• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Is Light Matter?

Is LIght Matter

  • Total voters
    105
ponderingturtle said:
Fully in the same quantum state? Hmm must read up more on BEC's


But pair production is not from two photons interacting, but one photon interacting with say an electron and turning into an electron and an antielectron(yes I know positron is the word, but antielectron shows that it is an antiparticle better)

Pair production is not caused by two photons annihilating each other, at least to my knowledge.




but why should it be considered matter? Is it supposed to have mass?

I might not have the best physics background here not having any graduate effects and no real particle physics background.
Click to expand...
The W+, W- and Z0 particles are force carrying bosons that have mass. The Higgs is conjectured to be a boson with a huge mass.

IXP
 
Damn it! As so often happens, a physics topic is completely monopolized by physicists who really know their stuff! Keep at it, guys. Fascinating.

I asked for evidence that photons could occupy the same space at the same time because I don't see how we could practically determine that. I don't doubt that you know based on theory but, while matter needs to obey Pauli, we have to obey Heisenberg. My question was more about method than veracity.

Still, you guys are just great to read. I hope you don't come to a consensus as that would spoil all the fun.
 
Dancing David said:
Ynot: are electrons matter?
Click to expand...
The popular answer seems to be “it depends how you define matter”, but then no definition follows. The definition I accept (rightly or wrongly) is as follows - Matter has mass and occupies space. Matter occupies it’s own space and cannot occupy the space of other matter. An atom is the smallest indivisible unit of matter. Anything subatomic is not matter. Electrons therefore are not matter, and neither is light.
 
ynot said:
The popular answer seems to be “it depends how you define matter”, but then no definition follows. The definition I accept (rightly or wrongly) is as follows - Matter has mass and occupies space. Matter occupies it’s own space and cannot occupy the space of other matter. An atom is the smallest indivisible unit of matter. Anything subatomic is not matter. Electrons therefore are not matter, and neither is light.
Click to expand...

Now we need a definition of occupying space. They obey the pauli exclusion principle so you only get one to a quantum state, and you could say that is occupying space. YOu can not pack an infinite number of them together.

BUt they are a point particle so they have no size.

Normal definitions of matter do not work at microscopic scales.
 
ponderingturtle said:
BUt they are a point particle so they have no size.
Click to expand...

Then they are an abstract concept and have no actual existence. Matter has actual existence.

Normal definitions of matter do not work at microscopic scales.
Click to expand...
If by “microscopic” you mean subatomic, then they are not matter (by the definition I currently accept).
 
Last edited:
ynot said:
Then they are an abstract concept and have no actual existence. Matter has actual existence.
Click to expand...

They do exist and take up space in the sense that nothing else can be in the same quantum space as they are. They are as much matter as anything else in that regard.
 
ynot said:
A poll to gauge opinion. Be a nice horsey and vote . . . please :)

ETA - Surely your vote would be a neigh
Click to expand...

HAhah. love it.

I voted no, because I recall from physics that light is photons which sometimes behave as matter and sometimes as waves.

Other than that, I'd have to go wikipedia the real answer.
 
ynot said:
The popular answer seems to be “it depends how you define matter”, but then no definition follows. The definition I accept (rightly or wrongly) is as follows - Matter has mass and occupies space. Matter occupies it’s own space and cannot occupy the space of other matter. An atom is the smallest indivisible unit of matter. Anything subatomic is not matter. Electrons therefore are not matter, and neither is light.
Click to expand...
Which means that protons and neutrons aren't matter either! And saying that anything less than an atom isn't matter kind of raises the question of what a Hydrogen plasma is, since it consists of free protons and electrons, neither of which is matter by the above definition.
 
wollery said:
Which means that protons and neutrons aren't matter either! And saying that anything less than an atom isn't matter kind of raises the question of what a Hydrogen plasma is, since it consists of free protons and electrons, neither of which is matter by the above definition.
Click to expand...

Damn you! I was comfortable dealing with matter on the atomic scale... actually that expression that I used would still be applicable to plasmas:

Matter is composed of elementary particles (and, I think, not the particles themselves). This would include plasmas, no?
 
