The universe, it's expanding faster and faster?

[GuidoHunter]

Don't worry about it, Brady.

You're right that internal forces are nonexistant. But the whole discussion is on what force IS acting on the galaxies. Assuming that the universe actually is expanding and accelerating (I still don't believe that irrefutible evidence has come up to prove this, but for the sake of argument I'll go with it), the only known force to make any difference is the gravitational force. Just as the gravitational force is negligible at the quantum level, the strong nuclear, weak nuclear, and electromagnetic forces are far too weak to have any effect on celestial bodies. And when talking about the expansion of the entire universe (or, at least, its edges), the gravitational force can only apply when you describe entire galaxies as individual objects.

So, you have to remember that, yes, every galaxy is attracting every other galaxy in its locality (locality is defined as the distance at which the gravitational force has an appreciable value). Because of this, the net force on each galaxy is canceled out, since outer galaxies pull one way on a given galaxy and inner galaxies pull the other way. However, shouldn't the outer (oldest) galaxies be pulled in since there is a net force on it? One would think, but the galaxies are still moving away from each other, and accelerating while doing it. This is the mystery. What is it that counteracts and even overpowers the gravitational force?

Brady, yes, the parallel universe theories exist, but I can't find any pertinence to this topic. Oh, and for an "answer" to your question of what the edge of the universe is, check out the thread to which I linked hata earlier. It really depends on your definition of universe.

And hata, does this resemble what you were trying to say?

--Guido

http://andy.mikee385.com

[Braydz]

Thanks Guido, that cleared up alot of things. And sorry for going off on tangents, I had something to link the parrallel universe to but I forgot as I was typing.

[hatakikakashi]

Excellent posts Brady and Guido

Don't worry about it, Brady.

You're right that internal forces are nonexistant...

the only known force to make any difference is the gravitational force. Just as the gravitational force is negligible at the quantum level, the strong nuclear, weak nuclear, and electromagnetic forces are far too weak to have any effect on celestial bodies. And when talking about the expansion of the entire universe (or, at least, its edges), the gravitational force can only apply when you describe entire galaxies as individual objects.

Yes this is what I wanted. I have a couple ideas.

Remember learning about electromagnetic forces and polarities that determine whether or not two objects are attracted to eachother or repelled? Also the strong and weak nuclear forces, one attracts and the other repels, not based on polarity but rather on the distance between subatomic particals. Lastly there is gravity, everyone knows that gravity attracts matter to other matter, and that the force of gravity is weakend by distance. But unlike electro magnetizm and the strong and weak nuclear forces there is no force to counteract gravity(that I know of),if there is however, perhaps the gallaxies are far enough away from the rest of the universe that gravity is no longer affecting them as much as this other force. Causing them to accelerate away from the rest of the matter in the universe. It makes sense to me when I think that the strong and weak nuclear forces are defined by the space between the objects they are affecting. When they are close enough together they are attracted to each other, but if too far apart they are repeled. Maybe gravity is the same way.

That's my first idea.

Also I'm sorry I called you all little kids, that was wrong.

[Braydz]

Alot of people at school call me weird because of some of the things I come up with, and I'm not sure if this counts as one of them.

I'm not going to go into any detail about quantum physics or weak and/or strong nuclear forces as I have not covered those topics yet, but maybe the universe is just a small part of something alot bigger. Going back to theories, I remember there being a theory that our solar system could be an atom of some much bigger "universe". I'm not sure if this is true or not, but just say this universe had the same, or very similar, laws of physics as what we have. If an item is stretched, this can weaken the bonds between the atoms that make up the item. Maybe, just maybe, our universe is experiencing something along these lines, just over a much longer distance of time. The galaxies, or atoms, are slowly being moved away from one another due to being stretched.

Yes, I know this is farfetched, but it's late, I'm busy packing for camp and I couldn't think of anything real intelligent to say.

