Why specifically do certain particles travel in waves?

Answer 1

This is a fascinating subject, which jill c has already mentioned.
I guess you refer to the observations that small particles such as electrons and even alpha particles, when passed through a grid of slits such as a crystal, form patterns that imply interference has occurred.

There are several experiments to show that photons interfere when passed through very narrow slits (The Young's Slit Experiment); this can be explained because photons show "wave-like" characteristics. The result is a series of bright lines where the photons hit the background. The geometry of the experimental device and the pattern are exactly related to the light's wavelength.

The surprising result of a similar experiment using "particles" like electrons is that these also form interference patterns, just as they would if they were actually waves! Measuring the pattern enabled scientists to assign a wavelength to the particles.

The second point of interest is that the wavelength associated with these electrons is a function of the electrons velocity - it's speed when passing through the slits.

Later it was noted that photons reacted with solids (see "Photoelectric Effect") in a way that could only be explained if the photons were also particles!

So experiments showed that both photons and (subatomic) particles displayed either wave or particle characteristics in experiments. These objects were said to display dual characteristics; shortened to "wave-particle duality".

This is not just a theoretical nicety. Computers and electron microscopes, along with thousands of other technological developments (such as solar energy power sources) use these observed features of atomic entities.

To return to your question, specifically, small objects in motion have an associated wavelength related to their velocity. There is also no reason to say that larger (macroscopic) objects (bullets) do not have a wavelength; just that the interference effects cannot be measured by experiment.

Richard Feynman was the most charismatic and exciting physicist ever to teach American students. His presentations and enthusiasm for this subject was natural and infectious.
The reference below is a University series of lectures, but is quite accessible to interested students at most levels.

Answer 2

Electron Interference
We've seen what happens when we shine light through two slits, or when water waves do something similar. But what do you think happens when solid objects go through the slits? I don't get it. What do you mean by solid objects? Like rocks? Solid things don't travel in waves, do they?


Let's forget about waves for a second and just keep it simple. Dr. Feynman liked to talk about shooting a machine gun at an iron plate with two slots in it. If there were a concrete wall behind the iron plate, what kind of pattern do you think the bullets would make?






Well, I would think bullets would just pile up behind the two slots. I guess they would bounce off the edges of the holes a little bit, so it wouldn't be real neat, but mostly they would just be in two areas.


Right! The bullets don't interfere with each other like waves do... Wait a second! But they might! Two bullets, one from each hole, might bounce into each other and knock each other all over the place. That's a kind of interference, right?





Let's think about that. For two bullets to bump into each other would mean they left the gun at the same time. Do machine guns work like that? I hadn't thought about it, but I guess not. No matter how fast the machine gun seems to shoot, it's still just one bullet at a time. So there's no way the bullets could interfere.



OK. Now we're going to try an experiment. Using our two slits from before, we're going to use an "electron gun" which shoots a steady stream of electrons, the same particles that orbit atoms, at a sensitive screen...


Like a machine gun that shoots really small bullets. Yes. Each time an electron hits the screen it will make a green dot. Try switching it on...

Answer 3

There are three types of waves:


Mechanical waves require a material medium to travel (air, water, ropes). These waves are divided into three different types.
Transverse waves cause the medium to move perpendicular to the direction of the wave.
Longitudinal waves cause the medium to move parallel to the direction of the wave.
Surface waves are both transverse waves and longitudinal waves mixed in one medium.
Electromagnetic waves do not require a medium to travel (light, radio).
Matter waves are produced by electrons and particles.

Answer 4

The force used to drive sound takes much more energy than the force that drives light and sound is created from vibrations light in concentrated forms such as a powerful laser could also cause vibrations as it hits some matter.

Answer 5

it depends what football team you support, each team has a diferent chant, hope this helps...