# Science Questions

## Do photons at light speed stop time?

Tue, 18th Mar 2014

### Question

Does time stop for photons travelling at the speed of light?

Tamela -   He’s probably been studying relatively longer than I have, but I’ll do my best.  So, absolutely right.  If the particle is approaching a speed of light and had a clock on it, we as observers of that particle going extremely fast would see that time slows down and approaches this sort of eventual stopping.  It is impossible to imagine the frame of reference at the speed of light- special relativity doesn’t really deal with that.  It takes the speed of light as a constant and that’s regardless of what speed you're going at.  So, even if you're 99% at the speed of light, you're still measuring c as c.  So in that sense, it is difficult to answer what kind of time is the photon experiencing.  But just to say that if you were a particle, maybe at 99% at the speed of light, in your own frame of reference, time is moving normally.  You have a much faster ticking clock compared to the observer that sees that time has nearly slowed down.  Actually, you’ve probably heard of this, but we’ve experimentally confirmed time dilation here on Earth.  There was an experiment back in the ‘70s that put these atomic clocks on commercial aircraft and had them fly around the Earth, both in the eastward direction and the westward direction, and we’re able to compare, once they got back on Earth with sort of naval observatory clocks.  Actually, there was this difference because they were moving faster than the Earth’s rotation at some point.

Chris - The great pyramids also distort time because they're very massive and so, they bend space time.  So, time travels at a different rate.

Tamela -   Exactly, yeah.

Chris -   Yes, which that really does blow my mind – the whole concept of you going near something very massive and time changes.  So, you go to Egypt, sit next to a pyramid and actually, time is distorted.  So maybe the Egyptians were on to something when they said that they were going to try and make their pharaohs immortal because relative to the rest of us they are ageing more slowly.

Tamela -   To extend this even further, if you go to a black hole and kind of start falling into a black hole, you're observer is seeing that time has nearly stopped for you as you fall towards it because you’ve warped that time so much.  So yeah, lots of interesting things going on.

#### Make a comment

Suppose we are in a lab whose frame of reference we label S. Let the particle of interest be at rest in an inertial frame S' which is moving relative to S with speed v.

When observers in S compare their clocks with those in S' then the clocks in frame S' will be determined to be running slower than those in frame S due to relativistic effects.

The problem with the question posed in this thread is that we cannot carry out such an observation with a clock in the same frame as the moving particles. It is therefore meaningless to speak of photons experiencing time to stop. It's not even clear what it means for a photons to "experience" something. Pmb, Thu, 20th Mar 2014

well you might as well ask if time stops for an electron travelling down a copper wire. "The electron" doesn't travel down the cable, it transfers energy down the wire at the speed of light (or close to it) and we measure the effect on whichever electron is at the other end of the wire, usually with the wrong assumption that its the same electron as the one we set off at the other end of the wire. It isn't. So what is travelling is energy which we detect as an electron. Same with photons, they only exist where we detect them.
So the question is, does time exist for energy which travels at speed of c. Answer is yes because it takes time for it to travel. It isn't instantaneous and we can measure that time. Only when the distance travelled is instantaneous could we say time has stopped. At least thats how I percieve it as I'm thinking aloud and probably getting it wrong. percepts, Thu, 20th Mar 2014

From my non-expert viewpoint it seems that there is all the difference in the world between "the speed of light" and "close to it".
We can measure the effects of time dilation at close to it, but not at c.

surely the time measured is time in the F of R of the observer and says nothing about any time/movement relationship in a speed of light frame, if one could be identified.  The answer must, I think, be that we cannot know.
Bill S, Thu, 20th Mar 2014

Photos have a wavelength that can be shifted but otherwise preserve their information content over vast distances. This is how the composition of stars can be determined. I doubt that this is like time being stopped for the photon. It has no rest mass so does time even apply in the same way? It is affected by gravity but does that include time dilation? jeffreyH, Fri, 21st Mar 2014

The phrase experience implies awareness. Panprotoexperientialism is an interesting topic but I believe you are after the most currently accepted view about light and time. To get at this you need to look at the current definitions for photons and time.

In the Neil's Bohr interpretation the photon is a reduction in the multiple probabilities within the quantum field to a single set.  This occurs when the probability for a photon in its quantum field overlaps with a probability in another quantum field, such as for an electron, resulting in an interaction and new quantum fields. In the Bohr interpretation there is not a wave or photon actually travelling through space at the speed of light.  However, the time distance intervals for the probabilities in the quantum field for a photon progress commensurate with the speed of light relative to the reference frame it is in.

www.plato.standford.edu/entries/qm-copenhagen

The Albert Einstein concept of time is that it is merely another dimension. As the values for a field in one dimension increases the value in other dimensions decrease to the point that the value in the fourth dimension is zero for a field that has a progression value equal to the speed of light in another dimension.

www.pbs.org/wgbh/nova/physics/special-relativity-nutshell.html

On the other hand if you are already aware of the prevailing theories and are taking a survey of how many members are comfortable with it; I am one of the ones who is not. Some of the current  giants in math are not happy with these principles.

