Does Time Exist at the Speed of Light?

[dewaite]

Does Time Exist at the Speed of Light?

I do not want to "speculate" but to me, if Light has a frequency and frequency is defined as 1/s or Hertz, then how can time not exist at c, when it is used to define a property of the only phenomena we know to move at c (light)? I hope this is a legitimate question and someone can explain this one to me. Simply put - How can light have frequency if time doesn't exist at c? ----- Consider this speculation if you must... Some "Accepted" Physical theories just are not based on sound reasoning.

Is the Only thing constant - the speed of light OR is "Change" the Only thing Constant? I can't imagine measuring light or any motion or frequency without Time, However i can measure time without light.

I know this can't be answered with current theory - i just want ya'll to surpass current limitations - they only exist by your definitions!

 

[Frame Dragger]

I do not want to "speculate" but to me, if Light has a frequency and frequency is defined as 1/s or Hertz, then how can time not exist at c, when it is used to define a property of the only phenomena we know to move at c (light)? I hope this is a legitimate question and someone can explain this one to me. Simply put - How can light have frequency if time doesn't exist at c? ----- Consider this speculation if you must... Some "Accepted" Physical theories just are not based on sound reasoning.

Is the Only thing constant - the speed of light OR is "Change" the Only thing Constant? I can't imagine measuring light or any motion or frequency without Time, However i can measure time without light.

I know this can't be answered with current theory - i just want ya'll to surpass current limitations - they only exist by your definitions!

This is not hard to explain at all, because your initial supposition that 'time does not exist at c' is wrong. Remove that, and the rest becomes fairly obvious. Why do you believe such a thing? Are you misinterpreting Time Dilation or Differetial Aging and assuming that time simply slows to a halt at c? That isn't true, and the afformention Relativistic effects are... well... relative.

 

[dewaite]

Perhaps i am misinterpreting relativity - to much web searching. According to the Lorentz transform, what happens to time at c? Does it become zero or something else? The indeterminant 1/0 - perhaps doesn't mean zero time.

If this effect is only relative, then what makes us see light in different frequencies? I have never heard any physicst state that time exists at c - they all say the contrary - assuming that a photon is everywhere similtaneously because of its zero time nature.

Maybe, I am being misguided. I question also - what happens to mass as it approaches c - does it get infinite? This seems implausible as well simply because an electron is the closest "natural" particle that we know is moving near c, yet it is also the lightest - if things got more massive as it approached c, then why at c does this mass suddenly disappear?

 

[Mentz114]

Perhaps i am misinterpreting relativity - to much web searching. According to the Lorentz transform, what happens to time at c? Does it become zero or something else? The indeterminant 1/0 - perhaps doesn't mean zero time.

The relativistic formulae do not give sensible answers for velocities equal to c.

If this effect is only relative, then what makes us see light in different frequencies? I have never heard any physicst state that time exists at c - they all say the contrary - assuming that a photon is everywhere similtaneously because of its zero time nature.

WE see light at different frequencies because it is a wave. The assumption above is wrong. There's no such thing as 'zero time nature'.

Maybe, I am being misguided. I question also - what happens to mass as it approaches c - does it get infinite? This seems implausible as well simply because an electron is the closest "natural" particle that we know is moving near c, yet it is also the lightest - if things got more massive as it approached c, then why at c does this mass suddenly disappear?

Yes, you are misguided. Mass does not increase with relative velocity ( recall that only relative velocities can be meaningfully discussed). Electrons can travel at different speeds ( always less than c in any reference frame ). Nothing that posses mass can be accelerated to c.

Do some basic research, you have lots of misconceptions.

 

[jp2code]

Maybe, I am being misguided. I question also - what happens to mass as it approaches c - does it get infinite? This seems implausible as well simply because an electron is the closest "natural" particle that we know is moving near c, yet it is also the lightest - if things got more massive as it approached c, then why at c does this mass suddenly disappear?

If I understand it correctly, as an object approaches to the speed of light, its mass can be transferred to an equivalent amount of energy. An electron is mostly energy with very little mass.

