Recent content by linklink

Do you mean the field lines leaving at the inner surface can pass through the ball somehow and enter at some points at the outer surface?

There are two hemispheric magnets, both of them have S on the outer surface and N on the inner surface. If I put them together to form a hollow ball, assuming they are so close that no empty space in the interface, what happens to the magnetic field (inside and outside)? Since magnetic field...

What I know is, for crystalline silicon, we will first make a big pillar of silicon, then cut it into pieces (wafer). Something have to be done to the wafer but I don't know what is it exactly. And finally cut the wafer into small chips. I totally know nothing about thin-film, but then I...

What is the different between thin-film PV cell and crystalline silicon PV cell? Are they using the same material but just differ in the fabrication process? Does a multi-junction PV cell belongs to thin-film or crystalline type?

Let me confirm that :) If Alan measures the wave, he will find: v' = 330+30 = 360 f' = f*330/(330-30) = (11/10)f λ' = v'/f' But if Bill sends out a light signal instead of speaking, Alan will measure the EM wave as follow: v' = v = c f' = f*c/(c-30) λ' = v/f' So Alan and Bill will...

I was thinking about how does the 3D glasses(not the one with red and blue lens) work. My first idea is that the lenses are polaroids with orthogonal polarization. So I got a 3D glasses from a cinema and try to prove it. I wear the glasses properly(with the arms on my ears) and then look at...

Thanks guys. I guess I got a better understanding about doppler effect now~

So...I could say that speed of any wave is constant. However, the properties of EM wave is different from other kinds of wave and light happens to be the only choice for SR to be correct. That's the idea, right?

what I think is if the receiver is moving towards the wave, the frequency appears higher and the wavelength appears shorter so that their product(speed) remain the same, is true for EM wave or any other wave?

I guess I misunderstand the meaning of doppler effect... Let's say Alan is stationary with respect to the air and Bill is moving towards him at 30m/s. The distance between Alan and Bill is 360m, and speed of sound in air is 330m/s. So if Bill speaks with frequency f, what Alan perceived is that...

Doppler effect told us that the frequency and wavelength changed but not the speed of wave if the transmitter or receiver is moving. Could I interpret Doppler Effect as follow: Frequency/wavelength change for different observers, however, the speed of wave is constant for all observers. If...