Time Machine will not be invented

[DaveC426913]

I think it follows from the Pauli Exclusion Principle, which states, simply, that " two solid objects cannot be in the same place in the same time."

( http://en.wikipedia.org/wiki/Pauli_exclusion_principle )

You just moved the goalposts. Now you're saying same place and same time. Who said they have to be in the same place?

Therefore, the same solid object can't be in two places at the same time.

Can you suggest any sources that state otherwise?

How does that follow from the above??

You're just making rules up.

 

[Ash Small]

You just moved the goalposts. Now you're saying same place and same time. Who said they have to be in the same place?


How does that follow from the above??

You're just making rules up.

Dave, You've misread what I said and you've mis-quoted me.

I actually said that it follows that "Therefore, the same solid object can't be in two places at the same time."

 

[Studiot]

If you traveled back in time, wouldn't all existence of you have shifted to the new time anyway?

That's another way of putting what I said.

 

[DaveC426913]

Dave, You've misread what I said and you've mis-quoted me.

I actually said that it follows that "Therefore, the same solid object can't be in two places at the same time."

No I have not, and no I have not.

Please note my post is broken into two parts, and each part directly addresses the direct quote from you.



You invoke Pauli Exclusion Principle, which talks about same place and same time. Since we are not talking about same place and same time, it is not applicable.

You then invent some sort of corollary rule out of thin air, about an object cannot be in two places at the same time. This is complete fabrication.

 

[Ash Small]

"If you traveled back in time, wouldn't all existence of you have shifted to the new time anyway? "

The simple answer is no.

Only the atoms within the time machine would travel back in time.

Some of the atoms that comprise you at the time that you travel back in time would have comprised, for example, the food you ate before you travelled. If you travel back in time a couple of months, some of those atoms that comprise you at the time of travel will comprise a cow or a potato at the time you travel to, for example.(Assuming you ate steak and chips before travelling)

So the same atoms would occupy different places at the same time.

(Unless you have a different explanation)

 

[DaveC426913]

So the same atoms would occupy different places at the same time.

Yes. If we posit time travel at all, the above statement is implicit.

Just as a person going back in time means he could come face-to-face with himself, so individual atoms going back in time means they can come face-to-face with themselves. No biggie.

 

[Ash Small]

No I have not, and no I have not.

Please note my post is broken into two parts, and each part directly addresses the direct quote from you.



You invoke Pauli Exclusion Principle, which talks about same place and same time. Since we are not talking about same place and same time, it is not applicable.

You then invent some sort of corollary rule out of thin air, about an object cannot be in two places at the same time. This is complete fabrication.

Dave, The Pauli Exclusion Principle states that if one particle is in state x, then another particle is in state y. Pauli actually does state that one particle cannot be in state x AND state y any more than two particles can be in state x or state y.

(BTW, Does the C stand for Cooper?)

 

[DaveC426913]

Dave, The Pauli Exclusion Principle states that if one particle is in state x, then another particle is in state y. Pauli actually does state that one particle cannot be in state x AND state y any more than two particles can be in state x or state y.

But one particle is not in two states at the same time. It's in two states at different times in its life.

You're got a "young" particle and a "slightly older" particle. PEP does not state that a particle can't be in state x at time a and then in state y at time b.

(BTW, Does the C stand for Cooper?)

No. It stands for Collins. About as common as Cooper.

 

[Ash Small]

But one particle is not in two states at the same time. It's in two states at different times in its life.

You're got a "young" particle and a "slightly older" particle. PEP does not state that a particle can't be in state x at time a and then in state y at time b.

I see your point, Dave.

The particle is older when it occupies the other state, even though it occupies both simultaneously.

(From the particle's time reference it doesn't occupy both states at the same time, although from the observer's time reference it does.)

 

[Time Machine]

Hello people,

Time Machine will not be invented. We will never travel in time, not in future, not in past.

On the basis that time is variable according to gravity intensity, perhaps the concept of time travel could be realized in that slower time could be created with gravity control. If passing through faster time/gravity variables in a slow/gravity controlled craft, time could potentially be travelled, not in, but through at a faster rate than usual. Perhaps?

