claforet

In classical mechanics, the flow of electrons through a wire will cause iron filings to align in the direction of the magnetic field which is perpendicular to the flow of the current. Just out of curiosity, has there ever been a similar experiment such that neutrons are fired at high speeds (comparable to electron speeds) down an axis to see if there is any comparable effect? I know the neutron is chargeless so it shouldn't cause any induction, but I'm curious to know if any such experiment has been undertaken. Thanks.

Thanks.

Does that really imply an acceleration? I'm not sure that's true. There is no curvature in the spacetime, it is just a closed gedoesic (there would no way to 'feel' that the spacetime is closed, the only indication that it is closed is that you can return to the point where you started without accelerating (which is what makes it closed)). The implication that the geometry is 'curved' as in GR would mean that the spacetime I'm talking about is embedded in a higher dimensional space which is curved as a result of some energy, which is not the case in my scenario. Spacetime can be both flat and closed (though it would be non-Euclidian).

Sorry, circular was the wrong terminology. I meant a 'closed' 1D Universe.

Hello, I have a question about the measurement of light speed and frequency. How are these physically measured? In particular, when we say the speed of light is constant, are we saying that the front tip of the wave always arrives at the same time or the end of the wave? I ask because it must take less time to resolve the frequency of a gamma ray, relative to a very long radio wave (i.e. the measurement of the frequency cannot be instantaneous). So the speed of information (which is frequency dependant) must not be constant (assuming one wavelength of any frequency corresponds to one unit of information). I'm just curious about the specifics of measurement and calculation. Thanks

Regarding ideal clocks. Let's say two spaceships each have there own clock which is a light source emitting waves with wavelength X (both clocks use the same wavelength). Now they move near the speed of light relative to each other and meet up again (let's imagine a 1D universe which is circular, so one ship can travel around the Universe and meet up with the stationary ship without acceleration). If each person measures time by the number of peaks in the light wave of there clock, and the speed of light is always the same, won't they agree on the total elapsed time (they will have to count the same number of peaks)?