The Definition Of Time, physics

Can anyone enlighten me, is there a mathematical definition of time itself.

We talk of time beginning with the big bang, to understand the nature of time would help me to understand what it is to be beyond time itself, to picture the universe without time, before the beginning. thanks.

Time is compeling kinetic energy to move objects in space. But energy not completely submits to time. More I do not know anything about time.

Hi Woodroyd,
I've always liked this short paragraph from Einstein's "On the Electrodynamics of Moving Bodies"

Quote:
If we wish to describe the motion of a material point, we give the values of
its co-ordinates as functions of the time. Now we must bear carefully in mind
that a mathematical description of this kind has no physical meaning unless
we are quite clear as to what we understand by “time.” We have to take into
account that all our judgments in which time plays a part are always judgments
of simultaneous events. If, for instance, I say, “That train arrives here at 7
o’clock,” I mean something like this: “The pointing of the small hand of my
watch to 7 and the arrival of the train are simultaneous events.”

This might not fully answer you, but I find it a good starting point!
Peace,
Ron

I've been looking through motion mountain; a free downloadable physics book, and it says that continuous space and time does not exist. (p.11) This makes sense.

But the wikipedia gives an equation. Equation_of_time

Many thanks for the replies, it is a difficult question and one that I still do not fully understand. Without time nothing exists, within time everything exists.
Rons definition of time is a good example, I also agree with Tracertong that continuous space and time does not exist however we know that time exists because we exist within it.

My next question is 'do we all think that time began with the Big Bang?'

And if it began then and did not exist before could we define 'before the Big bang' as being outside of time or without time or before time.

All physicists define time, more or less, as this: It is what you measure on your watch.

Graveyard or swing shift?

I asked my neighbor when will I die?

She said you will know in due time without delay.
What the is that suppose to mean?

Even though I have a sharpening business,I feel threatened. Every time she comes over,she asks me to sharpen knives.

She just left and I expect her to be back in an hour.
What should I do?

Oh yea,She seems healthier than me too.

Hi woodroyd, Ron, dimazin, TheUnknownUniverse, TracerTong et al,

The best way IMHO to think of time is through the concept of "events". These "events" define an "arrow" for time in an "eventscape" of a great number of sequentially connected and dependent events (we call causality). Ron is a very cleaver chap so what he has said is OK by me. After we have "solved" the problem of defining "simultaneity" and comparing things simultaneously then we need to look a little further. In one sense without any events happening at the absolute local level of our Universe then the progress of time relative to other places in the Universe where "more events" are happening define a kind of very primitive "clock". One way to "halt" the relative progress of events is with relative speed. Sufficient relative speed reduces the relative observed occurrence rate of events proceeding in another system under observation. This is relative to formerly synchronized clocks (a hard "ask" in many cases). The moving clock "loses ticks" relative to the stay at home clock.

As a "system" moves away from an observer closer to the speed of light the rate of events progressing in the other observed system "falls" in comparison to the first system. This phenomenon is not something that can be sensed with reference to only one set of synchronized clocks that remain in only a single inertial reference frame. It is a phenomenon that is only recognized by a comparison. In these systems that have measurable differential rates of events the limiting case is when one system is moving at a relative speed close to light, so close that the external observer can't determine the difference between the speed of the system and the speed of light. At the same time as this process of trying to measure this tiny differential speed difference between light and the observed system the measurable events are falling off to such an incredibly low flux that it would become harder and harder to determine the position and momentum of the moving particle. Simultaneously the frequency of these events is falling toward a zero in frequency which cannot be detected using conventional instruments. Since E = hf then these "events" defined by the photon exchange forces in our Universe carry less and less energy ... tending toward zero energy which is not able to be "sensed" using any conventional sensors. Now this is an actual velocity between the frames which is being measured to gain this insight. In most cases we cannot easily measure these stellar and galactic events progressing "far far away". There are no "johnny on the spot" observers and time of transit of light is not "instantaneous" and may take many millions of years. Simultaneity is once again a serious issue.

The extreme of this process leads to no observable events and thus "time" appears to be "relativistically" halted. I would point out that (counter intuitively) this does not happen simply for a particle moving away at almost exactly the speed of light and observed from a single point of view from "behind". Ignoring other effects (due to General Relativity and Doppler shift), the speed of any receding source object (of equally spaced flashes) can never appear to recede in excess of 1/2 the speed of light if observed from a single "rear" vantage point. This is because the "spreading" of light always travels at the speed of light and consider this problem as one involving a series of "chaser lights" draped along a "string" path in space where the globes are spaced at one light second apart and flash in a strict sequence starting at one end (the near end) and progressively flash in that rest frame at one second intervals along the string giving the appearance of a flashing source moving away from the observer at almost exactly the speed of light (as reckoned by using a tape measure laid out along the string). In this case we can actually make this process such that the chaser lights appear to to give an impression of moving at "exactly" the speed of light since nothing is actually moving in this case at all.. Each successive flash of light takes a further second to return to the first observer than the light from the previous flasher light and the effect is to only double the time the flash takes to return to base and so gives the appearance of the "flashing and moving source" traveling at only 1/2 the speed of light (rather than the full speed). Naturally this does not involve any Doppler Shift which would give it away as being not a true source of motion. Still this illustration will show you that the argument is correct and many standard texts also report on these "visual" phenomena.

