Photons have no time

[InfiniteNow]

Respectfully submit; a photon has a wavelenght. Will it not take a bit of time to traverse any point in space ? Will not a transverse wave have a front end and a back end, so to speak ?

 

Relative to what/whom? Relative to the photon itself, or relative to some external observer viewing it?

[kailas_knight]

I've been trying to read more and more about QM. Last night, I read that photons do not experience time. That a photon travelling through time (relative to an observer in inertial frame) is indistinguishable from an anti-photon travelling backward in time. Strangely, I'm okay with that.

 

However, I'm struggling to understand that a photon released from a star 10 million light years away, from the perspective of something else, will take 10 million light years to arrive, but in it's own frame of reference arrives immediately to all places.

 

Can someone help shed some light ( :rolleyes: ), and potentially assist me in clearing up mistakes in the above description? It sounds a lot like a photon is InfiniteNow, but I am trying to be objective. :phones:

 

 

hi i'm Kailasnath .S , I'm a 19 year old from India. I'm not an expert in Astronomy , but it's my key field of interest. I hope my reply will be helpful to you.

 

According to the Special Theory of relativity by Albert Einstein , light (photon) is the fastest thing in the universe ... and light is a stream of photons. when a photon is realeased from a star ,about 10 million light years away , from our perspective , that photon will reach us in 10 million years. but from the frame of reference of photon , it is emitted at some time t , but delta t=0 for traversing b/w any 2 points in space , because as velocity increases , the value of delta t decreases , and c is the highest velocity possible , so eventualy delta t decreases to the point of delta t=0 , at v=c . so a photon is emitted at t=t1 and ends it's journey at t=t1 , delta t=0.,ie , time "stops" for a photon, coz it's moving at c. the highest possible velocity.

 

 

photons move at velocity = c , but we dont . From the perspective of the photon , as soon as it it emitted , it instantaneously reaches the destination ( in the line of sight of the photon), in delta t=0 .

 

Speaking in terms of special relativity , when the velocity of something increases, so does it's mass , but this change in mass is significant only at large speeds.... when the velocity of something is 90 % of c , then, it's mass increases significantly , but when it comes much closer to c , it's mass rises exponentially... but matter cannot attain the velocity of light ......

 

because m = infinity for matter ,is a paradox in universe..it cannot sustain such an effect .....

[Mike C]

Respectfully submit; a photon has a wavelenght. Will it not take a bit of time to traverse any point in space ? Will not a transverse wave have a front end and a back end, so to speak ?

 

Yes!

But photons are not waves. They are pulses.

And they do have wavelengths.

A redlight photon has a wavelength of 6.56^-7 meters.

Its elapsed time is 2.188^-15 seconds.

 

Mike C

[InfiniteNow]

hi i'm Kailasnath .S , I'm a 19 year old from India. I'm not an expert in Astronomy , but it's my key field of interest. I hope my reply will be helpful to you.

Hi Kailasnath,

 

You and I have actually interacted a few times here on Hypography, so there's no need to be so formal. It's nice to see you again, and I hope you are well. B)

 

Thank you also for your information. This thread has now over 220 posts, so much of what you shared was already addressed, but a refresher never hurts. :rolleyes:

 

The photon, since it travels at c, has infinite time dilation relative to observers not travelling at c, but it also has infinite length contraction, which leads to being everywhere all at once.

 

It's fun stuff to discuss, isn't it? Makes no intuitive sense, but has a certain feeling of "Yes, as strange as that it is, it has to be correct!"

 

 

 

Speaking in terms of special relativity , when the velocity of something increases, so does it's mass , but this change in mass is significant only at large speeds.... when the velocity of something is 90 % of c , then, it's mass increases significantly , but when it comes much closer to c , it's mass rises exponentially... but matter cannot attain the velocity of light ......

That is true, but just remember, this thread is specifically about photons... which don't have any mass. They are massless, so no need to concern ourselves with the impossibility of c for objects which have mass... at least, not in this thread. ;)

 

Take care, mate. :phones:

[InfiniteNow]

Yes!

But photons are not waves. They are pulses.

Huh? That sounds new. Do you have a source?

 

And they do have wavelengths.

A redlight photon has a wavelength of 6.56^-7 meters.

 

How does something which, as you said, is not a wave have a wavelength? Your position is not internally consistent.

 

 

Its elapsed time is 2.188^-15 seconds.

Relative to what/who?

