[jeffreyH]

You wanted an experiment where the slits were smaller than the projectiles. I gave you that. And now you complain! There is no pleasing some people.

[alancalverd]

Eddington pointed out about 100 years ago that if a student of physics fell through an intact floor and rematerialised in the room below, he would not consider it a miracle but merely one of the less probable solutions to a multivariable equation.

Alas, this obvious and profound observation seems not to have reached the elementary school syllabus yet, though it is plain that the regular contributors here understand it.  What baffles me is why those who don't, frequently accuse us of sharing their delusions.

[Bored chemist]

You and I both know there is a certain number of atoms always anchored to spacetime.

Nobody knows that.
You imagine it and we listen fairly politely (then we go away and laugh behind your back).

In order to provide us with more comedy material, perhaps you would like to tell us what evidence you have for this... unorthodox... opinion?

[geordief]

Eddington pointed out about 100 years ago that if a student of physics fell through an intact floor and rematerialised in the room below, he would not consider it a miracle but merely one of the less probable solutions to a multivariable equation.

Alas, this obvious and profound observation seems not to have reached the elementary school syllabus yet, though it is plain that the regular contributors here understand it.  What baffles me is why those who don't, frequently accuse us of sharing their delusions.

Is there a (exponentially remote) chance that the  student rematerializes slightly lacking in physical integrity  ?

Say ,for example with a finger slightly longer?

Are there some scenarios that might be impossible no matter how remotely possible?

Edit : is it a reasonable observation that any body, alive or inanimate , goes through spacetime "shedding" countless parts of itself from one moment to the next as  "quantum components"  disappear  for their own quantum reasons leaving the persisting macro body to sail on in its new overall state regardless of what is happening to that body at the macro level?

[alancalverd]

Anyone who remembers "The Fly" will recall the problems of reassembling atoms in their original order. Indeed the fact that a double slit transfer redistributes stuff into a transform of the slit convoluted with the incident beam, suggests that the probability of recombination in a recpognisable order is even less than Eddington implied. But that classic film ignored the fundamental conservation of matter - the fly could not be more massive than the original, nor could Bart Simpson, in the famous spoof remake, get any smaller.   So no long finger, unless some orther bit is sacrificed..

[geordief]

Anyone who remembers "The Fly" will recall the problems of reassembling atoms in their original order. Indeed the fact that a double slit transfer redistributes stuff into a transform of the slit convoluted with the incident beam, suggests that the probability of recombination in a recpognisable order is even less than Eddington implied. But that classic film ignored the fundamental conservation of matter - the fly could not be more massive than the original, nor could Bart Simpson, in the famous spoof remake, get any smaller.   So no long finger, unless some orther bit is sacrificed..

Perhaps just musing ,but is there a definition of "order" in the way you have just used it that applies to quantum mechanics in a way that is different (or the same as) to the way it is used in classical mechanics?

I imagine there might be spatial order and temporal order -or is there a fusion between the two?

[alancalverd]

Mitotic  replication of DNA depends on a rigid spatial order derived entirely from modelled adequately by quantum mechanics.

[pittsburghjoe (OP)]

Observation is a property of spacetime. Stuff on our scale has never turned into a matter wave. There is a divide between spacetime and qm waves, apparently it's the number of atoms involved.

[Bored chemist]

Observation is a property of spacetime. Stuff on our scale has never turned into a matter wave. There is a divide between spacetime and qm waves, apparently it's the number of atoms involved.

Is that, by any chance, an attempt at proof by loud assertion?
Or maybe you have... you know.. maybe... some evidence?

[pittsburghjoe (OP)]

If matter waves can pass a slit smaller than the object they represent ..they are not physical they are waves of variables/information. The uncertainty principle is uncertain(fuzzy) because the objects has only been granted partial spacetime. Observation/Spacetime is what makes matter waves swap to physical objects. QM waves don't have time, gravity, or 3D. If QM waves are information the divide is how much information an object contains.