"We can't ignor the absurdity of the situation any longer. It's time to get to the bottom of what is really going on, and in the process cement our understanding of the fundamental nature of the universe," Frank Wilczek.

"I think there is going to be something else which replaces it," Roger Penrose.
sciconoclast, Sun, 30th Mar 2014

Personally I see another problem with this.

The photon should be travelling with the speed of light with reference to some 'stationary' point, right? Let's call that point "A", and let's call the photon "P".
Now, the photon traveling with the speed of light should have time stopped.
(it may be a photon or any other 'thing'), so time is 'slowed down'.
However, you could also say that point "A" is moving with the speed of light with reference to "P", right? So, you can equally say that the time at point "A" is now slowing down! so, time is slowing down and moving faster at the same time, which is an impossibility!( And beware, I am not talking about the so-called 'twin paradox'.)
Hence, it is all nonsense the relativity theory.and there is no application(s) for this,
no, also not gps.
Omaughuntinaser, Tue, 1st Apr 2014

Personally I see another problem with this.

The photon should be travelling with the speed of light with reference to some 'stationary' point, right? Let's call that point "A", and let's call the photon "P".
Now, the photon traveling with the speed of light should have time stopped.
(it may be a photon or any other 'thing'), so time is 'slowed down'.
However, you could also say that point "A" is moving with the speed of light with reference to "P", right? So, you can equally say that the time at point "A" is now slowing down! so, time is slowing down and moving faster at the same time, which is an impossibility!( And beware, I am not talking about the so-called 'twin paradox'.)
Hence, it is all nonsense the relativity theory.and there is no application(s) for this,
no, also not gps.

There is a continuous gradient of changing field strengths throughout the universe. These overlap. Some include feedback, as with gravitation. Two points in space-time can be equivalent in all aspects to one another but they will never be adjacent to each other. They will be separated by some distance, large or small. This is a highly complex situation and starts at the particle level. Relativity is probably the only reasonable tool that will describe this situation accurately. Its complexity is the worrying thing. jeffreyH, Wed, 2nd Apr 2014

So, what a strange reaction which says nothing at all.

Just writing, 'it is too complex', well, it is a bit of hogwash, right? ;)

it isn't complex at all. it is just a bunch of more than idiotic contradictions,

You just let yourself go to a few loops to make nonsense feel alllright.

sorry, won't work. ;)

Omaughuntinaser, Wed, 2nd Apr 2014

Personally I see another problem with this.

The photon should be travelling with the speed of light with reference to some 'stationary' point, right? Let's call that point "A", and let's call the photon "P".
Now, the photon traveling with the speed of light should have time stopped.
(it may be a photon or any other 'thing'), so time is 'slowed down'.
However, you could also say that point "A" is moving with the speed of light with reference to "P", right? So, you can equally say that the time at point "A" is now slowing down! so, time is slowing down and moving faster at the same time, which is an impossibility!( And beware, I am not talking about the so-called 'twin paradox'.)
Hence, it is all nonsense the relativity theory.and there is no application(s) for this,
no, also not gps.

If you'd read the original answer from TNS, you'd see that we can't actually talk about time stopping for the photon--at least not in terms of its reference frame--so the paradox doesn't exist in the first place.  jpetruccelli, Wed, 2nd Apr 2014

Omaughuntinaser, I've deleted your post since it included some language that exceeded the family-friendly nature of this site.  In addition, please review the site's acceptable usage policy, as posts are supposed to foster respectful discussion and yours have crossed that line.

You may want to post in New Theories if your goal is to argue against mainstream physics. jpetruccelli, Wed, 2nd Apr 2014

So, what a strange reaction which says nothing at all.

Just writing, 'it is too complex', well, it is a bit of hogwash, right? ;)

it isn't complex at all. it is just a bunch of more than idiotic contradictions,

You just let yourself go to a few loops to make nonsense feel alllright.

sorry, won't work. ;)

You mentioned relativity and how much nonsense it is. I was answering that point which you did state. Do you have short term memory issues? jeffreyH, Wed, 2nd Apr 2014

Is that accurate? Does the photon not travel at the speed of light with reference to any other object, moving or "stationary"?

Can a photon travel at any speed relative to anything, or anything to a photon, if relativity does not accord a photon a frame of reference? Bill S, Wed, 2nd Apr 2014

I found this in my notes from a few months ago, when I was thinking about claims that information could travel back through time.