[aytche]

Dear Photon lovers. Richard Feynman considered photons as particles and kind of moved on from waves. So a particle and carrier of the em force is emitted from some star which is receeding from us at high speed, maybe even accelerating. It experiences it's wavelength get red-shifted; that's got to hurt! Then while in transit, it gets red-shifted somemore by space-time itself; sort of like surfing on spacetime. Seems like a photon is interlocked to spacetime and therefore maybe has time/x component. At this point I return to examining my bellybutton. Greetings to all...

[CraigD]

Dear Photon lovers.

You better believe I’m a photon lover! :) According to best theory, photons are literally all that’s holding me, you, and everything that isn’t sufficiently massive to be gravity-dominated, together! :)

 

In addition to carrying electromagnetic energy from stars, flashlights, radio transmitters, etc., they carry the charge interaction that keeps electrons in the vicinity of protons, and thus atom together, and in the vicinity of one another, allowing interesting ensembles of matter like us to use interesting ensembles of matter like hypography to have this conversation. My fondness for them knows no end!

Richard Feynman considered photons as particles and kind of moved on from waves.

Feynman famously promoted the diagramming of photons, and all other sorts of particles as circles and lines on paper - Feynman diagrams – but he never, in anything I’ve read or heard of his, rejected wave-particle duality. ALL particles in the conventional quantum physics are both body-like, AND wave-like.

So a particle and carrier of the em force is emitted from some star which is receeding from us at high speed, maybe even accelerating. It experiences it's wavelength get red-shifted; that's got to hurt!

Though joking, this hints at a fundamental misunderstanding of relativity.

 

Red or blueshift relative some distant observer is not a characteristic of a photon that occurs because the emitter or the photon “knows” it is moving relative to the observer or any preferred inertial frame. A photon emitted from a star that ultimately interacts with an observer traveling toward the star, which the observer measures to be blueshifted, is no different than a photon produced by precisely the same stellar phenomenon that ultimately interacts with an observer traveling away from the star, which that observer measures to be redshifted. Photon red/blueshift depends on the relative velocity of the emitter and receiver.

 

In the same sense that, relative to themselves, photons have no time, they also have no frequency.

Then while in transit, it gets red-shifted somemore by space-time itself; sort of like surfing on spacetime. Seems like a photon is interlocked to spacetime and therefore maybe has time/x component.

What aytche is describing here appears to be the “tired light” hypothesis. Though an historically interesting hypothesis of several early to mid 20th century models attempting to explain the Hubble flow in other than simple geometric terms, and later, the apparent metric expansion of space. Unlike these and other cosmological models, no compelling theoretical explanation or observational evidence have lent much support to the hypothesis, so that only a small minority of scientists and science enthusiasts believe that the hypothesized effect exists.

 

The preceeding description fails to mention by name another source of photon frequency shift, gravitational redshift, which depends on the relative gravitational field strength of the emitter and observer. Though in all ordinary astronomy cases, a star or other massive astronomical object’s is greater than an Earth’s or space-based observer’s, resulting in redshift, in principle there is also such a thing as gravitational blueshift. An observer on Earth measuring light emitted from the Moon, or an observer on the surface of the sun observing light emitted from the Earth, would measure a slight blueshift.

[Mike C]

Huh? That sounds new. Do you have a source?

 

I did post an article about the 'Creation of Photons'.

 

How does something which, as you said, is not a wave have a wavelength? Your position is not internally consistent.

 

Plancks research and math has transformed the light we see as a photon rather than as a continuous wave as the 'standing waves' in the hydrogen atom are.

Bohrs 'planetary' model explains how the photons are created.

 

Relative to what/who?

 

The photon pulse is generated by the electron transitions and there is some time elapsed for these transitions .

 

Mike C

[HydrogenBond]

One thing everyone is overlooking is that although a photon is traveling at C it displays a finite time element called its frequency. The photon is displaying two references at the time. In other words, say we had a space ship with ten blinking lights, each with a different frequency. If we were to reach C, all these blinkers should converge into the same limit. But with photons there is no convergence but sustained divergence. How can photons show a wide range of finite time expressions even though all are at the limit of C where all finite expressions should converge into only one infinite expression?

 

To put in perspective say our space-ship with ten blinkers made it to C and we noticed that the blinkers are holding steady to their original frequency. They would not be displaying the correct time dilation indicative of C.

[InfiniteNow]

I think the only thing being overlooked in this thread is that the discussion is relative to a photon, not an outside observer.

[modest]

I think the only thing being overlooked in this thread is that the discussion is relative to a photon, not an outside observer.

