Life in a Freely Falling Elevator (Synopsis)

Imagine that you've got that absolutely weightless feeling, the kind you get when you lose your balance and hurtle towards the ground. Are you on a roller coaster? Did you fall out of an airplane? Or are you in an accelerating elevator?

Image credit: Dutch Experiment Support Center, via http://www.descsite.nl/Gravity_us.htm. Image credit: Dutch Experiment Support Center, via http://www.descsite.nl/Gravity_us.htm.

According to Einstein's Equivalence Principle, there's really no way for you to tell, not unless you've got some view of the outside world. What you might not realize is that there's an assumption at play here: that the kind of mass you experience due to gravitation -- gravitational mass -- is the same kind of mass that experiences an acceleration -- inertial mass -- when you apply a force to it.

How did this idea develop, and what are we doing to test it? Paul Halpern has the full story of what Einstein called his "happiest thought."

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Is it fair to say that Einstein’s showed that gravity is not a "force" until we detect a force carrier i.e graviton's?

By david hurn (not verified) on 17 Mar 2015 #permalink

I'm lost again. I like the concept of absolute space. It fits nicely with how the universe works in my head. I don't understand why the concept of absolute space needed to be abandoned. Austrian philosopher Ernst Mach was wrong, or least I think he was wrong. I would think that all you would need to find a measurable physical basis are some extremely accurate clocks. Send them off in different directions at different speeds and whichever clock ran the fastest was closest to stationary in absolute space.

Reality doesn't have to care whether you like it or not. It just is.

David, the idea of gravitons as exchange particles emerges from a quantum description of gravity, yet to be completed.

Denier, Mach's view was more philosophical, but Einstein's general relativity, inspired by it, has been tested repeatedly in precise experiments.

Wow, yes indeed, unlike experiments demand the need to update our picture of reality.

By Paul Halpern (not verified) on 17 Mar 2015 #permalink

"Send them off in different directions at different speeds and whichever clock ran the fastest was closest to stationary in absolute space."

Woundn't that be the one that stayed on Earth Denier? By your logic your experiment would not just prove absolute space, it would prove a geocentric unverse.

It would only define the inertial space they started off from, David.

It would do no such thing, denier. The problem with your idea is that it implicitly assumes that which you propose to find, namely that there is an absolute time. The question you miss when you state that the clock running the fastest is the one that is stationary with respect to absolute space is "the clock running fastest according to what observer?" Remember, time is not absolute and different observers will disagree as to which clock is the one running the fastest. All you are doing with your experiment is determining which clock is moving slowest with respect to your own reference frame, not which clock moves slowest with respect to absolute space.

@Denier
"I am still convinced of absolute spacetime..."
And some people are convinced that a god created the world in six days six thousand years ago. That does not make it so, especially when all the evidence points in a different direction.

"None of the observers can agree on what all the clocks say at any given instant. "
The concept of "any given instant" requires an absolute time, and as Sean said above, a necessarily circular argument. However, its existence is not required for your original argument in post #2 to fail. The clock left on Earth will still be the fastest when all the clocks have returned to a small region of space upon it where any errors in determining your hypothetical absolute time will be many orders of magnitude less than the apparent elapsed time differences between the clocks. The Earth would seem to be a special place fixed in your absolute space (Or more correctly as Wow pointed out, moving at a constant velocity though it, which I think Michelson and Morley demonstrated must be zero.)

I am still convinced of absolute spacetime

And I refer you back to my original statement: Reality doesn’t have to care whether you like it or not. It just is.

@David L #9

So you are telling me that if we had 2 perfectly synchronized clocks, and one was shot into space in such a way that it stayed stationary relative to the sun while the other was kept on the surface of the Earth, that when the clocks met back up on the surface of the Earth after the surface clock did a full orbit of the star and 365 rotations of the planet that the Earth surface clock would have run faster because although it traveled further it was never accelerated from its initial inertial frame while the space clock was accelerated and decelerated?

Denier, you would have to convert to proper spacetime events to calculate the actual answer, but the answer is a qualified yes, you can get exactly the scenario you profess.

