Heisenberg Uncertainty Principle?

Question

So, the Heisenberg Uncertainty Principle states that the location and velocity of an electron can never be determined simultaneously, correct? What if an atom and the surrounding electrons were to be at absolute zero, or 0 Kelvins? Wouldn't that theoretically halt the electron and draw it into the nucleus of the atom, thus making it possible to determine both the location and velocity of the electron?

Please tell me if I am onto something or if I just completely misunderstand all physics.

Answer 1

absolute zero is imposable to reach for that exact reason

Answer 2

And now for something completely different...

First, you're thinking of "velocity" and "position" in the classicaly sense, as an approximation of either. We can approximate our own velocity and position all day long, but we are neither point-particles nor waveforms. An electron is both. Calculate it's exact position or velocity and it is considered as a point-particle, not because it is one, but because you've turned a function into a datapoint. The underlying principles in Quantum Mechanics point out that electrons are both point-particles (when data mined) and wave functions (in terms of exact position. Why? Because until you nail it down, that electron has a chance, no matter how slim, of actually being on the other side of the Universe right now. This is why we come to the myriad conclusions of "tunneling" and "evaporation" from black holes. Although the gravity of a blackhole is enough to trap even light, at some point the wave function of an electron finally accumulates a high enough chance that the electron is outside of the blackhole and poof, evaporation. Or so our various theories seem to point out.

Now, how does this relate to your question? Simple, even if it were possible to reach absolute zero, you could not force the wave functions to remain stable. There will be a chance, regardless of how finitely small, that electrons jump the bonds of icyness, and beat the odds, so to speak. There are even theories that this is how universes are born out of "nothing", out of primordial cold. A chain reaction of electron shifting at absolute zero could cause gravitational effects that we cannot fathom yet.

Basically, if you want the answer to this, wait a few billion years for the big chill. We'll see whether absolute zero can hold that waveform down.

Answer 3

Not quite the same thing. A chemical bond vibrates, and you'd think if you approached absolute zero it would stop completely, but in fact by the rules of theoretical chemistry it has a minimum vibration level which is NOT zero.

Plus, electron motion can't be slowed by drawing heat from the system. If you heat matter high enough the electrons will draw energy from the heat and jump to a new energy state, one that eventually leaves the nucleus behind. You'll get PLASMA: matter where nuclei are dissociated from the electrons and everything bounces around like a very, very hot gas. Light (or even higher electromagnetic energy) is routinely given off from plasmas as electrons momentarily jump to lower states nearer a nucleus.

But it doesn't work in reverse. Cool something and the energy comes off the bond vibrations of a solid. The electrons are still happily "moving" in the empty spaces between the nuclei.

Ideas of electrons as "particles" orbiting a nucleus like it's a sun are a "classical" view of atomic physics. Think about it. If an electron were like that, the fact of a charge spinning in a circle would induce a radio wave, and energy would come out of the electron and it would orbit lower and lower until it fell in the nucleus. It would make sense, it is something tangible, but we know electrons aren't destroyed like that. In the new quantum physics, which explains things better even though the results go against our intuition, an electron is a sustained probability-wave that can only occupy certain energy-levels, including a minimum one.

The reason you can't tell both the position and the momentum of an electron with good accuracy at the same time is: electrons are invisible. How are you going to tell where it is? You have to "observe" it, some sort of action where you shine radiation on it. If you shine a light on me, I'm huge (TOO huge!), I'm not affected by the momentum of light photons, so you have a very good idea of my position and momentum. But an electron is small, it's going to be deflected by your "light probes." Any radiation you get reflected that tells you something about the electron's position is going to affect its momentum. You've fixed the electron's position at that moment, but you can't tell with accuracy how fast it's moving. Likewise there are electromagnetic probes you can do to tell an electron's motion, but you will lose information about its position as electrons are deflected around. No amount of instrumental refinement is going to change the fact you affect very small quantum particles with your probing, so Heisenberg's Uncertainty principle in math is:

delta-x * delta-p = a constant

where x is position, p is momentum, the Greek letter capital-delta is a sign for "change in ___".