 

[DaveC426913]

(From the particle's time reference it doesn't occupy both states at the same time, although from the observer's time reference it does.)

No, from the obsever's PoV, there are simply two particles in two different states. Particles do not wear nametags.

 

[DaveC426913]

On the basis that time is variable according to gravity intensity, perhaps the concept of time travel could be realized in that slower time could be created with gravity control.

Yes. One could slow time using either strong gravity or high relativistic speeds.

If passing through faster time/gravity variables in a slow/gravity controlled craft, time could potentially be travelled, not in, but through at a faster rate than usual. Perhaps?

Well, you could slow time, but you couldn't move backwards.

 

[Time Machine]

Well, you could slow time, but you couldn't move backwards.

Granted. No going backwards. But would my hypothetical parallel universe self experience time speeding up as a result, I wonder?

 

[DaveC426913]

Granted. No going backwards. But would my hypothetical parallel universe self experience time speeding up as a result, I wonder?

What?? What parallel universe self?

 

[Ash Small]

No, from the obsever's PoV, there are simply two particles in two different states. Particles do not wear nametags.

Dave, I hope I'm not going off topic here, but, from what you say, there could just be one set of elementary particles repeatedly traveling back in time until they caused the Big Bang.

Would this not violate the principle of Conservation of Energy?

 

[Time Machine]

What?? What parallel universe self?

Not really a serious question but more of an amusing ponder. Parallel universe as in Shrodinger's cat. Both dead and alive. If I slow time down for myself in this universe, would time speed up for me in parallel universe. Some reference was made as to Steven Hawking earlier in the thread...in that perhaps he actually did meet with time travellers as arranged in alternate universe.

As for creating gravity control in a craft, I realize the difficulties in encapsulating one field of gravity inside of the craft and keeping another out... interesting idea though.

 

[DaveC426913]

Not really a serious question but more of an amusing ponder. Parallel universe as in Shrodinger's cat. Both dead and alive. If I slow time down for myself in this universe, would time speed up for me in parallel universe.

There is no reason to suppose this.

 

[DaveC426913]

Dave, I hope I'm not going off topic here, but, from what you say, there could just be one set of elementary particles repeatedly traveling back in time until they caused the Big Bang.

What evidence do we have that particles are traveliing back in time?

Would this not violate the principle of Conservation of Energy?

LCE does not take time travel into consideration.

 

[Ash Small]

What evidence do we have that particles are traveliing back in time?


LCE does not take time travel into consideration.

We don't have any evidence (except, possibly, anti-particles)

I was just taking what you said to it's logical conclusion.

If it's possible for particles to travel backwards in time, you could start with one of each type of quark, etc., they could travel back in time, resulting in two of each type. They could then travel back a bit further, resulting in three of each type...

This process could continue until the conditions required for the Big Bang are satisfied.

(I'm not arguing in favour of this idea, it just follows from the point that you made.)

 

[Time Machine]

There is no reason to suppose this.

And also no reason to suppose not, I suppose. Not that it was a serious question...I'm not keen on parallel universes... wish I'd not mentioned it now. Time is more my area of interest.

 

[Brin]

We don't have any evidence (except, possibly, anti-particles)

I was just taking what you said to it's logical conclusion.

If it's possible for particles to travel backwards in time, you could start with one of each type of quark, etc., they could travel back in time, resulting in two of each type. They could then travel back a bit further, resulting in three of each type...

This process could continue until the conditions required for the Big Bang are satisfied.

(I'm not arguing in favour of this idea, it just follows from the point that you made.)

Three notes:
- Firstly, quarks don't exist in isolation.
- Secondly, Pauli-E says two fermions can't occupy the same quantum state/have the same quantum numbers. So even if quarks existed in isolation, they wouldn't have any problems because of the Pauli principle since basically they'd have different spatial locations.
- Thirdly, a particle spontaneously changing its four-momentum would violate something like Newton's first law (which holds in special relativity, but I don't know about GR... as I haven't gotten that far in this class!)

Then, I think you need to think a bit more about this before you arrive at its "logical conclusion." If you take ONE single particle, and make it move away from some point P in space time for like, 100 billion years, and then spontaneously jump it back to the beginning of time to have it travel out in another direction, then in essence you've altered the future of the particle, and it has never traveled 100 billion years, and so it will never see "itself" again.

