Recent content by RobtO

When I read about the launch location, it is explained that the French Guiana launch site was chosen because it is close to the equator, which means it started with a larger tangential speed than if it were launched from a US location. However, doing the numbers, I find that an initial...

I think option (1) is closest to the modern physicist's view. An object can emit energy, for example in the form of electromagnetic radiation, and its mass afterward will be less than its mass before. Or, a particle and its antiparticle can collide, and the result will be (can be)...

Not sure how you got 104. If I take the "near" distance to be 1000 km (pretty much right on top of them, if I did the Schwarzschild radius correctly), then I get a strain of 10-2. I don't think that would kill you. At the Earth-Sun distance from the merger, you wouldn't even feel it. Am I doing...

But doesn't the formula P(A|B) = {P(A \cap B) \over P(B)} reduce the conditional probability to relative frequencies?

Thanks for the responses. It seems that what folks are saying is: probabilities are what you predict, but relative frequencies are what you actually measure. If this is the case, I'm not sure why the authors make such a big deal about the distinction. In physics, of course, we constantly have to...

I am reading "The Quantum Theory of Measurement," by Busch, Lahti, and Mittelstaedt, and I came across this statement (p. 44, 1996 ed.): "The difficulties encountered in giving a precise formulation of this idea are due to the facts that relative frequencies are not probabilities, and...

Right. The wavefunction tells all. But it doesn't exist physically. (My interpretation, YMMV.) See jtbell's answer above. Evolving wavefunctions is all. Unless you subscribe to Bohm's version. One wavefunction. In principle, you'd see a diffraction pattern, just like with light. But I...

I used Ohanian's book for an undergrad course in general relativity and thought it was one of the best textbooks I've ever used. https://www.amazon.com/dp/0393965015/?tag=pfamazon01-20

As I understand it, a Majorana neutrino will look like an antineutrino in some reference frames. So, yes, it is the helicity that makes the difference, and, right, it is not Lorentz invariant.

You're right - in modern particle physics is is ASSUMED that particles are point-like (have no structure) and are described by one of the relativistic quantum equations (Dirac, Klein-gordon, etc.) These questions are not very helpful at our current state of understanding (except for mass...

But what about circular orbits at r=2M? Are they possible, too?

In MTW it is derived that a photon can orbit a black hole at a radius r=3M. However, the surface at the Schwartzschild radius r=2M is lightlike, isn't it? So can a photon orbit at both radii? What am I missing?

That's sort of close. Remember E=mc^2. So, if you smash particles together with enough energy, some of the time that energy will be converted into mass in the form of whatever particles are available. When you crank up your accelerator to a high enough energy to produce a new particle (b-b-bar...

A simpler way to see that the strong force beats EM is to note that atomic nuclei don't fly apart. Any nucleus with two or more protons experiences EM repulsion between the protons. Some stronger force must be holding them together.

Thanks for the link! I'll need to study that a while...