Quantum Theory

If a layman were to ask what is Planck's Constant and what does the figure 6.626 x10^-34 Js mean how could you describe what it means?

In the Feynman lectures on physics, I encountered a sum of sinusoids having almost identical frequency. The resulting sinusoid had a very small location in space, so to speak. My question is; is this resulting wave packet identical to what is called a photon? Consequently, the location in space is dependent on the number of sinusoids that are summed. If the number of sinusoids is finite, the wave packet will be periodic, and there by the same "photon" (assuming that the answer to my first question is "yes") is spread, like knots on a rope. What makes up all these sinusoids? (I have encountered a similar discussion in the "Beyond The Mechanical Universe"-video seri…

The Quantum Universe is perceived through theoretical mathematics, then super-imposed upon the 'Standard Model', and this process ultimately affects the 'Cosmological Model' as well. All science and technology becomes affected as a result of the 'domino-effect'. It has been suspected for many years, that this 'train' has skewered down a side-track! There is only one known way to determine 'the truth', and that is through the CERN LHC programs, but not without some extreme risks! The 5.8 billion dollar question is: 'will current Quantum Theory still remain intact?' http://thefifthknight.blogspot.com/ Remember: Follow the 'White Rabbit'!

I was wondering if anyone might have any ideas on this particular matter. If we are in space looking at any given planet..lets say earth, and we feel we are in fact looking at a sphere, could the possibility arise in our minds for a moment that were not at all looking at a sphere but a Hole in Space rather? If we stop to think that on earth where we are responsive to given pre-existing states of matter or particles acting and or reacting in relation to the given Magnetic / Electromagnetic fields Present, and we observe that on Table top or even the ground itself , a hole it comes to no surprise it takes on a 3 dimensional shape of a tube. regardless of the depth (let's …

In Quantum chemistry, some times the Hamiltonian is written as the combination of 1-electron and 2-electron contributions: H=[math]\sum<i|j>A[/math]+1/2[math]\sum<ij|kl>B[/math]. <i|j> and <ij|kl> are one and two electron repulsion integrals. In second quantization the coefficients A and B can be written as: A=<I|E[math]_{ij}[/math]|J> which is a linear contribution. This is easy to calculate. B=[math]\sum[/math][math]_{M}[/math]<I|E[math]_{ij}[/math]|M><M|E[math]_{kl}[/math]|J>-[math]\delta[/math][math]_{jk}[/math]<I|E[math]_{il}[/math]|J> where the first term is a bilinear contribution, the second t…

Mostly the waves can be classified into - 1) Mechanical Waves 2) Electromagnetic Waves 3) Matter Waves So is there any wave that can be seen

So I just wanted to know what people thought about the existance of time as a particle. Quite and interesting statement and one that definately "thinks outside the box", so what does everyone else think about it here.

String theory was discovered from the study of Regge trajectories in the scattering of mesons and baryons. Veneziano came up with a beta function amplitude to explain this phenomena. Nambu and Goto showed that such an amplitude can be obtained from a bosonic String theory. Very crudely, the scattering of four open string tachyons can be given at tree level by the S matrix amplitude: [math] S(k_1 ;k_2 ;k_3 ;k_4 ) \propto B( - \alpha 's - 1, - \alpha 't - 1) + B( - \alpha 's - 1, - \alpha 'u - 1) + B( - \alpha 't - 1, - \alpha 'u - 1) [/math] where the Euler Beta function is given by: [math] B\left( { - \alpha 'x - 1, - \alpha 'y - 1} \right) = \frac{{\Gam…

the question that dwells on almost any physics professor, of philosopher's mind is "Is time travel possible?" Well, why shouldn't it be?? We all are in fact time travelers ourselves. We all move forward in time, well, at least we all perceive to be moving forward in time. In fact, when you really think about it, we could all be moving backwards in time...time may not be moving at all. It could be stopped at the very moment that I am writing this...Of course you'll say "that's impossible, if time has stopped, how can I be reading this??" but we are forgetting the fact that maybe time has stopped for someone else. After all, time travel has a lot to do with perceptio…

I never learned QFT so I'll have to take your word for this until I learn it myself. Why did you qualify it with perturbative? Pete

Lee Smolin argues pretty convincingly that space is discrete at the Planck scale. He does so in the book Three Roads to Quantum Gravity, where he claims that each of the three roads (string theory, loop quantum gravity, and black hole thermodynamics) all paint a picture of discrete space. The string theory angle was an interesting one as to my knowledge string theory still used a continuous spatial background, but Smolin elucidated me as to the idea that strings are comprised of "string bits" which are discrete. I was wondering if there are any theories which specifically require space to be continuous and are incompatible with a discrete approach.

