Are we waves ?

[King E]

Quantum particles are waves. We are made up of them. So does that makes us waves?

Sorry for such a stupid childish question.

Edited May 28, 2020 by King E

[Halc]

19 minutes ago, King E said:

Quantum particles are waves.

No, they're not. If measured in the right way, they share some properties with waves, but they also behave in ways that waves definitely do not.

We are made up of them. So does that makes us waves?

This doesn't follow.  Just because I'm made up of cells doesn't imply that I am a cell.

[MigL]

Some of our properties ( and of our constituents ) can be described by a wave model ( and associated probability distributions ).

[QuantumT]

If our brain can be described as an instrument (it certainly bares the trademarks of one), then the wave/particles of our bodies are in a constant collapsed state, because the brain, as a detector, is always turned on.

Just my two cents.

[King E]

22 minutes ago, Halc said:

No, they're not. If measured in the right way, they share some properties with waves, but they also behave in ways that waves definitely do not.

 

This doesn't follow.  Just because I'm made up of cells doesn't imply that I am a cell.

Give an example that quantum particles behave in ways that waves definitely do not. Quantum particles always behave in the way waves do

[swansont]

1 minute ago, QuantumT said:

If our brain can be described as an instrument (it certainly bares the trademarks of one), then the wave/particles of our bodies are in a constant collapsed state, because the brain, as a detector, is always turned on.

Just my two cents.

There are two wave behaviors to consider: the wave function, from Schrödinger’s equation, and the matter-wave behavior from deBroglie’s equation. The two are not identical. The “collapsed state” issue applies to the former, not the latter. IOW, you will still have wave behavior even in a single quantum state 

1 minute ago, King E said:

Give an example that quantum particles behave in ways that waves definitely do not. Quantum particles always behave in the way waves do

No, I disagree. Quantum particles have quantized energy and a localized interaction region, which are not wave behaviors.

[King E]

4 minutes ago, swansont said:

There are two wave behaviors to consider: the wave function, from Schrödinger’s equation, and the matter-wave behavior from deBroglie’s equation. The two are not identical. The “collapsed state” issue applies to the former, not the latter. IOW, you will still have wave behavior even in a single quantum state 

No, I disagree. Quantum particles have quantized energy and a localized interaction region, which are not wave behaviors.

So you mean they have mass?

[swansont]

Just now, King E said:

So you mean they have mass?

Many have mass, sure, but quantized energy and localized interaction do not require mass. Photons exhibit these behaviors as well.

[King E]

2 minutes ago, swansont said:

Many have mass, sure, but quantized energy and localized interaction do not require mass. Photons exhibit these behaviors as well.

OK. what is the difference between particle and wave?

[MigL]

A classical particle can be localized, a wave cannot.
Even an elephant has a deBroglie wavelength.
It is exceedingly small, because it is equivalent to h/(m*v), and as such we don't even consider it.

[QuantumT]

20 minutes ago, swansont said:

IOW, you will still have wave behavior even in a single quantum state 

So, you're saying that (collapsed) particles display wave behavior? Where do we observe that?

[swansont]

19 minutes ago, QuantumT said:

So, you're saying that (collapsed) particles display wave behavior? Where do we observe that?

Send a particle through a double slit, and it will interfere. Through a single slit it will diffract.

[studiot]

1 hour ago, Halc said:

No, they're not. If measured in the right way, they share some properties with waves, but they also behave in ways that waves definitely do not.

 

This doesn't follow.  Just because I'm made up of cells doesn't imply that I am a cell.

Good thinking +1

1 hour ago, King E said:

Give an example that quantum particles behave in ways that waves definitely do not. Quantum particles always behave in the way waves do

Quantum tunnelling.

For good measure here is an answer to the obverse question. "Give an example that quantum particles behave in ways that classical particles definitely do not."

Anomalous Quantum Hall Effect.

Edited May 28, 2020 by studiot

[King E]

38 minutes ago, swansont said:

Send a particle through a double slit, and it will interfere. Through a single slit it will diffract.