I've personally always felt that from an observer's perspective time would appear to be moving progressively slower for an object as it goes faster and faster. From the object's perspective, the observer would appear to be moving progressively faster and faster. At the speed of light (my hypothesis, here), the object traveling at the speed of light would not notice any time dilation in its own reference frame and the observer would appear to be moving infinitely fast (whatever that means). From the observer's podium, the object traveling at the speed of light would appear to be frozen in time.

Crazy stuff to wrap my mind around, though.
~Joe

 

[dewaite]

The relativistic formulae do not give sensible answers for velocities equal to c.


WE see light at different frequencies because it is a wave. The assumption above is wrong. There's no such thing as 'zero time nature'.


Yes, you are misguided. Mass does not increase with relative velocity ( recall that only relative velocities can be meaningfully discussed). Electrons can travel at different speeds ( always less than c in any reference frame ). Nothing that posses mass can be accelerated to c.

Do some basic research, you have lots of misconceptions.

I am doing basic research right NOW. I asked what happens to mass as it approaches c? The rest may be misguided assumptions - so i want the scientific answer - Relavitivistic Mass - how does it change as one approaches c - increase or decrease?

 

[Frame Dragger]

I am doing basic research right NOW. I asked what happens to mass as it approaches c? The rest may be misguided assumptions - so i want the scientific answer - Relavitivistic Mass - how does it change as one approaches c - increase or decrease?

You need to begin with first principles again. Take this as friendly advice or don't, but you should listen to Mentz and start from the beginning. This isn't an insult, just a fact of life.

 

[Fredrik]

I am doing basic research right NOW. I asked what happens to mass as it approaches c? The rest may be misguided assumptions - so i want the scientific answer - Relavitivistic Mass - how does it change as one approaches c - increase or decrease?

No one uses the term relativistic mass anymore (except in dicussions like this). When when we say "mass", we mean rest mass, which is independent of velocity. (The statement that you might be looking for is probably one of the following: a) The work that needs to be performed to accelerate a massive particle to speed v goes to infinity as v goes to c. b) If E(v) is the total energy of a massive particle in an inertial frame in which the particle has speed v, then E(v)→∞ as v→c.)

Your concern about time at the speed of light is answered by the following, which I originally posted in another forum:

The reason why we associate a specific inertial coordinate system with the motion of an inertial observer is that there's a clock synchronization procedure that makes that the natural choice. All the statements about Lorentz contracton, time dilation, etc., are consequences of that choice. The claim that massless particles experience no time comes from applying the usual time dilation formula for speed v and taking the limit v→c, but there's no reason why we should think of the result of that procedure as "a photon's point of view". There is however a good reason not to: The clock synchronization procedure doesn't work for massless particles. See my posts in this thread (at Physics Forums) for more about this.

 

[mryoung]

newbie here,

hello everyone.

My take on this is that photons are in a time-less dimension.
if you are a photon, everything goes in an instant. you die immediately when you are created and you go instantly where you are directed.
that is why photons have no acceleration.

- about its light speed and other properties.
photons are time-less particles in a universe governed by time. it is like a 2dimensional lifeform being observed by 3d people like us. a dot for a 2d person may actually be a line passing thru a 2d plane when viewed by a 3d person. That is why we can observe light properties like velocities and frequencies that are non exisent to a photon's world

my way of treating the constancy of the speed of light is to treat the universe the way physicists have been treating it for decades. scientists have been graphing space time in an x-y coordinate system with y-axis representing space and the x-axis as time. any event can be plotted on this x-y axis. now what this does is actually slice our existence into different frames like movie films, a series of still pictures layed out in time.
each picture should contain the whole universe itself including every photons. except of course if a particle suddenly went out of our universe.

now... we live in one frame at a time (like movie films), but that frame moves at a constant but in a very fast rate. and to follow Einstein's relativity, that "frame rate" should be the same in any frame of reference. Although photon's speed is undefined in its world and infinite to ours, it has to pass thru these frames which limits its speed to c. it doesn't matter wheter the source of light is going away or towards an observer, the photons will go to its destination in an instant(in his world) but to the observer, and to any observer the speed of light is c. c is constant because our frame rates are constant.