The only way in which a true moving particle can move so that it "appears" to be receding at nearly the speed of light and suffer the effects of Relativistic Doppler Shift is if "something else" is involved.... In this case it is "Universal Spreading" due to Hubble Shift... frame dragging. It appears that "on average" every point in the Universe is moving away from every other point and depending on a factor that is proportional to the separation at any point in time .... Our entire Universe is continuously "accelerating away from everything else in it". This phenomenon has been known for a very long time and is reported incorrectly in many texts. The true speed of recession of objects must be corrected for Hubble Shift and with some events and geometry is a "serious omission" not to correct. A survey of distant objects show a plethora of objects moving near the speed of light... observed. The only conclusion that can be drawn from this is the Universe is a lot bigger than Special Relativity would suggest and has spread a lot more than we might hope for.

With the "onset of the halting of time" at the edge of the visible Universe the visibility of the system will become simultaneously increasingly difficult (understanding that the events of the emission of photons by which the system is seen are reduced dramatically and their frequency is lowering to a Doppler frequency approaching zero. Alternatively if the system is relativistically approaching at near the speed of light the first appearance of the system may be marked by the light "compressed" wavelengthwise along the direction of motion towards the observer so that the closer this system is to the speed of light it remains "invisible" for more and more time of it's travel as V -> C and the "visual onset" of this system in the region of the observer may be close to the first appearance of it locally with all the optical events that the moving system had emitted "compressed" over a very short period of time leading to unusual effects. One such confirming situation is the Jet from M87 which is directed towards our region of space. The light from this continuous emission phenomenon "appears" to be being emitted at a rate of 6 times the rate of light from other more normal sources. If you were "unaware" of Special Relativity then you would consider this light to be moving at six times the normal rate. As it is this effect is due to proper motion of the source (which is incandescent gas ejected in our direction from a black hole at nearly the speed of light "continuously").

This has not considered the effects of Gravity or of mass on time. The effects of mass on time leads to a relative slowing of relative time the deeper the source is "immersed" into the gravitational potential well. This can be confirmed with two synchronized accurate atomic clocks on successive floors of a single building, that is just how accurate clocks have become. The rate of time is measurably different due to gravitational acceleration. This can also be extended through the principle of equivalence to include conventional acceleration also "slows time" as an independent effect to "simple Special Relativity". Piecemeal treatment of Special Relativity can arrive at General Relativistic results. One of them is acceleration affects time because all accelerations are equivalent be they gravitational acceleration or "inertial" acceleration.

The "slowing of time" due to Special Relativity allows us to distinguish two clocks that were initially synchronized and are now in relative motion. There is a necessity to acknowledge here that at some time one of these clocks (or both) were accelerated relative to the other. Some very silly things have been said on this Forum about Relativity and it tends to lead those who do not understand to believe that Relativity (Special and General) is "bunk". Nothing could be further from the truth so be aware that there may be some silly arguments. The adage of "moving clocks run slow" should be restated more accurately "accelerated clocks run slower than less accelerated clocks".

This is the point at which General Relativity meets Special Relativity. By this means you may distinguish two travelers by an examination of their clocks as defining a worldline by virtue of their acceleration histories. The "most accelerated" traveler will "age less" (have less elapsed home time) than the least accelerated traveler (who stays at home) on a "round trip". This is the so called "Clock or Twin Paradox"... actually it is not a paradox at all and is the result of Time Dilation. The introduction of mass and thus acceleration breaks the global symmetry of Special Relativity resulting in only a local interpretation of the phenomenon. This symmetry breaking also results in General Relativity where spacetime curvature entirely defines the geometry of this space. This is clearly linked to the comparison between clocks in different frames.

There are also the possibility of Rindler Foliations in spacetime that define a geometry that differs from much of the rest of the geometry defined so far... I will lead you to read up on this and it also deals intimately wit the passage of time and the linked geometry of space.
7.5 Packing Universes In Spacetime

As a further amusement you may look here at this article where the WMAP Probe has shown up more interesting geometry in spacetime related to the Cosmic Microwave Background.
A cosmic hall of mirrors
Where I call your attention to this mapping...
2 Angular power spectrum
... and it's interpretation.

So here we started from events defining a primitive clock to the geometry of spacetime and the way this is connected to Special and General Relativity and to Gravitational Red Shift and the way that single points of view of our Universe may "mislead" us into thinking the Universe is smaller than we think to relative time dilation for travelers that undergo large accelerations. We then "touched" on Rindler Foliations and exotic geometry in spacetime connectivity leading to a Universe that may be closed.

So you then had the next question...

