Is All Motion Linked to the Big Bang?

[Namloh2000]

what the heck is motion anyway??

How can things even move?

 

[arildno]

The german philosopher Hegel liked Zeno's paradoxes a lot; perhaps you'll find your answer in "Wissenschaft der Logik"

 

[Alkatran]

How could things not move? If things couldn't move would you have a static universe, or no universe at all because everything was jammed into the same, unmoving spot? What if everything is moving at speed Y, except Object X, is X moving, or everything else? If it was X, if X is going c right and Y is going c left, what's the distance between them after 5 seconds?

You couldn't ask the question on how things move if they didn't, so they do.

 

[Namloh2000]

It was after reading all of Zeno's paradoxes that I decided to pose the question. I am also familiar with Hegel.

 

[MiGUi]

Let be an object in a n-dimensional space. If we have a frame system and it base of n independent coordinates {x_1, x_2, ..., x_n} to refer its position, we say that the object is moving or is variating its j-esim coordinate if
\frac{dx_j}{dt} \ne 0

Math is cool

 

[Stevo]

Let be an object in a n-dimensional space. If we have a frame system and it base of n independent coordinates {x_1, x_2, ..., x_n} to refer its position, we say that the object is moving or is variating its j-esim coordinate if
\frac{dx_j}{dt} \ne 0

Math is cool

You assume that your mathematics describes something physically real - you are assuming that real things move, which is precisely what we want to prove (or disprove).

Of course, we may define motion purely mathematically, but that doesn't answer the physical question of how things move.

 

[Stevo]

What Zeno was criticising was the view that space is a continuum. In mathematical terms, he was criticising the view that space is complete.

Zeno basically assumes two things: An infinite summation of objects of finite size will not converge; Any summation of objects of zero size will give zero.

What he purports to show is that if space is constituted by an infinite number of points (which allows for infinite divisibility), which have zero size, then you can't add them up to get a finite distance.

Of course, we know now why he's wrong. You can't deduce the length of a line by adding up the number of points on it. The number of points on any line is infinite, regardless of the length of the line.

 

[loseyourname]

Zeno's issue was that an infinite sum cannot be finite, that is, an infinite number of points cannot be summed up to equal a finite line. This is his first paradox, where he divides a line in half, then the half in half, and so on infinitely. If quantum theory is extrapolated to say that all quantities are made up of discrete units, then you can't even say that a line is made up of points. Points would have no real existence. Objects with no spatial extent cannot constitute an object that has spatial extent. Looking at it this way, you reach a point at which you no longer can divide the distance in half; there is a minimum distance. I'm not sure if this is the Planck length in M theory or in quantum theory, of if it is some other distance (I'm not that well-versed on physics). Does anyone here know?

Of course, I'm not considering Zeno's other three paradoxes of motion, but this should deal with the first.

 

[wuliheron]

According to the best theory today, motion/change and the lack of it are relative. If I could fly fast enough, it would appear that I am not moving, the Earth is simply rotating under me. Have I actually slowed down? There is no absolute standard for determining what is and is not moving. All we can note is that relative to something else we perceive motion or the lack of it.

As for Zeno, he believed the universe is indivisible, indestructable, immortal, and unchanging. All motion/change he insisted was illusory and God's creation is the imbodiment of timeless perfection.

 

[p-brane]

What is the reading on your radar gun when you measure the speed of a car going 90 miles an hour from your position on board a car doing 60 miles an hour? (Both cars are heading in the same direction)

 

[selfAdjoint]

At those speeds, the deviation between the correct relativistic addition formula and the approximate linear one are too small to measure without special equipment, so the linear answer 30 mph is OK. Now try it with the speeder going .9c relative to Earth and the radar going .6c.

 

[mikesvenson]

At those speeds, the deviation between the correct relativistic addition formula and the approximate linear one are too small to measure without special equipment, so the linear answer 30 mph is OK. Now try it with the speeder going .9c relative to Earth and the radar going .6c.

quite a difference there

 

[p-brane]

At those speeds, the deviation between the correct relativistic addition formula and the approximate linear one are too small to measure without special equipment, so the linear answer 30 mph is OK. Now try it with the speeder going .9c relative to Earth and the radar going .6c.

This is a good question. Do I calculate the relativistic time warp/differences that come with the proximity to doing 1.0c?

If fact, when we say that c equals 186,000 miles per second we can't be sure seconds are "seconds" at c since time is severely distorted at the speed of light. Damn physicists have to screw everything up!