[hatakikakashi]

No that's great Bradyz

The other idea I have is that there is a difference between space and void. The universe is contained by space, outside there is void. Void=nothing absolute nothing, no energy of any kind no matter of any kind. I don't know if there is infinite void for space to expand into. I like your idea that something on the "outside" is the cause because it kind of ties into what I was leaving out of my first post, (I had to check a couple of rooms out and was interupted) I had it for a while but now I can't remember what it was that came to me as clearly. It had something to do with space expanding at the speed of light, causing a sort of vacume effect on the matter closest to it, like the slipstream effect when racing cars, so the farthest gallaxies would be being sucked towards the edge of the universe.

It's time for me to get off of work here pretty quick so I have to leave before I get to finish, maybe I'll come up with an idea in my dreams. Anyways thanks for the input this is getting very interesting (for me at least).

[Braydz]

Ok, I have one quick question to ask before I go away for three days... The answer to this might make what I say in the future on related topics a little more correct than if I didn't ask this.

As I have mentioned above many times, I haven't covered alot, but I know a little bit of things I haven't covered. One thing I am unsure of is if space is filled with "quantum foam". I don't know what this is, what it does, but I have heard about it. Also, is quantum foam matter? I cannot find anything on the net that answers that question fully, or that doesn't answer it in terms I can understand. If someone could answer me this, that would greatly increase the validity of future posts by me in these topics.

[alainbryden]

Philotic connections.

[GuidoHunter]

Hmm, I've heard the term before, Brady, but I'm not certain I'm sure what it is.

My guess is that it refers to the seething sea of quantum activity that goes on in supposedly empty space. The vacuum energy gives rise to the creation (and subsequent annihilations) of all sorts of particle/antiparticle pairs and other quanta. All this takes place nearly instantaneously, but it has manifestations, like in the Casimir effect. The Casimir effect is the warping of spacetime using the virtual particles that exist in the vacuum but can't be observed by conventional means.

I could very well be wrong, but whatever.

--Guido

http://andy.mikee385.com

[Tasselfoot]

I HAVE ALL OF YOUR ANSWERS, MY YOUNG WANNA BE ASTROPHYSICISTS.

As I have said before, READ THE BOOKS I RECOMMENDED. Those 2 books will answer ALL of your questions and then some.

Quickly: The universe CAN NOT be accelerating or deccelerating. Think of it as a tight-rope walker, walking on his rope for eternity (or, like, 10 billion years). If he sways one little bit on the entire trip, he falls. The same is true for the universe. If the expansion speed does not remain constant, 2 things would happen. 1. Big Crush. 2. Acceleration into extremity... aka, everything would be infinately far apart from everything else.

Quickly: Quantom Foam = EXTREMELY small sub-atomic "stuff", slightly larger than the Plank size (Plank size is the smallest anything can possibly be). this stuff is supposed to be like a tiny foamy ocean that has the potential to be time warps. From what I remember, it can't even be proven that Quantom Foam exists... and certainly it can't be proven that it acts as a time warp.

[GuidoHunter]

Quickly: The universe CAN NOT be accelerating or deccelerating. Think of it as a tight-rope walker, walking on his rope for eternity (or, like, 10 billion years). If he sways one little bit on the entire trip, he falls. The same is true for the universe. If the expansion speed does not remain constant, 2 things would happen. 1. Big Crush. 2. Acceleration into extremity... aka, everything would be infinately far apart from everything else.

So why are those two things impossible?

--Guido

http://andy.mikee385.com

[Tasselfoot]

Oh. Because it already would have happened by now. There has been billions of years that the universe has expanded. Clearly, nothing has yet shown that there are signs of expansion slowing down. Plus, it likely would have already reached its apex growth and begun its contraction by now... Big Crush has pretty generally been regarded as not what is or will happen.

So, to tackle the fun part of what we've been talking about... accerating. Please explain to me what new force is being exerted NOW, after billions of years, that has just started the universe to accelerate, when it hasn't been after the first few nanoseconds of history. We have to assume that any acceleration would have been taking place over the entire course of universal expansion... which when calculated out, would result in what I said above, everything would be infinately far apart from everything else. Clearly, that isn't the case. Therefore, we have our tight-rope walker... he is carefully traveling across his rope at a constant rate, not wavering to one side or the other, and we have a constant velocity to the expansion of the universe.