[Bored chemist]

If matter waves can pass a slit smaller than the object they represent ..they are not physical they are waves of variables/information. The uncertainty principle is uncertain(fuzzy) because the objects has only been granted partial spacetime. Observation/Spacetime is what makes matter waves swap to physical objects. QM waves don't have time, gravity, or 3D. If QM waves are information the divide is how much information an object contains.

Pardon?

"If matter waves can pass a slit smaller than the object they represent ."...
  then sieves don't work.
But, they do.

[Colin2B]

Observation/Spacetime is what makes matter waves swap to physical objects. QM waves don't have time, gravity, or 3D. If QM waves are information the divide is how much information an object contains.

I did ask you to complywith our request not to post new theory in main physics section.
On this occasion we will move your thread, we probably wont be a generous next time.

[pittsburghjoe (OP)]

"If matter waves can pass a slit smaller than the object they represent ."...
  then sieves don't work.
But, they do.

Atoms bouncing off each other collapses their waves.

[alancalverd]

Mesoscopic objects obey newtonian mechanics because their summed probability wavefunction does not extend far beyond the classical object, as a fraction of the classical radius.

Imagine a hydrogen atom. Its effective radius is pretty much determined by Heisenberg. Now imagine a huge ball of frozen hydrogen. The indeterminacy of its radius is still that of one atom at the surface, because all the other particles' "fuzz balls" are random and thus sum to the classical volume of the object. 

[pittsburghjoe (OP)]

The point of this thread is for objects larger than a single atom that can still swap to matter waves.

[Colin2B]

The point of this thread is for objects larger than a single atom that can still swap to matter waves.

They don’t swap. You are still trying to use your misunderstanding of behaviour models.
They don’t behave the way you think they do.

Atoms bouncing off each other collapses their waves.

Results will differ.
Be specific. Which atoms, which specific wave equations, what conditions are you assuming for the collisions.

[alancalverd]

There is no swapping. Mesoscopic objects just behave like VERY large numbers of atoms.

[Bored chemist]

Atoms bouncing off each other collapses their waves.

That doesn't even parse.

There's something you need to understand.
It has already been pointed out, but you have missed it.
Imagine making a grating with a gap between the "wires" that's a little bit smaller than the molecules you are using.

Classically, no particles will get through it.

QM and the uncertainty principle means that a few will. They will quantum tunnel through.

Here's the bit you don't understand.
If you take the grating and hammer it until the wires are squashed flat and there are no gaps so it becomes a metal foil then repeat the experiment...

More atoms will get through the foil even though it no longer has gaps in it. (In some circumstances)

Do you understand that?
 The probability of tunneling is related to the thickness of the barrier.
Hammering it flat makes it thinner and so it's more likely that atoms will tunnel through.

Obviously, with the grating destroyed, there's no diffraction pattern.

And the (smaller number of) atoms that went through the grating before  you hammered it flat would also show no clear diffraction pattern because, at that level, the atoms are not going through the gaps.

It's the same , classically, with light
You know the equation
d sin θ =  λ
Where lambda is the wavelength and d is the spacing
you can rewrite that as

sin θ =  λ /d
Well, if you make d smaller than lambda then you are trying to find an angle where sin theta is more than 1, but that's impossible.

Diffraction doesn't work if the wavelength is bigger  than the grating's spacing.
And, returning to QM, a particle can't be "smaller" than the associated wavelength.

So, you can't sensibly calculate a diffraction pattern for the the experiment you have proposed.

So there's no way to say whether the particles would follow it or not.
And, as has been pointed out before, you also can't measure it because, in practice big  things don't go through small holes.

[pittsburghjoe (OP)]

Why can't you grasp that tunneling is even more evidence that matter waves are not physical?

[chiralSPO]

Why can't you grasp that tunneling is even more evidence that matter waves are not physical?

And why can't you grasp that tunneling (and uncertainty, and wave-particle duality, and zero point energy, and so on) are only indications that our macroscopic scale experience has little use on the molecular scale? It's not that the atoms and molecules are somehow non-physical (whatever that means), it's that the physics is different from what you think it should be!