Time Travel Is Impossible and heres Why!

[Lucidus]

Re: Time Travel Is Impossible and heres Why!

<div class='quotetop'>QUOTE(\"StarLord\")</div>

So, when everything compacts back to a single point, that certainly would supply the energy needed to make the Big Bang now wouldn't it?[/b]

I am not sure, because I am not suggesting that all matter and energy collapses back into a great singularity. What I am exploring is the idea that as space expands faster than the speed of light, eventually every subatomic particle will be so far and moving so fast away from any other other particle that the apparent universe may simply disappear. Or as you suggested maybe the energy in each subatomic will have to be released as the observable universe gets too tiny to contain it, thereby creating another big bang. Interesting.

 

[aurora51]

Re: Time Travel Is Impossible and heres Why!

<div class='quotetop'>QUOTE(\"StarLord\")</div>

So, when everything compacts back to a single point, that certainly would supply the energy needed to make the Big Bang now wouldn't it?[/b]

thats an interesting thought. do you suppose that there is an ongoing expansion, and then a contraction (compaction) of the universe back to the big bang? then everything starts all over again? maybe this is part of the closed time loop that people speak of.

 

[Harte]

Re: Time Travel Is Impossible and heres Why!

<div class='quotetop'>QUOTE(\"lucidus\")</div>

This may be off-topic, but this got me to thinking. As the universe expands at an accerlerating pace, our observable universe should get smaller and smaller as other objects move away from us at greater than the speed of light and we can no longer observe them. Eventually, if there is nothing to stop this expansion,the observable universe will shrink to the point that each subatomic particle is unable to \"observe\" or interact with another. In a way, each subatomic particle would exist in its own tiny universe. Weird. But if the expansion continues then eventually even the smallest particles will not fit in the universe.

I am probably wrong about this, but I thought it was interesting anyway.[/b]

I want to use this reply to address something I've noticed on this board.

It seems that many of you think that the expansion of the universe entails all the mass in the universe flying away from some central point. Nothing could be further from the truth.

All the massive things in the universe (galaxies, stars, planets, etc.) are moving according to the forces (mostly gravity) being applied to them. They are not flying away from us through space into some empty space beyond. It may be hard to visualize but space itself is what's expanding here. I'm sure many of you know this already, those that don't can find the "dots on a balloon" example by googling the expansion of the universe. There is no center of the universe. The entire universe occupies the same space (albeit much larger) that the original "cosmic egg" singularity occupied prior to the big bang.

This applies to your statement above, Lucidus. While it is true that constant acceleration will eventually result in (apparent) lightspeed, please remember that the masses themselves are not actually travelling at these speeds in the universe's reference frame. It is the reference frame itself that is changing. Nor is it necessary for the expansion velocity to reach the speed of light before other galaxies begin to disappear. It is the nature of the expansion (see dots on a balloon) that the further from the observer an object is, the faster it's apparent speed. This is the definition of the "observable universe", since there are trillions (probably) of galaxies that are distant enough to be travelling at apparent lightspeed and thus invisible to us.

As an aside, I should say that were we on a planet in one of those distant galaxies, we would notice no high speed, we would observe that on the average, every other galaxy was retreating from us, that the more distant galaxies were retreating faster and that the galaxy known as the milky way is invisible to us because it's moving away at the speed of light.

As for your idea about subatomic particles, sorry man but local effects rule. Although the universe is expanding, we (our bodies) are not (at least not due to the universe's expansion!) Local forces like the electromagnetism holding molecules together overcome the force of expansion. Were it not for the expansion, we would be a tiny fraction smaller because the EM forces would settle at a different equilibrium point. Local gravity is similar. Were it not for the expansion, we might orbit an inch or so closer to the sun.

However if the expansion continues, even at a constant rate (not accelerating), eventually most of the observable universe would be unobservable.

Don't forget that most of the stars you see in the sky with the naked eye belong to our galaxy though, and that the milky way is part of a galactic cluster known as the local group. Members of the local group are orbiting each other and will not be separated by the universe's expansion.

Harte

 

[Lucidus]

Re: Time Travel Is Impossible and heres Why!

