Does light weigh anything, and if so, how do you measure it?
2007-06-09 08:33:48 · 25 answers · asked by twopigbus 1 in Science & Mathematics ➔ Physics
Light does not have mass because light is a frequency which is measured per unit time. That is a hertz (1/sec). You can measure light with a photo-meter. That is a device that detects photons.
2007-06-09 08:39:20 · answer #1 · answered by Deevah 2 · 0⤊ 2⤋
No, light most certainly does not have mass. The only meaningful definition of mass is a bodies inertial resistance to a change in its velocity. In no sense can a constituent of light - a photon - be accelerated or decelerated. Therefore light cannot have mass.
It is appalling to see the number of comments erroneously stating that light has mass. Be absolutely and categorically certain, there is no sense in which that is true. It is true that light can be "bent" by gravity, however this is universally true, and due to the fact that light still has energy, despite not having mass.
2007-06-09 20:54:47 · answer #2 · answered by Alan C 1 · 0⤊ 0⤋
It has no rest mass, but it does have momentum according to the equation p = E / c where p is the momentum, E is the energy and c the speed of the photon.
The reason light appears to be "bent" by gravity is that gravity distorts space time (Einstein) into a curved shape and light follows that curve.
2007-06-11 08:11:33 · answer #3 · answered by Red Rose 7 · 1⤊ 0⤋
Well as far as i've been told it doesnt have mass, but it does have momentum...!!!!!!!!!???????????!!!!!! But definatly no mass or it cannot reach c!
It does get affect by gravity as some may/have pointed out but that is nothing to do with mass or anything like that its becuase time is slower the greater the gravitational field, and therefore the light waves are seen to (relatively) slow down the nearer they get to heavy bodies. They will also curve towards the mass due to refraction (if any one side of a wave is slower the whole wave will turn toward that side.
2007-06-11 04:34:00 · answer #4 · answered by Flash 2 · 1⤊ 1⤋
You might want to google or wiki. the word photon. Light doesn't really weigh anything but the really cool thing is light can be bent. Do some homework on it, there's plenty of info out there. Or just read Mercury 2010's response!
2007-06-09 15:41:51 · answer #5 · answered by Anonymous · 2⤊ 0⤋
If light had mass it could not travel at the speed of light.
2007-06-13 10:07:38 · answer #6 · answered by johnandeileen2000 7 · 0⤊ 0⤋
Light does not have a resting mass. Like all EM radiation, light is a disrupted electric field propogating through spacetime.
2007-06-10 07:02:26 · answer #7 · answered by Andrew H 2 · 0⤊ 0⤋
Light photons, even though they are energy, DO in fact have an infinitesimal amount of mass. Without any mass, photons could not be "bent" by gravitational fields. And according to E=mc2, ALL energy contains mass, and all mass contains energy.
2007-06-09 16:40:49 · answer #8 · answered by Steev 2 · 1⤊ 1⤋
light does not have a mass or weight. you measure the watt output
2007-06-09 23:52:46 · answer #9 · answered by einsteinliam2 4 · 0⤊ 0⤋
Yes, other wise kirks starship wouldnot have photon torpedoes! in actuallity,yes light does have mass (the photon) and hence weight. look at laser cutters of sheetmetal and other solids. light is a fantastic thing and its secrets have more yet to unravel
2007-06-09 16:04:16 · answer #10 · answered by Anonymous · 1⤊ 0⤋