Can something be in 2 places at the same time?

Originally posted by adam warlock
I think that you mean interference as the one seen in double slit like experiments where what we usually think of particles are shoot through the slits.

In this case it is also well known that even if you shoot one particle at a time, eventually the interference pattern shows up. And in this case either one assumes that individual pa is happening.

Have you ver read Feynman's QED The Strange Theory of Light and Matter?

I don't think self-intereference is so "spooky". In any case, I don't understand what you mean by a "statistical byproduct". Statistical byproduct of what?

On your latter question: yes, I have read it, though I get most of my knowledge of quantum physics from university courses.

Originally posted by KazetNagorra
I don't think self-intereference is so "spooky". In any case, I don't understand what you mean by a "statistical byproduct". Statistical byproduct of what?

On your latter question: yes, I have read it, though I get most of my knowledge of quantum physics from university courses.

I don't think self-intereference is so "spooky".
And I understand that some people may feel like that too, but self-interference is spooky at my eyes. Since this isn't a scientific matter I guess we'll have to live with diverging views.

In any case, I don't understand what you mean by a "statistical byproduct". Statistical byproduct of what?
I'm sure you're familiarized with Born's interpretation of the square of the wave function. So in the case of double slit like experiments, where we are just shooting a particle at a time, I'm saying that all we know is the individual particle wave function and that if we square the wave function and integrate we can calculate the probability of finding the particle in a given area of the target. Experimentally speaking: we shoot an electron at time to a double slit and place behind a target were we can record the position of arrival of any given electron. So every time we shoot an electron we get a spot in our target and after all electrons are shot we get the familiar interference pattern. But this interference pattern can be readily explained just by using Max Born's interpretation of the wave function and with the usual assumption that Quantum Mechanics is a linear theory.

On your latter question: yes, I have read it, though I get most of my knowledge of quantum physics from university courses.
I asked that because in it Feynman emphatically says that light is made up of photons and not waves nor some combination particle/wave. And he even says the experimental tests that were done to support that position. And it isn't a case of measuring the quality we were set up to measure, as it is said in the complementarity principle, because both the wave particle and corpuscle particle nature of light could be measured at the same time. And all that is measured is the the corpuscle nature. Things stopped being a philosophical debate and were solved in an experimental way. So that's why I said that I don't why still today you can see wrong things said in technical books. Back in the day what happened was that the measuring apparatus weren't as good as of today and the complementarity principle seemed to hold but nowadays people should really know better.
Another good resource to common fallacies in present presentations of Quantum Mechanics is http://www.amazon.com/Quantum-Mechanics-Development-Leslie-Ballentine/dp/9810241054/ref=sr_1_1?ie=UTF8&s=books&qid=1231593237&sr=1-1

And yes, I'm proponent of the shut up and calculate school of quantum mechanics. http://scitation.aip.org/journals/doc/PHTOAD-ft/vol_57/iss_5/10_1.shtml

Originally posted by adam warlock
[b]I don't think self-intereference is so "spooky".
And I understand that some people may feel like that too, but self-interference is spooky at my eyes. Since this isn't a scientific matter I guess we'll have to live with diverging views.

In any case, I don't understand what you mean by a "statistical byproduct". Statistical byproduct ...[text shortened]... anics. http://scitation.aip.org/journals/doc/PHTOAD-ft/vol_57/iss_5/10_1.shtml

I'm not claiming particles don't exist. I'm saying particles are waves. You can't cut an electron in two and get two electron waves, but it still acts like a wave. The old argument was over whether light was made out of particles or waves. It turns out photons (and all other matter) are composed of wave particles. Any particle will act like a wave on some small enough length scale.

Originally posted by KazetNagorra
I'm not claiming particles don't exist. I'm saying particles are waves. You can't cut an electron in two and get two electron waves, but it still acts like a wave. The old argument was over whether light was made out of particles or waves. It turns out photons (and all other matter) are composed of wave particles. Any particle will act like a wave on some small enough length scale.

Read more carefully what I wrote because I never said nor implied you said particles don't exist. I'd like to know where you got this idea from 😕

I used photons as an example cause that's what Feynman uses but all other particles are just particles too.

Originally posted by adam warlock
Read more carefully what I wrote because I never said nor implied you said particles don't exist. I'd like to know where you got this idea from 😕

I used photons as an example cause that's what Feynman uses but all other particles are just particles too.

Feynman argues the old particle/wave duality has been resolved, and matter in fact consists of particles. I'm saying the same thing.

Originally posted by KazetNagorra
Feynman argues the old particle/wave duality has been resolved, and matter in fact consists of particles. I'm saying the same thing.

I'm not trying to be argumentative just for the sake of being argumentative, but please explain how you are able to coherently adhere to this three quotes from you: "matter in fact consists of particles. I'm saying the same thing.", "I'm saying particles are waves.", "Any particle will act like a wave on some small enough length scale.", because the first one seems to be contradictory with the second and third one.

Originally posted by adam warlock
I'm not trying to be argumentative just for the sake of being argumentative, but please explain how you are able to coherently adhere to this three quotes from you: "matter in fact consists of particles. I'm saying the same thing.", "I'm saying particles are waves.", "Any particle will act like a wave on some small enough length scale.", because the first one seems to be contradictory with the second and third one.

I don't think they are contradictory. Matter consists of particles, which act like waves; but not continuum waves in the classical sense of the word. Basically, all I'm saying is that particles are not simply very small or even infinitely small "marbles", even though particles are in fact point particles. Confused? Welcome to quantum physics!

Originally posted by KazetNagorra
I don't think they are contradictory. Matter consists of particles, which act like waves; but not continuum waves in the classical sense of the word. Basically, all I'm saying is that particles are not simply very small or even infinitely small "marbles", even though particles are in fact point particles. Confused? Welcome to quantum physics!

Basically, all I'm saying is that particles are not simply very small or even infinitely small "marbles", even though particles are in fact point particles.
I don't even know what to do with this sentence...

Confused? Welcome to quantum physics!
No. Welcome to KazatNagorra's version of quantum physics.

What I mean is this. Particles are point particles in the sense that they have no degrees of freedom attributed to internal rotation and vibration. But they are not simply point particles because they are described by a wavefunction and show wave-like effects like interference and the Heisenberg uncertainty principle.

Originally posted by KazetNagorra
What I mean is this. Particles are point particles in the sense that they have no degrees of freedom attributed to internal rotation and vibration. But they are not simply point particles because they are described by a wavefunction and show wave-like effects like interference and the Heisenberg uncertainty principle.

But they are not simply point particles because they are described by a wavefunction and show wave-like effects like interference and the Heisenberg uncertainty principle.
Yes particles do show wave like effects but to explain them one doesn't need to resort to wave-like explanations.And the Heisenberg uncertainty principle (it really is a theorem!!!) in its most general form has nothing to do with wave behaviour. It is just a consequence of the fact of the operators which represent certain dynamical quantities don't commutate in a given representation.

Originally posted by adam warlock
[b]But they are not simply point particles because they are described by a wavefunction and show wave-like effects like interference and the Heisenberg uncertainty principle.
Yes particles do show wave like effects but to explain them one doesn't need to resort to wave-like explanations.And the Heisenberg uncertainty principle (it really is ...[text shortened]... rators which represent certain dynamical quantities don't commutate in a given representation.[/b]

I don't understand how you can avoid wave-like explanations of the behaviour of matter. I don't see why you would want to, anyway.

The Heisenberg uncertainty principle can be taken as an axiom or derived from the axiomatic definition of momentum, in any case it's not really relevant to our discussion.