do photons loose energy as they travel through air or do they just get spread out?

IAm5toned

IAm5toned

Well-Known Member
designs lighting systems for a living :/

lol, but i love a good discussion.

that article is 11 years old, btw.....

and i will argue and say they were NOT slowing down light.

a bose-einstein condensate is matter packed so densly and at such low pressure (aprox 1bill mB than atmospheric pressure) that when a proton strikes the surface of the condensate, the atoms of the condensate are so supercooled and slowed, that the interval between photon impact and photon departure is drastically reduced. there not changing the speed of light, they are slowing the time frame between the initial impact of energy, and then release of energy in the forms high energy particle emmission, aka light/photons.

law of conservation of energy man.... u cant slow down a particle w/out a transformation... and even then its not slowing, your simply converting one particle into heat/energy, which in turn excites another atom to emit a particle... what there slowing is the time it takes for that reaction to occur, NOT the speed of a photon, which, as i stated before, a universal constant....

at least thats the way i interpret it :)
 
Tym

Tym

Well-Known Member
IAm5toned said:
designs lighting systems for a living :/

lol, but i love a good discussion.

that article is 11 years old, btw.....

and i will argue and say they were NOT slowing down light.

a bose-einstein condensate is matter packed so densly and at such low pressure (aprox 1bill mB than atmospheric pressure) that when a proton strikes the surface of the condensate, the atoms of the condensate are so supercooled and slowed, that the interval between photon impact and photon departure is drastically reduced. there not changing the speed of light, they are slowing the time frame between the initial impact of energy, and then release of energy in the forms high energy particle emmission, aka light/photons.

law of conservation of energy man.... u cant slow down a particle w/out a transformation... and even then its not slowing, your simply converting one particle into heat/energy, which in turn excites another atom to emit a particle... what there slowing is the time it takes for that reaction to occur, NOT the speed of a photon, which, as i stated before, a universal constant....

at least thats the way i interpret it :)
Click to expand...
Actually no, I'm a theoretical physicist. Not that it matters though.

11 years old or not, it is still demonstrable. Need I mention that the conservation of energy is older than 11 years? No I don't cause it makes no difference, nor does the article I posted being 11 years old.
What does make a difference though, is that once the photon impacts anything... Well you should get the picture..
Yes it is slowing down light, no not the photon itself, but light itself. Nobody claimed the photons themselves were slowing down.
I'll say it again. Visible light that travels through transparent matter does so at a lower speed than c, the speed of light in a vacuum.

Alternatively, photons may be viewed as always traveling at c, even in matter, but they have their phase shifted (delayed or advanced) upon interaction with atomic scatters: this modifies their wavelength and momentum, but not speed.http://en.wikipedia.org/wiki/Photon#cite_note-90 A light wave made up of these photons does travel slower than the speed of light. Definite distinction between the light wave, and the photons that make it up.
 
D

Dako

Member
ah science. so what are your theories on physics tym? (unrelated to this discussion please, I think i got everything I could out of it)
 
C

chewy2282

Member
I am a firm believer that the density of the finished product is related to how fart your light is away from your plants. With that being said i use a 400watt light. I put it down about 6-9 inches away from my plants. I then blow a fan across the tops of the plants to pull the heat off(oh yeah i have a reflector thing that keeps hot spots away from the plant tops). Then i have my fan sucking the hot air off the top of the room. I average 1.5 to two 0nces a plant. I think its pretty good results for organic soils and fertilizers.
 
Brick Top

Brick Top

New Member
chewy2282 said:
I am a firm believer that the density of the finished product is related to how fart your light is away from your plants.
Click to expand...
PLEASE tell me you meant to type far and not; "fart."

But you belief is explained by what I already posted and what was mentioned by others.


Inverse Square Law, Light

As one of the fields which obey the general inverse square law, the light from a point source can be put in the form
where E is called illuminance and I is called pointance.
The source is described by a general "source strength" S because there are many ways to characterize a light source - by power in watts, power in the visible range, power factored by the eye's sensitivity, etc. For any such description of the source, if you have determined the amount of light per unit area reaching 1 meter, then it will be one fourth as much at 2 meters.
 
Ronjohn7779

Ronjohn7779

Well-Known Member
They scatter, reflect, refract, get absorbed. and bounce. They generally move at or near the speed of light. Different mediums will slow them down a bit. If I'm not mistake water does this (which is kind of why a pool warms up on a hot summer day). Water absorbs some of the energy as heat.

It's been a long while since I've taken a physics class so I could be off a bit, but I think what I wrote is "generally" correct.
 
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