The problem you have with the calculation is that you're in the gravity well of the earth when on the earth and not all the time when you've left the earth, and that acceleration from gravity exerts time dilation on the earthbound clock.

Simpler scenario would be to proffer two earths in the same orbit in opposition. One that moves from "Earth Prime" to "Earth Secundus" along the orbit will show less time having passed than the one sitting all the time on Earth. And starting from Earth Secundus would likewise indicate the same with respect to its reference.

Simpler would be to proffer no earth and both start out from empty space. No matter WHERE you started off in space, the one who didn't accelerate would show the longest time between the other leaving then returning.

Remember, you proffered a preferred inertial frame of space and the earth's orbit is not inertial. Including it breaks your assertion about a preferred space, since it has to be inertial.

@Wow #10

I am not convinced that your understanding of reality is reality. Here is another example to chew on:

There are 2 identical unstable particles traveling at he speed of light. Particle A is left to go on its way while Particle B is decelerated then re-accelerated to the speed of light.

Statistically which particle is more likely to decay first? Particle A was left in its inertial frame while Particle B was accelerated away from Particle A.

Denier, why complicate the issue. We already know with absolute certainty that the clock on a GPS satellite orbiting the Earth has to be constantly corrected to maintain synch with one remaining on Earth

I am not convinced that your understanding of reality is reality.

It's pretty convincing that your convictions aren't a useful indicator of reality, though.

There are 2 identical unstable particles traveling at he speed of light. Particle A is left to go on its way while Particle B is decelerated then re-accelerated to the speed of light.

Fair enough. A simple scenario open to solutions.

Statistically which particle is more likely to decay first?

Particle A.

And at #13. Once again you use a circular argument dependant on the concept of an absolute time.

Particles with mass can't travel at the speed of light, but let's say "very near the speed of light" for the sake of argument. To observers moving alongside the particles, they would have the same half life. An unaccelerated observer would see a differnce which would confirm the effects of time dilation over many such observations.

NOTE TO ABOVE: I ignore "Speed of light" because there is no reference to another particle to which their speeds could be measured, and that there is no particle that can go *at* the speed of light.

@Wow #15

I just don't see how the answer could possibly be Particle A. The time dilation that comes with traveling that fast should keep the particle in existence longer.

@David L #16

An unaccelerated observer would confirm the effect of time dilation which way?

The two particle experiment is being conducted in a big particle accelerator with an identical A ring and B ring. Both particles are accelerated to almost-C, then particle B is decelerated to half-C for a short period before being re-accelerated to almost-C.

I think detectors at the same place on the rings would more often then not detect that particle B (the decelerated particle) had decayed first.

I think you're forgetting about the implications of general relativity. Given an alternate scenario, namely Particle A moves at a constant speed of 0.99c with respect to a detector and particle B moves at a constant speed of 0.7c with respect to the detector. Which particle would be detected to decay first? The answer there would indeed be particle B. It experiences less time dilation than A.

Once you involve acceleration, though, the situation changes. General relativity tells us that accelerations are equivalent to gravitational fields, and that gravitational fields cause time dilation. I suspect (but I haven't done the math) that in your scenario, the time dilation from accelerating a particle from near c to 0.5c is greater than the time dilation of the particle travelling near c.

@Sean T #19

You are absolutely right with the acceleration time dilation but it misses the point. You can always overcome the acceleration dilation by holding Particle B at 0.5c at however long it takes to overcome the delta before the decay.

The thing I am trying to get a handle on is what happens when we remove the effects of information propagation speed limits by having the 2 particles run in rings right next to each other. Like you, I think particle B would decay first. Furthermore I think that if you have 100 different observers at random points in space, each going in a random direction at a random speed, that few or none of them would see particle A decay first.

It just seems to me that so many of the predicted effects of GR are illusions brought about by information propagation speed limits, but GR isn't wrong because the information propagation speed limits are built right in. I am semi-open to changing my whole view of how everything works but is it going to require experimental proof that kicks me in the face. My understandings of how gravity works, why there is a speed limit on light traveling in vacuum, and time dilation are all built on my understanding of how space itself is constructed, and everyone is shaking my pillars.

