Does light last forever? We see stars as they were billions of years ago by gathering far spread out and far travel light photons? If so is there a point were the photon would break down and disipate? DOes light go on for eternity albiet scattered so far apart that it is not detectible?

Does light age?

[edit on 25-9-2004 by Xeven]

I think you'll find the definitive answer by googling Einstein and Relativity.
Roughly though....Time passes slower the faster you travel, to the point where at the speed of light (a photon) time stops. Photons therefore have no concept of time, as everything in their 'lifetime' happens all at once. They only get destroyed (or rather converted into another form of energy) if they collide with anything. Not sure if photons actually 'wear out' over the years.
I think this is right.

Originally posted by Xeven
Does light last forever? yes

We see stars as they were billions of years ago by gathering far spread out and far travel light photons? true, witness Hubble & Vast Array Telescopes in several different bands of Electro Magnetic Spectrum

If so is there a point were the photon would break down and disipate?Yes, at the Event Horizon of (theoretical) Black Hole

DOes light go on for eternity albiet scattered so far apart that it is not detectible?Yes, AND with a large enough LENS (eyeball)...say Galaxy size...the very early universe would appear sharper/clearer/ distinct

Does light age?No, & neither do radio, microwave, gamma ray, etc etc etc...as they are energies

[edit on 25-9-2004 by Xeven]

...and Irma(s) next-to-last sentence...'wear out' of photons>> I think maybe the photons don't wear out, they are just covered up with layers of additional material[photons from other sources] which competes for the same 'space'...[here we go with the gigantic scale lens again]

just a rambling thought line, have a nice day/night

Some would say light last as long as its energy exists.
This is wrong.

Light = Energy

Energy and matter can't be destroyed, only converted into another form of energy or matter.

So light last as long as it isn't converted to matter or another form of energy.

Light/energy gets converted into mass and other energy's all the time.
Check out photosynthesis.

Well, that depends. Most light, such as that emitted by galaxies is diffuse - it spreads out in all directions in a spherical wave. That means that at a given distance, light intensity decreases by a factor of the distance squared. So after a few dozen light years, you'd only get a coulple hundred photons per square centimeter... Also, the light is likley to be absorbed by hydrogen clouds and such. Lasers, however, as their photons share a wave function and don't propagate spherically, have (theoretically, of course...) constant intensity at any distance. Which is why they're so neat.

Also, light can be lost if it goes into a black hole, or interacts with other non-baryonic stuff... electrons, for example.

Does light age?

There are such things as stupid questions. Light is the byproduct of a chemical reaction for crying out loud.

Does light last forever?

Check out the life cycle of a star.

We see stars as they were billions of years ago by gathering far spread out and far travel light photons?

I don't understand. This is also a stupid question, that is phrased in such a way that it has no answer.

If so is there a point were the photon would break down and disipate? DOes light go on for eternity albiet scattered so far apart that it is not detectible?

no, no


PS This thread is pointless.

[edit on 25-9-2004 by websurfer]

Woa, woa. Calm down Websurfer

Originally posted by websurfer
Does light age?

There are such things as stupid questions. Light is the byproduct of a chemical reaction for crying out loud.

Does light last forever?

Check out the life cycle of a star.

We see stars as they were billions of years ago by gathering far spread out and far travel light photons?

I don't understand. This is also a stupid question, that is phrased in such a way that it has no answer.

If so is there a point were the photon would break down and disipate? DOes light go on for eternity albiet scattered so far apart that it is not detectible?

no, no


PS This thread is pointless.

[edit on 25-9-2004 by websurfer]

Sorry for the stupid questions. You see, I am almost retarded, and I never went to school. I am just asking these stupid questions to try and catch up, best I can, with you well educated, higher class human beings. Please forgive my obvious stupidity. I'll try and ask smarter questions to stimulate your excellency.

X

[edit on 26-9-2004 by Xeven]

Please show some respect on this thread!

If you have nothing to add then please don’t,

If you can help answer the questions please do in a respectable manner,
thank you

Asala

Now back on top the topic at hand please,

Yes the light will continue going on forever unless it is absorbed by a material. While the light is travelling towards us it may inconter other planets, stars, gas clouds gravity wells etc, so only a fraction of it arrives at us.

When light gets absorbed, it hits an electron and exites it to a higher energy level and then it falls back to a lower energy level and re-emits the photon(i think)

Websurfer, not all people on these threads have an understanding of physics, chemistry, mechanics or what-not. There's no such thing as stupid questions Please try to be a bit more patient

Originally posted by websurfer
Does light age?

