timo

You can learn plenty of programming by yourself. Certain aspects may be more efficiently taught in courses, but for demands such unspecified as yours I'd vote for learn-it-yourself.

There is no time operator in mainstream quantum mechanics.

Terrible. Interestingly, leo.org translates the word with both, good and bad. Thanks for the comment; I'll edit my previous post accordingly. EDIT: No, I won't. The can-still-edit period seems to be over for that post.

Since I wouldn't know who of the regular members here should be able to help you on this (CharonY, perhaps), I'll give you a few bullet point comments. Keep in mind that while I have been formally employed at a Max Planck institute last year (not the one you are interested in, though), my knowledge stems almost exclusively from experience at my current university (where we have some collaborations with local MPIs - which is why I was paid from them). - Max Plack Institutes have a good reputation in research. - Students from MPIs are notoriously bad speakers and terrific teachers. - That is -presumably- because their supervisors push them into doing the lab-rat work rather than wasting their time with giving yearly progress reports and tutoring university students. - Pressure on PhD student in MPIs tends to be a bit higher than in German universities, but no where close to the horror stories one hears about being a PhD student in US universities. - Leipzig should be relatively inexpensive to live in. - The good looking women usually get on and off the train in Leipzig - People having lived there tend to say the city is nice (may be related to either of the previous points) - I have no clue about the particular MPI you are looking into, never even heard of it (but I'm not into neuroscience, so that doesn't say much) - Same for the Neuroscience Center of Zurich - You may be interested in this link: http://www.nncn.de/ (but it may also be inapplicable - "cognitive" is a buzzword to me).

My gut feeling is that in this case the point could also be that frames in relative motion with respect to each other have different measurements of the speed that the target approaches them with.

If by changing the looks of the Mediterranean sea you mean the rise in sea level due to the city sinking the answer is "not at all". A million tons of water is 1 mm height of water over a 100 km times 100 km square - the Mediterranean sea is much larger than such a square (and connected to the Atlantic, of course).

Virtual particles do not need to have an energy greater than the mass of the corresponding real particle. More precisely, they do not need to obey the relation that [math] E^2 = {\vec p}^2c^2 + m^2 c^4[/math], where m is the mass of the corresponding real particle and p is the momentum. They are virtual particles, not real particles. In fact, I believe it is better not to think of virtual particles as particles at all. But I am aware in an Internet forum there is no chance at all for this attitude to become acknowledged ("they are called particles, therefore they must be the kind of object I see in the pictures on Wikipedia!").

And of course the anonymous guy who wrote the Wikipedia article is much more credible than the anonymous guy who posts as "John Cuthber" on sfn

Only if the penguin drops the stick.

The virtual particles that I know conserve energy and momentum on every vertex in the diagram. I don't quite see how you can properly speak of an "energy dept" in this context.

It's not an answer to your question, but I can't help to wonder: If you have a university degree and research experience, why don't you apply for a real job rather than for volunteer work?

1) No. I edited the article describing an experiment into my previous post (I have not checked the guys' experiments, of course - they merely measured what everyone, including me, would expect to happen, anyways). 2) No. As a matter of fact, in quantum electrodynamics I think it follows pretty straightforwardly that in the limit of very high energies (where the mass of the electron is small compared to the energies) the probability for the process photon+photon -> electron+positron to happen is equal to that of the process electron+positron -> photon+photon. Extrapolating from the known is not a crackpot mistake. Claiming that the extrapolation must be correct (even in the face of contradicting experimental results or contradicting widely accepted theory) is.

