# The Naked Scientists Forum

### Author Topic: Is it possible that Photons can travel at any speed?  (Read 2506 times)

#### bcs4

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##### Is it possible that Photons can travel at any speed?
« on: 13/04/2014 18:15:29 »
I have been reading a bit here and it seems the vast majority of posters have a real "understanding (as much as that is possible)" of Physics (and ESPECIALLY as I now have memory of only basic Algebra and the ability to push the keys on a calculator).  You could safely describe me as a buffoon with an Intense, But Armchair Fascination Of (with) Physics, or I B A FOP.

If so, what forum might I post the following question?

Is it possible that Photons can travel at any speed, and if so, could that explain that light (more or less as defined) will be perceived as light when Photons travel at 186,000 mps in relation to the perceiving object's speed regardless of the Photon's actual speed?

« Last Edit: 13/04/2014 21:20:24 by CliffordK »

#### David Cooper

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##### Re: Can a layperson post here, and if so..?
« Reply #1 on: 13/04/2014 20:12:42 »
Photons are perceived as photons regardless of the speed they run into an object, but the frequency (colour) will be different depending on the speed difference - higher speed impacts make it more blue, while lower speed impacts make it more red. Because it's impossible to measure the speed of light on anything other than a round trip, that actual speed of the photon relative to the thing it runs into can never be identified. Einstein made an assumption that photons always hit everything at the same speed and designed a theory to fit in with that assumption. Lorentz allowed photons to hit things at different speeds and designed a theory to fit in with that instead. Both theories make the same predictions about almost everything, but Lorentz's is normally ignored and Einstein's is usually described as being proved every time an experiment fits with it, even if the result also fits with Lorentz's. Both those theories have light travelling at a fixed, universal speed though. If you want to vary it as an alternative way of dealing with things, you're going to run into a problem: a pulse of light flashed from a torch on the moon will reach the Earth all at the same time, but if it illuminates something rotating, part of that pulse may hit the side that's moving towards it while another part of that same pulse may hit the side that's moving away from it. If you want the speed of the light to vary so that its impact will be at the same relative speed in both places, its speed from the moon to the Earth will need to be different with the light pulse splitting up into different chunks to travel at different speeds in order to fit in with the speed of the things they will eventually hit when they reach their destination. I don't see a theory like that working. No, the light must all be travelling at the same speed.

#### bcs4

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• Posts: 15
##### Re: Can a layperson post here, and if so..?
« Reply #2 on: 13/04/2014 20:36:00 »
Instead of the difference in speed between blue shift and red shift, I am more interested in the possibility of photons at more radical speeds, say 1/3rd or 2/3 (or even 2 times) the theoretical speed of light.  Is there anything that would preclude the possibility of a very slow, or very fast photon either as emitted, or as the result of an angular strike?

Thanks very much for your post.  I hope this means that I can ask lay questions.  If so, which forum should this type of question be posed for the largest response?

#### cheryl j

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##### Re: Can a layperson post here, and if so..?
« Reply #3 on: 13/04/2014 20:49:12 »
I don't think there is anything wrong with posting a legitimate physics question in the physics forum even if it is simple and basic. Most people are very happy to help. If for some reason it seems better suited to another section (say chemistry or biology) the moderator might place it there, but you will see the redirection and be able to find your answer.

#### bcs4

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##### Re: Can a layperson post here, and if so..?
« Reply #4 on: 13/04/2014 21:10:39 »
Great!  Thx Cheryl!

#### CliffordK

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##### Re: Can a layperson post here, and if so..?
« Reply #5 on: 13/04/2014 21:17:32 »
BCS,
Welcome to the forum.  People of different knowledge are welcomed to participate in the forum.  I've moved the topic to new theories as it seems to be presenting an alternate view of light.  However, if you were clarifying a physics question with respect to mainstream physics, it would also be equally welcome in the Physics forum.

The speed of light does change through different media, so it is slower in water than in air.  However, at least frequency is independent of the speed of light.  So, say a supernova is observed in some distance galaxy.  The reds, blues, and greens, as well as UV and IR all arrive at Earth at the same time.

I did run into a note a while ago that the ultra high energy photons from blazar Markarian 501 seem to arrive about 4 minutes after lower energy photons.  It was suggested that could be due to a speed difference.  However, the relationship would have to be noted with other stellar phenomena, and the difference would have to increase linearly with distance.

#### bcs4

• Jr. Member
• Posts: 15
##### Re: Is it possible that Photons can travel at any speed?
« Reply #6 on: 13/04/2014 21:49:52 »
Sorry, I should have said speeds in a vacuum..

Surprisingly, I'm aware of the speed differences between high and low energy Photons (with low being faster, also seems odd), but their speed differences aren't enough of a variation for my use.

I'll pose a theoretical example for more clarity.

