# Matter travelling as waves

1. Jul 2, 2009

### Idyllic

Theres this retard on another forum preaching that matter travels as waves. And that he once calculated the amplitude and frequency of a baseball. Yes i know it sounds crazy, but tell me now that hes completely wrong. It really makes my blood boil reading all these posts about blackholes and space from people who have zero education above highschool in the field.

I'm ashamed and offended by everyone posting about things they know nothing and will always know nothing about.

Heres a post:

and the reply to my post:

2. Jul 2, 2009

### Pengwuino

Sorry, he isn't. http://en.wikipedia.org/wiki/Matter_wave

However, his idea that anti-matter exists because E=mc^2 is nonsense along the idea of anti-light (or well, an anti-photon is still a photon, its own antiparticle).

3. Jul 3, 2009

### Idyllic

Yeh but baseballs? come on.

4. Jul 3, 2009

Staff Emeritus
Do you have an actual objection? Besides calling people who disagree with you "retards"?

5. Jul 3, 2009

### Born2bwire

I've done that calculation too way back when in high school. I can't remember where it was used as an example/question. I used Giancolli's College Physics textbook in high school but I'm pretty sure they would not have deBroglie wavelength. Either way it probably is a very common example as it represents a large particle that will demonstrably have a very small wavelength.

6. Jul 3, 2009

### fatra2

Hi there,

Just to add my little opinion to this one. The "retard", as you call him, is quite right. You can calculate the wave function of a baseball. But saying that from E=mc^2 you can evaluate anything is completely ridiculous. To calculate the wave function of a particle, you need to apply a beautiful equation made by a good friend, Schrödinger.

For the rest of his post, about anti-energy and anti-light, I am tempted to call this dude the same as you, but I'll hold myself back. Matter/anti-matter is created from photons (energy). You don't need anti-photons to create anti-matter. This phenomenon is called pair-production, under certain condition a photon will trasnform itself into a pair of particle/anti-particle. This is where Einstein comes into play, with E=mc^2.

Oh, and by the way, Schrödinger's equation is quite pretty, but very complicated to solve completely, especially for big objects like a baseball.

Cheers

7. Jul 6, 2009

### JanClaesen

I'm a little confused about photons, so photons are pure energy, but not all pure energy are photons right, or aren't photons pure energy but just another form of energy, like mass?
These photons, hundred percent energy, are at the same time the messenger-particle in an electromagnetic field (a little side question, the light that is emitted by an electric shock comes from the plasma, because the air becomes charged, this has nothing to do with photons being the messengers in an electromagnetic field right?).
I have trouble understanding how 'light'-photons, 'messenger'-photons and these 'energy'-photons can be one and the same. Why does energy convert to mass anyway?

Are, according to quantum-physics, particles just another form of waves?

8. Jul 7, 2009

### fatra2

Hi there,

I don't know if you are confused, but your questions are certainly confusing. So many questions in such few words. My god.

To answer your questions, photons are pure energy. They are the only source of pure energy.

Then again, from quantum mechanics theory, photons can interact with matter as little particle (marble like). Therefore, photons also have a matter-like nature.

From the electromagnetic point of view, photons are simply a mixture of electric field interlaced with magnetic field.

The light emitted by very hot matter has nothing to do with whatever you said. To understand, you have to look at matter itself. If you heat up matter, you give energy to the atoms. The atoms get excited after receiving this energy. Electrons will step up a few notch on the atomic orbit, as an effect of this excitment. Once the electrons (after a few splits of a second) deexcite, energy will be emitted in the form of photons (something in the wavelength of visible light).

Nobody really knows why energy converts to mass and vice-versa. It seems to be a stochastic effect.

Now, for your last question, according to Schrödinger's equation, there is a duality between matter/energy. Energy (photons) can be seen as matter, and matter sometimes behaves as light. Very awkward, but terribly interesting.