Among the better known scientists who apparently subscribe to the view that photons do not experience time is Brian Greene.  He says:

http://www.pbs.org/wgbh/nova/physics/special-relativity-nutshell.html

“……the maximum speed through space is reached when all light-speed motion through time is fully diverted into light-speed motion through space—one way of understanding why it is impossible to go through space at greater than light speed. Light, which always travels at light speed through space, is special in that it always achieves such total diversion.”

The diversion he mentions is the diversion from motion through space to motion through time.

So having gone round in a few circles, we find that we will not be totally isolated from the scientific community if we claim that a photon passing through a double slit experiment “knows” everything about the set-up at the moment of its generation; so no information passes back through time.  However, if we make that claim publicly, we can be sure that we will bring down on our heads the disapproval and even scorn of many physicists.

Bill S, Wed, 2nd Apr 2014

What Brian Greene is saying there is that photons travel along light-like world lines.  There's no controversy there.  His description of motion through space vs motion through time is one way of describing time dilation and length contraction.

However, saying that we can look at the universe from the point of view of a photon is not controversial-- it's just plain wrong.

So if you're talking about world lines when you say "time stops for a photon," that's fine.  But I've yet to see a layperson mean this when they say such a thing.  They mean "if I imagine myself as being a photon, I would see everything frozen," or some variant of that, which is wrong.  We can't be photons and the question can't even be answered. jpetruccelli, Thu, 3rd Apr 2014

can't remember. ;) Omaughuntinaser, Thu, 3rd Apr 2014

just a cop out, Omaughuntinaser, Thu, 3rd Apr 2014

yes, why not? I think any speed from anything is always relative to another point.
photon or no photon.

and still my question isn't answered.

well, take something else then,moving with a lower velocity of light and you still have these problems.time is moving faster and slower which is an absurdity.

Relativity is all bollocks, and there is no need for it, nowhere,
just get rid of relativity and we might progress some more, Omaughuntinaser, Thu, 3rd Apr 2014

Nope. It's physics, whether you're able to understand him or not, he's correct. Pmb, Thu, 3rd Apr 2014

Nope. It's physics, whether you're able to understand him or not, he's correct.

So you can say I don't understand so you can keep your religion (belief system) intact.

However, you really haven't adress the issue I stated.

I understand, because you don't understand it at all.

Calling something 'physics' doesn't make it 'physics' does it now?

It really is al baloney.the Naked Emperor has No Clothes.

Omaughuntinaser, Thu, 3rd Apr 2014

The most fun thing to watch is to see no one here EXPLORING,only DEFENDING, the more than ridiculous science dogma's.

I understand, because when one domino falls.....

keep praying to science folks! :) Omaughuntinaser, Thu, 3rd Apr 2014

The only useful question is 'does it work?', and, judging by my GPS position, the answer is 'yes'. dlorde, Thu, 3rd Apr 2014

yes, I know about GPS, but has that to be done here? I have a thread about relativity being obsolete.

but ok,

GPS doens'n't need relativity theory,

AND, the problem I stated here is the same with GPS.

GPS works, yes, I don't deny that, However, it still works without so called relativity corrections.

the same as all other things that use 'relativity', they work just fine without relativity,

relativity is a hoax and a more than idiotic theory,

Furthermore, 'does it work' is not a usefull question for validating a theory offcourse.

Omaughuntinaser, Fri, 4th Apr 2014

Only for two minutes ...

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html RD, Fri, 4th Apr 2014

Nope, totally and provable untrue. it works just fine all the time,.

well, they can state whatever they want, it is really not true at all.
So, they are what is called lying.

Omaughuntinaser, Fri, 4th Apr 2014

Nope, totally and provable untrue. it works just fine all the time,.

well, they can state whatever they want, it is really not true at all.
So, they are what is called lying.

or call them 'myths' ;)

'science' is full of them, 'myths'

if 'science' repeats a myth enough, people start believing it, and the myth becomes fact.

It's all a scam.

Omaughuntinaser, Fri, 4th Apr 2014

The evidence I've seen suggests that is not the case:

According to Section 2.3.1 (Ranging Signal Carrier Characteristics) of the 'GPS Standard Positioning Service Signal Specification' (1995):

"To compensate for relativistic effects, the output frequency of the satellite's frequency standard -- as it would appear to an observer located at the satellite -- is 10.23 MHz offset by a Df/f = -4.4647 x 10-18 or a Df = -4.567 x 10-3 Hz"

In other words, the clock rate is compensated for relativistic effects before deployment of the satellite.

In section 2.5, it describes the user algorithms for "Correction of the code phase time received from the satellite with respect to both satellite code phase offset and relativistic effects".

