Spooky Physics: Signals Seem to Travel Faster Than Light

[Thunderbird]

Then you would have communication of information faster than light:naughty:

its not about speed, or traveling over distance's it is

Instantaneous.

[freeztar]

its not about speed, or traveling over distance's it is

Instantaneous.

 

Indeed. Quantum entaglement does not imply super-luminal speeds. Boerseun explained this well imo.

[Moontanman]

Indeed. Quantum entaglement does not imply super-luminal speeds. Boerseun explained this well imo.

 

Sooo, instantaneous isn't superluminal? I'm really trying to understand this, I'm not just being stubborn.

[Moontanman]

Indeed. Quantum entaglement does not imply super-luminal speeds. Boerseun explained this well imo.

 

I agree, boerseun's bricks did indeed explain it quite well, no action at a distance at all....... unless you get to choose the color of the brick on earth and therefore change the color of the brick at Jupiter.

[Overdog]

Sooo, instantaneous isn't superluminal? I'm really trying to understand this, I'm not just being stubborn.

 

You're in good company. Einstein was pretty stubborn about it too.

 

Edit:

 

What I mean is "No Problem..."

[Overdog]

Here's another article I found...

 

BBC NEWS | Science/Nature | Teleportation breakthrough made

 

And another:

 

Quantum telecloning: Captain Kirk's clone and the eavesdropper

[Moontanman]

The multi particle teleportation looks like a different animal to me or at least a much more complex one. I still don't see how the brick analogy is instantaneous transfer of a color.

[Moontanman]

Ok, you have two bricks, both have to be the same color but you don't know what color. You send one to Jupiter then you uncover the brick at home and you instantly know the color of the brick at Jupiter. That is not teleportation of information or anything else, it's just the ways things are, common sense. Now if you have the two separated bricks and you choose the color of one and it determines the color of the other then you have faster than light information exchange, you can call it teleportation or anything else but information has been transmitted faster than light. all of those more complex things in the links simply make it more complex not clearer. Now what is wrong with these analogies? Or is my interpretation of these analogies?

[TheBigDog]

Understanding entanglement is one of the missing links. Making it useful is the step after that. The two (or more) particles behave as one regardless of their physical separation.

 

Lets take Boerseun's example in a different light. I have two entangled particles that are shot in different directions. One particle passes through a gizmo that gives it positive spin. When that happens the other particle simultaneously gets negative spin - no travel, no time delay, they are the same particle regardless of what we would call distance. In software we would call this a "feature", not a bug - despite its apparent violation of the rules. If I were to entangle two laser beams so they were streams of entangled photons, and I were to pass one beam through a filter that changed it light frequency, I would observe a simultaneous change in the paired beam at the same distance from the source. At least that is how I understand it. The problem is that all of this happens at the quantum level, and there is so much other mystery there that cause and effect is always somewhat mysterious. I think that instantaneous communications will someday be realized through this strange natural phenomena, but we have years of research before we get there.

 

Bill

[Moontanman]

Understanding entanglement is one of the missing links. Making it useful is the step after that. The two (or more) particles behave as one regardless of their physical separation.

 

Lets take Boerseun's example in a different light. I have two entangled particles that are shot in different directions. One particle passes through a gizmo that gives it positive spin. When that happens the other particle simultaneously gets negative spin - no travel, no time delay, they are the same particle regardless of what we would call distance. In software we would call this a "feature", not a bug - despite its apparent violation of the rules. If I were to entangle two laser beams so they were streams of entangled photons, and I were to pass one beam through a filter that changed it light frequency, I would observe a simultaneous change in the paired beam at the same distance from the source. At least that is how I understand it. The problem is that all of this happens at the quantum level, and there is so much other mystery there that cause and effect is always somewhat mysterious. I think that instantaneous communications will someday be realized through this strange natural phenomena, but we have years of research before we get there.

 

Bill

 

Ok, I see what you are getting at, so you can choose the "color" of the brick after it leaves your lab? Can you change it back and forth in a pattern if you don't look at it? It's beginning to look a lot like faster than light communication!

[freeztar]

its not about speed, or traveling over distance's it is

Instantaneous.

 

It's not FTL in (perhaps) the same way (or at least a mental-model similar way) that a worm hole is not FTL. That's how I think of it anyways...

 

Just to note, we are all speaking in layman's terms about a subject that mostly evades such "easy to nail down" descriptions.

[Moontanman]

It's not FTL in (perhaps) the same way (or at least a mental-model similar way) that a worm hole is not FTL. That's how I think of it anyways...

 

Just to note, we are all speaking in layman's terms about a subject that mostly evades such "easy to nail down" descriptions.

