# Do the properties of matter waves mirror that of the particle?

1. Jun 11, 2012

### San K

Matter (deBroglie) waves is a concept and it's existence is not confirmed (?)..that said,

We know that - The de Broglie equations relate the wavelength λ to the momentum p, and frequency f to the total energy E (including its rest energy) of a particle

how closely do the properties of matter waves mirror that of the particle?

Let's take 1) photon 2) electron 3) Neutrino

we know a photon passes through a transparent object but it blocked by a opaque object.
the matter waves of a photon behave the same way.

an electron carries a charge and is effected by electro-magnetic fields, does it's matter wave behave differently?

a neutrino can pass through an opaque object/earth, what about its matter wave?

thus would the (properties of) matter waves of a photon differ from those of an electron and both differ from those of a Neutrino?

Last edited: Jun 11, 2012
2. Jun 11, 2012

### Simon Bridge

define "matter wave" - what are you talking about when you use these words?

The question makes no sense. But I suspect I see the confusion: matter has wave-like properties and the deBroglie wavelength works with the wave equations to predict what we see in, say, diffraction experiments.

The photon has no mass and so has no "matter wave". It has a wavelike nature and a particle-like behavior depending on how you observe it.

Generally - the wavelike behavior determines the statistics of the photons as particles - the probability of detecting a photon in a particular place. Lots of photon give rise to the commonly observed behaviors like transmission and reflection and absorption.

Again - this makes no sense - the wave behavior of an electron is statistical in nature, just like the photon.

... note: the Earth is not opaque to a neutrino. Again - the question makes no sense.

These particles all display both particle-like behavior and wave-like behavior. The wave is the particle. The particle is the wave. The properties of both together give us the observed behavior of the thingy.

Each of these exhibits the behavior of classical waves which are not behavior of classical particles - for instance, diffraction and intereference. None of these is a classical wave nor a classical particle - they are themselves.

3. Jun 11, 2012

### San K

hi simon, thanks for responding.

matter wave = deBroglie waves = wave-function = probability wave

http://en.wikipedia.org/wiki/Matter_wave

every particle is to have a matter wave.

Per the deBroglie-Bohm (one of the many interpretations/hypotheses) the wavefunction travels through both slits, but each particle has a well-defined trajectory and passes through exactly one of the slits.

4. Jun 11, 2012

### Simon Bridge

I'm not doubting the existence of matter waves - the term is just frequently misused.

It is not useful to refer to the QM wave-function as a matter wave. It leads to the kinds of confusions you have written eg. it implies that photon have matter in the same sense as a lump of rock.

Of course, mass and energy are equivalent so we do our physics in terms of energy ... in which case "matter" corresponds conceptually to rest-mass energy. The photon's rest-mass energy is zero. Anyway - these are not energy waves either :) they are probability waves.

Probably the best lay description of wave-particle duality I have heard comes from Richard Feynman ...

... you should probably also see the other parts of the series, but this one deals with your questions somewhat.

Remember - wavefunctions are not physically present: nobody has ever observed one. They don't travel, but we talk about them as if they do because it helps us think about them. It's a metaphor.

If you follow the feynman lectures you'll also see that we don't actually know the particles follow a well defined trajectory at all ... we know where they start out and where they are likely to end up but, having detected one, we have no "well defined" idea how it got there. That's what gives rise to the quantum interference: we cannot know it's trajectory without destroying the interference.

Last edited by a moderator: Sep 25, 2014