Sciencemadness Discussion Board - Quantum Mechanics

Quantum Mechanics

glymes - 1-6-2016 at 00:48

I was engaged in a very interesting discussion with a bloke by the name of Angus Freeman yesterday, pertaining to the matter of quantum mechanics.

1) Why could one not compress photons into an extremely small space to create extreme amounts of power? Because they have no mass and no volume, which makes them really not exist in a practical sense. Also, I believe that any energy in them would diffuse and constantly move position, making harnessing it impossible.

2) How would one plan a matrix for problems involving more than 4 dimensions of time-state existing in superposition (what I'm talking about here, more exactly, is whether one could plot matrices for the existence of 'white holes,' in which time is backwards.)

3) Would there not also be an enormous amount of energy that can be stored in one place through a plasmatic supercapacitor (plasma, compressed and transported in order to supply enormous amounts of power.)

4) Finally, a solution to the Grandfather Paradox. If you go back in time and kill your grandfather, there are now two possible histories existing in superposition, and you exist in the one in which you kill your grandpa and then everything turns out completely differently.

Fulmen - 1-6-2016 at 01:19

I think the concept of time travel is fundamentally flawed. For instance, wouldn't sending something back in time decrease entropy and increase the total amount of mass/energy in the universe?

HeYBrO - 1-6-2016 at 02:26

pretty sure 1 would not work due to the Heisenberg uncertainy principle

MrHomeScientist - 1-6-2016 at 06:03

Being bosons, you could condense photons into a Bose-Einstein Condensate where they all occupy essentially the same state. But this requires cooling to near absolute-zero, which of course means extracting almost all energy from the system. So I doubt you'd be able to get any energy out of such a system.

Your fourth point is one possible interpretation, the 'many-worlds' interpretation. As explained by Doc Brown: https://www.youtube.com/watch?v=gVx4OOcIRXg
Another interesting possibility is the Novikov Self-Consistency Principle, which states that it is impossible to change the past in a way that would create a paradox. No matter what you do, circumstances and physical law will prevent you from killing your grandfather. The Wiki article on this has an interesting quote:

Quote:

You cannot will yourself to kill your younger self if you travel back in time. You can coexist, take yourself out for a beer, celebrate your birthday together, but somehow circumstances will dictate that you cannot behave in a way that leads to a paradox in time. Novikov supports this point of view with another argument: physics already restricts your free will every day. You may will yourself to fly or to walk through a concrete wall, but gravity and condensed-matter physics dictate that you cannot. Why, Novikov asks, is the consistency restriction placed on a time traveler any different?

This principle is a key part of the plot in the game Quantum Break, which is a really innovative game that I highly recommend just for the way they tell the story.

The other two points are a little beyond me!

Fulmen - 1-6-2016 at 10:08

"physics already restricts your free will every day"
I don't buy it, physics isn't conditional. In order for this to be right physics for an object sent back in time would be different to regular objects.

aga - 1-6-2016 at 12:11

agaspace to the rescue !

Time travel is not only possible in agaspace, but absolutely essential.

It appears that highly complex arrangements of particles, such as a Human, simply could not exist if the Time component of their particles were changed in this way.

The arrangement would no longer be what one would recognise as a Person, at all.

Not suggesting anything about 'spirit' etc here, just that if that 'person' was sent back in Time, they would be literally all over the place, same as if they were hit by a train, but with less debris and not so much blood.

When What and Where seem to be very much interconnected.

glymes - 1-6-2016 at 12:39

When I'm looking into the matrix problem, the main thing that I've come up against is the fact that time cannot be quantatised: it can be measured, but from a purely 'space' perception, it doesn't exist. And as far as there is nothing to measure what exactly is time, any problems involving dual time streams in superposition will be nearly impossible.

aga - 1-6-2016 at 12:41

may as well ask:-

what is mass ?
what is energy ?
what is magetism ?
what is time ?

all same-same.

glymes - 1-6-2016 at 12:51

Hold on. If time is energy, why not be able to transfer it? That probably violates a rule somewhere, but if the Law of the Conservation of Energy is correct and Agaspace is a thing, time must be transferable.

Ergo, time travel...

Fulmen - 1-6-2016 at 12:59

I think it's hilarious (and slightly sad) that physicists discuss the topic of time travel without having the faintest clue about what time really is. Forget grandfather paradoxes, that's the first major hurdle to overcome.

On a similar note, here is a thought that would explain why the speed of light is constant: To me it appears quite similar to measuring the speed of a clock hand with the clock itself as the reference. In that reference frame the second hand will always rotate at one round per minute, regardless of it's "actual" speed.

aga - 1-6-2016 at 13:07

Time is a distinct 'thing' from mass, energy, etc.

At least mathematically.

There exists the possibility that none of these are distinct at all.

