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brunoeinstein
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Do photons remain stationary in the fourth dimension?
Do photons age?
Thanks! :)
Do photons age?
Thanks! :)
Photons are truly amazing! I want to talk about a few details here because I hear them a lot.pallidin said:Photons are fascinating to me. Example, as far as I know, photons do not exist when not moving.
And that a photon goes from zero to c instantaneously is equally fascinating, as I thought that nothing could go faster than c. "Instantaneous" is certainly much faster than c.
Much for me to ponder and learn...
I think the idea is great, but the math is very different. There's a huge difference here between the speed of light, and arbitrarily CLOSE to the speed of light. Its the same difference as between a black-hole, and just a really big star... the math gets angry at certain values :Pbrunoeinstein said:well, we can take the limit i suppose ... and at 100%, it will have stopped, i would imagine.
I find this to be one of the most intriguing ideas in physics, and It feels like the kind of thing that might have deep meaning that no one has yet uncovered.brunoeinstein said:interesting fact:
the velocity of all objects through spacetime is c.
zhermes said:Photons are truly amazing! I want to talk about a few details here because I hear them a lot.
1) Photons don't "go from zero to c." They just start out at c, continue at c, and end at c :)
Which ties into what you said at first: you can't have a photon that isn't moving [at c].
DaTario said:I am curious to hear (read) how do you deal with refraction, created either by material medium or by gravitational (general relativity) effects.
It seems reasonable in these contexts to think of photons accelerating.
bcrowell said:Photons always move at c. Velocities less than c for an electromagnetic wave are the velocities of the wave formed by the superposition of the incident wave and waves reemitted by the charges oscillating in the medium.
DaTario said:If this is true then if you put a large (1 m thick) slab of glass in front of a photon source, and set a photo-detector after this slab, then you would be able to measure time intervals consistent with c velocity of propagation from the source to the detector, as the main wavefront is always present.
If they're 10 billion years old, how do they not age? :Pbkelly said:Our telescopes receive photons that are upwards of 10 billion years old. That seems to indicate they do not age.
Fredrik said:For something to actually age, it needs to have an internal structure that can change with time. No elementary particles do, so they can't really age.
For something to really experience the passage of time (or anything else), it needs to be conscious. Things without internal structure certainly can't be conscious.
DaTario said:The word "certainly" seems to be inappropriate as we don't even know how to define consciousness. And it seems also to be quite risky to assume that the consequence of a particle not having internal structure is its being unable to present complex behavior. It is more a question of words here, as I agree in general with the estimatives you presented.
Fredrik said:Something that isn't capable of storing information can't be considered conscious, and a physical system that doesn't have distinguishable states can't store information.
Fredrik said:The problem is that the standard synchronization procedure doesn't work for null geodesics, i.e. for the curves that can be world lines of massless particles. So the term "experiences" is undefined for photons.
No, not at all. I don't know a definition of the word "incomplete" that would make SR incomplete, except of course "incomplete"="isn't an exact description of all phenomena", but with that definition, all theories are incomplete. SR is as complete as a theory can get.Nisse said:Would it be fair to infer from this that Relativity is an incomplete theory?
I googled and found at least one person who claimed that the answer is "infinite", so I assume that this is what you had in mind, but I would say that this claim is false. I assume that it comes from the fact that the set of spin-1/2 states can be mapped bijectively onto a sphere. Since there are infinitely many points on a sphere, you could argue that there are infinitely many states that the system can "be" in. But it's not at all obvious that a state can be said to represent the particle's properties. The only thing we can be sure of is that it represents the properties of an ensemble of identically prepared systems.DaTario said:An alectron for instance has spin, and therefore allows one to store 1 qbit. How much information (classical information) can be stored in 1 qbit. Do you know?
Fredrik said:No, not at all. I don't know a definition of the word "incomplete" that would make SR incomplete, except of course "incomplete"="isn't an exact description of all phenomena", but with that definition, all theories are incomplete. SR is as complete as a theory can get.
I googled and found at least one person who claimed that the answer is "infinite", so I assume that this is what you had in mind, but I would say that this claim is false. I assume that it comes from the fact that the set of spin-1/2 states can be mapped bijectively onto a sphere. Since there are infinitely many points on a sphere, you could argue that there are infinitely many states that the system can "be" in. But it's not at all obvious that a state can be said to represent the particle's properties. The only thing we can be sure of is that it represents the properties of an ensemble of identically prepared systems.
Well, the unstable ones can decay, so I would say that elementary particles can age. Since the proper time along a photon's worldline is 0 then it could make coordinate-independent sense to say that a photon does not age.Fredrik said:For something to actually age, it needs to have an internal structure that can change with time. No elementary particles do, so they can't really age.
