Will the Expanding Universe Eventually Become Invisible?

[Whateverworks]

Hello.

I've been having some thoughts about the universe and I want to share them.

If we consider a couple of facts;

1) The Universe haven't been here forever. (It had a beginning)
2) The speed of light is NOT infinite but have a speed at 3x10^5 km/s

With those two facts we get an "edge" of the universe.
We also know that the universe its expanding and actually is accelerating in its expansion which is a consequence of what I would guess would be "dark energy".

Our horizon in the universe is about 14 billion years, we don't know if the universe is twice our horizon or infinitely larger than our horizon same if your a ship at sea you got a horizon with you in the center of a perfect circle but you don't know how much bigger the ocean is than your horizon.

My curiosity is;

The universe is an accelerating expanding place and at SOME point galaxy's would be so far away from each other that they will become invisible and we won't be able to see or detect the cosmos as we can now.

Am I correct or have I completely misunderstood something?

/WeW

 

[marcus]

... facts;

1) The Universe haven't been here forever. (It had a beginning)
...

facts?

I don't think it was ever taken as fact. Until around 2005 it was kind of the preferred opinion. People thought and talked along those lines ("before bang is meaningless") without conclusive evidence.

As of now, however, there is no scientific reason to take as a fact that time does not continue on back before bang. Some models break down at bang, others do not. AFAIK, the different models still have to be sorted out by confronting them with observational data.

 

[marcus]

...
Our horizon in the universe is about 14 billion years, we don't know if the universe is twice our horizon or infinitely larger than our horizon same if your a ship at sea you got a horizon with you in the center of a perfect circle but you don't know how much bigger the ocean is than your horizon.
...

That's essentially right. In standard cosmology it is taken for granted that the U is much bigger than the portion of it that we can currently observe.

The whole U is what cosmologists study, using theoretical models which are fitted to the small observable piece of it.

The "observable universe" just means the part that we have so far received light from (or other signals, other sorts of waves we might try to figure out how to detect). As time goes on the amount that is "observable" very slowly changes---as more data comes in---so the "observable" is not a definite fixed amount. We just think of it that way because percentagewise it changes slowly.

Currently we are receiving light (and making careful maps of it) that was emitted from matter which is now estimated to be 45 billion lightyears from us. When it emitted the light we are now receiving this matter was 41 million lightyears from us. In other words that matter which we are now observing is now about 1100 times more distant than it was when it emitted the light.

You can think of that matter as roughly speaking sitting on our "horizon" if you like. It is approximately at the edge of the "observable" region of the U.

But to get a sensible workable model of the U we have to include the rest as well. Because what is beyond horizon affects what we can see. Different observers of course have different horizons, and are causally influenced by their own regions. The edge of the observable is not a real physical edge. You pointed out the analogy of the ship at sea, which is a good one.

 

[Whateverworks]

Thanks for your reply's Marcus. I will do some "homework" now :)