Were it to travel back like fifty years and alter its own course, similar things would occur. It'd be rewriting itself.

Ergo, you'd never see a "big bang."

If there were a parallel universe theory, then one couldn't travel backwards in the same timeline. Only "sideways" to other timelines. Then you just end up with a bunch of parallel universes with particles going in different directions. You'd never see a big bang in this case either.

 

[Ash Small]

Three notes:
- Firstly, quarks don't exist in isolation.
- Secondly, Pauli-E says two fermions can't occupy the same quantum state/have the same quantum numbers. So even if quarks existed in isolation, they wouldn't have any problems because of the Pauli principle since basically they'd have different spatial locations.
- Thirdly, a particle spontaneously changing its four-momentum would violate something like Newton's first law (which holds in special relativity, but I don't know about GR... as I haven't gotten that far in this class!)

Then, I think you need to think a bit more about this before you arrive at its "logical conclusion." If you take ONE single particle, and make it move away from some point P in space time for like, 100 billion years, and then spontaneously jump it back to the beginning of time to have it travel out in another direction, then in essence you've altered the future of the particle, and it has never traveled 100 billion years, and so it will never see "itself" again.

Were it to travel back like fifty years and alter its own course, similar things would occur. It'd be rewriting itself.

Ergo, you'd never see a "big bang."

If there were a parallel universe theory, then one couldn't travel backwards in the same timeline. Only "sideways" to other timelines. Then you just end up with a bunch of parallel universes with particles going in different directions. You'd never see a big bang in this case either.

I never said quarks could exist in isolation.

I was merely taking the point that Dave made that a particle could exist in two places at the same time if it was 'older' at one location to it's logical conclusion.

The point I was making is that if there were only six quarks at the end of time, and they traveled back in time, so that there were 12, and then those twelve trevelled back in time, making 18...etc...eventually, due to the fact that they all start in the same place and have no external influence acting upon them, eventually you'd reach the conditions required for the big bang.

I personally believe that Pauli exclusion prevents time travel. I was just taking the point that Dave made to it's logical conclusion.

 

[Brin]

I misread, you wrote "Quarks etc" I didn't mean to suggest that your whole argument was destroyed because of this. You could just pick some other fermion.

Anyways, those were just notes which can be overcome, as you can see I permitted those and gave your idea a chance. I understood your idea, and it still failed.

You seem to have ignored this.

I reiterate, Pauli Exclusion doesn't prevent time travel and it doesn't have to. The time travel we seem to be talking about is pretty much impermissible for other paradoxical reasons. However, your idea makes no sense to conquer "time travel," by parallel universe theory method. So, you haven't conquered "time travel" in general, and definitely not because of Pauli-E.

 

[Ash Small]

I misread, you wrote "Quarks etc" I didn't mean to suggest that your whole argument was destroyed because of this. You could just pick some other fermion.

Anyways, those were just notes which can be overcome, as you can see I permitted those and gave your idea a chance. I understood your idea, and it still failed.

You seem to have ignored this.

I reiterate, Pauli Exclusion doesn't prevent time travel and it doesn't have to. The time travel we seem to be talking about is pretty much impermissible for other paradoxical reasons. However, your idea makes no sense to conquer "time travel," by parallel universe theory method. So, you haven't conquered "time travel" in general, and definitely not because of Pauli-E.

I never mentioned parallel universes, Brin, that was someone else's post. I merely stated that, due to Pauli Exclusion, the same particle cannot occupy two different states at the same point in time. Dave said that a particle could, if the particle was a different age, I then took his idea to it's logical conclusion,ie that the universe 'could' be comprised of only one of each elementary particle, if each particle of each type was the same particle, but a different age. I still believe that Pauli excludes this possibility.

 

[DaveC426913]

I was just taking what you said to it's logical conclusion.

If it's possible for particles to travel backwards in time, you could start with one of each type of quark, etc., they could travel back in time, resulting in two of each type. They could then travel back a bit further, resulting in three of each type...

This process could continue until the conditions required for the Big Bang are satisfied.

(I'm not arguing in favour of this idea, it just follows from the point that you made.)

