The Heisenberg Uncertainty Principle

[Rade]

I have what is most likely a simple minded question. Suppose it was possible to build a quantum machine that could measure (observe) itself internally for both position and momentum at different times. In this case, would such an entity also be able to measure both position and momentum simultaneously and thus violate the HUP ? It seems to me that all historical thinking on the HUP deals with the predicted outcome of an "external" observer viewing some object, and not an "internal" observer viewing itself...but I may be incorrect, that is why I ask.

 

[cozzmikjoker]

I have what is most likely a simple minded question. Suppose it was possible to build a quantum machine that could measure (observe) itself internally for both position and momentum at different times. In this case, would such an entity also be able to measure both position and momentum simultaneously and thus violate the HUP ? It seems to me that all historical thinking on the HUP deals with the predicted outcome of an "external" observer viewing some object, and not an "internal" observer viewing itself...but I may be incorrect, that is why I ask.

Seeing through the eyes of a quantum particle. I've wondered what that would be like for a long time.
Would it be like determining the state of a quantum cat? Maybe it would see things so weird, the information would be lost in translation. What do you think?

 

[invincible_me]

1) But what if we invented new scanning systems which wouldn't cause the same problem, that is, without probing particles with other particles?
...the major probs of misconception are, we try to see things much in same respective we are thriving in...imaginination...scanning is to get the information of a subject ..which are then trasformed into digital signals...and are intepreted on other end by other hardware<<like comp>>..now the best way to get information of an object is through light...the same way our vision works...but when we goo deep in side a new world...i.e. when we are somewhere near atomic dimensions ...the concept of measuring ...throu light,,laser,,magnetic fluctu,,potential reader..all precise ways are one or other for of energyand if they will interact with that small masss object..will make a good mount of difference...i.e. i would measure a jet liner with a object whose lenth relativly measurable to it...for eg..1 jet liner = 2 big bus...not like 1 jet liner = 1000000000000 ants...so if we wana measure position of elctron we want a light beam of small wavelength...so we get the position...but small wavelenth light is of high energy and would add up k.e...thus change its velocity...so ne way we could measure it prisicely...

<<<<ABSOLUTE ZERO>>>>ACC to me in absolute zero we will absorb all of its energy and will end up in neutral atom...obviously when we ccool objects their energy is absorbed there by reducing its vibration...

 

[werner heisenberg]

Tthe matter is not that if we want to measure the exact velocity we must accept an inexact position, the problem is that the electron BECOMES bigger. (as James R put it *it actually makes little sense to talk about exact positions or momenta*)

What is very interesting in this subject is Bohr's complementarity principle. He claimed in it that the reason of the uncertainty are the choice of one of the side of the wave-particle duality to measure the fenomenon.
Neither position and velocity nor energy and time can be measured with arbitrary precision. For Bohr that proved his point of view. A particle is often decrived in terms of its velocity and energy while a wave often is descrived with the space-time parameters, that is, position and time. So when you choose (and you have to) to measure either the particle side or the wave side you must accept some uncertainty in from the side you have not choosen.

 

[cozzmikjoker]

Dr. kaku will be on Art Bell Sunday Jan. 22

What can I say but IT'S ABOUT TIME!
I hope to call in and nail doc about his claims that a black hole cannot be created without the power of the sun.
Cern just might be getting there.

Condoloences to Art on the recent tragedy but glad to see him come back. Especially with Dr. Kaku now!

 

[Manchot]

Hey, here's something that I'm wondering. Say you measure the position of a particle. The particle's wavefunction then collapses to that position eigenstate, temporarily forming a delta function with a standard deviation of zero. Doesn't this violate the uncertainty principle? Or, since the particle's momentum's standard deviation is then infinite, does the infinity "cancel" out the zero?

 

[profilexis]

I think that when any particle reaches 0° K, this happens:
the superstring creating the particular particle stops vibrating, therefore forms an infinite line and the particle created by these vibrations ceases to exist.

 

[DaveC426913]

Correct me if I'm wrong, but here is an (admittedly simplistic) rationalization of why you can't cool anything to absolute zero: *how* would you do it?

A particle can only lose heat by transferring its kinetic energy to another particle (since that's what heat is). That energy can only be transferred in discrete quanta. Once you have an electron at its lowest level, it is still bouncing off the walls of your container - albeit with little energy. Since any counter-force is also quantized, there just isn't any way to bleed that last little bit of energy off the particle.

 

[cozzmikjoker]

"A particle can only lose heat by transferring its kinetic energy to another particle (since that's what heat is)."

So does this mean if a particle could wander like into a field of nothing but dark matter or some kind of vacuum, then it could not lose its heat? Or would the argument be that "virtual particles" are everywhere, so there would always be particles around to transfer heat to...


"Since any counter-force is also quantized, there just isn't any way to bleed that last little bit of energy off the particle."

The movie "Hard To Kill" comes to mind.

 

[Mace Williams]

Scientists and engineers are trying to figure out how to build Quantum Computers. If I understand correctly, one intriguing by product of that effort is observing pairs of photons 'entangling' with each other and thereafter whatever happens to the one seems to simultaneously happen in the other, no matter their subsequent position or state relative to each other.

Perhaps this suggests future applications where velocity can be measured in one entangled photon and position in the other. But then, wouldn't the phenomena that occurs during the entangling permanently skew the data?

The overall problem with this whole line of questioning is the 'fact' we'll eventually be forced to face: everything is happening everywhere all at once, and everything affects everything else. Eternity is now. Everywhere is here.