 

[Frame Dragger]

newbie here,

hello everyone.

My take on this is that photons are in a time-less dimension.
if you are a photon, everything goes in an instant. you die immediately when you are created and you go instantly where you are directed.
that is why photons have no acceleration.

- about its light speed and other properties.
photons are time-less particles in a universe governed by time. it is like a 2dimensional lifeform being observed by 3d people like us. a dot for a 2d person may actually be a line passing thru a 2d plane when viewed by a 3d person. That is why we can observe light properties like velocities and frequencies that are non exisent to a photon's world

my way of treating the constancy of the speed of light is to treat the universe the way physicists have been treating it for decades. scientists have been graphing space time in an x-y coordinate system with y-axis representing space and the x-axis as time. any event can be plotted on this x-y axis. now what this does is actually slice our existence into different frames like movie films, a series of still pictures layed out in time.
each picture should contain the whole universe itself including every photons. except of course if a particle suddenly went out of our universe.

now... we live in one frame at a time (like movie films), but that frame moves at a constant but in a very fast rate. and to follow Einstein's relativity, that "frame rate" should be the same in any frame of reference. Although photon's speed is undefined in his world and infinite to ours, it has to pass thru these frames which limits its speed to c. it doesn't matter wheter the source of light is going away or towards an observer, the photons will go to its destination in an instant(in his world) but to the observer, and to any observer the speed of light is c.

the speed of light is almost 90 degrees in the space time axis, so, a particle moving faster than the speed of light will be at exactly 90 degrees. as a result, the particle would seem to exist in more than one place at the same time, it would create a particle beam but this beam is composed of only one particle. if a beam stretches from Earth to sun, long as it may seem, it is made up of one particle. The problem is, it also exists in just one frame, so it disappears in an instant.

https://www.physicsforums.com/archive/index.php/t-319308.html

and https://www.physicsforums.com/showthread.php?t=315122

 

[Naty1]

dewaite...I wouldn't take all the above too, too seriously...the situation is rather complex...
At least one famous physicst has said time does not exist for photons...those of the cosmic background radiation are exactly as they were when emitted after the big bang and are just reaching us now...

But I would agree that thinking of light as a frequency based phenomena is not the best way for thought experiments in all situations...say the photoelectric effect, for example...

Because we don't understand time precisely, nor likely speed, nor why c is a limiting speed in this universe, etc,etc, it's kinda hard to draw unambiguous conclusions about how they all combine.

 

[Mentz114]

The phrase 'Time does not exist for photons' has a mystical ring to it, but has little physical significance. It's an anthropomorphism of 'photon', itself a doubtful concept outside quantum interactions.

But I would agree that thinking of light as a frequency based phenomena is not the best way for thought experiments in all situations...say the photoelectric effect, for example...

But the frequency of the light is crucial in understanding the PE effect ! That's the whole point - the frequency has to be such that the light quantum has enough energy to overcome the work function.

 

[edpell]

I'll jump in. At rest (and approximately for v<<c) the time axis and the travel axis are orthogonal. As v approaches c the two axises are no longer orthogonal. At v=c the two axes are coincident. If you know the photons position you know its time and likewise if you know it's time you know is position.

From a math point of view this is easy and reasonable. From an intuition point of view ... well I have been thinking about it for over 30 year and still find it unintuitive.

 

[danielatha4]

Would it not be safe to say, that if a light beam moves past an observer at c (which it should) then a clock aboard that light beam will not tick?

 

[Fredrik]

No, because you're describing a logically inconsistent scenario.

 

[Frame Dragger]

No, because you're describing a logically inconsistent scenario.

As in this entire thread... which should be locked, then burned. Then the ashes should be compressed into a 1 caret diamond, and fired into space from a submarine railgun. Requiem In Astro Pacis.

 

[edpell]

Would it not be safe to say, that if a light beam moves past an observer at c (which it should) then a clock aboard that light beam will not tick?