If there were an object traveling at 86,000 MPS with an aperture pointed directly forward, would it perceive photons entering the aperture at 100,000 MPS as light?

If there were a fog of Photons travelling at all speeds and directions in the "vacuum" there would be photons entering the aperture at 186,000 MPS regardless of the speed of the perceiving object.  If so, the stoppage of time at the speed of light would be variable based on the speed of the perceiving object.  That would seem to unlink the speed of light and the stoppage of time.

« Last Edit: 13/04/2014 21:58:39 by bcs4 »

#### David Cooper

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• Posts: 1505
##### Re: Is it possible that Photons can travel at any speed?
« Reply #7 on: 14/04/2014 17:49:57 »
Imagine two torches which are switched off and are travelling in opposite directions at very high speed. As they pass each other, they contact for a moment and both of them emit a pulse of light. On their line of travel is a camera which will receive these pulses of light - one torch is moving towards the camera and the other is moving away from it. Both pulses of light reach the camera at the same moment, so the speed of light through space is fixed, the only thing being affected by the speed of the emitter (torch) being the frequency of the light. So, you aren't going to get different speeds of light off objects moving at different speeds no matter how you move them or try to reflect light off them.

In the case you've just described, a moving camera encounters photons. You appear to be suggesting that there are photons moving at many different speeds and that the camera will not see the ones that aren't travelling at 186000M/s, so it's only aware of the ones travelling at the right speed for it, but that idea will fail because the light signal will be detected by the camera too late. Let me reverse my torch thought experiment to show you why:-

Imagine two cameras moving at high speed past each other. A torch far away will emit a pulse of light which will reach the cameras at the exact point when they are passing each other. One of the cameras is moving towards the torch while the other is moving away from it, but they both detect the light at the same instant and tell each other when they have detected it. In a real world experiment, they would agree that the light reached them both exactly as they were passing each other. With your mechanism of light travelling at all possible speeds from just over 0 to just under 2c the cameras would not detect photons unless they're going at 186000M/s relative to them, which means that one of the cameras will detect the light long before the cameras pass each other, while the other camera will detect the light long after the pass.

So, you've come up with an innovative theory (which shows that you have a substantially better-than-average mind), but sadly it doesn't fit the universe we exist in.

[Edited to turn m/s into M/s to remove ambiguity: M stands for miles.]
« Last Edit: 16/04/2014 18:35:41 by David Cooper »

#### bcs4

• Jr. Member
• Posts: 15
##### Re: Is it possible that Photons can travel at any speed?
« Reply #8 on: 14/04/2014 19:18:28 »
You're correct if Photons can only travel at 186,000 MPS which is certainly the accepted theory (fact?).  We might currently be unable to detect Photons at any other speed (which may be because our sense of sight only sees light at 186,000 MPS, and thus limits experimentation and observing to results of that speed).  The multi speed/multi angle Photon would seem to change the relationship between light and time.

Imperceptible Photons (and everything else traveling at imperceptible speeds) might even contribute to dark matter/energy.

I'm sorry to drone on about this, but I just can't get past the accepted fact that every wave that can travel through a vacuum just happens to go 186,000 MPS, and that manditory speed is somewhat randomly assigned by our sense of sight..

Regardless, thank you very much for your (perhaps continuing?) responses.

#### David Cooper

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##### Re: Is it possible that Photons can travel at any speed?
« Reply #9 on: 14/04/2014 21:48:22 »
You're correct if Photons can only travel at 186,000 MPS which is certainly the accepted theory (fact?).  We might currently be unable to detect Photons at any other speed (which may be because our sense of sight only sees light at 186,000 MPS, and thus limits experimentation and observing to results of that speed).  The multi speed/multi angle Photon would seem to change the relationship between light and time.

I've just shown you a way of ruling out photons travelling at other speeds, unless the ones not moving at 186000M/s can't be detected at all, not even by things moving relative to them at 186000M/s.

Quote
Imperceptible Photons (and everything else traveling at imperceptible speeds) might even contribute to dark matter/energy.

They wouldn't contribute in any useful way if they can't be detected at all, and their distribution would not match up with the distribution of dark matter unless they are dark matter and not photons, in which case there is no need to call them photons.

Quote
I'm sorry to drone on about this, but I just can't get past the accepted fact that every wave that can travel through a vacuum just happens to go 186,000 MPS, and that manditory speed is somewhat randomly assigned by our sense of sight.

The speed isn't assigned by our sense of sight. The photons go at that speed and our eyes detect them regardless of what speed they may actually hit our eyes. We can't measure the speed of light in a single direction, so we have to divide into different camps of belief or unbelief. Some people believe that the speed of light relative to us is always the same simply because it is always measured as being the same speed on a 2-way trip. Others believe it varies but that it is impossible to show this through measurement because only round trips can be measured. Others keep an open mind on the whole issue and consider it possible that it is constant or that it varies.
« Last Edit: 16/04/2014 18:37:17 by David Cooper »

#### bcs4

• Jr. Member
• Posts: 15
##### Re: Is it possible that Photons can travel at any speed?
« Reply #10 on: 14/04/2014 23:09:23 »
AAAAHHHHHH!  I understanding your example now, and it answers my question perfectly!  Believe it or not, I was only using half my brain in the attempt, with the other half perplexed by your choice of flaming "torches" and the panache that would have been required in their handling.