Cheers

9. Jul 7, 2009

### JanClaesen

Thanks, it is a little clearer now! I'm sorry but I tend to be confused with it comes to quantum physics. ;)

The Coulomb-force decreases over the distance with 1/r², so it takes more energy to go from the the K to L-shell than from the L to M, so the light emitted when the electron falls back has a higher frequency (=more energy) when it falls back from L to K than from M to L, and would it fall from M to K, it has the highest frequency, is this correct?

10. Jul 7, 2009

### fatra2

That seems correct

11. Jul 9, 2009

### vin300

I agree with you.
Well, is the original one talking about me?
No.
I would like him to try some link on de broglie hypothesis and know that Einstein wasn't a retard to get a noble prize for his "particle light" assumption.

Last edited: Jul 9, 2009
12. Jul 9, 2009

### kevinfr0st

firstly iv got to think how long will it be befor i get banned from here,when all want to know is why the youngs doubble slit experiment is all rubbish and seeing people use the cat in a box rubbish to explain the experiment (i know the cat in a box wasnt for youngs experiment it was for some thing else,but was then used as a example)
2nd i never made a comment on the base ball
i comented on the reaction to some one thinking retards cant have a voice,if i thought that electrons traveled in a cork skrew path and that if you looked at the cork skrew from side on you would see the wave patteren,and then to say that i was then looking at cloud chamber videos on youtube, and looking at the trailes that were made in the chamber looked to me as if they had a cork screw pattern,you would rubbish it with out even thinking about and even if there was a glimmer of a slim chance that it might make sence would you even bother to look at videos of cloud chambers on youtube ?NO BECAUSE IM A RETARD

13. Jul 9, 2009

### kevinfr0st

sorry found out i broke room rules part of question was about some one not wanting to have a voice but went off subject wasnt a attempt to take over or flaming as it is called
sorry

14. Jul 9, 2009

### Staff: Mentor

Energy is a property of an object. Photons have not only energy, but also intrinsic angular momentum (often called "spin").

15. Jul 9, 2009

### Civilized

I have always been appalled by the "calculate the wavelength of a baseball" problems because this calculation does not correspond to anything that anyone could ever measure. At the QM level the momentum of a baseball is not even well defined, unless perhaps the baseball existed in a region at absolute zero temperature.

The verdict is that assigning a wavelength to a baseball is nonsense, but that this kind of nonsense is also taught in high school physics and is excused by the idea that it will raise the student's interest.

16. Jul 9, 2009

### vin300

Yes, I agree that there is no way of assessing the wavelength of a macroscopic object. If the momentum is 1 kgm/s, the wavelenth is 6.63*10^-34metres, which does sound like nonsense.

17. Jul 9, 2009

### Nick89

We were told the baseball example too on the very first QM lesson, and I think it is purely to bridge a gap between the quantum world students are about to learn and the 'normal' world around us. If you're not going to show the students that, even 'theoretically', with loads of false assumptions etc, a baseball would not exhibit measurable wave behavior, then you are bound to get questions like "but why doesn't a baseball wave?"...

18. Jul 9, 2009

### Staff: Mentor

I agree, and would also point out that a photon has lots of linear momentum too. In fact, it is not "pure energy" but energy maximally "contaminated" by momentum.

19. Jul 10, 2009

### turin

You cannot calculate the wavelength of a baseball. For instance, you cannot just assume that there is a ψ for the baseball that obeys Schroedinger's equation for V=0. I suppose that in principle maybe the wave function can be calculated. But you must consider that a baseball is a composite of zillions of ψ's, and these ψ's interact with even more interactions that appear in the potential term in Schroedinger's equation. Even assuming that V were somehow known, there simply are not enough computational resources on the planet to calculate such a wavefunction in your lifetime (OK, I am making assumptions at this point).

The calculation of the QM wavelength of a baseball is absurd, and it only gives a dangerously small amount of knowledge to students.