swansont

I was joking about the use of "midterm" for exams that do not take place mid-term (and take place more than once). That always annoyed me when I was TA-ing in grad school, because all of the physics professors seemed to do it.

Midterms in September? Are you done at the end of October, or did you start in July/August?

That post is perfectly consistent — the system becomes more tightly bound, energy is released and the mass decreases.

It doesn't. Mass decreases in fission of heavy isotopes and fusion of light ones.

What would be the next step is to devise a way to test for these items to be confirmed or falsified. Each and every one. However, many of these are demonstrably false (nuclei comprised of deuterons — hydrogen would be surprised to find this out — and a universal reference frame, to name two). Perhaps you could read a few physics texts to see what we know and why. If your hypothesis requires all of these be true (i.e. they depend on each other) than the whole shebang is false.

! Moderator Note An understatement, to be sure. FYI, vuquta has been banned (details in the banned user log post), so there is no further point in responding to him

OK. Sorry for the misunderstanding.

Short answer is no. Most matter with which we are familiar is either baryons (neutrons and protons) or leptons (electrons), and both baryon number and lepton number are conserved quantities. The photon is neither, so while photons can be created, matter does not just turn into photons. You would have to start with the total baryon or lepton number at zero, e.g. matter/antimatter annihilation.

The wavelength in a medium is lambda/n, where n is the index of refraction

vuquta has been banned for repeated thread hijacking, reintroduction of topics of closed threads, and soapboxing

Except that it does — spacetime is bent by energy.

V=IR So, yes, though normally the cause and effect are reversed — you raise the PD in order to increase the current.

Yes, they are different things. I meant energy conservation does not apply between frames or with multiple frames, since it is not an invariant quantity.

I see nothing in D H's post that would lead one to conclude this. Yes, it did. It had a 100-day travel period. SR reciprocity assumes an inertial frame of reference, and SR does not account for gravitational effects. An orbit is not an inertial frame, and gravity is present. ——— Incidentally, the measurement of time dilation has been done in an accelerating reference frame, sans gravity. Mossbauer spectroscopy using a rotating cylinder. You can solve it with either the kinematic dilation or use a potential from acceleration, like you do in GR. Either way, you get v^2/2c^2 Measurement of the red shift in an accelerated system using the Mossbauer effect in Fe-57 Phys. Rev. Letters. 4, 165 (1960) H. J. Hay, J. P. Schiffer, T. E. Cranshaw, and P. A. Egelstaff Measurement of Relativistic Time Dilatation using the Mössbauer Effect Nature 198, 1186 – 1187 (22 June 1963) D. C. Champeney, G. R. Isaak and A. M. Khan

IIRC, two neutrons cannot form a bound state. Even of they could, it would be unstable and decay, either splitting it up or forming Deuterium. Larger collections would likewise be unstable — there would always be unoccupied proton states representing a lower energy state. They might be formed temporarily in a reaction, but would not be a final product. Neutronium can form because of the large gravitational energy involved, but this will only manifest itself when you have a lot of mass.

Have at it. (Moved this to a new thread so spammer could be banned)

! Moderator Note I don't think you've gotten bad information here, so if you are feeling frustrated with the concept, please don't take it out on others Yes; that's not being contradicted here. Mass is a form of energy. Photons are something else that can have energy.

No, not really. It's not like all of the rotation is along parallel axes throughout the universe. That's not even true in our solar system.

If the supernova releases more energy than the gravitational well's depth, then it won't have to re-collapse, but even if it is less, there will be a distribution of energies given to the particles. Some would have enough energy to escape, and we know that a supernova leaves behind a core. The gravitational potential energy of a uniform sphere is -3/5 GM^2/r, and even though the sun isn't uniform, this gives us a starting point. This potential energy is of order 10^41 Joules. if you took the mass of the sun as Hydrogen and converted it all to Helium, you would release ~10^45 Joules, so it seems reasonable that a supernova of a sun-like star is capable of blowing itself apart.

It will have a slightly smaller energy, because of the energy it has transferred to the target, which is p^2/2m, and since the photon's momentum is E/c, the energy reduction is E^2/2mc^2, so the fractional reduction in the photon's energy is its energy divided by twice the mass energy of the object it hits.

However, the effect is noticeable on smaller objects — the forces and torques on satellites and asteroids has a measurable effect. http://en.wikipedia.org/wiki/Yarkovsky–O'Keefe–Radzievskii–Paddack_effect http://www.sciencemag.org/cgi/content/abstract/131/3404/920 http://repositories.lib.utexas.edu/handle/2152/6623

The Crookes radiometers you can buy use heating, not radiation pressure — they rotate the wrong way for radiation pressure to be the cause. Absorption gives a momentum kick of p = E/c to whatever absorbed the photon. But if it's reflected, it gets an additional kick, since the photon goes back in the direction from which it came. This second kick will be slightly smaller since a tiny amount of momentum and energy are transferred to the target. But as an approximation, it will be 2*p

c being constant in all frames refers to inertial frames while the Sagnac effect is due to an accelerating frame, so consistency isn't expected. No competent physicist expects to measure rotational Sagnac using a MM interferometer; the null result from that experiment was not an attempt to measure rotation.

And because of length contraction, you won't have clocks in agreement at other points — clock synchronization uses d=ct

! Moderator Note This is ridiculous. Thread closed