There are such things as stupid questions. Light is the byproduct of a chemical reaction for crying out loud.

Does light last forever?

Check out the life cycle of a star.

We see stars as they were billions of years ago by gathering far spread out and far travel light photons?

I don't understand. This is also a stupid question, that is phrased in such a way that it has no answer.

If so is there a point were the photon would break down and disipate? DOes light go on for eternity albiet scattered so far apart that it is not detectible?

no, no


PS This thread is pointless.

[edit on 25-9-2004 by websurfer]

There's no such thing as a stupid question. If you don't ask questions, you never learn.

Light is not the byproduct of chemical reactions. Light is the result of a change in energy state of an electrically charged particle. It's what propagates the EM force. Chemical reactions are not required for this to occur.

The life cycle of a star has nothing to do with whether a photon can exist forever or not.

The second question does have an answer: Yes. That's how a telescope works. It gathers light over a larger area than the eye covers, and focuses it, increasing the inbound flux to the eye or film or CCD.

Wow, im glad someone finally set websurfer straight...

The lifecycle of a star infact does not have anything to do with the life of a photon. The lifecycle of a star has to do with the gasses that the star is made up of. Once the stars energy source (the gasses) are used up, then the lifetime of the star ends.

Good Job UT!

Awesome topic!

The answer is yes, photon moving through uniform vacuum of space at the speed of life is timeless, for time stops! A photon that has travelled billions of light years would arrive at a destination where those billions of light years passed by, but the photon would have not 'aged' a second.

Caveat emptor, space is full of gasses, masses, other energies (ie, gamma rays), and GRAVITY.

Gravity can dilate time for photons, though, as it bends, distort, even slow down the speed of light (ie, black hole)

Not sure how much maximum, gravity can accelerate the speed of light/photons, though. Anyone knows the upper limit beyond the "speed of light"? For photons, or any atom/ic particle of measurable or greater mass.

Originally posted by minnow
Awesome topic!

The answer is yes, photon moving through uniform vacuum of space at the speed of life is timeless, for time stops! A photon that has travelled billions of light years would arrive at a destination where those billions of light years passed by, but the photon would have not 'aged' a second.

Caveat emptor, space is full of gasses, masses, other energies (ie, gamma rays), and GRAVITY.

Gravity can dilate time for photons, though, as it bends, distort, even slow down the speed of light (ie, black hole)

Not sure how much maximum, gravity can accelerate the speed of light/photons, though. Anyone knows the upper limit beyond the "speed of light"? For photons, or any atom/ic particle of measurable or greater mass.

Its thought that photons are able to exist because of an electromagnetic field which permeates all of space-time and universe...

photons are created when a charge is accelerated, or when electrons change energy states ( a few other ways too im sure)..

So how do you perceive the existence of the photon? Is all of space a subtle electromagnetic ocean, in which an accelerated charge will transfer its energy into the form of a rippling wave in this ocean/field?

If time slows down the faster you travel towards the speed of light then yes. At light speed time is said to stop , according to relativity.

Of there is no ticking of time for light then can be said to be timeless in the strict sense of the word. Time is relative which is why we see light. We are on a different timeline to the photons we are seeing. For a photon witnessing human existence one must assume our time flys by at the speed of light also.

Originally posted by TheMindWar
Of there is no ticking of time for light then can be said to be timeless in the strict sense of the word. Time is relative which is why we see light. We are on a different timeline to the photons we are seeing. For a photon witnessing human existence one must assume our time flys by at the speed of light also.

That's a cool thought,

Does anyone really know for sure if a photon won't run out of energy or fizzle out eventually though? We've only seen 13 billion year old photons. In theory I suppose they wouldn't, but no one has seen a trillion lightyear-old photon before.

Originally posted by jessejamesxx

Originally posted by TheMindWar
Of there is no ticking of time for light then can be said to be timeless in the strict sense of the word. Time is relative which is why we see light. We are on a different timeline to the photons we are seeing. For a photon witnessing human existence one must assume our time flys by at the speed of light also.

That's a cool thought,

Does anyone really know for sure if a photon won't run out of energy or fizzle out eventually though? We've only seen 13 billion year old photons. In theory I suppose they wouldn't, but no one has seen a trillion lightyear-old photon before.

its thought they wont fizzle out, because it is thought that space is a vacuum,,, and so if there are no forces present,, there are no forces to stop the photon.. because a photon is considered to be a self propagating electromagnetic field particle...