Do you mean all matter, or just Baryonic matter? :duck:
 
Amapola said:
A *POLL* to decide whether light is matter or not? Yikes. :boggled:
Click to expand...

Why not? (or should I ask Y-not? :) ) Since it is said light is both a particle and a wave.....

Never ridicule a poster's honest questions: Ever! A lot of you know it all people here (or should I say it is simply a facade) who always get smart and tell others like me to read up on some facts first, haven't a clue yourselves!...otherwise your ego would be brimming with telling me...us...what you know about it yourself!

If any of you asked me how some part on a car, or dryer, or water heater, or house framing theory, or much of what makes a house work, I'd be glad to tell you, because I know! I'm not going to tell you to go research it before asking.

This is just something I've had to get off my chest. Sorry.
.................

Are we supposed to simply accept that this "photon" is like a nothing but is a quasi-particle of sorts that nobody can explain?

I did vote "no", though, without reading posts first. It is obvious there is nothing there because a 1 million candle power flashlight aimed at a hair will not move a hair! You'd think with anything with mass behind it traveling at 286, 000 miles per second would at least ruffle a hair, even if there was a trillionth of a gram of weight to some particle in the light.
 
Besides Cuddles, are there any physicists among the voters?

Linda
 
Jimbo07 said:
Damn you! I was comfortable dealing with matter on the atomic scale... actually that expression that I used would still be applicable to plasmas:

Matter is composed of elementary particles (and, I think, not the particles themselves). This would include plasmas, no?
Click to expand...
Damn you! Given you said much the same as I did, I was hoping you would have a good answer (I haven't).

I’m sticking with the “Matter has mass and occupies space” bit, but I guess the “Anything subatomic is not matter” is under review
 
fls said:
Besides Cuddles, are there any physicists among the voters?

Linda
Click to expand...
Did you vote after Cuddles? If so, did his vote effect yours? How do you now Cuddles is a physicist? Why am I asking you so many questions?

ETA - I’m more of a fizzy cyst
 
Last edited:
Yes a poll will help establish a scientific consensus, especially in the absence of indisputable facts. Then we should go to the UN.
 
fls said:
Besides Cuddles, are there any physicists among the voters?

Linda
Click to expand...

I believe Yllanes is a physicist, although I don't know if he voted or just posted.

ponderingturtle said:
Fully in the same quantum state? Hmm must read up more on BEC's
Click to expand...

Yep. Subatomic particles get up to some pretty weird stuff.

But pair production is not from two photons interacting, but one photon interacting with say an electron and turning into an electron and an antielectron(yes I know positron is the word, but antielectron shows that it is an antiparticle better)
Click to expand...

Sorry, pair production wasn't what I meant to say there. You are correct that it is a result of a single photon, or other particle, decaying to a particle and it's anti-particle. To be honest, I'm not sure why I mentioned it at all.

Having done a little research it seems that although some theories consider the photon to be its own anti-particle, this is not the generally accepted view. Several people, including de Broglie, have proposed an anti-photon, but as far as I know it is currently thought that force carriers, including the photon, don't have anti-particles. Seems I was wrong on this point.

but why should it be considered matter? Is it supposed to have mass?
Click to expand...

Yes. In fact, that's the reason it is still hypothetical - it has a very large mass that requires energies greater than current accelerators can reach to produce. Assuming it exists of course. The photon is probably unique in being massless, although some theories say that the graviton is also massless. Assuming that exists.

ynot said:
The popular answer seems to be “it depends how you define matter”, but then no definition follows. The definition I accept (rightly or wrongly) is as follows - Matter has mass and occupies space. Matter occupies it’s own space and cannot occupy the space of other matter. An atom is the smallest indivisible unit of matter. Anything subatomic is not matter. Electrons therefore are not matter, and neither is light.
Click to expand...

Atoms are indivisible? That will come as a bit of a surprise to, well, everybody.
 
You must log in or register to reply here.

Back
Top Bottom