Time began with the first "clock" in our Universe. That was the first event. The first "event" would require the first appearance of matter in our Universe since photons alone have no mass and without any particle to scatter them there are no events. The photons themselves travel at the speed of light and so "suffer the most extreme form of time dilation and space contraction" that special relativity provides... they move along "null geodesics" in a flatspace which have zero dimensional spatial length and occupy zero time.

This means that before the appearance of mass, infinite time dilation and infinite space contraction are a "singularity" and are not definable events in our Universe... real events only showed up after matter came on the scene probably condensing from out of the primordial "light". At that point "suddenly" we have space and time evolving with that mass on which events can now "operate". So now we have events too that are defining time for us again. Before the big bang is the place where our Universe came from and cannot be defined by a measure of time in our Universe but the event may be relevant to the "mother" Universe from which this influx "we live in" poured from. It is potentially "unknowable" but it is nice to conjecture that our Universe is like a single elementary particle "created" by an event in some other source Universe resulting in "everything" we now see around us. We are all just "hidden behind a very dark wall" that light can no longer penetrate since that "first light".... This may be through Rindler Foliations or through spacetime curvature "closing" our spacetime off as a kind of "compactification".

Maybe we are inside a Black Hole falling and expanding as a sequence of events into time created by this process forever and we call this expanding "droplet" the result of "Hubble Shift"?? The "darkness" being the inside of "our own Black Hole". In space nobody can hear you weeping and your teeth gnashing at the "bottom" of this "bottomless pit"... Still... it's not bad really!

Cheers

This post has been edited by Good Elf on Sep 27 2008, 03:00 PM

The Good Elf sounds like he knows his stuff, but I'd just like to add a couple of simple concepts to the mix at a different level (not contradicting anything he said).

Einstein himself argued that the concept of "simultaneity" (two events, separated in space, happening at the same time) was nonsensical, in his book, "Relativity". He argued that it would be a matter of perspective whether those two things happened at the same time or not, so the concept didn't really make any sense.

Then Wolfgang Ketterle (sp?) made a Bose-Einstein condensate about the size of the period at the end of this sentence. The basic concept of a BEC is that it's comprised of many particles that are all in the same quantum state, so if you do something to one side of the period, you do it to the whole period simultaneously (as if hitting it from all directions at once). I e-mailed Ketterle when I first read the article and congratulated him on his discovery, telling him that I felt he'd discovered something more significant than he seemed to realize in his comments at the time. (To which he replied that "it's just cold gas with odd properties".) I told him that if it worked like I thought it worked, then it would be a special instance where Relativity might not apply and that he should look for temporal and gravitational anomalies close-by the BEC. He replied that I was a crackpot and told me to quit wasting his time with my e-mails (three, total).

A couple years later, he measured the speed of light "through" a BEC sample and found that the speed of light in a BEC is about what you'd get from a slow-ball pitch, so the index of refraction of a BEC is something like 17,000,000. Glass is about 1.5, give or take, and I think diamond has the highest index of refraction, somewhere around 2. (I'll look it up after I write this.) My thought on this is that he didn't measure really slow light, he actually slowed time down local to the BEC.

But a couple years later, he won the Nobel Prize in Physics for his discovery.

I'm still waiting for him to look for gravitational anomalies.

ANYWAY, sorry about the rant, but sometimes it helps to vent.

The second point I'd like to make about time is that it's assumed to progress uniformly, like soldiers marching in a parade. I think it's more like a New Orleans funeral procession, where they play sad music taking the guy to his grave, then play Dixieland music on the way back, dancing and celebrating his life. (Time being like the mourners dancing down the street on the way back, rather than marching in-step like a parade.) In both instances, the group sets out in the same direction and moves, on-average, at the same rate, but when you get closer to the Dixieland dancers, sometimes they move forward, sometimes they stay in one spot, then they move forward faster than the crowd to catch up. It would explain a lot of otherwise perplexing phenomena in QM.

The next point comes from a literal interpretation of the Copenhagen Interpretation, where "a system exists in a superposition of all possible states until observed, and that it's the act of observation that forces the system to adopt a single-valued state." A system existing in a superposition of all possible states doesn't sound to me like it's obeying a single clock, like Big Ben, it sounds to me more like time for that system doesn't advance in time until it's observed. At which point the time-frame of the observer determines which of the possible states is "real". (Sorry, I tend to put quotes around "real" a lot.)

And one final point, asking what happens when someone drops out of time - that one is pretty simple to answer (from the perspective of the observers left behind), he never does physically leave. That would defy too many of the most fundamental physical laws. Imagine you're at your desk, feet up, thinking about quitting time, and some alien approaches you and kidnaps you - Poof! Beamed up away from your desk straight into the spaceship. You cruise the galaxy at transwarp speeds, have sex with a green alien slave-girl, save the universe from Ming the Merciless, get a kiss on the cheek from Princess Leah wearing her brass bikini as she puts a medal on your chest, and Ping!, you're back at your desk, feet still up on it, and your boss glaring at you.

