swansont

We know it can be bent and it can expand.

This is basic algebra. If it's causing you problems you need to refresh yourself on it. Physics is going to be mighty difficult to do otherwise.

There are basically four ways to get EM radiation accelerate a charge, and Maxwell's equations give you this result. This is responsible for things like bremsstrahlung, like in an x-ray machine (slamming high energy charges into things) or antennas for radios annihilate a particle and an antiparticle have an atomic reaction, e.g. de-excitation (E-M force) have a nuclear reaction, e.g. a decay or de-excitation (nuclear forces) So the question is a bit ill-formed, at this level. There really isn't a fundamental origin. Photons have energy, so basically any interaction can give you photons.

The wavelength dependence on speed is non-Newtonian and nonlinear — it varies inversely with [math]\gamma^2[/math] http://pbpl.physics.ucla.edu/Research/Theory/Free-Electron_Laser/

part a: acceleration is a vector part b: you only substituted in for a; the 2d is missing. (You've also assumed that the electron strikes a plate by using that calculation)

One major problem I see is that corporations have a huge influence on government, which helps to perpetuate the corporations and the people who run them. I think it's undemocratic to have the volume of your voice be proportional to the size of your wallet, or worse, the much larger wallet you control by virtue of running a corporation of which you may only own a tiny fraction. IMO, corporations are not people and should not be afforded the same kind of rights, and money isn't speech.

I'm both a physicist and a non-physicist when nobody's looking.

AFAIK the period of oscillation of the magnetic field depends on the original magnet spacing and the electron speed. If you want a higher frequency, you speed up the beam.

That would be "impart angular momentum to thermodynamically energized organic accretion discs." He has a degree in astrophysics, after all.

Oh, definitely. There seems to be an attitude of entitlement to success rather than to opportunity, and it's becoming more and more pervasive.

GR breaks down at the very small scales where quantum effects are seen. See the "Quantum and Relativity" thread, in theaters now. http://www.scienceforums.net/forum/showthread.php?t=26246

This is discouraging to hear. In this day and age, with the ease of information flow, I'd expect the bar to be raised, not lowered, since it takes less time to search for and identify sources of information. The only mitigating factor would be that with more information available, sorting the wheat from the chaff is tougher. Equally sad is that a professor would be willing or compelled to let this slide. That person either isn't doing their job properly, or isn't being allowed to. The mention of faculty-wide rules indicates that at least some of this attitude is being dictated from above. Institutionalized lowering of the bar to keep allowing one to continue to declare "success" is disheartening.

http://www.scienceforums.net/forum/showthread.php?t=22093 http://www.scienceforums.net/forum/showthread.php?t=170 http://www.scienceforums.net/forum/showthread.php?t=10369 http://www.scienceforums.net/forum/showthread.php?t=10315 The search function is a useful tool

But there is an indirect interaction. According to QED photons should have a lower-order interaction with other photons, but this would be very weak and only become noticable when the photon density is very high. IIRC it involves each photon becoming a virtual electron/positron pair and interacting, so the probability scales with photon energy.

My experience with GR is qyuite limited, but AFAIK it depends on how he measures it. If you confine yourself to a locally flat region, you will get c. If you don't, you will get something else. And radially you will have gravitational length contraction, so if you don't have flat spacetime, you will get different answers for radial and transverse values.

It's not cyclic, since the lifetime will be dilated by a factor gamma that has a speed dependence, i.e you can make a specific prediction and measurement. A lifetime increase that was e.g. half as big or twice as big would falsify, not support, SR. And the muon lifetime has indeed been measured for muons brought to rest by capture in a plastic scintillator. http://web.mit.edu/c_hill/www/muons_paper.pdf

Space is not devoid of matter/energy. There is what is called the zero-point energy, and particle/antiparticle pairs briefly pop into existence and annihilate everywhere.

The pressure you feel in your fingertips is indeed the electromagnetic repulsion of the atoms. Interacting like that is the quantum equivalent of touching.

I would say yes. e.g. http://adsabs.harvard.edu/abs/1985E&PSL..73..407F http://www.agu.org/pubs/crossref/1995/95GL02064.shtml There are lots of links to different compositions. Though it seems that not only does composition matter, but whether you have a eutectic mixture or not matters, too.

I would imagine it's going to depend on the chemical composition. There are different types of lava.

Actually serious7 has been talking/asking about speed and has been using distance (scalar) and not displacement (vector). So speed is appropriate for that.

If we knew specifically what it was, it wouldn't be called dark matter. That's the placeholder name given to whatever is responsible for the observed deviation from known physics in galactic behavior.

But it gives the eruption temperature as the starting point. There's either bad geology or bad physics here, methinks.

As the units imply, the specific heat capacity tells you how much energy per degree per kg it takes to heat or will be given off by cooling the substance. So [math]Q = mc\Delta T[/math] However, this does not account for heat of fusion as it solidifies, and solids will typically have a different heat capacity as it cools below this point. So either it's a really badly written question, and you need to solve for m, or there's more information needed.

I was able to dole out reputation, so it appears it's been enabled down to the resident expert level, at least.