 

Something of mass cannot accelerate to c.... except from a photon's perspective? The photon sees us as having the property of infinite mass, yes?

 

Also, what does one photon look like to another photon?

 

I suppose these are division by zero problems.

 

-modest

[InfiniteNow]

Something of mass cannot accelerate to c.... except from a photon's perspective?

It was not my intention to suggest that... it's more that since the photon travels at c it experiences infinite length contraction and time dilation and hence is everywhere all at once (when described in human perceptual terminology).

 

The photon sees us as having the property of infinite mass, yes?

 

I really can't say that I know the answer to that one. What do you (or others) think?

 

 

I suppose these are division by zero problems.

 

That seems a rather valid point. Also, in the spirit of full disclosure, and as was discussed earlier in the thread, it really makes no sense to suggest that a photon has a frame of reference. It doesn't.

 

Just a thought experiment really, and I've been trying to steer those who don't bother reading before posting to stop talking about wavelength and frequency and such because that's all relative to something other than the photon itself.

 

 

:phones:

[modest]

I think the only thing being overlooked in this thread is that the discussion is relative to a photon, not an outside observer.

Something of mass cannot accelerate to c.... except from a photon's perspective?

It was not my intention to suggest that...

 

I know - I'm sorry for implying that. My only intention was to bring the discussion back on topic with a new question (i.e. "from a photon's perspective").

 

it's more that since the photon travels at c it experiences infinite length contraction and time dilation and hence is everywhere all at once (when described in human perceptual terminology).

 

Yep, I got that and agree completely. But wouldn't anything the photon observes also have infinite mass - I think so.

 

Also, in the spirit of full disclosure, and as was discussed earlier in the thread, it really makes no sense to suggest that a photon has a frame of reference. It doesn't.

 

I think the only way a photon can be an "observer" is to interact with the observable. If and when it does that, it's no longer traveling at c. Also, I guess the universe would be too length contracted and time dilated to observe when traveling at the speed of light. So, I agree. It seems neither practical nor useful - but still really cool to think about.

 

-modest

[Mike C]

To All

 

Those speculations about time dilation and infinite mass at 'c', are just speculations.

I do not believe in Einsteins solutions because they are so miniscule, that the spiritual mind can manipulate these tiny discrepencies.

This may surprise a lot of people about this existence of spirit and mind influences, but they are REAL in my opinion because I have witnessed such events.

 

I know science refutes 'spirit' but I do not, even though I consider myself a scientist .

 

Thank you for understanding.

 

Moses and Mohammad heard voices. So does that mean they were nuts?

Ha ha.

See how many people believe in these two. Amazing!

 

Mike C

[InfiniteNow]

I do not believe in Einsteins solutions because they are so miniscule, that the spiritual mind can manipulate these tiny discrepencies.

This may surprise a lot of people about this existence of spirit and mind influences, but they are REAL in my opinion because I have witnessed such events.

 

And you were proven wrong in this very thread when you used to post under username "New Science."

 

 

You're still wrong. Your personal anecdotes do nothing to overturn the decades of empirical evidence.

 

 

 

Moses and Mohammad heard voices. So does that mean they were nuts?

Ha ha.

See how many people believe in these two. Amazing!

 

Mike C

 

This would be known as the Galileo Gambit, and it neither a) supports your claims, nor :D refutes existing ones.

[InfiniteNow]

Is it impossible to stay on topic in this discussion or something?

 

 

For the love Thor, look how many members in this thread have been banned. :D

 

 

Has the idea under discussion not been adequately described? Come on, people!

[HydrogenBond]

Nobody addressed the point that photons move at C, which should cause all photons to appear the same using the principle of SR. Yet photons can display a wide range of finite expressions in distance and time, even while going at C. A mass object moving toward C would display the entire system undergoing time dilation. One would not have one part of the space-ship looking like it is moving different than C. With the photon, even at C it doesn't show what one would expect from something at C. The radio wave photon moving at C is not contracted to a point but still displays distance affects in meters.

 

The analogy is a train 100 meters long. At C, the train would appear to skinny down to a point. If it still looked like it was 1 meter, we would assume it was not traveling at C. The photon we know is at C, yet we also know it can appear in a whole range of sizes in terms of the wavelength it is given off. It is traveling at C while creating an output with finite parameters in space-time.

 

If photon with a given wavelength, i.e., from a blue light, was in a space-ship and we increased the velocity of that spaceship toward C, the photon's wavelength would get distance contracted. How can the photon show another level of distance contraction when it is already at C?