 

[mikesvenson]

Is it true that every object down to the smallest is completely at rest in relation to itself, and it only is in motion in relation to some other perspective? Wouldnt that mean that every object in existence is in motion at every speed in every direction up to c simultaneously when in relation to every other existing object?

 

[selfAdjoint]

Yes. If I am unaccelerated then relative to myself I am at rest. Then as you say given any velocity vector whatsoever, of speed less than c, there can be an observer traveling inertially on the reciprocal vector and they will see me as possessing that velocity.

This works for everything massive, down to the smallest. Massless objects like photons don't have rest frames, so the reasoning doesn't work for them.

 

[mikesvenson]

if any object is at all relative velocities up to c when in relation to all other objects, like you confirmed, then would that mean since mass increases with velocity, that every object has every amount of mass in relation to every other object?

 

[selfAdjoint]

Well, I don't use the formalism where mass increases. I use the invariant mass formalism and put the increase into the energy. So that your statement would become an object has every possible energy with respect to other intertial frames. Yes.

 

[p-brane]

All of this may explain the old saying "all things being equal".

I'm enjoying the expansive chat you all'r' havin'. Thank you.

"Massless objects like photons don't have rest frames, so the reasoning doesn't work for them."

Photons would not be photons if they were at rest. Yes?

 

[mikesvenson]

"Massless objects like photons don't have rest frames, so the reasoning doesn't work for them."

Does that imply that photons exist outside of the dimension of time?, since time is the measured duration for a constantly changing position of massive objects?

Photons would not be photons if they were at rest. Yes?

Does that mean "at rest" = no motion = no time? Wouldnt that mean the photon would indeed exist as a photon, but frozen in its inertial frame? Isnt this the trueth behind the existence of instances in constant change and reformation(motion, or time)?

 

[selfAdjoint]

The photon, as p-brane said, doesn't have a rest frame, or any inertial frame (if it had any inertial frame, you could transform it to a rest frame). The photon moving at c experiences no proper time.

 

[mikesvenson]

so a photon never experiances time?

 

[selfAdjoint]

Never. "I'm emitted/I'm absorbed. End of story." Now, WE see it as traveling for billions, maybe, of years, but that's us and our relation to it. In its own relation to itself it is timeless. And its path through spacetime is a Null Geodesic, an arc along which proper time is always zero.

 

[p-brane]

Never. "I'm emitted/I'm absorbed. End of story." Now, WE see it as traveling for billions, maybe, of years, but that's us and our relation to it. In its own relation to itself it is timeless. And its path through spacetime is a Null Geodesic, an arc along which proper time is always zero.

Thanks for the answer SelfAdjoint. By the way, I was credited with something you wrote earlier by mikesvenson.

You say that a photon, relative to itself, would not know time. Of course this is absurd since photons have no sense of anything, they seem to lack senses all together. At least by our standards.

However, if I were a photon, with my senses intact, traveling at c I may not notice the time but I would notice the Null Geodesic arc tugging at my relativistic mass as I sped along it.

This sensation I would be feeling, burning into an arc, would serve as an indication that a change was taking place... a shift and perhaps a change in location.
As far as I know time is the measurment of CHANGE in relation to one's position to the change and to the changes created by one's existence and what one would call one's EVENT horizon.

So, if the light wave could tell us what time it was in the realm of lightwaves, it might say... "oh, just 29 minutes, 42 seconds NNNW of the universal p-brane's true North". And if we knew what kind of conditions that meant for the little lightwave we'd have a good idea of whether or not it was dinner time, breakfast or cocktail hour for the little bugger!

So, since a photon traveling at c does continue to "experience" change, then I propose that there is a certain framework of "time" that could quite probably be calculated. I could be way off with this proposal as well.

 

[selfAdjoint]

However, if I were a photon, with my senses intact, traveling at c I may not notice the time but I would notice the Null Geodesic arc tugging at my relativistic mass as I sped along it.

Even as a massive object, you don't feel "gravity tugging" as you travel along a geodesic (i.e. fall). You may feel the wind in your face, but astronauts in zero-g and skydivers do not feel gravity.

 

[mikesvenson]

And its path through spacetime is a Null Geodesic, an arc along which proper time is always zero.

Could you explain to me what Null Geodesic means in relation to light and why it defines a proper time of zero?

Even as a massive object, you don't feel "gravity tugging" as you travel along a geodesic (i.e. fall). You may feel the wind in your face, but astronauts in zero-g and skydivers do not feel gravity.

I've never heard of this term (Null Geodesic) and the closest I've come to understanding it is when I read the above quote.

I'm sure a complete definition is available somewhere on the internet, if you don't wish to explain it to me, do you have a good link?