Certainly by using a 'fixed' reference, they are distinct.

glymes - 1-6-2016 at 13:28

Hold on. If time is energy, why not be able to transfer it? That probably violates a rule somewhere, but if the Law of the Conservation of Energy is correct and Agaspace is a thing, time must be transferable.

Ergo, time travel...

blogfast25 - 1-6-2016 at 16:20

Quote: Originally posted by glymes

Hold on. If time is energy, why not be able to transfer it? That probably violates a rule somewhere, but if the Law of the Conservation of Energy is correct and Agaspace is a thing, time must be transferable.

TIME IS NOT ENERGY.

Period.

Quote: Originally posted by glymes

I was engaged in a very interesting discussion with a bloke by the name of Angus Freeman yesterday, pertaining to the matter of quantum mechanics.

1) Why could one not compress photons into an extremely small space to create extreme amounts of power? Because they have no mass and no volume, which makes them really not exist in a practical sense. Also, I believe that any energy in them would diffuse and constantly move position, making harnessing it impossible.

2) How would one plan a matrix for problems involving more than 4 dimensions of time-state existing in superposition (what I'm talking about here, more exactly, is whether one could plot matrices for the existence of 'white holes,' in which time is backwards.)

3) Would there not also be an enormous amount of energy that can be stored in one place through a plasmatic supercapacitor (plasma, compressed and transported in order to supply enormous amounts of power.)

4) Finally, a solution to the Grandfather Paradox. If you go back in time and kill your grandfather, there are now two possible histories existing in superposition, and you exist in the one in which you kill your grandpa and then everything turns out completely differently.

Meh.

I've refrained from replaying to this post so far, because near-total bollocks is hard and time-consuming to scientifically refute.

If you want to understand QP and Relativity, study it from the ground up and refrain from making statements that are at best poor SciFi, at worst meaningless word salad, "Angus Freeman" not withstanding.

Go on, start bleeting about Free Speech and "open mindedness", you know you want to!

[Edited on 2-6-2016 by blogfast25]

woelen - 3-6-2016 at 00:02

Traveling backwards in time simply is not possible. We all travel forward in time and the speed at which we do that can be varied. We can slow ourselves down in time by moving in space. We travel with a constant speed of c (speed of light), where traveling one second through time is equivalent to moving a distance c along one of the space axes. If we move faster through space, then less is left for moving through time. The total length of the "speed" vector equals c. If we move at a speed near c through space, then only very little is left for moving through time.

Time Travel

wg48 - 3-6-2016 at 07:27

I recall an article in Scientific America that suggested that time travel did not violate any know principals of physics and described a time machine.

From memory machine consisted of a very dense (approaching black hole density) cylinder several kilometres in length and a few kilometers in diameter spinning with a peripheral speed near the speed of light. Apparently the huge mass and relativistic rotation distorted space time in such a way that paths round the cylinder resulted in a path in time as well either forward or back in time. Time travel would only be possible to a point in time when the machine existed.

I searched for the article but did not find it.

blogfast25 - 3-6-2016 at 11:14

Quote: Originally posted by wg48

I recall an article in Scientific America that suggested that time travel did not violate any know principals of physics and described a time machine.

From memory machine consisted of a very dense (approaching black hole density) cylinder several kilometres in length and a few kilometers in diameter spinning with a peripheral speed near the speed of light. Apparently the huge mass and relativistic rotation distorted space time in such a way that paths round the cylinder resulted in a path in time as well either forward or back in time. Time travel would only be possible to a point in time when the machine existed.

I searched for the article but did not find it.

There's quite a wide variety of contraptions out there that are supposed to allow backward time travel or superluminal speed. The general consensus is that they can't work.

The other [other than near-c speeds] way of 'forward' time travel is by means of intense gravitational fields, which slow down time.

Fulmen - 3-6-2016 at 12:31

WG48: IIRC this was mentioned in one episode of "through the Wormhole" with Morgan Freeman. If so, the cylinder would have to infinitely long to work.

wg48 - 3-6-2016 at 14:03

Quote: Originally posted by blogfast25

Quote: Originally posted by wg48

I recall an article in Scientific America that suggested that time travel did not violate any know principals of physics and described a time machine.

Snip

You have me intrigued. Can you give me some detail of one of time machine contraptions?

The the article was written by a legitimate physicist and was based on only know physics. The only limitation was the practical difficulty of constructing it. An understatement.

The only objection that made sense to me was that such a closed loops would be unstable because a particle traversing the loop would be duplicated and hence the number of particles double with each travers of the loop. Apparently creating particles from nothing. The counter argument was that the machines creation would require huge amounts energy so it could not be said that the particles were created from nothing.

blogfast25 - 3-6-2016 at 15:03

Quote: Originally posted by wg48

No. Because I don't want to detract you with what is mostly nonsense.

'legitimate physicist' is an appeal to authority type fallacy. Einstein, undoubtedly one of the greatest physics minds of the 20^th century, was wrong about early Big Bang theory and about QP (initially at least). Known fallacies (Cold Fusion and Poly-water, e.g.) have been published in reputable journals, as have the occasional deliberate science hoax.

