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dyosh
Light is affected by gravity. Surely that means that light has a mass, however minute. If this is so then it also has a resistance, any particle does if you push against it, again however minute. So from this i conclude that you can run faster and jump higher in the dark. The difference is probably undetectable.

I am quite sure I'm wrong somewhere along the line, but it all makes sense to me.
AlphaNumeric
Light has momentum so when you're standing in the sunshine, you're constantly being bombarded by light which exerts a small pressure on you. This means when you jump, you've got an extra force pushing you down than just gravity. If you did do it in the dark you would jump slightly higher (assuming you could perfectly replicated the jump) but it'd be fractions of a millimetre.
fivedoughnut
The sun exerts gravitational influence....so you should be able to jump a little higher....although the magma / crust would also swell in its direction producing the opposite affect. Basically get a super sensitive gravitometer and record a few thousand readings from mid-day and midnight and you'll know the answer.

Everything's easy when you're a crank biggrin.gif
fivedoughnut
QUOTE (AlphaNumeric+Oct 13 2006, 09:54 PM)
Light has momentum so when you're standing in the sunshine, you're constantly being bombarded by light which exerts a small pressure on you. This means when you jump, you've got an extra force pushing you down than just gravity. If you did do it in the dark you would jump slightly higher (assuming you could perfectly replicated the jump) but it'd be fractions of a millimetre.

...fractions of a millimetre, get the scale correct dude (zepto, yoctometre might be more appropriate)
dyosh
cheers dudes

is there any particle with less mass than a light particle
El_Machinae
Light doesn't have mass. It has momentum, but in a way different than the type that involves mass

To have less mass than light would require negative mass. I know of no such beast.
NeoDude
Light is not affected by gravity because it has mass. It is affected by gravity due to the fact that is travelling through a mass-induced-curved space-time. Or something. tongue.gif
PhilP
How much is the earth's gravitational pull affected by the moon, which effects tides of course. Would not athletic feats be improved when the moon is overhead? Feats such as running, lifting, jumping etc.
El_Machinae
Yeah, absolutely. You'd be best off waiting for a solar eclipse; that way the sun AND the moon are above you.

That said, I'd imagine that the effect would be minor. reallllly minor.
PhilP
Yes, no doubt. The Sun I think is too far away to have any measurable effect on us personally, though of course we see much greater effect on larger objects. The moon being so much smaller, but much closer, would have the greater exertion I feel.
Nessus
Actually the tidal force produced by the sun is only 1/2 or so that of the moon. So if the moon does have a greater effect but not that much greater (definatly measurable if the moons force is measurable, and no doubt orders of magnitude higher in effect than weither the light is on your head or not)
Freke1
QUOTE (NeoDude+Oct 16 2006, 04:35 AM)
Light is not affected by gravity because it has mass. It is affected by gravity due to the fact that is travelling through a mass-induced-curved space-time. Or something. tongue.gif

Does this mean that a straight line in space-time bends too? Lets say You shine a flash into space - if You are unlucky with the positions of the masses You might illuminate Your own behind. Just wondering! smile.gif
besttech01
Light cannot escape a black hole's gravitational field..
bigjbird82
Light has to have mass that is why it is classified as having particle and wavelike characteristics (dual wave particle theory). the particles of the light do have a mass. which is also why if light is shined (in a vacume) toward a wheel the wheel will rotate. i forget what this experiment is called or who did it but it is true. and it can bend because of this.
AlphaNumeric
Having momentum is not the same as having rest mass. The photon has momentum but no rest mass.
bigjbird82
it does have particles whch is considered to be energy which in the e=mass times the speed of light squared. therfore light does have mass but it is a type called realitivistic mass which can be argued upon but the fact does stand that light does have mass.
Zephir
QUOTE (AlphaNumeric+Oct 25 2006, 08:45 PM)
Having momentum is not the same as having rest mass.

Having rest mass in not the same as having mass.
AlphaNumeric
That doesn't mean you can replace the p in E^2 = (mc^2)^2 + (pc)^2 because the m in that equation IS rest mass.

If you're going to start talking about photon relativistic mass you have to make sure you're replacing the right things in equations with the correct equivalents or you end up mixing up rest and relativistic masses, as you did if you think you replace p with mc in E^2 = (mc^2)^2 + (pc)^2 .
bigjbird82
OH, ok I see what you are saying.
but the question is then still does light have mass?
i will do some reserch and get back on tomarow with experiments and theorys to prove weather or not it really does have mass.
dyosh
but momentum is a force and can't a force only be exerted on something with a mass
VertCoach
dyosh has a point, though wether you can really jump higher in the dark is probably something we shouldn't be worried too much about. No use in jumping high if no one can see you!
Precursor562
QUOTE
is there any particle with less mass than a light particle


If the graviton particle exists then it would most likely be smaller than a photon.
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