Photons carry energy, but have no mass by themselves.
This is correct, and according to Einstein's theories photons (or anything else) can only travel at the speed of light if they are massless. Only on science fiction shows like Star Trek do bodies with mass travel at (or beyond) the speed of light.
Kerry
The emulsion would increase in mass by a tiny, tiny amount. The siliver halide crystals' shared electron clouds would "capture" (some of) the photons and change their internal quantum mechanical state, moving to a slightly higher energy level. The resultant mass change would be equal to (in the MKS system) the captured-electron-energy (in newtons) divided by the speed of light squared. The demoninator is very large (9x10^16 m^2/s^2) and the numerator has to be very small, also. The resultant mass change is probably less than the mass of one electron. Somebody out there calculate the lux-seconds exposure for 18% gray on 100ASA film which gives your favorite density for that (in logD), then covert this to MKS and divide by 9x10^16, and you will then have your answer, in kilograms. Me, I'm going to go watch the X-files with no lights on and leave the calculations to bigger geeks.
LOL...glad to see I am not the only one with all this time on my hands...:-)
LOL...glad to see I am not the only one with all this time on my hands...:-)
But look at the bright side! Do appreciate these priceless (I wouldn’t say useless) tides of information to broaden our horizons. Additionally, all this time spent on threads like this prevents us to make bad and boring photographs and thus the hapless public and we all benefit :-)))))
Linhof is working on a device to compensate for this. It is very, very expensive.
My film definately gets heavier when I make an exposure. Its all the !@#$%^&*( dust that attaches itself to the film. Its like some freaky parasitic mating ritual.
hmmm..you know now that I think about it, I think it does get heavier after exposure, must be the reason the effing backpack is twice as heavy going back to the car than it was leaving it...:-)
So does gamma, which I heard constantly bombards the earth and adds to the fog of film, also lighten the weight of film? Or ...
Film gets lighter, but only when the fog is lifting.
Not true Kerry!
>Only on science fiction shows like Star Trek do bodies with mass travel at (or >beyond) the speed of light.
Every time I walk into B&H all the cash in my wallet disproves Einstein... it flies into their cash register at SEVERAL times the speed of light!
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