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An Interesting thing About Light
October 26, 2017 at 6:41 pm
I was just thinking (shut up, Iggy) about light and my thoughts led me to a curious conclusion. Not being a scientist, I may be totally wrong, but then again, I may be half right. What do you think?
I mentioned some time ago that when we turn a light switch off the photons that have already spread throughout the room disappear. So radiation of visible light is not separate from its source.It just occurred to me that this means that while the light from a star a million light years away will take a million years to reach us, when that star dies, it won't take a million years for the radiation that has reached us to disappear.
Have any scientists written about this behavior of light? I'd like to know what they have to say.
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RE: An Interesting thing About Light
October 26, 2017 at 6:44 pm
An interesting thing about light; it's better than heavy.
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RE: An Interesting thing About Light
October 26, 2017 at 6:56 pm
The photons don't disappear, they are scattered or absorbed by solid objects.
If our sun were to wink out right now, we wouldn't know it visually for about 8 minutes. Alpha Centauri, 4.4 years
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RE: An Interesting thing About Light
October 26, 2017 at 7:16 pm
(This post was last modified: October 26, 2017 at 7:17 pm by ignoramus.)
Correct Rhonda.
Quite a good portion of the night sky has long died.
We are basically seeing a snapshot of how things were millions/billions of years ago due to the speed of light limit...
So much for 'wish upon a star'!
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RE: An Interesting thing About Light
October 27, 2017 at 10:33 am
(October 26, 2017 at 7:16 pm)ignoramus Wrote: Correct Rhonda.
Quite a good portion of the night sky has long died.
We are basically seeing a snapshot of how things were millions/billions of years ago due to the speed of light limit...
So much for 'wish upon a star'!
The beauty of it is, we can still wish on any star that's still visible because if it were dead the radiation would be gone like a light bulb. Look at it this way, light travels at a limited speed, but we're not talking about light traveling. We're talking about photons being cut off from their source. They don't travel back to the source, so they don't take the same amount of time to disappear as they took to get here.. They're just no longer visible.
This does not preclude the idea that the photons are dispersed or absorbed.
The god who allows children to be raped out of respect for the free will choice of the rapist, but punishes gay men for engaging in mutually consensual sex couldn't possibly be responsible for an intelligently designed universe.
I may defend your right to free speech, but i won't help you pass out flyers.
Those who can make you believe absurdities, can make you commit atrocities.
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Nietzsche isn't dead. How do I know he lives? He lives in my mind.
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RE: An Interesting thing About Light
October 27, 2017 at 6:11 pm
(This post was last modified: October 27, 2017 at 6:11 pm by ignoramus.)
Bad news everybody!
Our beloved sun, exploded in a fiery death 3 minutes ago.
Pease, nobody panic for the next 5 minutes....Just go on about your business.
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RE: An Interesting thing About Light
October 27, 2017 at 6:24 pm
(October 27, 2017 at 6:11 pm)ignoramus Wrote: Bad news everybody!
Our beloved sun, exploded in a fiery death 3 minutes ago.
Pease, nobody panic for the next 5 minutes....Just go on about your business.
I suppose if it really did happen I'd whip it out and try to time the orgasm juuuuust right.
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RE: An Interesting thing About Light
October 27, 2017 at 8:36 pm
(October 27, 2017 at 6:24 pm)Aegon Wrote: (October 27, 2017 at 6:11 pm)ignoramus Wrote: Bad news everybody!
Our beloved sun, exploded in a fiery death 3 minutes ago.
Pease, nobody panic for the next 5 minutes....Just go on about your business.
I suppose if it really did happen I'd whip it out and try to time the orgasm juuuuust right.
That would be one HOT handful.  
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RE: An Interesting thing About Light
October 28, 2017 at 1:35 pm
(This post was last modified: October 28, 2017 at 1:37 pm by c152.)
I don't think that's how light works. Once a photon leaves its star they are separate and the photon will carry on regardless of the fate of what ever source it was created by. That's why, as Cthulhu Dreaming mentioned, it takes time until the last photon from a dying star reaches us and it disappears from our sky. So they aren't connected, the photon and the star, the light of a star is just a continuous stream of photons.
And when the star dies its last photons are sent out and it's sort of like unplugging your vacuum cleaner and rolling up the chord, it takes time before the end of the chord reaches the vacuum cleaner. Basically the earth is a vacuum cleaner and stars are just millions of chords that may or may not be rolling up right now and we won't know it until the final photon reaches us.
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RE: An Interesting thing About Light
October 28, 2017 at 2:29 pm
(This post was last modified: October 28, 2017 at 2:29 pm by vorlon13.)
as the universe expands, the 'free range' photons will have their wavelength increase and increase and increase
and as the wavelength increases, the energy of the photons decreases
the process 'never' stops
trillions and trillions of googolplexes years and those wavelengths are billions of billions of light years long, the photon energies are vanishingly minute
and the universe continues to expand
relentlessly diluting itself in the void that becomes closer and closer to infinite every billion billion years
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