I am completely with you here both in terms of consciousness and experience. Attributing consciousness to fundamental particles is just an absurd thing to do in physics (how would you experimentally test that), and the usual meaning of experience is undefined for null worldlines.Fredrik said:For something to really experience the passage of time (or anything else), it needs to be conscious. Things without internal structure certainly can't be conscious.
What we mean when we say that an object or a particle "experiences X" is that in the coordinate system that the standard synchronization procedure associates with the object's world line (or its tangent), some sequence of events is described as "X". That's how the term "experiences" is defined in the context of special and general relativity. The problem is that the standard synchronization procedure doesn't work for null geodesics, i.e. for the curves that can be world lines of massless particles. So the term "experiences" is undefined for photons.
I would say that the measured decay rates are the strongest evidence we have for the particles not aging. If the properties of a particle don't change with time, the probability that it will decay during the next second must be independent of how much time has passed since the particle's creation. This implies an exponential decay rate. So the theory that particles don't age (i.e. the theory that particles don't have any properties that can change with time) predicts the correct decay rates.DaleSpam said:Well, the unstable ones can decay, so I would say that elementary particles can age.
DaleSpam said:Well, the unstable ones can decay, so I would say that elementary particles can age.
...in the majority of circumstances (slow speeds) most of an objects motion is thru time, not space...the maximum speed through space occurs if all of an objects motion through time is diverted to motion through space...thus light does not get old; a photon that emerged fromthe big bangis the same age today as it was then.
For something to actually age, it needs to have an internal structure that can change with time.
How do you define "age" when the "older" version of the same thing is indistinguishable from the younger?Naty1 said:I disagree...an object without internal structure CAN age...maybe it doesn't change, however...so trying to measure the passage of time utilizing such "something" that does not change would be futile.
Very good point. I certainly had not considered it that way. The lifetime of people is not governed by an exponential law precisely because they do age, meaning that the likelihood of decay in the next year changes as a function of the number of years since birth.Fredrik said:I would say that the measured decay rates are the strongest evidence we have for the particles not aging. If the properties of a particle don't change with time, the probability that it will decay during the next second must be independent of how much time has passed since the particle's creation. This implies an exponential decay rate. So the theory that particles don't age (i.e. the theory that particles don't have any properties that can change with time) predicts the correct decay rates.
So, although you can say that the proper time along a photon's path is 0 you cannot associate that with aging one way or the other.
MDT & Brian Greene’s Elegant Universe:
In An Elegant Universe, Brian Greene almost characterizes Moving Dimensions Theory’s deeper reality:
“Einstein found that precisely this idea—the sharing of motion between different dimensions—underlies all of the remarkable physics of special relativity, so long as we realize that not only can spatial dimensions share an object’s motion, but the time dimension can share this motion as well. In fact, in the majority of circumstances, most of an object’s motion is through time, not space. Let’s see what this means.” Space, Time, and the Eye of the Beholder, An Elegant Universe, Brian Greene, p. 49
Right here Brian almost grasps MDT. But time is not a dimension. Time is an emergent phenomenon that arises because the fourth dimension is expanding relative to the three spatial dimensions at the rate of c. Let’s rewrite Brian’s paragraph with MDT's insights:
“Einstein found that precisely this idea—the sharing of motion between different dimensions—underlies all of the remarkable physics of special relativity, so long as we realize that not only can the three spatial dimensions share an object’s motion, but the fourth dimension, which is moving relative to the three spatial dimensions, can share this motion as well. In fact, in the majority of circumstances, most of an object’s motion is through the fourth dimension, not the three spatial dimensions. Let’s see what this means.” Space, Time, and the Eye of the Beholder, An Elegant Universe, Brian Greene, p. 49
Most objects are traveling far less than c through the three spatial dimensions. Thus most objects are traveling close to the rate of c through the fourth dimension. To be stationary in the three spatial dimensions implies a velocity of c through the fourth dimension. Ergo the fourth dimension is expanding relative to the three spatial dimensions. To be stationary in the fourth expandning dimension, as is the timeless, ageless, nonlocal photon, implies a velocity of c through the three spatial dimensions. Ergo the fourth dimension is expanding relative to the three spatial dimensions.