 

[loseyourname]

Even as a massive object, you don't feel "gravity tugging" as you travel along a geodesic (i.e. fall). You may feel the wind in your face, but astronauts in zero-g and skydivers do not feel gravity.

What of test pilots and astronauts in the shuttle as it takes off from the cape? Granted, it isn't gravity that they are feeling, it is the acceleration of their vehicles created by whatever propulsion they are using, but why should a skydiver not feel the acceleration produced by gravity? If this is indeed the case, it would seem to be due to the fact that the acceleration is a constant 1g, whether the skydiver is still in the plane or falling. But if the acceleration were to change, then it would be felt, would it not?

 

[selfAdjoint]

Since you are "going with the flow" of gravity by falling (and accelerating) as fast as it wants you too, there is nothing to feel. Believe me this is true: a falling person is weightless. The astronauts and cosmonauts in zero-g are constantly falling, since they are in orbit. The misnamed g-forces that pilots feel during maneuvers have nothing to do with gravity. From a spacetime viewpoint, those maneuvers are highly non-geodesic.

 

[loseyourname]

Okay, back up a little here. What is the distinction that you are drawing between accerelation due to gravity and all other types of acceleration? I mean, g-force or not, I can feel the acceleration when I take my foot off the brake of my car, and it isn't a fast car. Are you basically saying that when an object accelerates due to gravity, because it is simply following the normal curvature of spacetime, that it feels nothing? But if is accelerating due to some other force, it will be felt because it is then not moving along the normal curvature?

I have to admit that I don't know what you mean by geodesic in this case. I know what a geodesic dome is, but I can't imagine any way in which space could be warped into such a shape.

I don't see why you think the g-force is misnamed. It just means that the force experienced is equal to 9.80m/s^2 multiplied by the mass of the object in question, does it not? It seems a natural enough benchmark, if a bit colloquial, kind of like the English customary system of weights and measures.

 

[mikesvenson]

Okay, back up a little here. What is the distinction that you are drawing between accerelation due to gravity and all other types of acceleration? I mean, g-force or not, I can feel the acceleration when I take my foot off the brake of my car, and it isn't a fast car. Are you basically saying that when an object accelerates due to gravity, because it is simply following the normal curvature of spacetime, that it feels nothing? But if is accelerating due to some other force, it will be felt because it is then not moving along the normal curvature?

It seems to me that you would not feel the constant pull of gravity while in a free-fall, since relative to the g-force, you are not moving. Although you
would feel the acceleration up to the g-rate. Like you would feel the acceleration in a car up until the car stopped accelerating and maintained a constant speed.
In a car, while releasing the brake you feel acceleration. But if you accelerated up to 10mph, then maintained that speed, you would feel no more acceleration. Relative to the motion of the car, you are not moving.

The freefall concept works about the same way. You first have to accelerate up to the speed of gravity, and that's the only acceleration you feel.

 

[p-brane]

Thanks SelfAdjoint.

Ok, minus gravity and its tug in the resistance of an arc. Is there a (changing) location of the photon and does a (changing) location constitute a framework for a time dimension? Does entropy effect a photon and would that also not set up a framework of time at any speed... including c?

As far as I can tell, (so far), is that: unless light waves are quantum in nature and exist as an undivided unit everywhere at once, in every state - it is probable that it is possible to designate a measurement or dimension of time in such a state as c.

 

[selfAdjoint]

I think some of the questions can be answered by some quotes from MTW's Gravitation, at the start of their Chapter10,"Affine Geometry: Geodesics, Parallel Transport, and Covariant Derivative".

> Free fall is the "natural state of motion," so natural, in fact, that the path through spacetime of a freely falling, neutral test body is independent of its structure and composisiton (the "weak equivalence principle"...)

> Ask for the maximum amount of information tied up in each trajectory. Is it merely the sequence of points along which the test body falls? No; there is more. Each test body can carry a clock ([independent] of structure or composition of test body). The clock ticks as the body moves, labelling each event on its trajectory with a number: the time \lambda when the body was there. Result: the free-fall trajectory isnot just a sequence of points; it is a parametrized sequence, a "curve".

> in the curved spacetime of Einstein...these parametrized free-fall trajectories are the straightest of all possible curves. Consequently one gives these trajectories the same name, "geodesics", that mathematicians use for the straight lines of a curved manifold...

Finnally, from Chapter 13,
>Concord between locally straight lines and geodesics of curved spacetimes demands that timelike geodesics have extremal proper length...

 

[loseyourname]

The freefall concept works about the same way. You first have to accelerate up to the speed of gravity, and that's the only acceleration you feel.