Your boss never saw you leave his timeframe, and he's PO'd that you're daydreaming during working hours. Did you actually leave and come back at the same instant, or were you daydreaming? Who can say? One thing, though, is that the laws of the universe that your boss lives in can't be broken from *his* perspective, or it'd violate the basic principles of physics (including Relativity, which says that no one's frame of reference is preferred over anyone else's).

So if you *could* travel in time, like from one time to another and back again, to all observers, you never disappeared.

And to make matters worse, it'd be pointless to tell anyone about your trip, because if you *did* change anything in the past, then it's already been changed in the past of the people who you've come back to. It'd be like me saying that I went back in time and prevented the Third World War, you know, the one back in the 80's where 90% of life on earth was wiped-out in a nuclear holocaust. A simple "thanks" would be adequate, but cash donations are always welcome, too.

If I there had, actually, been a nuclear holocaust in the '80's, and I actually *did* go back in time and stop it from happening, then you'd never have heard of it because in your timeline it never happened. So there'd be no point in me telling you about it, you'd never believe it, because it never happened in your timeline. And the laws of physics that require continuity from one moment to the next would preclude my disappearing and reappearing at a different time. So you never disappear, and you can't bring information back (none that'd matter, at least). Talk about your thankless jobs...

Incidentally, I did actually e-mail Wolfgang Ketterle before he measured the speed of light "through" a BEC, and he did call me a crackpot years before he won the Nobel Prize in Physics. One problem that I'm surprised no physicist has spotted in his explanation of light slowing down by a factor of 17 million or so, is that whenever light encounters a boundary between two media of different indices of refraction, there's a reflection that's proportional to the ratio of the differences between the two indices at the boundary, and the amount of light propagating through the boundary is at most one minus that reflectivity. Light going *through* a droplet of a BEC would be traversing *two* boundaries, so you'd end up with the amount of light on the other side being inversely proportional to the square of the ratio of the indices. What's 1/17million, squared? And just how damned bright *was* that laser he shined "through" the BEC?

My take is that the light never went *through* the BEC, it was delayed in time and tunnelled past it. Since everything "inside" the Bose-Einstein Condensate is in the same state at the same time, and simultaneity in this universe, according to Einstein's reasoning, is nonsense, that whatever's "inside" the BEC, isn't playing in *our* space-time.

As for the question of what happened before the Big Bang, I'd leave that one alone. Steven Hawking has been taking guesses about it all his life, and look what happened to him. Some things we aren't meant to know, and probably shouldn't speculate about. Before the universe began? - That's God's domain, not for us to speculate about. We probably couldn't understand it even if we were told what happened by God himself.

Luckily, it won't be on the Final Exam, either.

Hi wcelliott, woodroyd, Ron, dimazin, TheUnknownUniverse, TracerTong et al,

This is an old problem... those who never measure systems (Mathematical Physicists) vs those that actually measure systems (Experimental Physicists). Philosophy vs experiment and practicality. In our world Physics is about "all those applications" not about the maths and wondrous spacetime diagrams. Physics is "science" not "philosophy"... where there is a mutual dependence on and between the theory and the experiment... In the end the experiment is the deciding factor and no theory is about to depose the properly contrived experiment... It is always the other way around... theory must give way to experimental results ... which is after all the Universe "herself" speaking "loudly" and authoritatively about herself.

It is important to distinguish one important aspect of Relativity from it's other aspects. Clock synchronization is "most important". While it is quite right to think that there is no "absolute simultaneity" in all circumstances, the mere separation in space does not mean that event simultaneity is always impossible. Global frames of reference are also not possible in Special Relativity but practical local inertial frames of reference are indeed possible and to have a "frame" it must consist of extended sets of points not just a single point at an origin. Special Relativity is of no practical value unless you can "construct" an inertial reference frame that spans the space and the time. This is not just a series of coordinates defined along the X,Y and Z axes but it absolutely must include time as one of the coordinates. The frame defines simultaneous events as events in the one inertial frame all having the same time coordinate. The creation of this frame is provided in Einstein's Theory by the exchange of light flashes between distant centers. A flash of light is emitted from one point and "bounced" off a mirror at the second point in the one inertial frame and then reflected back to source like in certain experiments to evaluate the speed of light. The timing of these three events geometrically define a simultaneous time at distant points and be used to synchronize "distant" clocks in the one inertial frame. This process can be repeated for as many points needed. Relativity then is about comparing the lack of simultaneity "between" relatively moving frames.
Wikipedia: Einstein synchronisation

The "rigidity" of this (or any) "freely falling" coordinate system can be maintained using an interferometer and the constancy of the fringes ensure that the two points are not in relative motion. Frames that are in relative motion cannot guarantee that any simultaneity can be found. That is "one" part of the theory while the other important part is the definition of inertial frames of reference which are a definition of simultaneity within a frame and a means of clock synchronization. Without inertial frames of reference which include time, spacetime could not be tested to be in accord with Special Relativity.