dx(4)/dt = ic
Brian Greene continues:
“Motion through space is a concept we learn about early in life. Although we often don’t think of things in such terms, we also learn that we, our friends, our belongings, and so forth all move through time, as well. When we look at a clock or a wristwatch, even while we idly sit and watch TV, the reading on the watch is constantly changing, constantly “moving forward in time.” We and everything around us are aging, inevitably passing from one moment of time to the next. In fact, the mathematician Hermann Minkowski, and ultimately Einstein as well, advocated thinking about time as another dimension of the universe—the fourth dimension—in some ways quite similar to the three spatial dimensions in which we find ourselves immersed.” Space, Time, and the Eye of the Beholder, An Elegant Universe, Brian Greene, p. 49
What Greene misses is that the time measured on your watch—the ticking seconds—is not the fourth dimension, but it is a phenomenon that emerges because the fourth dimension is expanding relative to the three spatial dimensions. The time measured on a clock or watch relies on the emission and propagation of photons, be it in the context of an unwinding clock spring or an oscillating quartz crystal, or even the beating of a heart. And photons are matter that surf the fourth expanding dimension. As time is so inextricably wed to the emission and propagation of photons, and as photons are matter caught in the fourth expanding dimension, our notion of “time” inherits properties of the fourth expanding dimension. But the fact is that time emerges from a deeper physical reality—a fourth dimension that is expanding relative to the three spatial dimensions.
Brian Green continues on, heading off in the wrong direction that just misses the central postulate of MDT:
“Although it sounds abstract, the notion of time as a dimension is actually concrete.”
But it is not. Can you move to where your watch reads three seconds back in time? Or can you move to where your watch reads an hour back in time? We can walk left or right. We can climb up or down. We can move forwards or backwards. But we can’t move through time like we can through the three spatial dimensions. This is because time, as measured on our watch, is not the fourth dimension, but it is a construct we have devised which is based on the fundamental fact that the fourth dimension is expanding relative to the three spatial dimensions, governing the emission and propagation of photons, by which time is known and measured on our watches.
Brian Green continues on,
“When we want to meet someone, we tell them where “in space” we will expect to see them—for instance, the 9th floor of the building on the corner of 53rd Street and 7th avenue. There are three pieces of information here (9th floor, 53rd Street, 7th avenue) reflecting a particular location in the three spatial dimensions of the universe. Equally important, however, is our expectation of when we expect to meet them—for instance, at 3 PM. This piece of information tells us where “in time” our meeting will take place. Events are therefore specified by four pieces of information: three in space and one in time. Such data, it is said, specifies the location of the event in space and in time, or in spacetime, for short. In this sense, time is another dimension.”
But again, time is different from the three spatial dimensions. Time is inextricably wed to our sense of the past—the order stored in our memory, long with our ability to imagine and dream of future events. The present is where we put our dreams into action. However, the time defined by past, present, and future is not a dimension akin to the three spatial dimensions, but rather it is a phenomenon that emerges because the fourth dimension is expanding relative to the three spatial dimensions, at the rate of c.
You write, "So I don't think Einstein and Minkowski went far enough. They covered measurement, and how events in one reference frame would appear to an observer in another reference frame. That is quite useful in itself, but the real picture seems to be fundamentally much larger than what they covered. We need to go beyond Einstein and include temporal motion, which in turn requires a consideration of non-directional motion, speeds greater than light, non-locality, and so forth. Even better, we need to learn how to think in terms of "motional dimensions" directly, instead of space and time dimensions."
Yes! Feynman sought this mechanism for the ever constant motion of time! He sought source of time's arrows and assymmetries!
And MDT provides this *physical* mechanism for time and all change, and a while host of other physical phenomena.
Indeed, MDT finally provides, in Feyman's words, "the thing that makes the whole phenomena of the world seem to go one way." Time has a definitive arrow because the dx4/dt=ic, or the fourth dimension is expanding relative to the three spatial dimensions at the rate of c. Ergo radiation, which is but matter caught upon the expanding nonlocality of the fourth exapnding dimension, expands outward, but never inward. Ergo time and all its arrows and asymmetries, as well as entropy, as more fully elaborated on in my paper.
Feynman stated, "Now if the world of nature is made of atoms, and we too are made of atoms and obey physical laws, the most obvious interpretation of this evident distinction between past and future, and this irreversibility of all phenomena, would be that some laws, some of the motion laws of the atoms, are going one way – that the atom laws are not such that they can go either way. There should be somewhere in the works some kind of principle that uxles only make wuxles, and never vice versa, and so the world is turning away from uxley character to wuxley character all the time – and this one-way business of the interactions of things should be the thing that makes the whole phenomena of the world seem to go one way. But we have not found this yet. That is, in all the laws of physics that we have found so far there does not seem to be any distinction between the past and the future. The moving picture should work the same going both ways, and the physicist who looks at it should not laugh."--(The Distinction of Past and Future, from The Character of Physical Law, Richard Feynman, 1965)
MDT has finally found "the thing that makes the whole phenomena of the world seem to go one way."
To be stationary in a lab means to move at c through the fourth dimension. So it is that absolute rest may be defined as maximal aging, but this can never be ascertained in an inertial frame cutoff from the surrounding environment, as time is measured relative to the velocity of light and distance, which are ultimately measured relative to time. This tautological definition of time and the velocity of light and the velocity of light and time is something Einstein noted.
Dr. E (The Real McCoy)