It becomes meaningless to treat electrons as billiard-balls. They are smeared-out probability waves that might occupy a range of positions and momentums.

That's only the beginning of goofy results from quantum physics.

Answer 4

As per uncertainty principle
∆x * ∆v = h/m

For an electron h/m = 7 cm^2/s.

∆x * ∆v > 7

Consider an electron with in an atom, the diameter of which is 10^ (-8) cm.

The electron can be any where with in this distance.

The ∆v ;( note that this is not the velocity of electron, but the uncertainty of the velocity of electron) is nearly 1,000,000,000 cm.

Therefore,the concepts of an electron in an atom, an electron path of transition from one energy state to another are meaningless.

In short, an atomic electron is quite different from an ordinary particle.


But in experiments like Wilson cloud chamber we come across ∆x = 1mm, and hence
∆v = 7 meter /s. But compared to the high speed of the electrons say 1000 meter/s this uncertainty of 7m/s can be neglected.

Conclusion; velocities of electrons within an atom is meaningless.

Answer 5

The idea behind the uncertainty principle is a simple one - velocity is measured by how fast a particle moves between two points, but position is measured at a point, so either you have simultaneous measurement of the position and you can't find the velocity, or you have a measure of how fast it's moving, and you don't know exactly where it is. But if you define it to be stationary, than you know the position 100% because it's not moving - it has a velocity of 0 relative to you. That's just assuming it won't ever move again, which theoretically could happen at 0 K. But if you define anything not to be moving, then you do know it's position 100% - it's just when the velocity isn't zero that you have uncertainty.

Answer 6

You misunderstood the temperature. Temperature doesn't freeze electrons but molecules. Therefore at zero Kelvin the molecules are still, however electrons still run around nucleus the same way as at any other temperature. This is one thing.
Heisenberg principle is entirely different story. It is valid generally for all matter starting from very small like electron around nucleus or free electron up to very large body like the Earth and Moon.
Therefore two things temperature and Heisenberg principle are orthogonal (not related).

Answer 7

You are describing something that is sometimes called "zero point energy".

Because of Heisenberg's uncertainty principle, even at absolute zero, there is some quantum movement of subatomic particles.

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In physics, the zero-point energy is the lowest possible energy that a quantum mechanical physical system may possess and is the energy of the ground state of the system. The concept of zero-point energy was proposed by Albert Einstein and Otto Stern in 1913, which they originally called "residual energy" or Nullpunktsenergie. All quantum mechanical systems have a zero point energy. The term arises commonly in reference to the ground state of the quantum harmonic oscillator and its null oscillations. In quantum field theory, it is a synonym for the vacuum energy, an amount of energy associated with the vacuum of empty space. In cosmology, the vacuum energy is taken to be the origin of the cosmological constant. Experimentally, the zero-point energy of the vacuum leads directly to the Casimir effect, and is directly observable in nanoscale devices.

Because zero point energy is the lowest possible energy a system can have, this energy cannot be removed from the system. A related term is zero-point field, which is the lowest energy state of a field, i.e. its ground state, which is non zero.[1]

Despite the definition, the concept of zero-point energy, and the hint of a possibility of extracting "free energy" from the vacuum, has attracted the attention of amateur inventors. Numerous perpetual motion and other pseudoscientific devices, often called free energy devices, exploiting the idea, have been proposed. As a result of this activity, and its intriguing theoretical explanation, it has taken on a life of its own in popular culture, appearing in science fiction books, games and movies.....

Answer 8

thats a cool question. let me state first that i have no clue whatsoever. here are my random thoughts

It is impossible to reach absolute 0. perhaps the principle does not apply for this. It's like a paradox almost.
My friend (who's much smarter than me) says that the question you're asking is almost like asking "Can god make something so heavy that he cannot lift it himself?"

hopefully someone else answers this questoin for you. but i have to commend on you on coming up with this question

Answer 9

absolute zero is kinda of like the speed of light. you can get very very close and see alot of very strange things from getting that close, but it cant be attained.