# How could the universe be speeding up?

1. May 30, 2005

### j6p

If there was some kind of a push from an initial big bang, shouldn't we be slowing down? I would think that when a projectile leaves the influence of a propelling force it should start slowing down.
In our case the propelling force would be the big bang and the material universe would be the projectile.

2. May 30, 2005

### Art

Negative energy is one theory. This is theorised to have existed in abundance during the universe's inflationary period and some believe still abounds today

3. May 30, 2005

### selfAdjoint

Staff Emeritus
If the Einstein equations describing the universe have an extra term in them, the so-called Cosmological Constant, they will automatically generate the expansion energy, which will always be there, and won't run out or down. It turns out that they can use the estimated acceleration, which they can calculate from observing ancient supernovas, to figure the value of the consmological constant, known as Lamba ([tex]Lambda[/tex}.

It works out to be extremely tiny, but not zero. This is a puzzle, because theorists could understand if it were zero, or if it were some ordinary number like 3 or 100 or something, but almost zero but not quite seems to call for an explanation, and while there are dozens of papers proposing one answer or another, none of them has convinced a large number of cosmologists that it is right.

4. May 30, 2005

### Pengwuino

After the projectile leaves hte "influence", it continues on at a constant speed. You might be getting confused because we see things different on earth.. but its because theres air resistance. If there was no air resistance, u could throw a ball and it wouldnt slow down a bit.

5. May 31, 2005

### j6p

Ya got me Pengwuino, I didn't think of that. But on the same line of thought, it wouldn't speed up.

As for the negative energy, that's what I believe it is. I'm trying to figure out how they (negative and positive energy) separated. My mind keeps taking me to the place where our universe is expanding into. What I see is an area of negative energy but if that were the case then we would be being pulled, stretched into that negative space and not pushed from a gigantic internal explosion. Could it be possible that there is something beyond our range of detection that is an area of negative energy or something like that? It would explain a lot of stuff.

6. Jun 1, 2005

### selfAdjoint

Staff Emeritus
It isn't expanding into anything. What is happening is that the distance between things is increasing.

7. Jun 1, 2005

### j6p

So if the universe started to collapse, that would mean that the distance between things is decreasing and there would be no outside.
What comes to mind is: what would be left in the space where those things were, before they collapsed. I figure there has to be something that the fabric is expanding into, it should be displacing something.

8. Jun 8, 2005

### sd01g

It is obvious to most people (at least to me and maybe j6p) that 'space' is necessary for any and all movement from the atomic level to the galactic. When anything moves, it is changing it's location in space. This is true both empirically and rationally. The Universe is moving and expanding in space. Whether one calls this space 'anything' or 'nothing' does not matter. How it moves or why it moves does not matter. Where it's final location is does not matter. The Universe is moving from space into space. Thank you for considering my opinion.

Last edited: Jun 8, 2005
9. Jun 8, 2005

### Pengwuino

There seems to be a large # of people who do think it matters. All this stuff me

10. Jun 12, 2005

### Gaijin

why not slow down

what about Gravity?

wouldn't that measure out ot something in the long run

i dont know much about it, but does gravity from one huge obeject(a galaxy) acting on another object ever reach 0 or does it just get very very small with increasing distance?

11. Jun 12, 2005

### εllipse

It just gets smaller.

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