You're a little bit off, because there is no such thing as a speed of gravity. Gravity pulls you downward at a constant rate of acceleration, meaning in a freefall, you are always moving faster. The only reason this is not, in fact, the case for a skydiver is because of air resistance, although if they dove head first, rather than splayed (which, of course, is why they do not dive head first), then they would be constanstly accelerated.

Anyway, Adjoint just gave a good explanation. I see what he was saying now. Maybe I'll read that book.

 

[loseyourname]

Here's a pretty damn good explanation:

What happens is that in non-euclidean geometries, the notion of 'straight line' gets a bit wierd.

Imagine an ant walking along the surface of a cylinder. Even though the ant is walking along a 'locally straight line' (a geodesic), it's walking along something that we (as outsiders) might percieve as a curved line. Similarly, if the ant is walking in a locally straight line on a moving turtable, although the ant is moving in a locally straight line, the path it describes is not straight.

Classically, it's assumed that space-time is euclidean (or flat), so a 'locally straight' line is also a straight line. And that gravity is a force that perturbs motion that would otherwise go along this straight line. Einstein postulated that the path that an object takes under the influence of gravity is the 'locally straight' path. This is intemately related to the notion that gravitational and inertial massess are the same. Since we can describe the paths that objects take under the influence of gravity, we can plot them, and describe the 'shape' of space-time.

It's also worth noting that for GR to work, you have to imagine a 4D warped space (which would be embedded in 5-space) and not a 3D space, since GR includes time as one of the dimensions.

 

[p-brane]

Speaking of motion.

Is it only light that (appears to) travel as fast as light?

Does this include the full spectrum of light like ultra-violet, gamma, X radiation, infa-red and the ones I haven't mentioned? Thanks.

 

[Les Sleeth]

Is it only light that (appears to) travel as fast as light?

You're a little bit off, because there is no such thing as a speed of gravity.

Actually, fairly recently I believe, gravity was confirmed to travel at light speed.

 

[Les Sleeth]

The misnamed g-forces that pilots feel during maneuvers have nothing to do with gravity. From a spacetime viewpoint, those maneuvers are highly non-geodesic.

Something I've wondered is, since there is no way for an observer in an accelerating frame of reference to distinguish between "g-force" and gravity, is it possible both are related to the some single underlying physical law? I believe I've heard that some thinkers postulate an as yet undetected field might exist in space (the Higgs field?) which sits dormant until either mass or acceleration take place with in it, which then causes the field to constrict in proportion to the object's mass or the force of acceleration. I always thought that made sense because both mass and force are due to energy concentrations.

 

[loseyourname]

Actually, fairly recently I believe, gravity was confirmed to travel at light speed.

That statement was made in reference to the speed of a falling object pulled by gravity, not the speed of the propagation of gravity waves, which as far as we can tell, do travel at the speed of light. In contrast, a falling object will never move at constant speed in the absence of air resistance.

 

[Les Sleeth]

That statement was made in reference to the speed of a falling object pulled by gravity, not the speed of the propagation of gravity waves, which as far as we can tell, do travel at the speed of light. In contrast, a falling object will never move at constant speed in the absence of air resistance.

Well, mostly I wanted to answer p-brane (very funny handle!), but forgot to include his quote initially. And then I started wondering what you meant when you said "there is no speed of gravity." I thought I understood mikesvenson's meaning when he said "reaching the speed of gravity." I figured he was referring to getting to the point where any initial boost or retardation was overcome, and one was falling in synch with the force of gravity. So I couldn't see why you said he was "off" unless you were talking about something else, and hadn't heard about the recent confirmation of predictions about the speed of gravity waves.

Getting back to the question of what is motion (a great question I think) . . . defining it by formulas and pointing out the special circumstances of relativity doesn't (philosophically speaking) explain what the heck it is.

I've thought that in the current conditions of our universe, motion wouldn't be possible without entropy. It seems both motion and change are related to the "winding down" of our universe. Motion, for example, has been the agent of change since the big bang.

 

[p-brane]

There is a speed of [the effect of gravity. Gravity, as a source of the effect, stays where it is: in my book at least.

The most important part of my question is whether or not gamma, Xradiation, Ultraviolet waves, Infared, neutrinos and other incidental electromagnetic spectrums all "travel" at the "speed of light". (?)

 

[Les Sleeth]

There is a speed of [the effect of gravity. Gravity, as a source of the The most important part of my question is whether or not gamma, Xradiation, Ultraviolet waves, Infared, neutrinos and other incidental electromagnetic spectrums all "travel" at the "speed of light". (?)

