# pmb

Senior Members

379

1. ## Fields and dimensions

That's also part of linear algebra, which I use quite often.
2. ## Fields and dimensions

As an undergraduate one of my majors was mathematics. One of the required courses was abstract algebra. While I'm sure that group theory and all the stuff about fileds and rings is useful somewhere in physics, I myself have never had cause to use it need it in my studies an research.

Edit: (Never mind.)
4. ## Particle wave duality

Do you except cyberbucks? If so then here {cha-ching! - \$11.00}. I added a doller for prompt service. The wave characteristics of particles also applies to single particles. When a single particle approaches a step potential part of the wave is transmitted and part is relfected. That's the wave character manifesting itself. A wave function can apply to single paricles. A wave can be a continuous superposition of waves to give a wave packet too. That wave packet can scatter off of a point potential like the potential associated with a nucleus.
5. ## Big Bang

Engineers rarely take more than Physics IO, II and III. Even then they quickly forget most of it. And those courses don't even touch base with astronomy or cosmology.

That's not quite right. I wasn' concerned about his actions. That was taken care of in the other forum. I asked the following question and after presenting the example I inquired And that is the essenf this thread. And I've been nothing except very polite' date=' reasonalble and logical in all my reponses and inquiries. The example is completely anonymous. Both the name of the person and the name of the forum is kept a secret so as to esure that this doesn't get at all personal. In fact when someone, who also frequents that forum, mentioned his name I promptly asked then to delete th

No. The first five responses were explaining why his thread served its purpose without the part that I told him was wrong. Those responses had absolutely nothing to do with my argument.

Sorry. I don't want to give more life to something which was merely an inquiry. Recall, again what a personal attack is That's quite different than a simple attack on a person? An attack on a person need not have anything to do with a argument. It could just be anger at a person. You seem to be reading it literally where in fact its taken as a single term which has the above meaning. The actual argument was me explaining that a particle with rest mass can't travel at the speed of light. His character assasination never mentioned that argument. That's what makes it a personal att
9. ## Particle wave duality

Also, I wouldn't say that the properties of spacetime couldn't be explained by QM. E.g. nobody has ever used QM to derive the expression for time dilation or length contraction. Black holes can't be explained by QM either. Myself, I never use wide sweeping generalizations like that. There are always exceptions to every rule such as the ones I mention here. Young's double slit experiment is a good example of the wave-particle duality. If you set up an ensemble of such experimental set ups and let just one photon go through the double slit and then compare all the results then (1) in each
10. ## In the absence of a heat source how long would it take for the earth to freeze solid?

That's a very complicated problem to solve. It depends on the thermal properties of the various kinds of matter which the earth is made up and how that matter is distibuted It's possible to solve it but IU sure don't know how to do it. One needs to be skilled in thermodynamics to solve a problem like that and thermodynamics was always my worst subject.
11. ## Why do scientist, religion and quantum physicist talk bad about each other??

I believe that is an inaccurate perception. I think about 35% of all physcists believe in God. The 65%who don't certainly don't all speak badly about religion. Sure they do. I believe that's a false impression that you gained somewhere/somehow. Perhaps from the few who are very noisey on that kind of thing. I'm a physicist and I'm a Christian and I certaintly don't think that way. Even when I wasn't religious I never thought badly about people who were religious Oh, I don't know about that. I tend to disagree on that point. I believe that such people believed in God but perh
12. ## Who do you think were the most influencial persons in human history?

In my opinion Jesus is the most influential person in the history of the world.
13. ## Big Bang

You do understand, don't you, that its not that the galaxy is moving through space, its just that there is space being created inbetween gallaxies and that yields an effective increasing distance at a rate which makes the distance between some gallaxies appear faster than the speed of light?
14. ## Particle wave duality

Wonderful. Well said sir!! So well put that it brings a tear to me eye!
15. ## Particle wave duality

I found where Feynman explains in QED that electrons have a wave-like property. It's on page 84.
16. ## Particle wave duality

I think that its a fair way to speak though. It would become cumbersome to keep repeating according to the laws of physics as they are presently known ..... I always take that as a given and that the scientist who says those things understands that.
17. ## Particle wave duality

Consider a large number of Young's Double Slit experiment. Allow just one photon to go through the slit. It will be detected on the screen behind it by the "click" of one photon detector. If you were to look at the ensemble of all those experimental setups you'd see that there is an interference phenomena present. Its for this reason that its said that there is a wave-particle duality and why Feynman said "It's like neither.' Note: The quote from Feynman's QED only addresses light/photons. It makes no mention of electrons. I have the check the context. What page is that on?
18. ## Critical Thinking Skills

I do have a psychological disorder which affects my memory. ADD etc. It's terrible. I lost my keys again today the third time within the last month. It sucks big time. So sure, that could be the case. Or maybe I only hit preview! Yeah! That's the ticket! I think that's what I did! Yay! I figured it out. Thanks.
19. ## Particle wave duality

I love the way Feynman explains it in his Lectures. In V-II page 1-1 Someone once coined the term wavicle (http://en.wiktionary.org/wiki/wavicle) as a comprimise but it never really took. Today physicists ue the term "particle" not because they behave like particles, but because there is no other term and its good enough since nobody ever gets confused by it and actually thinks that photons and electrons are "really" particles. Although I'm sure there are a lot of people who are confused on this point. The wave function, like any mathematical quantity in physics, is a quantity that has
20. ## Particle wave duality

The thing about quantum mechanics is that you can't talk about what a system is doing until you make a measurement. Asking about an electron is doing when it hasn't been observed is a meaningless question in QM. There are states in the atom which stationary states. Once you measure owhat state its in then you can make a statement about it.
21. ## Critical Thinking Skills

This is wonderful. Everyone chipping in with other ways of thinking is a great way to add to the spirit of this page. I want to thank everyone for their contribution and sat "Keep'em cummin". Note: Somethings wrong. Several times now I've posted a message only later to see it missing. What's going on?

Please don't put words into my mouth. The thought of "picking on me" never entered my mind. Btw, I made a mistake. Oh, for crying out loud is not an attack, its meant to show the emotion of either frustration, exasperation, or annoyance. See http://en.wiktionary.org/wiki/for_crying_out_loud. In any case I deleted that comment because I thought that it was unwarrented. Sometimes we all say things we regret later. I've decided to delete those things when I can so as to be as polite as I can. I imagine that's fine with you? That's correct. They are. And yo used it wronig. The only way I

You are very wrong. So wrong that I'm quite surprised by this response. Let us, for the sake of argument, say that it was an attack on you (which it really wasn't. It was an observation). It's not an ad hominem because its lacking that part instead of the arguement since I addressed your argument. And just because I observed that you seemed impatient it doesn't mean that its a personal attack. Are you telling me that Oh, for crying out loud. cannot be interpreted as you being impatient? And are you saying that when someone observes you being impatient and mentions it that you think its an atta

I didn't ingnore that at all. I did a detailed analysis in a previous post and you for all practical purposes ignored it. You mad no of my detailed analysis. You're merely repeating your claim now. Which is what the opponent did by claiming I was out to get them. That was an attack on my character. The criteria of an ad hominem is Whenever we attack a person instead of his or her argument. I've explained, many times now, that the opponent, instead of addressing my assertion that v = c does not hold for partilces with non-zero rest mass, attacked my character by claiming I was out
25. ## Why is there a reputation system?

Aethelwulf - Take my word for itmy friend, don't continue. Any attempt at explain yourself and your point of view, regardless of the circumstances, always looks bad. Nobody can win under such circumstances. Just a friendly suggestion.
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