# Electron is it a particle or wave ?

1. Apr 1, 2013

### Ahmed_Pysics

Hi everyone !!

I have this a question about electron, is it a particle or is it a wave, or maybe both sometimes particles and sometimes wave or both in the same time ??

2. Apr 1, 2013

### ash64449

It is a particle with wave nature

3. Apr 1, 2013

### ash64449

Or we can say that it is just an excitation of electron field.

4. Apr 1, 2013

### M. next

Well, first electron was thought to be only a particle. Further experiments, showed that it does have a wave nature. Read about deBroglie's wavelength for detailed information.

5. Apr 1, 2013

### ash64449

This is the question that troubled me a lot.. If electron is a wave, then what is "waving"?

6. Apr 1, 2013

### Ahmed_Pysics

So electron is a particle with wave nature
mmm interesting !!
Thanks guys !!

7. Apr 1, 2013

### tensor33

The usual interpretation is that it is a "wave of probabilities" The amplitude of the wave is related to the probability of finding the electron there. So really nothing is waving, it's just a way of describing the particle.

8. Apr 1, 2013

### ash64449

So it not waving... So in order to describe its properties,it is given wave probabilities right?

9. Apr 1, 2013

### tensor33

Right

10. Apr 2, 2013

### Staff: Mentor

Its neither - its quantum stuff. Sometimes it behaves like a particle and sometimes like a wave but in reality its neither. I know Feynman says its a particle because you only ever get single clicks in a photon detector for instance - it's never detected as anything other than something 'discreet'. But understand its not a particle in the classical sense - it is something different - a quantum particle.

Thanks
Bill

11. Apr 2, 2013

### Ahmed_Pysics

So the behavior of an electron still a mystery !!

12. Apr 2, 2013

### DiracPool

Its a Wavicle! No, wait...its a "Par-tave." Say that with a snobby accent like Thurston Howell. "Look, Marge, there goes one of those 'par-taves' again, ringing my detector. They are soooooo annoying."

13. Apr 2, 2013

### Ahmed_Pysics

Wow Mister Dirac is here, what an honor.
Thanks for passing ;)

14. Apr 2, 2013

### Staff: Mentor

No - we know how it behaves - its quantum stuff - its just not particle or wave - or visualisable in terms of everyday pictures - but that doesn't mean we don't 'understand' it.

Thanks
Bill

15. Apr 2, 2013

### Ahmed_Pysics

ok !!
so quantum stuff
Thanks bhobba

16. Apr 3, 2013

### Naty1

"..is it a particle or is it a wave.."

yes!!!!!!!!!

but there is a LOT more to just what a particle may be:

beyond quantum theory:

String theory suggests that it may be the configuration of higher dimensional spaces that influences string [particle] properties....their vibration patterns and energies for example ....so when spacetime jiggles around or morphs from one region to another it seems plausible that our perception of particles might also change...because they change.

This provides an insight into how the expansion of distance in our universe creates particles.

Carlo Rovelli says it this way:
Other cases where geometric circumstances create real (not virtual) particles are Hawking radiation at Black hole horizons and Unruh radiation caused by acceleration of observer. So it seems that expansion of geometry itself can produce matter.

Within quantum theory:

Rovelli:
"There is not a definite line differentiating virtual particles from real particles — the equations of physics just describe particles (which includes both equally). The amplitude that a virtual particle exists interferes with the amplitude for its non-existence; whereas for a real particle the cases of existence and non-existence cease to be coherent with each other and do not interfere any more. In the quantum field theory view, "real particles" are viewed as being detectable excitations of underlying quantum fields.."

17. Apr 3, 2013

### Ahmed_Pysics

What a lovely replay Naty1
I really like it
Thanks

18. Apr 3, 2013

### BacalhauGT

there are "particlaves". everything propagates like a wave and interact changing its energy and momentum

19. Apr 4, 2013

### Ahmed_Pysics

20. Apr 4, 2013

### phynoldus

Wave or particle?

Hi,
I was just wondering is an electron a wave or particle or even a particle with wave nature?

21. Apr 4, 2013

### Bill_K

22. Apr 4, 2013

### ZapperZ

Staff Emeritus
phynoldus: Your thread has been merged to an existing thread on the identical topic. As has been suggested, please read the content.

And for future reference, the question on whether an electron (or any other quantum particle) is a wave or a particle is typically not a "high energy physics" topic.

Zz.

23. Apr 4, 2013

### BacalhauGT

each class of particles has a different dispersion relation http://en.wikipedia.org/wiki/Dispersion_relation

the wave is a function of space and time and you can do the fourier tranform. So we have (Quantum mechanics is that) for each f and waveleght:

E=h f
p = h/ wavelenght

A wave is composed by different frequencies and waveleghts.

Each "particlave" has a property, a mass (can be 0) and a dispertion relation (E(p)) (there are another properties...).

For example for a photon you have: E=pc dispertion relation is:
f h = hc/ wavelenght -> f = c/ wavelenght as you expect for light!

For a classic particle is (small energy): E=p^2/2m + u(x). try to see whats the dispertion relation :P

If you see, you will understant that for this dispersion relation, the Differential equation (each dispertion relation has one) for wavefuncionhas to be the Schrödinger equation :P

hope you understand. I tryed to explain it in a easy and Understandable way.

I think its wrong to say "things are particle OR a wave". things are other entity, with both properties. when those things propagates, you have some properties from waves. when interact, thigs change energy and momentum (the wave can have a spectrum but theres thecolapse ofthe wavefunction). E = h f and p = h / waveleght make the "bridge" between wave and particle properties

Sorry my english :)

hope i was hepful

Last edited: Apr 4, 2013
24. Apr 4, 2013

### Naty1

yes, when 'things interact things change'.....from Leonard Susskind's description 'propeller particles'

So while we are at it describing particles, electrons or otherwise, let's take a look at the 'size of a fundamental particle' and see there is no 'real' answer, at least no simple one. The Standard Model of particle physics is a model with point particles and quantum fields...maybe that view is a bit too simple:

From Leonard Susskind [whose work in black hole complementarity has won him widespread recognition] THE BLACK HOLE WAR, Chapter 20:

[Susskind is relating here views of quantum field theory and string theory and while he uses 'atom' in the following description, he is could just as well have used 'particle', electron or 'photon'

[This refers to the fact that a hovering observer and a free falling observer will 'read' very different radiations emanating from a black hole horizon. So the observed 'size' of a particle, the very existence of a particle and it's energy is impacted by the presence of a cosmological horizon.]

[Susskind compares such 'particles' to a rotating airplane propeller....where maybe all we can see is the hub, and maybe the inner portion of the blades....but progressively faster high speed photos [better resolution] would reveal additional extended structure....we can see further out on the rotating blades....see further quantum jitters otherwise hidden from us!!]

{# What he is implying is that finer resolution requires shorter wavelengths...higher frequency and hence more energy...and that disturbs the very particle we are trying to observe preventing us from viewing it as it really is.]

Note that a free unbounded electron extends all over the place; it's unconstrained. Put it in a potential well...or any structure.... and it becomes 'confined' as can only have certain discrete energy levels...and certain spins. This means an electron in a hydrogen atom and one with a metallic lattice have different energies...and different sizes!!

So in my earlier post where I mentioned string theory suggests that hidden dimensions affect the properties of particles, you can imagine here a connection between the physical size of a particle and observable dimensions....that is, degrees of freedom affect the size of particles!!

So now a 'point' particle and a' wave' can each take on additional characteristics and behaviors.

25. Apr 4, 2013

### phynoldus

Thanks! it is really interesting :)