Quantum particles are not little spherical balls. They are just localized waves. At all times, their behaviour is described by a wave function. If quantum particles are sent through double slit, we obtain an interference pattern which tells that they are waves. If the particles are sent through single slit, a non interference pattern is obtained. But the non interference pattern does not tell the opposite of what interference pattern tells. The non interference pattern does not mean particle. It just means we are inconclusive about waviness. So quantum particles are waves but their tininess can give them some semblance of location. In general double slit experiment is not a wave test or particle test. Its a 'which way' test. The point is to test which way something went. For example, did a photon went through slit A, slit B or both slits simultaneously.

[Halc]

30 minutes ago, King E said:

Quantum particles are not little spherical balls.

Indeed, and nobody is claiming they are, although your choice of the term 'particles' carries a bit of that connotation.

Quote

If quantum particles are sent through double slit, we obtain an interference pattern

If one quantum particle is sent through a double slit, we observe one point (where it is measured), something a wave sent through the slits will not do.  The probability curve of where that measurement will be taken is what resembles an interference pattern.

No wave exhibits quantized behavior like that.  Sound (an example of an actual wave) passed through slits will be measured in all locations, not just one, and its intensity (yes, an interference pattern) will drop off as a function of distance from source to measurement.  A photon or electron exhibits no similar behavior, being measured at full mass/energy at the measurement location and not measured at all at any other location. Sound (or any other real wave) ceases to propagate if you take away its medium.  There is no medium for a photon or molecule passing through the slits, and yet they still arrive at the measurement location.

Edited May 28, 2020 by Halc

[swansont]

41 minutes ago, King E said:

Quantum particles are not little spherical balls. They are just localized waves.

Waves are localized?

Quote

At all times, their behaviour is described by a wave function. If quantum particles are sent through double slit, we obtain an interference pattern which tells that they are waves. If the particles are sent through single slit, a non interference pattern is obtained. But the non interference pattern does not tell the opposite of what interference pattern tells.

I never claimed it was “opposite”

 

Quote

The non interference pattern does not mean particle. It just means we are inconclusive about waviness. So quantum particles are waves but their tininess can give them some semblance of location. In general double slit experiment is not a wave test or particle test. Its a 'which way' test. The point is to test which way something went. For example, did a photon went through slit A, slit B or both slits simultaneously.

It’s a wave test, to be sure. Classical particles do not interfere.

Photons undergo interactions with only one atom, even though its wavelength is much larger than the atom, and other atoms are around. That’s not how waves behave.

 

[Mordred]

Good discussion on wave particle duality. The main point is all particles exhibits point like (particle like) and wavelike characteristics.

[StringJunky]

There are no particles, there are only fields - Art Hobson. 

https://arxiv.org/ftp/arxiv/papers/1204/1204.4616.pdf

Edited May 28, 2020 by StringJunky

[Strange]

2 hours ago, StringJunky said:

There are no particles, there are only fields - Art Hobson. 

https://arxiv.org/ftp/arxiv/papers/1204/1204.4616.pdf

One lesson that one can take from that article is that waves/particle/fields are not what these thing are, they are just how we describe them. 

The map, not the country

[Mordred]

3 hours ago, Strange said:

One lesson that one can take from that article is that waves/particle/fields are not what these thing are, they are just how we describe them. 

The map, not the country

In all the years I have watched your posts. This is one of the best replies I have seen. Highly accurate +1. ( Not to say your replies have been inaccurate. I particularly like the ramifications of this simple but profound reply)

Fields for example is an abstract descriptive for a group of mathematical objects (scalars, vectors, spinors, tensors) under a geometric basis. In the QFT formalism which the Hobbs paper supports the field has probability path integrals (Feymann path integrals)

 Wavefunctions of the Schrodinger equation involves probability functions. The pointllike attributes can be described by the DeBroglie or Compton wavelength.

 In all the three dynamics they break down to descriptives. 

The OP is correct in that an elementary particle has no corspuscular (matter like ) constituents ie not little billiard balls.

 However particles can be described as field excitations which has both point like and wave like characteristics(side note another descriptive I have seen you often state.

Physics doesn't describe reality) is also very apt. Physics describes what we can observe. Though it also speculated on the unobservable for example virtual particles.

Edited May 29, 2020 by Mordred

[Strange]

10 hours ago, Mordred said:

In all the years I have watched your posts. This is one of the best replies I have seen.

Well, thank you.