Heisenberg's Uncertainity Principle?

Question

Heisenberg's Uncertainty Principle says that we cannot determine both the exact position and velocity of a particle at the same. However, can't the particle be brought to a stop and thus, the principle be violated? Or would it break out due to something like Pauli's exclusion principle? How does it work? What if a particle temperature is reduced to an absolute zero? Won't it be totally out of energy??

Answer 1

sounds like you're trying to use a quantum phenomenon on a classical particle.

it's just not like stopping a ball...

it's not that you cant 'see' where it it, it's that its position is never a clearly definable point

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it is also NOT because "you cant get all the energy out, so it still moves" and it's even more fundamental than bouncing photons off it. that's just an analogy

all the information you can know about a particle is in its wavefunction. in the case here, you can see that by restricting it's position (trying to 'see' it, reducing L) you are actually increasing its energy. there's no way around it
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/schr.html#c4


that, as strange as it may seem, is nature

Answer 2

A few points about Heisenberg's Uncertainty Principle:

1. It is really only apparent with very very very small things (think sub-atomic level and smaller).

2. If you know a sub-atomic particle has a velocity of zero, how do you know where it is? If you bounce a photon off of it to "see" it and determine its position, the photon will transfer some of its energy (the change in velocity to "bounce" will require a force to act on it from the particle) to the particle. This will mean that at a particular instance in time, you will know where it is / was. BUT the act of measuring its position will apply a force resulting in it having a velocity that cannot be determined with complete accuracy.

On the subject of temperature and energy:
Things with a temperature of absolute zero can still have energy relative to other objects around them (eg they may have kinetic energy, just not heat energy). Think of it this way, if you drop a cannon ball with a temperature of absolute zero (assuming this temperature was possible) on your toe, it would still hurt due to the transfer of energy from the ball to your toe.

Answer 3

The Heisenberg uncertainty principle restated is really a principle of underterminancy. Since it take time to measure a moving mass it is evident that instantaneous time cannot be exactly determined since Time is non- linear.
Since velocity is the ratio of the distance traveled by the mass,velocity cannot be measured instantaneously .It can only be calculated.
What can be measured is mass motion from a zero point frame of reference(rest frame) to an end point frame of reference. The difference between those two points is the motion that occurred in between is space. If we measure the time between those two point will have the total travel time of the mass in motion.
The Ratio of a set space traveled to the average time travelled is an average velocity. Therefore we can only measured and determine average velocity and not the instantaneous velocity that the mass travelled in the space of those two point.

Now when a mass is given power to move the energy of motion can be calculated it we know how much mass loss occurred during the motion of the mass as it reached its final velocity.Momentum is always equal to the motional energy of a mass divided by the final velocity. Howver since we cannot measure the final velocity it can only calculated by knowing the average velocity.
Momentum involves a mass that changes with velocity multiplied by a changing velocity. Hence Heisenberg's Principle says that we cannot measure and know both at the same time at a particular location of space.

All micromasses in the Universe are in continual motion ,nothing in the Universe comes to a halt. The universe is a dynamic system. Particles like electrons and protons are mass structures that can gain and lose mass as a function of temperature energy.
When an atom is frozen at the near absolute zero temperature, it does not mean that its energy structural content is zero. It would still exist as an atom.
The absolute temperature cannot be reached because there is always a residual temperature energy in the Universe of 2.7K.

The Pauli Exclusion principle is a different definition. It just indicates that two equal mass structure cannot displace the same space at the same time.Hence theorethically if atoms in a material where at absolute zero temperature Energy, they would be packed at a limit and cannot displace any other space but their own. Hence Pauli exclusion principle applies.

The electron inside the atom at absolute zero would then be moving very close to the speed of light and the atom would occuppy minimun volume and the electron mass would also be reduced to a minimum.This indicated that at the zero degree absolute temperature energy, Atoms reach their minimum mass levels.

When in a lab a mass structure is brought to reach near zero K, the mass(atoms) in the material still has kinetic energy relative to the sun,since its also moving at the same speed as the earth that its sitting on.

Hope this answers all the points you made in your question.

Answer 4

No, an electron (for example) cannot simply be brought to a stop. The uncertainty principle actually disallows this. This is part of why we talk about electron clouds rather than electron orbits.

At absolute zero, there is still a remnant vibration (the zero point energy) that is primarily due to the uncertainty principle.

Answer 5

If you stop the particle, you will not know at all its position

Answer 6

I thought that we (mankind) were already making dark matter, I believe, in which case we know the speed and position of the dark matter at all times? Do we not?

Answer 7

It impossible to achieve absolute zero because there is no truly isolated space in the universe.