# (properties of) what travels through all possible paths?

1. Apr 16, 2012

### San K

We don't know what travels through the various paths, however we can, at the least, talk about the properties of what passes through......

So the question is: What are the properties of matter (or de Broglie) waves?

Most of the below may be debatable

- it travels in the form of a wave

- its does get blocked by opaque obstacles

- it passes through transparent obstacles

- if it can effect the path of the photon, it must be something physical travelling through time and space

- A) it travels at the speed of light

- B) some properties of it travel, at the least, 10,000 times faster than light

- they can interact with other matter waves

- amplitude of probability travels and is mathematically calculable

- they do exist, however we are unable to measure/detect it directly with the current state of the art

- the photon travels through one of the slits and the wave through both (else you cannot explain how a bucky-ball passes through both slits and recombines perfectly)

2. Apr 17, 2012

### Staff: Mentor

That is just a mathematical description.

"opaque" and "transparent" might be a bit misleading, as they are usually used for light. An electric field might be an obstacle for a charged particle. The full earth is nearly transparent for neutrinos of low energy.

While that is true for light, it is not true for matter.

No.
You can try to get some properties to travel with arbitrary speed if you use some collapse interpretation of the wave function, but it is tricky to define "properties" then.

That depends on the interpretation

That is true.

To detect particles, you need an interaction with the particle. An interaction with the particle changes its properties. Sounds obvious, when stated like that? ;)

I would call the wave "the photon". In the same way, a bucky-ball can pass through both slits. But with the de-Broglie-Bohm interpretation of quantum mechanics, this is true and the particles actually pass through one slit.

3. Apr 17, 2012

### San K

Does/would the matter wave (de Broglie wave) of a neutrino travel through earth/opaque obstacles?.... just like a neutrino does

it would be interesting to find out the answer

4. Apr 17, 2012

### Staff: Mentor

What are "opaque obstacles"? Opaque for what? For neutrinos of some energy? For photons of some energy?

What is the difference between "a neutrino" and "the matter wave of a neutrino"? ;)

5. Apr 17, 2012

### San K

Case/Scenario 1: opaque for light/photons
Case/Scenario 2: opaque for neutrinos

a neutrino is a particle form.
the matter wave is the wave form of the neutrino (with or without the particle...depending upon your favorite interpretation...;)...)

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

let's put the same thing differently.....would a neutrino show single particle (double slit) interference within/inside earth?...

however I am not sure how we will be able to make a double slit apparatus for a neutrino.....;)

Last edited: Apr 17, 2012