I would say there are vast differences between massless things and massed things.

Light carries it's own clock just count the number of waves passing by.

A clock made of massed parts will if started at rest in our frame, then brought to a high velocity relative to our frame, then held at that high velocity for some time (in our frame), then brought to rest in our frame will show fewer clock tricks than a clock that stayed the whole time at rest in our frame.

I do not think you can ever get a massed object to the speed of light. It takes an asymptotically raising amount of energy to push the object faster as we get near c.

 

[danielatha4]

Ok, then let me rephrase my question as an attempt to understand what it was dewaite was referring to.

If a clock is traveling a constant velocity with respect to an observer then as its velocity approaches c, then the rate at which that clock ticks approaches... ?

Out of my own curiosity, how would this affect observed frequency?

 

[edpell]

If a clock is traveling a constant velocity with respect to an observer then as its velocity approaches c, then the rate at which that clock ticks approaches... ?

zero.

 

[danielatha4]

right, so is the frequency of light affected by relative time measurements?

 

[edpell]

right, so is the frequency of light affected by relative time measurements?

The frequency of light is changed by relative motion (i.e Doppler Effect).

I have no idea what the phrase "relative time measurement" means.

 

[mryoung]

As in this entire thread... which should be locked, then burned. Then the ashes should be compressed into a 1 caret diamond, and fired into space from a submarine railgun. Requiem In Astro Pacis.

hey wait... this is fun for people like us. it keeps us interested in science. you don't have to get in of you're not interested.

 

[mryoung]

in the photon's reference frame, space and time axis coincide that is why those in the "know" wouldn't accept it as a valid reference frame. and they are RIGHT.

the universe cannot be observed in the photon's point of view, you are everywhere and nowhere at the same time and oops, maybe i shouldn't use the word "time".

but just for the fun of it why don't we describe it the way it is. Einstein did it, he gave up giving reasons to experiments giving the same speed result for light and said it out loud "well maybe the speed of light is constant".

if t=0 for a photon, then maybe time doesn't exist for a photon. but it doesn't mean that time doesn't exist for us as well. if space is extremely contracted for a photon, then maybe it is just a point- for itself only, but that doesn't mean it cannot be seen with a frequency by other observers.

so, light has frequency and speed for observers like us but not to photons.
we see its clock drop to 0 ticks but a photon would ask "what's a clock for?"

 

[Frame Dragger]

in the photon's reference frame, space and time axis coincide that is why those in the "know" wouldn't accept it as a valid reference frame. and they are RIGHT.

the universe cannot be observed in the photon's point of view, you are everywhere and nowhere at the same time and oops, maybe i shouldn't use the word "time".

but just for the fun of it why don't we describe it the way it is. Einstein did it, he gave up giving reasons to experiments giving the same speed result for light and said it out loud "well maybe the speed of light is constant".

if t=0 for a photon, then maybe time doesn't exist for a photon. but it doesn't mean that time doesn't exist for us as well. if space is extremely contracted for a photon, then maybe it is just a point- for itself only, but that doesn't mean it cannot be seen with a frequency by other observers.

so, light has frequency and speed for observers like us but not to photons.
we see its clock drop to 0 ticks but a photon would ask "what's a clock for?"

This isn't physics or science, but metaphysics and philosphy. Nothing wrong with that, but it's best not to confuse the two.

 

[mryoung]

This isn't physics or science, but metaphysics and philosphy. Nothing wrong with that, but it's best not to confuse the two.

yup... good use of the brain, keeps me interested in relativity. i wish i know more but the high level math is just too much for me. its not metaphysics for me, just a different perspective from everyone else.

 

[Frame Dragger]

yup... good use of the brain, keeps me interested in relativity. i wish i know more but the high level math is just too much for me. its not metaphysics for me, just a different perspective from everyone else.

It IS metaphysics, but that shouldn't discourage you. There is a lot of relativity that you can understand without ever learning math. Most of the concepts are abstract and not arithmatic (I find that easier), and therefore lend themselves to a semi-linguistic interpretation.

