Light is a Particle!

Using duct tape and a laser pointer, you can show that light behaves like a particle!

[JeffersonLab]

Light isn't matter, so it has no chemical composition.

[SkuHax]

Did a failed experiment replace Steve's mind with a cat's mind?

[davidisawesome]

Because if you dissect the law of gravity down to the essentials, gravity affects not only objects with mass, but with energy. Since light carries or possesses energy, it is affected by gravity.

[assassin]

Light is both a wave, and a particle.

[JeffersonLab]

Photons have no mass. Talking about a photon's rest mass doesn't make any sense... When are photons ever at rest?

[JeffersonLab]

This is showing that light is quantized. An experiment very similar to this was one of the primary stepping stones leading to the development of QM.

[sammy]

Oh light, why you so complicated and shy when observed.

[JeffersonLab]

E=mc^2 applies to particles with mass (which light does not have) that are at rest (which light is not). The full form of the equation is E^2 = (mc^2)^2 + (pc)^2. So, for massless particles, E = pc. See watch?v=NnMIhxWRGNw for a nice explanation of this.

Light is affected by gravity because matter warps the very fabric of space-time. Light just follows the curvature.

[JeffersonLab]

No, light is a massless particle. It has zero rest mass. None. Zilch. Nada. Light does carry momentum, but that isn't the same thing as having mass.

The solar wind is something entirely different. It is made of actual particles - protons, electrons, etc... - that have left the sun at high speed. The solar wind is NOT composed of light. According to Space Weather, the speed of the solar wind, at this moment, is 290 km/sec. That's 3 orders of magnitude slower than the speed of light.

[JeffersonLab]

Light isn't matter. It doesn't have mass.

[JeffersonLab]

No, it's because green photons are more energetic than red photons.

[JeffersonLab]

Light is a form of energy. You can't combine it with particles of matter to form 'compounds, ' for lack of a better term.

[JeffersonLab]

Depends. If the pink object is just a pink object, without a fluorescent dye, then the blue laser will make a blue spot. If it has a fluorescent dye, the color you get would be dependent on the characteristics of the dye.

[JeffersonLab]

This seems to be a cousin of the photoelectric effect. Electrons aren't liberated from the material, but I think they are being transferred from one molecule to another, based on the relative continuity of the emitted spectrum.

[JeffersonLab]

We don't have a blue laser, so we can't test it. My guess is that it won't be the same orange color since the blue light's greater energy will allow the dye to fluoresce over a greater range. With a green laser, the highest energy photon than the dye could possibly emit is green. Blue light opens up the 'green to blue' range that's 'above' green light's reach.

[JeffersonLab]

Not really. Light has wave-like properties and particle-like properties.

[JeffersonLab]

Because gravity is a warping of space-time caused by objects with mass. Light is 'pulled' by gravity because light follows the warping of space-time. Think of an ant crawling on a curved sheet of paper. As far as the ant is concerned, it's crawling in a straight line although it's really following the curvature of the 'space' it's in.

[JeffersonLab]

An object -with mass- appears to become more massive as its relative speed increases. Photons are massless to begin with.

[codediporpal]

Yeah, I learned in high school that gravity acts on mass, and that the attractive force between two objects is directly proportional to the mass of objects. That was Newton's theory (I think?). The theory fit most observations, but there was mounting evidence 100+ years ago that it was not totally correct. That's where Einstein's theories of relativity come in. Galaxies can bend light so much that astronomers see double images in the distant sky.

[GameSlimeOG]

Right, but it is particle. Particles make up matter. So, can we combine light with other particles to form matter?