I don't see how that follows. We were talking about time travel technology. How did we get to an idea of particles spontaneously travelling backwards en mass?

 

[DaveC426913]

And also no reason to suppose not, I suppose.

Yes there is. Occam's Razor and the Scientific Method.

We don't suppose faeries and unicorns for the same reason.

 

[Ash Small]

I don't see how that follows. We were talking about time travel technology. How did we get to an idea of particles spontaneously travelling backwards en mass?

Whatever the method of time travel, Dave, whether by machine or otherwise (the mechanism isn't important here), Pauli states that each fermion has it's own 'associated state' within space-time.

This has been accepted since 1927, and time travel would violate this principle.

 

[pallidin]

Ever notice how we seem unable to change the past, but most certainly capable of affecting the future?
The future, it seems, immutably relies on the "past' for part of it's "Now"

 

[DaveC426913]

Whatever the method of time travel, Dave, whether by machine or otherwise (the mechanism isn't important here), Pauli states that each fermion has it's own 'associated state' within space-time.

This has been accepted since 1927, and time travel would violate this principle.

Argh! Are you ADHD? Stay on freakin' topic!

If you want to talk about PEP, then there's nothing that excludes it. Find me a reference to PEP that talks about a particle traveling into its own past.



If you want to talk about particles traveling back in time, then well, what are we talking about? We went from a time machine to recreating the Big Bang in nothing flat.

 

[Studiot]

It's a long time since we heard from the OP.

Perhaps he really meant that a Time Machine will not be invented because he is a Time Lord and has already invented one.

 

[Ash Small]

Argh! Are you ADHD? Stay on freakin' topic!

If you want to talk about PEP, then there's nothing that excludes it. Find me a reference to PEP that talks about a particle traveling into its own past.



If you want to talk about particles traveling back in time, then well, what are we talking about? We went from a time machine to recreating the Big Bang in nothing flat.

I feel I'm repeating myself here Dave. The time machine would comprise of fermions and leptons. The fermions cannot violate PEP, PEP ties the fermions to one state in space-time. time travel would violate PEP.

Fermions can move in space-time, but they can't jump, either in space or in time, from one state to another.

Please come up with an argument that I haven't replied to already.

(BTW, I wasn't re-creating the big bang, I was extrapolating your earlier reply to 'explain' it.) :-)

 

[DaveC426913]

The fermions cannot violate PEP, PEP ties the fermions to one state in space-time. time travel would violate PEP.

Nothing in PEP addresses a particle moving backward in time to join its earlier self. Nothing in PEP says two particles can't exist near each other while being in the same state.

For one, PEP applies to particles in the same atom. No one says an atom traveling backward in time somehow overlaps itself physically.

You are reading far too much of PEP into this scenario.

 

[Ash Small]

Nothing in PEP addresses a particle moving backward in time to join its earlier self. Nothing in PEP says two particles can't exist near each other while being in the same state.

For one, PEP applies to particles in the same atom. No one says an atom traveling backward in time somehow overlaps itself physically.

You are reading far too much of PEP into this scenario.

Dave, If two particles were in the same state they would be super-imposed, PEP excludes this. They can be identical in all other respects, but they cannot occupy the same space at the same time.

They are each associated with their own unique state in 'space-time'.

 

[DaveC426913]

Dave, If two particles were in the same state they would be super-imposed, PEP excludes this.

Show what this has to do with what we're talking about.

They can be identical in all other respects, but they cannot occupy the same space at the same time.

Nobody said they have to.


These are both red herrings. Who claimed the particle traveling backward in time must occupy the same space as its younger self?

I have an atom in a beaker on my desk. I send it backward in time; it appears in another beaker a foot to the left of the first one. Show how PEP disallows this.

 

[Ash Small]

Show what this has to do with what we're talking about.



Nobody said they have to.


These are both red herrings. Who claimed the particle traveling backward in time must occupy the same space as its younger self?

I have an atom in a beaker on my desk. I send it backward in time; it appears in another beaker a foot to the left of the first one. Show how PEP disallows this.

PEP states that each fermion has it's own unique state associated with it in space-time (singular).

You show me where it says otherwise, and says a fermion can exist in two states in space-time.