Recent content by vanesch

For every 250 pulses, themselves made up of gazillions of neutrinos. Of the some 10^20 protons that were sent to the target, some 10^4 neutrinos were detected. That means a "quantum efficiency of detection of 10^-16 or so. Ok, there is the conversion of proton to neutrino, don't know how much...

I was talking about beta and thought about a series development in beta, but now you come to say it, for most relativistic corrections the first non-zero term term is beta-squared. So this pushes the effects indeed in the 10^-12 range or so. I guess this closes the discussion about a...

Well, I don't want to know how the GPS system actually works, what counts is what is the result of it. If it gives you the synchronised reference time in a stationary frame, then you assume that they have build in all necessary corrections to do so. What I wanted to say was that if you...

Right. I stand corrected. I didn't realize that the GR effect was important here, as Vanadium stated that gravitational effects account for something like 10^-10 and I took that for granted. However, SR effects account for about 10^-6 (relative velocities), so if what you say is correct...

I'm having difficulties imagining how you can have a simultaneous time coordinate in a rotating frame. After all, as compared to an inertial frame, clocks at the poles don't suffer any time dilatation as their velocity wrt the inertial frame is 0, while clocks at the equator which have a...

Mmm, but how come then that they find agreement with a land-based survey, which measures in the rotating frame, as they say, in the paper ? Now, I know this is somewhat ridiculous, because the people of the experiment also know all this. It is just that I'm trying to wrap my mind around...

You're right that it is 10^-6 and not 10^-5 (as I mentioned in another post). It might even be taken into account (seems elementary), but I haven't seen it mentioned in the article.

It was Vanadium who mentioned this, earlier in the thread (too lazy to look up the post). If something, I'd bet more on the "simultaneous time coordinate" at Gran Sasso and at CERN. Simultaneity is frame-dependent, and in order for it to make sense as a measurement of "c" (assuming flat...

I guess just as many people here, it is tempting to "guess what went wrong" in this experiment, but some modesty is of course in order as the people looking at this result aren't idiots. So it is fair to assume that the things that have been mentioned in the paper are "well-done" and it is...

If you're talking about *detection* of neutrons, well, you're right: particle detectors want to see charges and neutrons don't provide them *directly*. But there are ways to provide these charged particles *indirectly*: * for fast neutrons, elastic collision will set nucleae of the material...

Yes, you're right of course. My aim was rather pedagogical, because it seemed to me that the OP hadn't grasped the difference between the (Platonic ? ) physical concept of "time" which is not really well-defined outside of a given theoretical frame, and which *might* turn out to be discrete (or...

Well, that would only indicate that the "continuous" model is a bad model, but it wouldn't make the taking of the derivative within the continuous model problematic. BTW, if we could NEVER approach any discrete system more or less reliably with a continuous model, then most fluid dynamics...

The point is that in those situations where you are supposed to take a derivative wrt time, you are working with a *theoretical model* that assumes that time is a *real number* (that is, an element of R). In other words, you are working within the frame of a theoretical model, and within that...

That's a PoV I never thought of but might be extremely relevant actually. The problem to be adressed is not Little Johnny's limited abilities, but teacher Big Joe's limited abilities. Maybe indeed, the right school program is one that is stupid-teacher-proof. :bugeye:

Volume comes up: - The volume of a parallelepiped equals the determinant of the 3 x 3 matrix made up by its 3 "base vectors". (if "oriented" lefthanded, it will come out negative).