Clifford produced a really cool movie on the Laser effect, explained so that pretty much anybody can understand it. No calculations required.
To learn more about this, go here.
Here, at the shores, we update you on news way after they break out. When they have become oldies. In cyberspace, this is after a couple of days.
Wow! I hadn’t known that excited atoms contained photons! This is amazing!
I always thought that the photons were created when they were emitted. I had no idea that they were paired up with the atoms all along. This makes a lot more sense then those silly ideas I learned in 6 years of graduate school.
Dear Carl, a number I just wrote to Tommaso’s blog should be reduced to 0.0001% now.
Surely you’re joking, right? Photons can’t be stuck to an atom. Photons are particles of light that are always moving by the speed of… guess what? By the speed of light. It’s never zero. In fact, it’s always constant, in all reference frames.
By the atom-photon pairs, Clifford simply meant excited atoms. But they don’t have any photon bags in them. The photons are literally created when they’re emitted by the atoms (which would be hard for Clifford to visualize with the people). The number of photons is not conserved in the real world.
The identical question of non-existing “photon bags” was being explained by Richard Feynman to his father, see
http://www.google.cz/search?q=feynman+father+“photon+bag”
It was in the BBC Horizon program with Feynman, too (see YouTube).
“He [Feynman's dad] was happy with me, I believe. Once though when I came back from MIT, I’d been there a few years, he said to me, ‘You’ve become educated about these things, and there’s one question I’ve always had that I’ve never really understood very well, and I’d like to ask you now that you’ve studied this to explain it to me.’ And then he said that he understood that when an atom made a transition from one state to another it emits a particle of light called a photon. That’s right. And he says, ‘Is the photon in the atom ahead of time that it comes out, or is there no photon in there to start with?’ I said, ‘There’s no photon in it, just that the electron makes the transition, it comes out…’ He said, ‘Well, then where does it come from and how does it come out?’ So I said…of course I couldn’t answer him…the view is that photon numbers aren’t conserved, they’re just created by the motion of the electron.”
“I couldn’t try to explain it to him something like…that the sound that I’m making now wasn’t in me. It’s not like my little boy who said when he was just little, one day he started to talk, he was talking, and he suddenly said that he could no longer say a certain word (the word was ‘cat’) because his word bag has run out of the word ‘cat’. So there’s no word bag that you have inside so that you use up the words as they come out, you just make them as they go along, and in the same sense there was no photon bag in an atom, and when the photons come out they didn’t come from somewhere, but I couldn’t do much better. He was not satisfied with me in that respect and I never was able to explain any of the things that he didn’t understand.”
It’s at 4:10 of this video:
Carl,
Look at the 10.2 eV photon in the Lyman series of hydrogen n = 2 to n = 1 quantum transition. ½ the energy of the photon, 5.1 eV, comes out of the electron energy and ½ the energy, 5.1 eV, comes out of the electric field energy stored between the electron and the proton. 10.2 = ¾ x 13.6 = 2 x ½ x ¾ x 13.6 = 2 x 5.1
See http://vixra.org/abs/0907.0009 for a complete elucidation.
Dave Degner
Lubos, of course I was joking, LOL. I’m making fun of Clifford making a movie that supposedly explains how lasers work.
By the way, I had an almost identical conversation (to the one Feynman describes with his dad) with a guy at the chess club a few weeks ago. But he was convinced that a neutron had a proton, an electron, and a neutrino inside.
A good short way of explaining why this isn’t the case is to point out cases where an atom absorbs one photon, and then emits two.