It is also essential to also define a "zero" of time (in a similar way to the way we define a zero in the other coordinates). It may be arbitrary but without having "equivalent measuring rods for space and time" and a "vertex", all practical measurements in physics would be pointless and without any basis of experimental verification. The use of the "measuring rods" must be "corrected" to be local measurements. Unfortunately many measurements of theory are not made locally and hence that is why I emphasized some points in my previous post. Theories are used to fill in the details and that is where a lot of testing must occur.

Experimentally this is what is actually done and all the philosophy does not remove the importance of this principle of measurement. Physics is not a philosophy... it is a natural science and relies on the measurement of natural phenomena. This distinguishes quantum "expectation values" in Quantum Physics which are not measurables from these "physical" system measurables.

Other principles come into play when there is "propagation" or "translation" between frames and then I would point out that electromagnetism has both the near field approach and far field approach to the problem. Recent experiments in Switzerland has highlighted this problem.
World's Largest Quantum Bell Test Spans Three Swiss Towns
Very accurate experiments may be carried out with a high degree of correlation that have tested Special Relativity to the highest possible experimental level of verification even when the system is not ideal the "error" is not in the theory but still in the instruments. Special and General Relativity are used "exclusively" (with extensions) in the GPS system... and resolutions of the order of centimeters are very possible and very practical (over the entire earth's surface) with the right equipment. To do that it requires that we are able to define "simultaneity" of atomic clocks and this is absolutely essential as it is an "everyday" necessity for this stuff to work.

The issue regarding the BEC... It is interesting but I guess the argument is "dispersion" through a "block of refractive material" is not quite the same as the slowing time in empty space. Consider a block of glass... we are unable to survive in that "medium". However there are cases of light's velocity being modified in free space in a vacuum such as in optical vortices. I think that phenomenon needs to be concentrated on at the moment for interesting phenomena but I will certainly give you that BEC's are a very interesting case requiring more investigation. That phenomenon is all tied up with Electromagnetically Induced Transparency and with Negative Refractive Indices, optical wormholes and "invisibility" etc.

Regarding "time travel"... It is not what most people think. There will not be any paradox since events happen and eventscapes are generated and modified on a ad hoc basis. Do not worry yourself with "science fiction" scenarios. They do not happen. Time travel is not something we can "make up as we go along"... some things are permitted while some things are not. The idea of dropping out of time does not "normally" occur. The events generated by time travel are well understood in terms of very standard existing events. I will make an analogy that if everybody believes that there are pixies at the bottom of the garden that does not guarantee that they are really there. In the same fashion what "people say" about how time works is not necessarily the way it really is. What I can say is we can understand events mapping out the way to the future. These "events" I have outlined in an event driven Universe are not paradox... they just do not conform to the conventional form of time travel people "want". I make no apology for the way the Universe actually works and I will not try and bend the rules to fit any "private Idaho". The "experiment" works (the Feynman-Stueckelberg Interpretation)... It is people who refuse to accept that it is true.

Cheers

Ron

QUOTE: "We have to take into account that all our judgments in which time plays a part are always judgments of simultaneous events. If, for instance, I say, “That train arrives here at 7
o’clock,” I mean something like this: “The pointing of the small hand of my watch to 7 and the arrival of the train are simultaneous events.”

Simultaneous events - does that implicate that the small hand and the train are simultaneous together at the same place at that specific time ?

I don't disagree with anything you've said, and as I said before, it sounds like you know what you're talking about.

I would, however, take the position that philosophy at some point in physics has its uses, if only in illustrating paradoxes where further research could find more interesting phenomena. And ultimately, once we find the Grand Unified Theory/Theory of Everything, physicists may desire to get back to their original goal of not merely explaining *how* things work, but *why* they work the way they do. That's been abandoned for good reasons for a long time, incorporating the "why's" with the "how's", as the "how's" have generally been fairly accurate even as the "why's" were way off-base (and usually got in the way of progress). Einstein's derivation of Relativity itself was based on a gedanken (thought experiment) if I'm not mistaken, so I don't think they should be abandoned completely.

I've always been interested in how physics implements "barriers" of all sorts. Nothing can travel faster than the speed of light, but last I heard, electrons tunnel through barriers in *zero* time, according to an elapsed-time experiment done in Australia (and no doubt repeated everywhere by now). This doesn't violate Relativity, though, as there's *no point in time* where an electron can be measured traveling faster than the speed of light. It doesn't accelerate up to and then beyond C, it just leaves here and arrives there in the same instant. (Correct me if the experiment has been debunked.) You can't accelerate a spaceship up to and beyond the speed of light, either, but when you start getting close, weird things start happening to the perception of time and space. Theoretically, if there were an infinite power source and you *could* accelerate through C, at the very instant you're passing C, you have no depth in the direction of your velocity, and just after that, the equations describing your various states have that pesky square-root of negative one in them. We know this number from complex algebra as having the meaning of introducing orthogonality to the original frame of reference. Once again, we disappear from this space to a space that is orthogonal to ours. It's interesting to me what happens to gravity when masses have that "square-root of negative one" in them - gravity would become repulsive, right?

