I’m surprised nobody has posted about finding the speed of light with a chocolate bar and a microwave, because I find that absolutely mindblowing.
The basic experiment is to take the turntable out of the microwave and put in the chocolate, nuke it for a couple of seconds until part of the chocolate starts melting and then measure the distance between the melting patches. If you have a standard microwave, you’ll be on a frequency of 2.45 GHz (you can check this online or in the manual). Multiply the distance between the spots by 2,450,000,000 (or whatever the frequency is) and then by 2 and you will end up with c, to within whatever accuracy you measured the melting spots.
I guess if you were really skeptical you could say that you have no reason to believe that v = f * lambda, or that the manufacturers of microwaves or rulers were colluding to decieve you, but I think this is around the point where you can start claming the evidence of your eyes is decieving you and so on—too skeptical to add anything useful to the discussion.
This is actually a really good example of what I wanted.
I think I have a lot of reason to believe v = f lambda—It follows pretty much from the definition of “wave” and “wavelength”. And I think I can check the frequency of my microwave without any direct assumptions about the speed of light, using an oscilloscope or somesuch.
I’m surprised nobody has posted about finding the speed of light with a chocolate bar and a microwave, because I find that absolutely mindblowing.
The basic experiment is to take the turntable out of the microwave and put in the chocolate, nuke it for a couple of seconds until part of the chocolate starts melting and then measure the distance between the melting patches. If you have a standard microwave, you’ll be on a frequency of 2.45 GHz (you can check this online or in the manual). Multiply the distance between the spots by 2,450,000,000 (or whatever the frequency is) and then by 2 and you will end up with c, to within whatever accuracy you measured the melting spots.
I guess if you were really skeptical you could say that you have no reason to believe that v = f * lambda, or that the manufacturers of microwaves or rulers were colluding to decieve you, but I think this is around the point where you can start claming the evidence of your eyes is decieving you and so on—too skeptical to add anything useful to the discussion.
This is actually a really good example of what I wanted.
I think I have a lot of reason to believe v = f lambda—It follows pretty much from the definition of “wave” and “wavelength”. And I think I can check the frequency of my microwave without any direct assumptions about the speed of light, using an oscilloscope or somesuch.