I have now decoded your foreign language and replaced the incorrect "torches" with the correct "flashlight" and all is right in my world.  ((Smiley face) I don't feel comfortable using emoticons)

Thank you!
« Last Edit: 14/04/2014 23:12:15 by bcs4 »

#### jeffreyH

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• The graviton sucks
##### Re: Can a layperson post here, and if so..?
« Reply #11 on: 15/04/2014 18:41:44 »
BCS,
Welcome to the forum.  People of different knowledge are welcomed to participate in the forum.  I've moved the topic to new theories as it seems to be presenting an alternate view of light.  However, if you were clarifying a physics question with respect to mainstream physics, it would also be equally welcome in the Physics forum.

The speed of light does change through different media, so it is slower in water than in air.  However, at least frequency is independent of the speed of light.  So, say a supernova is observed in some distance galaxy.  The reds, blues, and greens, as well as UV and IR all arrive at Earth at the same time.

I did run into a note a while ago that the ultra high energy photons from blazar Markarian 501 seem to arrive about 4 minutes after lower energy photons.  It was suggested that could be due to a speed difference.  However, the relationship would have to be noted with other stellar phenomena, and the difference would have to increase linearly with distance.

The results from blazar Markarian 501 are interesting. I wonder if it is something delaying the photons as suggested? I can't really buy the idea that the photon is slowed down. Of course it could be that the higher energies have a different interaction with the gravitational field.
« Last Edit: 15/04/2014 18:55:05 by jeffreyH »

#### jeffreyH

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##### Re: Is it possible that Photons can travel at any speed?
« Reply #12 on: 15/04/2014 19:08:27 »

"A much more controversial observation is an energy dependence in the speed of light of cosmic rays coming from a short burst of the blazar Markarian 501 on July 9, 2005. Photons with energies between 1.2 and 10 TeV arrived 4 minutes after those in a band between .25 and .6 TeV. The average delay was .030±.012 seconds per GeV of energy of the photon. If the relation between the space velocity of a photon and its energy is linear, then this translates into the fractional difference in the speed of light being equal to minus the photon's energy divided by 2×1017 GeV. The researchers have suggested that the delay could be explained by the presence of quantum foam, the irregular structure of which might slow down photons by minuscule amounts only detectable at cosmic distances such as in the case of the blazar.[7]"

Now the fact that the magnitude is 2×10^17 GeV and not 1.5×10^17 GeV or 3×10^17 GeV or any other value leads me to believe it is a gravitational effect. This is very counter intuitive because you would think lower energy photons would be affected more. How often have results been counter intuitive though?

#### David Cooper

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##### Re: Is it possible that Photons can travel at any speed?
« Reply #13 on: 15/04/2014 19:08:38 »
Ah yes! I completely forgot that the word "torch" is understood very differently in American English as opposed to English as spoken in England and the rest of the UK. I'll be more careful in how I use that word in future.

#### aasimz

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• Posts: 42
##### Re: Is it possible that Photons can travel at any speed?
« Reply #14 on: 15/04/2014 22:00:09 »
Sorry, I should have said speeds in a vacuum..

- We know that particles other than photons -normal matter- will have a velocity which approaches the speed of light when they approach the event horizon of a massive black hole

- Could the light particles -photons- go FTL when they approach the event horizon of an extremely immense, huge & massive black holes, it's a quite big possibility I believe

- As it's almost a fact -at least for me- that everything in the universe was moving at a velocity that's waaaaaaaaay FTL at the time immediately following the Big Bang.

- This also lead us where light would be slower billions of years later.

- As for the question of the topic, I believe at this era of time it's apparently there are some conditions where it's possible but not in most of the universe.
« Last Edit: 15/04/2014 23:04:12 by aasimz »

#### bcs4

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• Posts: 15
##### Re: Can a layperson post here, and if so..?
« Reply #15 on: 16/04/2014 16:27:01 »
I did run into a note a while ago that the newbielink:http://en.wikipedia.org/wiki/MAGIC_%28telescope%29#Observations [nonactive].  It was suggested that could be due to a speed difference.  However, the relationship would have to be noted with other stellar phenomena, and the difference would have to increase linearly with distance.

Since it was a short burst, is it possible that the event was such that it released low energy photons 4 minutes prior to releasing the high energy photons?

#### The Naked Scientists Forum

##### Re: Can a layperson post here, and if so..?
« Reply #15 on: 16/04/2014 16:27:01 »