How could the universe be speeding up?

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In summary, the discussion covers the concept of negative energy and its role in the universe's expansion, as well as the idea of the universe expanding into something and the role of gravity in this expansion. The conversation also touches on the idea that space is necessary for movement and that the universe is constantly moving from space to space. The discussion concludes with the question of whether gravity ever reaches zero or just becomes very small with increasing distance.
  • #1
j6p
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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.
 
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  • #2
Negative energy is one theory. This is theorized to have existed in abundance during the universe's inflationary period and some believe still abounds today
 
  • #3
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
j6p said:
I would think that when a projectile leaves the influence of a propelling force it should start slowing down.

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 there's air resistance. If there was no air resistance, u could throw a ball and it wouldn't slow down a bit.
 
  • #5
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
j6p said:
My mind keeps taking me to the place where our universe is expanding into.

It isn't expanding into anything. What is happening is that the distance between things is increasing.
 
  • #7
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
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.
 
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  • #9
sd01g said:
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.

There seems to be a large # of people who do think it matters. All this stuff :confused: :confused: me
 
  • #10
why not slow down

what about Gravity?

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

i don't 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
Gaijin said:
what about Gravity?

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

i don't 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?

It just gets smaller.
 

1. What evidence supports the idea that the universe is speeding up?

Scientists have observed that the light from distant galaxies appears to be redshifted, meaning they are moving away from us at an accelerated rate. This supports the idea of an expanding universe and suggests that the expansion is accelerating.

2. How could the universe be expanding at a faster rate?

One explanation for the accelerating expansion is the presence of dark energy. This mysterious force is thought to make up about 70% of the total energy in the universe and is causing the expansion to accelerate by counteracting the force of gravity.

3. Is there any other possible explanation for the accelerated expansion?

Some scientists have proposed alternative theories, such as modifications to Einstein's theory of general relativity or the existence of a new particle called the "quintessence." However, these theories have not been widely accepted and dark energy remains the leading explanation.

4. How does the accelerating expansion impact the future of the universe?

If the expansion continues to accelerate, it is possible that the universe will eventually reach a state of "heat death," where all energy is evenly distributed and no work can be done. However, this is just one of several possible scenarios and the exact fate of the universe is still uncertain.

5. What ongoing research is being done to better understand the accelerating expansion?

Scientists continue to study the properties of dark energy and its effects on the expansion of the universe. They also use advanced technologies, such as telescopes and satellites, to gather more data on distant galaxies and their movements. Additionally, ongoing experiments in particle physics may provide new insights into the nature of dark energy.

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