What is the explanation for the slowing down of light to a snail's pace when it enters a Bose–Einstein condensate, only to regain its normal speed as it leaves ? Experiments have shown that a laser pulse several miles long is reduced to just a few microns in length when it strikes a Bose–Einstein condensate. Then, slowly passing through the medium, as it reaches its exit point, the laser pulse regains its length and speed. Must we now assume that, when testing the limits of our physical environment, there are in reality no constants ?

The new Large Hadron Collider is coming online soon. It is said to be able to create micro black holes. I immediately admit that any knowledge I have about micro black holes comes from the main stream media (including wikipedia), and is therefore not very good. So, I read about the Hawking radiation, which states that the speed at which a black hole is emitting matter (the rate at which is loses weight) is inversely proportional to its weight. According to this theory, the micro black holes are harmless, because they will in fact lose all their matter so fast, that it might seem a small explosion. http://en.wikipedia.org/wiki/Micro_black_holes But, I also read…

Could the uncertainty of a hydrogen atom be directly related to its superposition? Such as a measurement performed at any giving time would reveal data with of course a limitation being the uncertainty principal, so would that in a sort equal to superposition of the hydrogen atom being a constant?

I didn't know if I should put it here or in the Relativity forum, I suppose this is a more suiting place. I'm kinda rusty regarding general theory of relativity, but as I got it (as I remember) it is not possible to get a relation between an event/"time" inside the event horizon and time outside. For instance, for an observer outside the blackhole nothing will ever pass the event horizon. Now suppose A and B are two persons, outside the event horizon of a black hole. They each have a particle a and b respectively, and the particles are entangled. Person B starts moving towards the black hole, and when he passes the event horizon he will perform a measure on hi…

Hi all, apologies for cross posting, but I really need some sanity checking done on these equations, especially in my proving [math]E=mc^2[/math] from the Planck constant. http://www.scienceforums.net/forum/showthread.php?p=414167 I think the SFN Mods would probably prefer comments in the originating thread. Cheers.

I Just finished watching The Elegant Universe by briane green (if that's how you spell his name). I have the book which i will read soon but I have one question. Knowing now that everything could be made up of strands of vibrating energy, and knowing that a human brain emits an electromagnetic signals, can these signals have any effect on strings? I've heard a few people talk about this on the internet. Just a thought, tell me if I'm wrong.

I don't understand it!

I was folding a blanket today and noticed the ripples forming in it. I don’t know why but this made me think of spacetime warping. Can quasi local phenomena be somewhat viewed like that dependent on scale?

I have a few questions about anti-matter that I was hoping some of you could answer. First of all what processes do we know about that create generate anti-matter and what circumstances create better conditions for the anti-matter to be generated. And what particles does that include? I have heard about electron/positron pair production but what about proton/anti-proton? Secondly I have heard about a hypothises about neutron/anti-neutron occilation where a neutron can become an anti-neutron and vise versa. What is the standing of this theory?

In many body problems does the uncertainty principal lead to the difficulty of predicting quantum behavior for a molecular structure? Another way I will word the question is that if the uncertainty principal is physically responsible for say the wavefuntion of a molecule? As such that the uncertainty principal itself in relation to superposition is what you are observing at any giving moment in say a many body system or molecule.

And here I thought that spin didn't correlate to actual spinning. I'll hit google. edit: Google had one hit...a PhysOrg forum thread

About every day life of the elementary particles (simplified) This is what I think about some of elementary particles behavior, avoiding much math. The elementary particle jumps from one location to another with the set of locations discontinuous and not linearly ordered. What is far with the standard distance can be near with the jumps. So, two particles can have an action one on the other after having taken a "distance" one from the other. The two particles could be within a limited number of jumps one from the other. Therefore, there could be an unexpected correlation. Time itself is discontinuous and not linearly ordered. So, there are no causa…

Could conservation laws possibly be a product of environment as a witness or constant monitoring by the environment? I am not asking for a direct yes or not as I don’t know if that exists just more or less why do universal conservation laws appear in any system that QM interacts with. Such as with the standard model, how could conservation laws come to exist universally within such? It would seem some mechanism has to exist that would define consistent relative "outcomes" such as angular momentum. This question hinges on if say classical reality emerged from the quantum. Why would any particular direction or an arrow of time even emerge, or a point like particle fo…

a lil help please... how did brownian motion provide evidence for the existence of atoms?