So the Big Bang happened (if it did) and some matter was accelerated (maybe) to speeds faster than light, then that matter would repel itself with a force proportional to 1/r2, essentially leaving the ordinary sublight matter (what we're made of) behind as it accelerated away. (Nothing in Einstein's theory that precludes acceleration in objects already going *faster* than the speed of light.) Cosmologists agree upon there being an "inflationary" phase of the Big Bang, but steer clear of explaining where it came from (at least, I haven't heard an explanation). Maybe it's as simple as the matter created had speeds that spanned sublight to superluminal, and the superluminal matter accelerating due to the repulsive gravity had an effect on the normal (subluminal) matter. "inflating" the universe.

Another issue comes to mind, if this were true - would the particles and antiparticles created be entangled? Are the particles in this known/seen part of the universe entangled with their twins at the outer "skin" of this universe?

Just some interesting questions to ponder, I don't know the answers, myself.



This post has been edited by wcelliott on Sep 28 2008, 11:36 PM

Good Elf

QUOTE: "It is also essential to also define a "zero" of time (in a similar way to the way we define a zero in the other coordinates). It may be arbitrary but without having "equivalent measuring rods for space and time" and a "vertex", all practical measurements in physics would be pointless and without any basis of experimental verification."

I like to ponder about this - in that I think it constitute quite a challenge-

you say: "in a similar way we define a zero in the other co-ordinates".

And then I wonder - what is a coordinate - what is a usefull co-ordinate in space - or in Physical ?

Can we operate a co-ordinate without a yardstick - and how do we define a yardstick -

Can we make a yardstick out from dimensionless points - ?

Can we mathematically construct a scale saying that this is placed here and this is placed there - relative to each other and well-defined in a 3D or a physical context ?

Can we mathematically define a scale so it is not just an enormous amount of figures saying nothing about relative position in space if we do not already have a defined space with a defined yardstick ?

Or put differently - can we accurately and ideally exactly describe a physical event - a physical happening - by use of figures - by use of pure mathematics without having a one-to-one relationship between a figure and a dimension

Can we define or construct a dimension without having already a dimension at hand ?

And in that case - then exactly what IS a dimension ?

Am I asking a right question in the wrong way - or Am I asking a wrong question ? - or ?

Hi wcelliott, bukh, woodroyd, Ron, dimazin, TheUnknownUniverse, TracerTong et al,

Don't get me wrong. I am not trying to put a damper on creative thinking. Creative thinking is the source of all wisdom. But in the end this thinking must "fit" our natural environment to be useful. First comes the theory then the experiment. Alternatively the experiment might come first and then we need to do catch up with theory. In the end though it is experiment that decides it the theory is right or wrong. Still it is good to think out of the box... I am going to take some "liberties" in the latter part of this post all in the interest of "serendipity".

IMHO all things are "possible" but not all "questions" can be answered. That is simply because most "questions" that people ask are poorly constructed. This is not meant to be a criticism it is simply a statement of the "human condition". If you can ask the right question then the answer is already within grasp. This because if you understand the question you ask thoroughly then the answer is not too far away. The only thing we must be on the lookout for is being misled by our innate hubris.

Lets fundamentally analyze the problem of "accelerating through the speed of light". Many people "suggest" that this is impossible because the relativistic mass would increase to infinity and there is that old chestnut of an irresistible force meeting an immovable object. In actual fact this is all a misunderstanding of physical law... what Einstein himself said about "relativistic mass" was...

Interpreted this means that "rest mass" is the only "real mass". There is an equivalence of mass and energy but raw energy is not the same as pure mass.

Again we see that the former World expert on "mass" and "gravitation" points the fickle finger of fate at this "misunderstanding". Mass is not connected with any structural change in a body. For instance if the relativistic mass of a body "increased to a million times" it's rest mass and this was an "astronaut", surely you would think he would die of an instant heart attack? ... such would be the load on his vital organs. This does not happen. This is cannot have any relationship to a Theory that suggests that the laws of the Universe are the same "everywhere". Any accelerated person is piecemeal "inertial" if we instantly cut out the acceleration. Then the traveler is suddenly in a rest frame (given some short period for the forces to equalize). This is because the velocity of any particle "relative" to some other moving frame is not clear, unless there is direct "point to point interaction" the influence on nearby bodies probably goes relatively unnoticed.

In fact acceleration is subject to a "constant of integration" which is arbitrary. The Universe is"full" of moving particles. Some of these have a relatively high velocity relative to a particle while others have a low velocity relative to the same particle. You probably have a relative velocity near the speed of light when compared to some distant bodies in space. These bodies have little or no apparent influence on us. The proximity of such bodies should not make any direct difference provided the rest masses of these bodies is small (no huge tidal forces acting). Which velocity "determines" the relativistic mass? Obviously it is all relative and there is no absolute frame of reference to choose. What we really know is that for properly synchronized systems that have been subject to acceleration, a time dilation can be calculated in any case of any two particles so we may be able to, "in theory", compare the rate of time in two different moving frames possibly centered on two separate relatively moving particles.