I agree that it's a good use of the brain, just hold yourself to a higher standard; you deserve it!

 

[mryoung]

It IS metaphysics, but that shouldn't discourage you. There is a lot of relativity that you can understand without ever learning math. Most of the concepts are abstract and not arithmatic (I find that easier), and therefore lend themselves to a semi-linguistic interpretation.

I agree that it's a good use of the brain, just hold yourself to a higher standard; you deserve it!

ok, we're going off topic but i'll still ask, what is metaphysics for you?
if its "The theoretical or first principles of a particular discipline" then i'll take it. thank you even.

nothing new for me to understand in relativity just the math, you know, differential eqns.. i appreciate the principles and actually in awe about them.

comming up with the idea of a "frame rate" makes it easier for me to understand why lightspeed is constant in all FOR.

dewaite hasnt replied if anyone has already satisfied his question. wish he would reply soon

 

[Frame Dragger]

ok, we're going off topic but i'll still ask, what is metaphysics for you?
if its "The theoretical or first principles of a particular discipline" then i'll take it. thank you even.

nothing new for me to understand in relativity just the math, you know, differential eqns.. i appreciate the principles and actually in awe about them.

comming up with the idea of a "frame rate" makes it easier for me to understand why lightspeed is constant in all FOR.

dewaite hasnt replied if anyone has already satisfied his question. wish he would reply soon

Ok, let me be very clear, I'm not trying tp diminish your accomplishment at all. Unless we start with formal physics in infancy, we tend to start with the metaphysics, which I would define as: theories decribing reality which are beyond the scope of science, but especially physics.

The issue arises here: your 'trick' to help you with (admittedly non-human-scale) problems in the field is fine, agreed. You're aware that it isn't a real physical description of the universe. This is however, how people can be lead astray to pseudoscience, because GR/QM don't answer all of the questions. They don't tell you why scalars are what they are, which may or may not be metaphysics for instance.

So, I've been general, now let me be specific: the question, "Does time exist at the speed of light?", which you described in terms of photons existing in a timeless fashion. There are models which describe the universe in terms of imaginary time as a structure, and in that sense your description is pretty good. So why am I whining, you have to be asking yourself by now?

What is time? What is the nature of a photon's existence in the brief period before absorbtion, or emission? In some ways you can avoid pondering the imponderables (ha) by constructing a 'toy' model to consider. When you've reached your limit, fair enough, but by your own admission that's not the case for you.

Photons can't exist in a timeless fashion... maybe a Planckian fashion? Really nothing but a photon could tell you, and they are notoriously closed mouthed. I'm horribly biased here, but maybe you'd find it interesting to do a little research on the Ergoregion of a Kerr Black Hole. My handle (Frame DraggING) occurs in that region, where at an extreme a counter-rotating photon could appear stationary relative to a photon outside of the ergoregion.

Basically, when "infinity" to use a terrible word, appears (such as no time, or endless time etc) it's usually a sign that a theory can no longer make valid predictions, NOT that those infinities exist.

Finally, for the record I'm not impuning your overall grasp of the concepts of SR/GR, in essence it's just time to circle back away from the HUGE and unanswerable questions, and work with models that might illustrate those points in a more scientific fashion.

 

[mryoung]

hmmm... :-)

i thought you were not trying to diminish? anyway, we're not discussing anything new anymore, let's just go to another thread...

 

[AWA]

I'd like to say there's nothing wrong with the kind of questions people like dewaite asks,nobody should be put down for asking such questions. They are exactly the kind of questions that Einstein often asked himself from the age of 16 until he discovered special relativity and kept asking them all of his life.It is not metaphysics. Posts by Fredrik and Framedragger in this thread seemto me to be in that sense discouraging for newcomers or laypeople in physics.
Mryoung, I have had similar intuitions to what you describe,and I've always wind up thinking that in some way spacetime must be emergent and don't exist in the microscopic level but emerges in the macroscopic level. I always thought it was nonsense from my crazy imagination but recently string theorist Erik Verlinde has come up with a hypothesis in which spcetime as well as gravity are emergent. So maybe, but only maybe this thougth experiments are not so useless, inconsistent, deserving to be burned, etc