These algorithms are detailed in Section 2.5.5.2 (Satellite Clock Correction), where it explains the offset coefficients transmitted from the satellite, and states:

"Since these coefficients do not include corrections for relativistic effects, the user's equipment must determine the requisite relativistic correction. Accordingly, the offset given below includes a term to perform this function."

The algorithms follow.

A detailed explanation is given by Neil Ashby in 'Relativity and the GPS'.

I think not. dlorde, Sat, 5th Apr 2014

I have no problem with that.

That’s probably what tripped me up. I thought that we couldn’t apply time dilation equations to photons.
Bill S, Sat, 5th Apr 2014

Another sign of ignorance. Little does this flamer know, when the system was placed in orbit there was, effectively, a switch that when thrown takes relativity into account. The fact is that the system didn't work until that switch was thrown - More evidence of this flamers massive ignorance. Pmb, Sat, 5th Apr 2014

Provable?  Perhaps you could explain that in simple terms that even I could understand.
Bill S, Sat, 5th Apr 2014

You sound like a teenager who thinks he knows everything and I certainly won't waste anymore time with a ignorant troller like you.

Folks - Why are we bothering with this person? He's obviously a good for nothing troller and not worthy of recognizing his/her presence here. Forget this idiot and let's get back to discussion between intelligent, mature people and not the likes of this troller. Pmb, Sat, 5th Apr 2014

At least this is true in your case... lightarrow, Sat, 5th Apr 2014

At least this is true in your case...

Please don't feed the trolls. Pmb, Sat, 5th Apr 2014

I gotta say!  There's a couple cranks on this site!  Spinning wheels, no gain.

Einstein's math says (Max Born, "Einstein's Theory of Relativity") that at "c". space (length) in the direction of travel = 0, and time also = 0.    I personally think this implies that we are not getting a length/time  (186,000 miles / 1 sec) sort of answer, even though we think that's the kind of measurement we're making.  It seems to say that the measurement is more about a kind of distortion or warp or drag that spacetime represents, compared with a whole 'nother ball game for light (and the electromagnet and gravitational fields).  That would also explain why any mass, at any spacetime speed, will always fall short of reaching "c" by just about 186,000 mps!

It's sort of saying that space and time are 186,000 mps "off" or "slower than" the singularity - simultaneity -  absolute connection - kind of state that light and fields exist at.  Maybe they exist as a "background singularity" that never broke symmetry with the Big Whatever.

Also, to one of the early comments, electrons do in fact travel down conduction wires.  They stroll down the wires from atom to atom, at a relaxed pace.  The electromagnetic field these moving charges generate propagate along the wire at "c".  The willingness of metal atoms to let go of an outer electron is why wires carry electricity.

zunimtn
zunimtn, Sun, 6th Apr 2014

Light is the true relativity. It is applied across the universe equally. Its speed is the same through every inertial frame of reference. It doesn't know nor care what gravity or perception speed the inhabitants have... Light is cosmic.., identical across all of it... Forget what you've read about light photon's duality... The delivery of light has two separate and distinct parts and operations... First there is the particle that is called a photon travelling at the speed of light that is transmitting a single frequency that is radiating outward.., also at the speed of light. The key to producing the light spectrum is that the forward going wave front cannot get out of the way of the transmitter radiating it.., so it blue shifted into extinction... All parts of a wave cannot be in the same place at the same time. But outward from that center line of travel, as the degree increases, one will see lower and lower wave lengths traveling outward. They are simply being blue shifted less and less. From that forward direction to the 90 degree point.., one will see the entire electromagnetic spectrum, which of course includes the visible portion, being laid out to a flat plane just ahead of the photon in all directions around the exact center.... That plane representing the wall in your living room for example... The visible spectrum will look like colored circles much like a target. Light produces a virtually endless, or cosmic wide electromagnetic spectrum.. From the ultimate self extinguishing shortest wavelength possible to the lowest which is cosmos long...Size wise, the visible will take up the equivalent to a pixel on your monitor... It will be make one tiny spec of light that with many more photon arrivals will make up the entire image of their source... We then with our frame's particular mental perception speed, adjusted up or down by our velocity through the cosmos, will look for the frequency that equates to what we have evolved to see as say the color blue... Once we alligh with what is familiar to us we will have found our frame's portion of the cosmic electromagnetic spectrum... It will be a different portion for every frame... But each will see the frequency that to them is blue. This is all seen and developed from proven science... Light is the true relativity... There is no time... There are *many* more details at http://www.thecosmosreconsidered.com No more paradoxes. There is no time. Time is simply a survival mechanism. A hard drive storage system in our brain. We can 'remember' what happened to Fred when he jumped off that cliff trying to fly like a bird... :) That doesn't mean there is Time... It's an illusion. Floyd Baker, Fri, 10th Apr 2015