In the one inertial frame time and distance are fixed rigidly "according to rule". Moving any particle in an inertial frame actually moves the particle "out of the frame"... there is no "inconsequential relative movement"... everything must be accounted for in the end and even small velocities and small accelerations result in a loss of synchronization between formerly synchronized clocks in the frame. Many theoretical approaches seem to suggest that "relativistic effects" may be ignored for very low velocities... wrong... what about "de Broglie Matter Waves"?

Of specific note is the influence of velocity on the de Broglie wavelength of matter particles. As V -> 0 the wavelength of the particle approaches "infinity". More correctly it is expressed in the de Broglie-Einstein Relationship where the wavelength is inversely proportional to the "relative momentum".
Wikipedia: Einstein de Broglie Equation
In fact the "low velocity end of Special Relativity" is every bit as significant as the 'high velocity end"... the particles "at rest" lead to spatial "delocalization". A particle in a box can never actually be at rest. There will always be a wavelength due to the lowest modes of motion and the "unobserved" particle in a box is delocalized as V -> 0. Therefore the particle is no longer a "particle" but a wave and occupies an eigenstate depending on the box geometry.
Einstein and de Broglie Relationships "compared"
Here we see de Broglie's wavelength and frequency compared with Einstein's length and time. These are "reciprocal concepts". With Matter Waves wavelength is to be compared with "reciprocal length" because velocity is to be found in the denominator of the de Broglie relationship and de Broglie frequency is to be compared with time (reciprocal frequency). These are orthogonal properties as mentioned previously.

"Wavelets" accelerated in "particle accelerators" end up looking like point particles rather than wavelets. The harder they are pushed the more they obey particle dynamics. These wavelets could be protons, electrons, neutrons etc... it really does not matter all ave a wavelength or a frequency at any relative velocity but clearly at around zero relative velocity the packet wavelength dominates all aspects of "locality".

So I have argued strongly "against" the idea of Magic in quantum physics. The ability of an electron to tunnel depends on the ability of the wavelet to be sufficiently delocalized and "diffuse" to have a significant portion of it's packet extending beyond any barriers that confine it. The lower the velocity the larger the possibility that the particle can move beyond the barrier. Recall that high energy electron hardly ever move beyond the potential barrier ... consider the electrons in the main ring at CERN... they have enormous energy but are highly confined and never tunnel out of the ring. It is safe to stand near the ring and electrons have almost no possibility to penetrate the walls of the confining vacuum vessel. Alternatively a Bose Einstein Gas at nearly absolute zero degrees Kelvin can "seep" through any wall in a pretty short time. This is because the kinetic energy around absolute zero of electrons or gas particles is very low so the penetrating wavelength is quite long. The point is if you "measure" the velocity of the electrons at the point of penetrating the walls of the vessel, the 'probe" used to measure this system will provide a "kick" to the system sufficient to shorten the wavelength of the particles so much that the chance of it escaping through the wall is reduced to only a tiny minuscule possibility.

It is not a case of relativistic mass as we have discussed, and it is not a case of any weird perceptual thing... on the contrary... perception is unaltered. Lets say you have been able to accelerate this astronaut to 99.99999999% the speed of light (relatively). In the rest frame of the astronaut things appear relatively unchanged. He feels no perception of speed (except for an external source of radiation coming from the cosmic microwave background that he will now need protection from). This "effect" is such that provided with a source of acceleration, there is "apparently" no upper bound to the speed of the spaceship. Any speed is possible from the point of view of the traveler. So you see there is no "upper speed limit" imposed. The astronaut looks out of the ship through a viewing port and you would indeed see that "Star Trek" effect of stars zipping bye and space will have a tunnel shape as viewed externally. This is not what is seen in the inertial frame of the space ship... there is no change what so ever to what he say "back home".

The clocks all run the same, the length of his ship appears unaltered etc. However on a round trip returning to earth perhaps many thousands of earth years will pass while he will have experienced only a day or two of travel (in an extreme scenario). In actual fact what has happened is as our traveler "zoomed" off into space the ship's clock begin "losing ticks" relative to the stay at home clock. In the extreme case almost all the ticks were lost and our traveler relative to the stay at home "twin" became almost "frozen in time". Time still progressed very slowly but in such a fashion that this "rate" made those external effects possible such as the apparent the external tunnel vision... the Star Trek effect and the effect that there seemed to be no upper limit to speed. For instance if our traveler traveled 100 light years and only one second of ships time ticked away then the speed that the traveler would "reckon" would be 100 light years /sec speed... a light year is the distance light travels in a year.... 1000 trillion kilometers/sec.
Wikipedia: Light Year
Still as far as the twin at home sees is this traveling twin was "frozen" and his trip to an absolute minimum of 100 years to travel 100 light years.... and more like a lot more.

