Wait a minute? Expansion since the Bg Bang?

If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Well, we're not sitting still, we're moving with everything else.

Relativity. The big bang also didn't happen with Earth at the center, so we can only see that expansion is happening relative to other objects, so we'll still be able to see things for a long time to come.

~Namaste

reply to post by jiggerj


From my understanding , that's why too many galaxies are billions of light years away from us and scatterd all over the universe .

Originally posted by SonOfTheLawOfOne

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Well, we're not sitting still, we're moving with everything else.

No we're not. Our galaxy is being pushed away from every other galaxy (except for Andromeda), and every other galaxy is being pushed away from every other galaxy.

Originally posted by jiggerj

Originally posted by SonOfTheLawOfOne

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Well, we're not sitting still, we're moving with everything else.

No we're not. Our galaxy is being pushed away from every other galaxy (except for Andromeda), and every other galaxy is being pushed away from every other galaxy.

With all the collisions that happen between galaxies just proves your statement is wrong. Every galaxy in the universe is moving and picking up speed.

Originally posted by Dr UAE
reply to post by jiggerj

 

From my understanding , that's why too many galaxies are billions of light years away from us and scatterd all over the universe .

But that's not the point. Consider the material that made up our galaxy. Even while that material was forming just after the Big Bang, the universe was expanding. Now, let's say that some material to make up another galaxy was right next to our material 14 billion years ago. For 14 billion years it's been moving away from our material. Not just moving away but increasing in speed exponentially. That OTHER material (now a fully formed galaxy) should be long gone and out of our sight by now. And that's just the material that was next to ours. All the other galaxies that formed further away from us should be that much further away.

reply to post by jiggerj

That OTHER material (now a fully formed galaxy) should be long gone and out of our sight by now. And that's just the material that was next to ours. All the other galaxies that formed further away from us should be that much further away.

As you pointed out in another thread...we are seeing the stuff where it was, not where it is.

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Wouldn't that depend on how fast the universe were expanding? Anything beyond 14b light years away from us is beyond our visible horizon. I wonder how much stuff exists beyond that horizon.

reply to post by jiggerj


People will tell you to think of moving points on an inflating balloon, but don't. Instead, think of your breath in the cold air - a miniature whirlpool of convection... It is all convection.

Rate of expansion of the universe has been estimated at 70km/s/Megaparsec. Which means that the further away a galaxy is, the faster it is traveling away from us.

1 Megaparsec = 3.262e+6 Light Years
1 Light Year = 9.460e+12 kilometers
Therefore, 1 Megaparsec = 3.086e+19 kilometers

This means that a star that was 1 Megaparsec away from earth's position at time 0 would have traveled: 4.415e+17 kilometers away from earth since the beginning of the universe 14 billion years ago.


The farthest galaxy we have imaged is Abell 1835 IR1916 at 1302 billion light years away = 1.231692e+25km.

This means, a galaxy that is 2.790e+7 Megaparsecs (9.1e+13 light years) away from earth today and all closer galaxies would still be visible to an observer on earth when the universe is twice as old as it is today.

If none of that made sense to you, moral of the story is that we are dealing with such vast distances that the (relatively) young universe hasn't had enough time to "scatter" galaxies far enough apart yet to prevent light from those galaxies reaching us. However, it is theorized that one day in the distant future this will be the case.

Originally posted by buster2010

With all the collisions that happen between galaxies just proves your statement is wrong. Every galaxy in the universe is moving and picking up speed.

Well, that's another curiosity. The galaxies aren't moving away. The space between them is filling in with dark matter and is pushing the galaxies apart. Imagine you making a smoke ring on one side of a fan while I make a smoke ring on the other side, and we did this 14 billion years ago. The air filling in the space between smoke rings is pushing the rings further and further apart. I can't stipulate this enough: it's been going on for 14 BILLION years with the distance between smoke rings increasing exponentially!



The smoke rings represent the material that will make up two galaxies. After 14 billion years of expansion (of the space between galaxies filling in with dark matter) there is no way the Andromeda galaxy should be close enough to collide with the Milky Way.

reply to post by jiggerj


Remove the fan, the exponential incrementation, and then add an ambient room temperature of nothing, and the physics of convection. Things will cluster to other things of similar density.

Some still believe infinite can have a start, can change, or have an end.

I urge those to reconsider an alternative to anything they've ever been told.

Originally posted by SonOfTheLawOfOne

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Well, we're not sitting still, we're moving with everything else.

Relativity.

The big bang also didn't happen with Earth at the center, so we can only see that expansion is happening relative to other objects, so we'll still be able to see things for a long time to come.

~Namaste

I thought red shift and blue shift indicated we were reasonably central to the universe, thats a theory and we know how rock solid a theory is, so I am told

Originally posted by Phage
reply to post by jiggerj

 

That OTHER material (now a fully formed galaxy) should be long gone and out of our sight by now. And that's just the material that was next to ours. All the other galaxies that formed further away from us should be that much further away.

As you pointed out in another thread...we are seeing the stuff where it was, not where it is.

So, even though we're seeing the light from those galaxies, what we're really looking at is empty space?

reply to post by jiggerj

So, even though we're seeing the light from those galaxies, what we're really looking at is empty space?

What we are looking at is light. Light which originated from a galaxy a long time ago. If that galaxy was far enough away at the time the light left it, yes. It is no longer there because it moved on before its light reached us.

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

What we can see of the universe is what we are able to see after 14 billion years of expansion.

There is a lot more of the universe that we can't see than we can see.

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Galaxies weren't formed from day one of the big bang.

It took billions of years for everything to cool down and form, and to form into Galaxies

Originally posted by buster2010

Every galaxy in the universe is moving and picking up speed.

They are not actually picking up speed. This is a common misconception when talking about the rate of expansion of the universe:

The further away a galaxy is away from us, the faster it must be moving to have gotten that far (assuming we started in the same place). For each Megaparsec that it is away from us, it is traveling 70 km/s faster than if it were one megaparsec closer.

This is what is meant by the rate of expansion. The galaxies are not actually picking up speed.

Originally posted by jiggerj

Not just moving away but increasing in speed exponentially.

Furthermore, this rate of expansion is not exponential, but linear.

Originally posted by jiggerj
If the universe has been expanding for 14 billion years isn't that more than enough time for all of the galaxies (and all of the material that makes galaxies) to be gone from our sight? We're talking everything moving away from our point in space for 14 BILLION years.

Scientists think eventually, what you suggest will happen, and we won't see anything but our own galaxy, so right idea, wrong time frame. 14 billion years just hasn't been long enough for that to happen, but at some point in the future, it will.
Some galaxies may already be beyond the observable universe and as time progresses more will be beyond our ability to observe.

Originally posted by Saurus
They are not actually picking up speed. This is a common misconception when talking about the rate of expansion of the universe:

The further away a galaxy is away from us, the faster it must be moving to have gotten that far (assuming we started in the same place). For each Megaparsec that it is away from us, it is traveling 70 km/s faster than if it were one megaparsec closer.

This is what is meant by the rate of expansion. The galaxies are not actually picking up speed.

That was the 1997 view. It changed in 1998 with the discovery of "dark energy", and the change has pretty much been accepted, though the galaxies aren't moving through space, rather space itself is expanding:

Dark Energy

The discovery in 1998 that the Universe is actually speeding up its expansion was a total shock to astronomers. It just seems so counter-intuitive, so against common sense. But the evidence has become convincing.