Nothing's perfect!

[Edited on 3-6-2016 by blogfast25]

aga - 3-6-2016 at 15:16

Quote: Originally posted by wg48

You have me intrigued

With current knowledge of physics, time travel in the reverse direction cannot happen.

At some future time, you already will have had hadden knowned how it was wentended wosen done, as you will, in fact, be your own grandfather.

Marvin - 4-6-2016 at 03:48

wg48 is talking about a Tipler cylinder. When I went to university the first two papers I looked up first were "Possible High Tc in the La-Ba-Cu-O system" and "Rotating cylinders and the possibility of global causality violation".

Travelling backwards in time is allowed by general relativity. This is not as weird as physics gets, the basic laws allow for negative mass, negative energy and gravity that pushes. These solutions are routinely ignored by everyone from high school students to Nobel prize winners because they don't correspond to anything anyone has ever observed.

glymes - 4-6-2016 at 09:54

Surely you could use a finitely long cylinder and negative energy?

aga - 4-6-2016 at 11:32

Quote: Originally posted by Marvin

Travelling backwards in time is allowed by general relativity. This is not as weird as physics gets, the basic laws allow for negative mass, negative energy and gravity that pushes.

Ghastly thoughts !

If people were to even try to consider those notions, there is a serious danger that a New idea will be had, which would be absolutely horrid.

blogfast25 - 4-6-2016 at 12:22

Quote: Originally posted by aga

If people were to even try to consider those notions, there is a serious danger that a New idea will be had, which would be absolutely horrid.

Ho, ho-bloody-ho...

Oh G-d. Not the return of the 'our idaes is being suprezed!' brigade, please (this time suppressed by Big Time, I suppose)

Calculate how much money you'd have if you travelled back in time a 1000 years, deposited £1 in a bank there (say interest rate of 3%) and returned to the present.

Then tell me again how people aren't to make reverse time travel possible.

But it won't work. Do you understand the Grandfather paradox and its implications?

[Edited on 4-6-2016 by blogfast25]

Marvin - 4-6-2016 at 12:46

These things do get investigated,

https://en.wikipedia.org/wiki/Breakthrough_Propulsion_Physic...

But they lead nowhere until a lever in the real world is found.

Fulmen - 4-6-2016 at 14:51

Quote: Originally posted by Marvin

Travelling backwards in time is allowed by general relativity

That doesn't mean it's possible.

We already know that GR has limited range, and that there are significant lapses in our understanding of the makeup of reality. And we don't even know what times really is. We cannot make any accurate predictions on this with our current understanding.

wg48 - 5-6-2016 at 00:56

Quote: Originally posted by Marvin

wg48 is talking about a Tipler cylinder. When I went to university the first two papers I looked up first were "Possible High Tc in the La-Ba-Cu-O system" and "Rotating cylinders and the possibility of global causality violation".

Travelling backwards in time is allowed by general relativity. This is not as weird as physics gets, the basic laws allow for negative mass, negative energy and gravity that pushes. These solutions are routinely ignored by everyone from high school students to Nobel prize winners because they don't correspond to anything anyone has ever observed.

Thanks for that. Now I have a name for it I have found lots of info on it even a wiki page https://en.m.wikipedia.org/wiki/Tipler_cylinder

In the approximately 40 years since Tipler proposed his time machine more analysis has been done. Originally the cylinder had to be infinitely long to enable a solution to be found for the field equations. It was assumed or hoped a finite cylinder would work too.

However according to wiki Stephen Hawkings has proved that no smooth solutions exist for finite cylinders.

So sadly no Tipler time machine. But then that's only due to Hawkings a respected physicist who has got other things wrong LOL

[Edited on 5-6-2016 by wg48]

Marvin - 5-6-2016 at 05:53

Fulmen,

These things are allowed but they don't appear to match real observations. That was my point. However, so far all real observations about gravity are predicted correctly by GR. It's not a T.O.E. and the accelerating universe doesn't seem to have a good explanation yet but GR just secured a pretty major win with the direct detection of gravity waves.

I don't know what you mean by not knowing what time is. It's the fourth and final macroscopic dimension and we travel in 4D at a constant speed of c. Warping of the four by mass/energy explains gravity. The direction we travel is of increasing entropy, non coincidentally a requirement for computing devices like brains. Saying we don't understand time seems like not understanding width or length.

wg48,

Didn't occur to me to see if Wikipedia had anything, cool page.

This would probably produce better discussion on a physics forum, it's a bit out of place here. Perhaps it already has.

PHILOU Zrealone - 5-6-2016 at 10:34

Michael Jackson with its famous "Moonwalking" was "traveling backwards/backsteps in time"

An infine or finite long rotating axe of black hole matter spinning at speed of light would collapse on itself...because of its innerent gravity.

[Edited on 5-6-2016 by PHILOU Zrealone]