For the nth time, read Faster than the speed of light. It is a VERY interesting discussion, isn't considered mainstream at the moment, but as far as I know, provides the best theory for Big Bang expansion as far as accuracy to present day conditions and knowns of the past.

[Matthew4444]

While I hate to argue against someone who is clearly more informed than me in this area, I feel like I should throw in my own ideas. I doubt that the outer edge of the universe is accelerating, but rather we are decelerating. It could be (this is more of a wild guess than a theory) that the force of gravity closer to the center of the universe is slowing down matter in general. So because we are moving slower, it appears to us that the edge of the universe is accelerating, even though it's still moving at the same speed.

And about Tass' logic on why the universe can't be accelerating or decelerating: you say that the universe can't be accelerating or decelerating because there has been no evidence to prove it, even though the basis of most ideas on this topic is that the evidence stated in the first post is credible.

PS - what would you say is the reading level of Faster than the speed of light? It looks interesting, so maybe I'll try reading it sometime.

[Tasselfoot]

I'd say its advanced high school or college... but, that is the nature of the material. It is not a simple subject matter, and I recommend you know the basics of relativity before reading it.

And matt... that is the logic of those who are much wiser than I. I'm guessing its because its either impossible or extremely difficult to prove the nature of the cosmos....... plus, as I said, if the universe was accelerating or decelerating, the effects would be obvious. Since they aren't, it isn't happening. In addition, the reason that the universe ISN'T decelerating is from the initial force of the Big Bang. That is the force that is counter-acting gravity.

While your guess is a decent idea, it is in clear violation of the laws of physics.

As I said, it is accepted by the greatest minds in this field that the universe is not accelerating or decelerating. The reason as to WHY is what they all can't prove. And again, I feel, as do others wiser than myself, that FttSoL is the best explanation as to WHY, even though it violates the most time old principle of physics, a constant speed of light. Then again, he only says that there was a VSL in the nanoseconds after the Big Band, after which light slowed down to what we now know it as. Only through the VSL does the current nature of the universe make sense. The tight-rope walker example is not mine, its from the book.

[FlashStinger]

Point 1, The theory that the universe is expanding and accelerating is very well accepted. Point 2, That theory is also very widely not accepted.

My theory, The universe that is "expanding" is already there. It takes time for light to get here, yeah my theory is easily disproven but w/e, and we constantly see more and more universe, because the light is just now getting to us. The fact that objects traveling in space stay at a constant speed is irrelevant to space. The rules of the universe only apply to things inside the universe. As for the point of all this, who knows. Up until the last 700 years, the world was flat to our knowledge, 100 years ago we learned how to fly, 50 years ago we were in space, ten years 20 years ago we discovered aids, and now we have quantum computing, who knows which theory will win the race to be the "right" one.

-Stinger

[hatakikakashi]

One, You can't say something is impossible just because it hasn't happend yet. Two, We don't know how old the universe is. Three, we don't know how old it will get.

Just because you want it to be so, doesn't make it so. The fact of the matter is, that's what seems to be happening. If our observations are showing something that the laws of phsyics say can't happen, then either the observations are inncorrect or the laws need to be modified to explain them. Like I said before science changes and grows as we learn more. Phsyics can't explain everything, therefore it's not 100% complete, there is room for emprovment.

I did explain before why this force wouldn't manfest itself untill later in the development of the universe, the matter wasn't far enough away yet. In my hypothesis I suggested that gravity had two sides and they were based on the distance between matter. I'm not saying that's right, but it did answer your question on why it hadn't happened earlier.

Oh and before we found that it wasn't happening the universe could easily be decelerating! Just because it's not yet, why do you assume that it has to do it right this minute? How do you know that the universe isn't still in it's begining stages? Even though it's billions of years old how do you know it won't be around for tens of trillions of years more?

Also if you define void outside the universe as I have then the universe is expanding at the speed of light.