 

[Frame Dragger]

I'd like to say there's nothing wrong with the kind of questions people like dewaite asks,nobody should be put down for asking such questions. They are exactly the kind of questions that Einstein often asked himself from the age of 16 until he discovered special relativity and kept asking them all of his life.It is not metaphysics. Posts by Fredrik and Framedragger in this thread seemto me to be in that sense discouraging for newcomers or laypeople in physics.
Mryoung, I have had similar intuitions to what you describe,and I've always wind up thinking that in some way spacetime must be emergent and don't exist in the microscopic level but emerges in the macroscopic level. I always thought it was nonsense from my crazy imagination but recently string theorist Erik Verlinde has come up with a hypothesis in which spcetime as well as gravity are emergent. So maybe, but only maybe this thougth experiments are not so useless, inconsistent, deserving to be burned, etc

This is a common argument, "x, y, or z notable figure had wild theories too!" Yes... the difference is that for every world full of people, there are only a handful of Einsteins in a generation if at all. Of course, let's be fair to Einstein shall we, and aknowledge that he produced results before anyone bothered to listen to him. Interest in what he thought when he was a teenager waxed AFTER confirmation of Relativity by Eddington and others.

People ARE recognized for their genius, and in a world where Brian Greene can pump out novels about whatever version of String Theory he's into today, or Depak Chopra hasn't been trampled by hippos (personal dream). Being on shakey experimental ground, or proposing new theories (with evidence) isn't slammed the way it used to be... just ask Galilleo Gaililei.

If you want to put forward a radical new idea (ATM, whatever), you'd better lead with your math, or your experimental evidence, and NOT just a reformulation or bastardization of existing theories.

@Mryoung: I'm not trying to, and if I am insulting you I apologize. Another thread it is.

 

[AWA]

The only radical idea I try to put forward is that it is okay to discuss physical ideas in a forum about physics, and not just give answers out of the textbook which we all can read by ourselves, maybe I'm wrong but at least i would expect that from a physics forum.

BTW what's ATM?

 

[Frame Dragger]

The only radical idea I try to put forward is that it is okay to discuss physical ideas in a forum about physics, and not just give answers out of the textbook which we all can read by ourselves, maybe I'm wrong but at least i would expect that from a physics forum.

BTW what's ATM?

"Against The Mainstream"

 

[jtbell]

The only radical idea I try to put forward is that it is okay to discuss physical ideas in a forum about physics, and not just give answers out of the textbook which we all can read by ourselves, maybe I'm wrong but at least i would expect that from a physics forum.

Please read the Physics Forums Global Guidelines which all members agree to abide by when they register to post here. You can find them by clicking on the word "Rules" at the top of every page here. Pay particular attention to the section Overly Speculative Posts.

Speculation is of course a part of scientific research, as an initial stage in formulating theories and hypotheses to test against experiment. However, PF is not a research forum. Its mission is educational, to help people understand physics (and other sciences) as it is currently being practiced. This includes new ideas that have been developed in the research community, have been published and are being debated there. It does not include generating our own speculations, or helping to promote speculations that are not part of current research.

 

[Frame Dragger]

Please read the Physics Forums Global Guidelines which all members agree to abide by when they register to post here. You can find them by clicking on the word "Rules" at the top of every page here. Pay particular attention to the section Overly Speculative Posts.

Speculation is of course a part of scientific research, as an initial stage in formulating theories and hypotheses to test against experiment. However, PF is not a research forum. Its mission is educational, to help people understand physics (and other sciences) as it is currently being practiced. This includes new ideas that have been developed in the research community, have been published and are being debated there. It does not include generating our own speculations, or helping to promote speculations that are not part of current research.

To be clear, speculations within the context of a friendly discussion are one thing, compared to starting threads dedicated to some random conjecture? I hope? The rule I assume one lives by is that you try not to be overly tangential, and not at all if you're being speculative, and not to begin with pseudoscience. Please correct me if I'm mistaken.