<div class='quotetop'>QUOTE(\"Harte\")</div>

This applies to your statement above, Lucidus. While it is true that constant acceleration will eventually result in (apparent) lightspeed, please remember that the masses themselves are not actually travelling at these speeds in the universe's reference frame. It is the reference frame itself that is changing. Nor is it necessary for the expansion velocity to reach the speed of light before other galaxies begin to disappear. It is the nature of the expansion (see dots on a balloon) that the further from the observer an object is, the faster it's apparent speed. This is the definition of the \"observable universe\", since there are trillions (probably) of galaxies that are distant enough to be travelling at apparent lightspeed and thus invisible to us.

As an aside, I should say that were we on a planet in one of those distant galaxies, we would notice no high speed, we would observe that on the average, every other galaxy was retreating from us, that the more distant galaxies were retreating faster and that the galaxy known as the milky way is invisible to us because it's moving away at the speed of light.

As for your idea about subatomic particles, sorry man but local effects rule. Although the universe is expanding, we (our bodies) are not (at least not due to the universe's expansion!) Local forces like the electromagnetism holding molecules together overcome the force of expansion. Were it not for the expansion, we would be a tiny fraction smaller because the EM forces would settle at a different equilibrium point. Local gravity is similar. Were it not for the expansion, we might orbit an inch or so closer to the sun.

However if the expansion continues, even at a constant rate (not accelerating), eventually most of the observable universe would be unobservable.

Don't forget that most of the stars you see in the sky with the naked eye belong to our galaxy though, and that the milky way is part of a galactic cluster known as the local group. Members of the local group are orbiting each other and will not be separated by the universe's expansion.

Harte[/b]

Thank you for this explaination Harte, I instictively thought that there must be something wrong with the idea that I proposed. There is a good article explaining this in Scientific American also. Even though space itself is expanding, galaxies, stars, planets, people, and atoms do not get any larger(due to expansion at least).

 

[Harte]

Re: Time Travel Is Impossible and heres Why!

<div class='quotetop'>QUOTE(\"lucidus\")</div>

Thank you for this explaination Harte, I instictively thought that there must be something wrong with the idea that I proposed. There is a good article explaining this in Scientific American also. Even though space itself is expanding, galaxies, stars, planets, people, and atoms do not get any larger(due to expansion at least).[/b]

Lucidus,
I read that article last month. The article suggested that many professionals asked the same types of questions as you and I do about the nature of the expansion. Of interest to me was the part about seeing distant galaxies even after they reached lightspeed due to the effect of the expansion. That blew my mind. I'd never even thought about that.

Anyway, I tried to be careful in my last post not to offend those out there that know about the nature of the expansion. My sister, a NASA engineer, still refuses to believe me when I talk to her about it, so misunderstanding of the phenomenon is not uncommon.

Harte

 

[StarLord]

Re: Time Travel Is Impossible and heres Why!

So, where does 'Dark Matter' fit into the scheme of things?

 

[Harte]

Re: Time Travel Is Impossible and heres Why!

<div class='quotetop'>QUOTE(\"StarLord\")</div>

So, where does 'Dark Matter' fit into the scheme of things?[/b]

Starlord,

As far as I can remember, dark matter was an invention (prediction) to help explain a thing (speed of expansion) that turned out itself to be wrong. As I recall, Cosmologists were once in a tizzy over the "missing mass" that should be in the universe to account for the apparent gravitation that was slowing the expansion. I believe that no dark matter was ever found. Doesn't mean it doesn't exist. I'm pretty fuzzy about this though, haven't read much about it in the last couple of years.

You got anything Lucidus? Aurora51?

Harte

 

[artsouth]

Re: Time Travel Is Impossible and heres Why!

of course time travel exisit.........time as we know it, is a man made measerment, based on the rotation of the earth around the sun, once you get off of this rock then you have no way to really measure time other than your watch, all time exisit at the same time .makeing time travel possible

 

[artsouth]

Re: Time Travel Is Impossible and heres Why!

i also belive in time slips and in some circles of belif, there may be 275 plus known dimentions, i know that i saw on anomolieis about 8 months ago this guy claimed to be able to travel to them, he had what appeared to be a homemade vidio of him useing a lazer type device he claims to have built himself ... the video was pretty convinceing...his name is steven here is the link to that vid....


http://www.anomalies.net/time_travel/steve.html

 

[Billy Pilgrim]

Re: Time Travel Is Impossible and heres Why!

I do agree that time travel will require travelling to a earth that is in a different place in the universe. That's why I always use a wormhole when I travel in time. It takes you from one time and place in the universe to another.