You probably should have said "I've never seen light beams reacting with another. I also would not understand how that should be possible. Therefore, I believe that there is no photon-photon interaction". That would, I believe, describe your reasoning rather accurately. It also wouldn't be too stupid: Extrapolating from the known into the unknown is certainly better than completely wild-guessing. Of course, in this case it happens to be wrong (you linked an article talking about a photon-photon -> matter experiment yourself). But learning from mistakes is often the most effective way of learning (if the mistake is properly reflected upon). For the sake of completeness, here's the paper that the NY-times (presumably) talks about: Original publication on PRL: http://prl.aps.org/abstract/PRL/v79/i9/p1626_1 Publically-available pdf: http://slac.stanford.edu/pubs/slacpubs/7500/slac-pub-7564.pdf

I think your inherent assumption that the Pauli principle is (exclusively) responsible for the interaction between particles is rather dubious

The main problem with this question is that "pure energy" is a substance only known to science fiction authors and participants of internet forums, not to scientists. The most widely known process to convert kinetic energy into mass is shooting particles with high kinetic energy onto each other, creating new particles in the collision. Such machines are called "particle accelerator" or "colliders"; the machine most widely know these days probably is the "Large Hadron Collider" (LHC).

Warner Heisenberg later worked as a producer of Hollywood movies, but almost went bankrupt due to the notoriously blurry images in his films. Only by a drastic strategy change by his half-brother and partner Fineman, who specialized on movies that were entirely hand-drawn, the company could be saved and became a famous icon of the US entertainment industry. (sry, could not resist. no offense meant)

Given that Ziyonex said "I know the point I want to expand about is m so that I can obtain a good approximation for m + ∆m" I think that much was already clear.

Kind of my thoughts, too. Plus, it's rather easy to ignore the speculations forum entirely - as I actually do (a user setting to auto-ignore threads in selected forums would still be cool).

I would expand f(m+dm), since that physically makes the most sense. But it is easy to see that the (final) result is the same as if you try to expand f(m+dm)-f(m) or (f(m+dm)-f(m))/f(m). If you don't see that, you may want to try out the other two ways to get a better understanding of the Taylor expansion.

"Your life consists of sliding on a horizontal, frictionless surface" is quite an uncommon phrasing of a math question. Anyways, the goal here is to calculate [math]\Delta f[/math] as a result of the mass increasing by 2%. There is no [math]f(\Delta m)[/math] that you could expand. My guess is that you have not fully understood Taylor expansions. The Taylor expansion is a method to estimate the value of a function f at a point x from the function's properties at another point x0. Hint: [math]\Delta f = f(m + \Delta m) - f(m)[/math]. I don't quite see how to calculate the result to one significant figure, given that no numbers are given.

You have this process at first order tree level with an intermediate Z boson in the s-channel or via an intermediate W in the t-channel (which is the analogue of e+ e- -> photons). Not sure what "double W-boson exchange" is, but of course you can construct higher-order Feynman diagrams, too.

Since this is a physics "0/0" it must be related to the Planck units.

The former statement does actually not imply the latter - they are merely not mutually exclusive. That's pretty much the mainstream view of quantum mechanics (note that I edited out part of what you said, which may have altered your original statement). EDIT: Oh, and of course one usually doesn't speak about "any one universe" but about "any one result of a measurement" (which is effectively my comment above: using the term "universe" sounds cool but adds nothing).

I haven't tried it myself, but you could try to use the very first hit that Google returns: http://wiki.answers.com/Q/Determinant_of_matrix_in_java

Forget about "integrated vs. instantaneous". I was assuming you were having a particular form of experiment in mind. The key problem is: The wave function f(x) at some instant tells you the probability to find a particle at a certain location in case you look for it in this instant. You, however, are speaking about probabilities over a period of time - which is why I said "integrated", since that is usually what you do in some way if you extend something instantaneous over a time interval. The process of "observing" a particle in the context of QM is -to my knowledge- an instantaneous event (*), not a process that extends over some time interval. Therefore, it has no duration. Therefore, you'd have to define what you mean by "observe longer" (*) There is an interesting issue with this statement: QM is supposed to end in classical physics provided one looks at it in the proper limit. Since observations in classical physics are intervals that extend over some time, this raises the question how you'd get from the instantaneous event to the time interval. This is in fact exactly the point that is most unclear in your post. As indicated, I don't know the answer to this question. Since the measurement process is QM is not understood very well (at least according to the people of our mathematical physics group) it may be that this is in fact unknown - but it is more likely that I just don't know the answer.