we are only able to see at most 13.7 billion light-years away, since we can only see light that's had time to reach us.
But that light started on its journey at 380,000 years after the Big Bang and has been travelling every since until it reaches us. So we can see light that started out on its journey 13.7 (minus 380,000) years ago.
The light didn't have to go out to somewhere and then come back - it started out there and we're just now seeing it.

A quick additional note you might find interesting:
The universe itself is actually a lot larger than the obvious of 13.7 light years radius - that's because since light first was formed the matter has condensed to form galaxies, and since the universe is expanding (taking everything along with it) those galaxies are now 46.5 billion light years away, so the universe is estimated to be 93 billion light years across.

Answer 5

You should familiarize yourself with one of the features of light called the 'Doppler effect.' It's very similar to the Doppler effect of a moving source of sound. Also remember that it takes light time to get from one place to another.

Astronomers use the Doppler effect to determine a couple of things about far distant celestial objects, like distance and how fast they're receding from us.

It's also important to understand that when it's said the universe is 13.7-billion years old it's meant that the *observable* universe is that age. There are incredibly immense regions of the universe that we can never see, simply because space there is expanding faster than the speed of light. Many astronomers estimate that the *entire* universe is something like 50 orders of magnitude larger than the part of it we can see.

Answer 6

The universe is expanding and creating space and everything in it. Just because a galaxie is 13.2 billion years old doesn't mean that it had to travel that distance before it was created. It was created 13.2 billion years ago as we can observe it in time. Since the universe is expanding in all directions at the same time everything is seen to be moving away from us but we are not at the center of the universe. The most distant galaxies are found in all directions from us but they did not travel there or the gases they are composed of, from a central point as we can obseve it. They were created at a place in time but not in distance.

Answer 7

Galaxies are like raisins in bread dough. As it cooks the bread expands and the raisins on each side get further away from each other. Since the fabric (space) of the universe is actually swelling like the bread galaxies aren't actually "moving" apart and hence aren't limited by the speed of light.

Answer 8

Galaxies travel sub-light. Cosmic Rays were first and they could easily be twice or three times as far as the furthest galaxy or sun.

Answer 9

Well, when the big bang occurred, it's not like galaxies were instantly formed, it took a while for stars to form, then for an star clusters, then entire GALAXIES.

Also, our instrumentation isn't perfect at the moment, just getting better.