 

Obviously I need to try harder to understand it, to me it looks like an assumption that has got out of hand. I can see the higher dimension idea quite well but I've been told so many times there is no such thing it's difficult to bring that one back to life. Lets not stop here but go on, I will get my mind around it eventually.

[Thunderbird]

Obviously I need to try harder to understand it, to me it looks like an assumption that has got out of hand. I can see the higher dimension idea quite well but I've been told so many times there is no such thing it's difficult to bring that one back to life. Lets not stop here but go on, I will get my mind around it eventually.

 

I do not think anyone has got their mind completly around this as yet. Our minds just are not capable to grasp quantum level particle physics. What we can do however is attempt to leave the Newtonian framwork behind and accept that the building bocks of reality are not separate solid objects, but more akin to how we see a spectrum light, that the world we think we know so well my in fact be a hologram. :hyper:

[Moontanman]

I do not think anyone has got their mind completly around this as yet. Our minds just are not capable to grasp quantum level particle physics. What we can do however is attempt to leave the Newtonian framwork behind and accept that the building bocks of reality are not separate solid objects, but more akin to how we see a spectrum light, that the world we think we know so well my in fact be a hologram. :hyper:

 

I have always been able to visualize higher dimensions relatively easily but this one thing escapes me. On the one hand they say no information is transfered but then they say information on one particle defines the other no matter how far away it is. Like saying white is white except when it's black.

[Boerseun]

Coming from a bit of a different angle, I think the brick analogy might have obfuscated matters slightly.

 

A physical property such as the colour of a brick might not be the best example, because what happens at the quantum level is that one property gets modified when another property gets probed. When you look at a brick to determine the colour, you do not change any other property - the brick stays exactly the same.

 

On the quantum level, if we determine the brick to be yellow, we had to somehow probe the brick in such a way that another property gets modified. Sorta like Heisenberg will have it - you can know the velocity of a particle or its position in space, but not both - probing the velocity changes the position, and determining the position alters the velocity.

 

So, bringing the brick analogy closer to quantum mechanics, if we were to observe the brick to be yellow, the act of observation changes the brick into a rubber duck. Which means that if you're discussing quantum "entangled" bricks, you can't use it for information interchange, because the entanglement works both ways - you paint the Earth brick yellow as a signal which can be modulated so that information can pass to a brick observer on Jupiter, who notices the colour change, but his observation instantaneously changes both the Earth-brick and Jupiter-brick into rubber ducks. Some other property will be sacrificed in probing any one specific property.

 

Bricks aren't the best example, because they exist at the macro level where there are no disruptive actions needed in probing it.

 

But don't let me fool you, however. I still don't get it.

[modest]

I agree completely with MTM and I'm a bit surprised no one yet has.

 

You can't paint earth. All you can do is measure the color and the color is random. Whatever color you measure, you know someone on Jupiter will measure the opposite - but it is still random from Jupiter's perspective. Thus no FTL.

 

As wiki has it:

 

Now suppose Alice is an observer for system A, and Bob is an observer for system B. If Alice makes a measurement in the {|0>, |1>} eigenbasis of A, there are two possible outcomes, occurring with equal probability:

 

1. Alice measures 0, and the state of the system collapses to |0>A |1>B.

2. Alice measures 1, and the state of the system collapses to |1>A |0>B.

 

If the former occurs, then any subsequent measurement performed by Bob, in the same basis, will always return 1. If the latter occurs, (Alice measures 1) then Bob's measurement will return 0 with certainty. Thus, system B has been altered by Alice performing a local measurement on system A. This remains true even if the systems A and B are spatially separated. This is the foundation of the EPR paradox.

 

The outcome of Alice's measurement is random. Alice cannot decide which state to collapse the composite system into, and therefore cannot transmit information to Bob by acting on her system. Causality is thus preserved, in this particular scheme. For the general argument, see no-communication theorem.

 

Quantum entanglement - Wikipedia, the free encyclopedia

 

~modest

[A23]

On separability : it is proven that the cos(a-b) function could not be separated and hence should violate a certain inequality.

 

But it is obvious that :

 

[math] \cos(a-b)=\cos(a)\cos(b)+\sin(a)\sin(b)=\sum_i f_i(a)f_i(b)[/math]

 

and the latter can easily be put on the integral form :

 

[math] \cos(a-b)=\int F(a,s)F(b,s)\rho(s)ds [/math]

 

and hence there should exist no "unseparability" in this case, and hence no contradiction with causality ?

 

 

In fact in QM we could only say : we consider separately, or not...since we cannot make abstraction of the observer ?