The de Broglie wavelength is given by h/p. where h is Planck's Constant, and p the momentum. This is true for electromagnetic waves as well as matter waves. So when you walk, you have a wavelength. You can be described as a wave as according to your momentum = mass x velocity. Diffraction is the spreading out of a wave, so to speak, when it passes through a properly sized aperture, like this. And like this So here is the problem. Is it possible for a large object, like a person, to diffract by walking through a doorway slowly enough? By moving very very slowly, we can make the momentum p as small as we want. In turn we can adjust our wavelength to match the size of the aperture - the doorway - which should make us diffract, or spread out like the white light above. What would it mean for a massive object to diffract? It would mean existing in more than one place, for one. Would we dematerialize at the atomic level? Hint: Planck's constant has a value of 6.62607004 × 10-34 m2 kg / s So your momentum would have to be on the same order of magnitude as Planck's constant, to have a wavelength of about 1 meter - the width of a door. How fast would you be moving to have a momentum equal to Planck's constant, yielding a wavelength of one meter, exactly.
Yes, they do, but they typically average out to classical expectations. In fact this is a core principle of QM. It must translate to the macroscopic world. In fact, that is at the core of the Schrodinger's cat paradox! That is the point. This particular problem devised by yours truly, addresses this concept head on. It first occurred to me during a physics lecture and ended up ruining an lecture period. Suddenly I was filled with dread fear of doorways. At any moment I might be deconstructed and scattered to the winds.
I suppose if we break the Macro down to the Micro/Quantum level your point would be valid, but it would be for all things. Quantum theory however, was developed explicitly to NOT deal with macro dynamics.
Wrong. It must be consistent with classical mechanics. This is not my opinion it is fact. It is a requirement of the theory itself. Why do you argue when you have never formally studied the subject? It is arrogant and foolish. Jerking off on the internet does not make you an expert.
If University training is a requirement to comprehend advanced scientific theory then I am indeed deficient. However I said nothing of being consistent with classic physics I simply stated quantum physics and theory were developed to deal with the aspects it cannot.
If you simply apply the formula in the opening post to your whole body, you get a maximum speed of about 10^-35 m/s for diffraction to occur. That's a speed of less than the diameter of a nucleus in a trillion years. Phew, there's no need to worry after all. Nobody is able to stand that perfectly still. Of course, that calculation is completely unrelated to reality. While quantum mechanics applies to everything, including your body, it doesn't apply to your body as a whole, but to all constituent parts of your body, the doorway, and whatever else is involved. The de Broglie wavelength is useful when it comes to describing the motion of free particles. If the particles in your body were free to move, however, you would have disintegrated already. There are countless bonds between them, holding you together, preventing you from diffracting all over the place and allowing you to walk, breathe, think and more.
The one point you missed: Thermal energy. Just the motion of molecules in the body due to thermal energy causes the velocity limit to be exceeded. There are reason why it fails at the macroscopic scale, but not because QM is violated in some fashion. QM is and must be consistent with classical mechanics. What happens at temperatures near absolute zero is more interesting. This isn't the first time I've seen this solution in regards to the velocity of the body as a whole and the time involved. While in principle we should see a QM effect at the macroscopic scale, the universe isn't old enough for it to be possible. Funny how sometimes eternity is the only problem with running an experiment. Making door frames safe again!
PS. Near absolute zero, the body could still be treated as a wave having a de Broglie wavelength. So we would still expect a sinusoidal distribution of many bodies as such, if projected onto a target. We would still expect a diffraction pattern... given a few quadrillion or quintillion years to run the experiment!
Meant to add this: Likewise, if we allow photons to pass through a property sized slit, one at a time, we get a diffraction pattern, but only after many photons are incident on the target. Each photon strikes the target as a particle. But how it gets there, is spooky. It must be interfering with itself in multiple paths! So it doesn't take just one path. It takes all paths!!! The wavelike nature is manifest as a diffraction pattern after many photons have struck the target. A large body moving slowly enough through an aperture at near absolute zero, should act the same way. What is true for photons is true for matter waves. But as indicated, it would require a million-trillion years to get the results.