That's an easy one which even I, a layperson, am confident to answer. ALL EM travels at light speed in a vacuum, from the slowest to the highest frequency. No exceptions.

 

[TeV]

whether or not gamma, Xradiation, Ultraviolet waves, Infared, neutrinos and other incidental electromagnetic spectrums all "travel" at the "speed of light". (?)

Nutrinos are the part of electromagnetic spectrum?Since when?
Neglecting "neutrinos" in the package ;-):Electromagnetic waves all "travel" at the "speed of light" in vacuum regardless of their frequency.Great J.C.Maxwell concluded this first.

 

[RAD4921]

Motion is relative

All motion is relative to its frame of reference. To speak of absolute motion is meaningless.

 

[Les Sleeth]

All motion is relative to its frame of reference. To speak of absolute motion is meaningless.

In the situation of motion relative to its frame of reference, there are several distinct things present. There is a frame of reference, there is relativity, and there is motion. Looking at things analogously, just because a human being can't exist without space doesn't mean it's meaningless to contemplate a human being apart from space.

As far as I know, no one used the term "absolute motion." We are wondering what exactly motion is. Think about it . . . why should there be movement? What is causing movement? If we don't take motion for granted, to me anyway motion seems very strange.

 

[RAD4921]

Absolute motion

Motion can only appear if you are using a frame of reference, comparing one part of the universe to another. If you use the universe as a whole for a frame of reference then motion doesn't exist. It is an illusion.

 

[Les Sleeth]

Motion can only appear if you are using a frame of reference, comparing one part of the universe to another. If you use the universe as a whole for a frame of reference then motion doesn't exist. It is an illusion.

You might be correct, but I don't think that's what Namloh is getting at. (Of course, the universe itself moves as a whole -- as expansion. What is the whole universe moving in relation to?)

Namloh first asked "how can things even move?" I think this question is great because movement is something we just take for granted. There are some pecularities associated with movement. Theoretically at least there is an upper limit to speed of movement, and it produces relativity effects, especially accelerating movement. I think it is interesting that movement always involves entropy (overall anyway); since there is absolutely nothing that doesn't move, it is an indication about the fate of the universe (and maybe it's origin too). We speculate that at absolute zero there would be no movement, but we also believe absolute zero is impossible to attain. Did all movement begin with the big bang? Did some sort of movement precede the big bang and cause it?

One can see movement as a deep subject when one considers how things move in relation to consciousness. In China, ancient philosophers believed this, so much so that China's most enduring philosophy came to be one that developed principles dealing with change (movement is change). In that case, to achieve the desired results one ponders how to take action in accordance with current conditions, the flow of change, and known change principles.

Still, no one has answered Namloh's question of what movement is. We might know how it happens and what conditions are required, but we don't know why it happens.

 

[p-brane]

Nutrinos are the part of electromagnetic spectrum?Since when?
Neglecting "neutrinos" in the package ;-):Electromagnetic waves all "travel" at the "speed of light" in vacuum regardless of their frequency.Great J.C.Maxwell concluded this first.

Sorry and thank you. Neutrinos excluded.

However, if anyone knows the speed at which neutrinos travel; that would be interesting to know.

Quote from SelfAdjoint"From a spacetime viewpoint, those maneuvers are highly non-geodesic

Ah. I was imagining light waves and their dubious counterparts, the photons, traveling along the arc of one of Buckminster Fuller's geodesic domes and experiencing a "g-force" relative to their motion. Thus I mistakenly imagined that the photon could,topographically, be considered in its own time frame. I thought that time would exist for a photon traveling at c. But no!


Les Sleeth, Thanks for the confirmation on the speed of the light wave frequencies including Infared etc.

 

[Loren Booda]

We infer motion by feeling the vector boson (photon, graviton) action impingent upon us.

 

[Loren Booda]

Neutrino velocity varies near the speed of light according to its relativistic kinetic energy/momentum.

 

[Les Sleeth]

We infer motion by feeling the vector boson (photon, graviton) action impingent upon us.

Hi Loren, your input is interesting as usual.

To your response I want to say . . . maybe, but do you have an opinion about what causes the vector boson effect? I continue to see the answer to the question of what motion is as incredibly significant. Because we can explain the mechanics of something doesn't mean we've understood the causes of what is most immediately observable, or why it happens. In the case of motion, it is so key to every single aspect of our existence, I think it begs for deeper understanding.

 

[Loren Booda]

Right now it remains fundamental until something like superstrings manages to explain it with a more basic theory. I doubt we shall ever be truly satisfied with an explanation for something so intrinsic as motion.