So why can't a "boost" take our traveler past the speed of light just pushing it 0.00000001% faster?? It is simple... time would stop for our traveler and all processes relative to "home" would be "almost" entirely arrested if we could make it reach a relative velocity indistinguishable from C. At the exact speed of light all process would stop with time. There can be no actual acceleration since acceleration is the rate of change of distance with respect to time. No time ... no rate of change... no "push" taking it past the speed of light. All kinetic process relative to the external frame "ceases" at the speed of light. That is why a photon can "last forever" frozen in time as it flies through empty space between the stars. Now in the frame of the traveler "nothing has happened". Relative to other relatively moving objects in the Universe his speed is nothing like C so the effect is not the same. The progression of time between different frames is different depending on the relative velocity while the progress of time in the rest frame of the traveler is as it always is... no perceptible effect. These effects, according to the traveler, are all happening to everybody else but not to him. Now you can appreciate that this is entirely "relative" and continuous phenomena with a singularity at C. In one sense travel at nearly the speed of light is virtually no different to sitting in a comfy chair in your lounge and watching Star Trek... you would have no sense of motion or speed other than what you see on the "external view screen".

Some scientists would say this is "indistinguishable" mathematically from the concept that the mass of the traveler becomes nearly infinite... I totally disagree. Why some scientist say these things is a complete puzzle to me... what I know is they all know this is strictly incorrect. I think it is because some scientist are part scientist and part showman.... but "mostly" nearly all "magician" who want to put on a good entertaining show. Go figure!


So you want to travel faster than light? You can't travel 'faster than light" but you can beat light in a race to some point in space if you take a "shortcut". So you need to first find that shortcut between the two points you need to move between, I suggest translational spatial frame dragging rather than "brute force". Make sure this distance is able to be traversed in the time you want to spend. Failing that calculate what energy you are prepared to "spend". You will get some figure that suggests a maximum amount of mass that can be accelerated to achieve this task. You then need to ensure that your system mass is equal to or less than this figure. You then need to cancel that excess mass such that Force required is sufficiently small due to a sufficiently reduced mass. The mass of a "particle" is the amount of space time curvature the particle produces. This needs to be substantially canceled artificially with some kind of 'field" (a mass canceling field). Electromagnetic "force" must be used to replace this "mass" influence. We know that the trade off is of the order of 10^41, an electromagnetic field (if at all possible) is quite capable of performing this operation exchanging potential energy for kinetic energy.

Technically we still have some problems... he he he! "In theory" it is possible but some form of Electromagnetic Lorentz Symmetry Breaking will be necessary.

So as alternatives we can create a shortcut between points in spacetime, or reduce the mass of a system sufficiently to accelerate it appropriately and the amount of actual acceleration will relate to the time of transit... Alternatively you can build a TARDIS where you can combine space travel with time travel to arrange the greatest flexibility. Cancel time of travel with trading of with travel in space. You can reverse this operation for the return journey. All right these are fanciful but I predict able to be done in the future... maybe not the immediate future.

I do not think we can accelerate anything "faster than light" but the speed of light is different in different regimes. Without elaboration there is a "near field" with Gravity. This can extend to "infinity" through Mach's Principle. The speed of light in the near field can "infinite". The "near field" is the rest frame of the "virtual photon". The inflationary phase of the Big Bag is still not over. The Universe is still expanding and it is apparently "accelerating". This is due to lateral frame dragging. Any speed is possible when you involve frame dragging. This is inertial acceleration... a bit of a contradiction of terms but nevertheless it does occur because we see it. It is not due to any dumb "explosion" at T = 0. Every point is moving away from every other point. This can be simulated once again by removing he system mass then you can move points where ever you want anytime you want. This results in Rindler Foliations and these foliations may be shortcuts between points in spacetime without recourse to "wormholes" (which are gravitational objects). These "foliations" are a form of electromagnetic wormhole where the mouths of some electromagnetic constructs are connected by spacetime defects called instantons. Travel through these entities may be possible if we could only cancel mass.

There is a fair degree of speculation there but there is also a underbelly of experimental science that indicates to me technical possibilities not beyond our reach. For instance the possibility of "instantaneous communication" is already possible in the near field of matter waves.

If communication then why not transport or at least a telepresence... instantly... to the distant planets for instance, provided a near filed form of communication using the matter wave interferences. That would be "as good as" being there and a lot safer than actual personal interplanetary travel.
World's Largest Quantum Bell Test Spans Three Swiss Towns
Physicists Seek Answers to Quantum Correlations
"Space-like Separation in a Bell Test assuming Gravitationally Induced Collapses" Authors: D. Salart, A. Baas, J.A.W. van Houwelingen, N. Gisin, H. Zbinden
"Connection speeds" for spacelike separation without timelike separations in excess of 10000 times the speed of light have been recorded in the near filed... this being 18 Kms in this case. No laws broken here.

Cheers

This post has been edited by Good Elf on Sep 29 2008, 02:16 PM