I just don’t see how the answer could possibly be Particle A. The time dilation that comes with traveling that fast should keep the particle in existence longer.

This is because your requirement "going at the speed of light" was nonsensical, so I ignored it.

"Particle A and B going at the speed of light" even if you make that "near the speed of light" requires "with respect to what reference?" to be answered for it to have any meaning. Since we only have two particles, we have no reference other than the particle A or B, equivalent since we start off with them at the same speed as each other. But since they are with reference with themselves always where they are, their speed is zero.

An unaccelerated observer would confirm the effect of time dilation which way?

The observer doesn't define any absolute reference, denier.

This is the basis of your problem, and one that Sean T tried to tell you, but you weren't listening.

You cannot define an observer has having a special and absolute reference frame.

The thing I am trying to get a handle on is what happens when we remove the effects of information propagation speed limits by having the 2 particles run in rings right next to each other.

How is that supposed to stop information propogation?

...we remove the effects of information propagation speed limits by having the 2 particles run in rings right next to each other....

A particle travelling close to c in a ring two miles in circumference reverses its velocity vector 186,000 times a second. Makes your one-off 0.5c excursion look pretty insignificant.

It's reality that's shaking your pillars not us. Being only "semi-open" suggests you are as happy building walls around your pillars as sorting out their foundations. Working on the assumption that you are genuinly seeking to understand, let's go back to basics.

We have known for over a hundred years that light travels at the same speed in all directions when measured on Earth. That constitutes "experimental proof that kicks me in the face" surely. I see only two explanations. Either there is no absloute space, or the entire universe spins arouind the Earth every twenty-four hours. Do you propose a third?

@ Denier

your question in #11 is your answer, that is the reality. Altough some technical aspects are a bit off, in essence, yes that's exactly what happens. And it happens every day as others have pointed, GPS wouldn't work otherwise, the whole is compensating for relativistic time dilation between two clocks.. one on the ground, and one in orbit. The same thing happens for any two, three.. any no. of clocks/observers anywhere.

There is no other way for speed of light to be same in every reference frame, something has to give... and it was space and time.. otherwise "c" couldn't be constant.

By Sinisa Lazarek (not verified) on 20 Mar 2015 #permalink

@20: technically all your examples of particles moving in circular paths are about special relativity, not GR. An example of time dilation in GR would be something like this: imagine for the moment that Earth and Mars are not moving with respect to each other. You are standing on Earth watching me through a telescope, while I am standing on Mars watching you through a telescope. Because the Earth's gravitational force on you is greater than Mars' is on me, time passes slower for you than it does me. Your clocks will run slower and you will age slower, even though neither of us are moving with respect to the other.

GR time dilation cannot be explained by your idea of information speed causing a problem, because in an absolute space framework there couldn't be any time dilation between objects that are stationary with respect to each other no matter what the speed of information. So, your idea is just wrong.

Incidentally, the GPS corrections are actually a mix of GR and SR effects, and they partially cancel out: the satellites' movement with respect to us means its clocks will run slightly slower in relation to ours, but the satellites' being higher in the Earth's gravitational well means its clocks will run slightly faster in relation to ours. The effects are not equal (the satellites' SR dilation is greater than our on-Earth GR dilation), so there is some residual dilation that must be corrected.

@David L #24

The third option:

I see space as a matrix of point objects. An individual point object is capable of holding the information that represents the particles in the standard model and relational data that governs movement probability. In any given clock cycle particle information can stay stationary in the matrix or it can transfer to an adjoining point object.

There is an overhead to particle information transfer that takes one clock cycle. Information that stays stationary in the matrix during the clock cycle is matter and experiences time. Information being transferred during the clock cycle is energy and does not experience time.

C represents information transfer during every clock cycle. A particle moving at 0.5c would spend half of absolute time as information transfer and half as time perceiving matter. I see GR as mathematically describing the perception veneer between 2 objects over time, not the quantum mechanical reality of what is actually happening on the fundamental level in very real absolute space and time.

@Sinisa Lazarek #25

Something does have to give, but I don’t believe it is space and time. I believe that what gives is perception. GPS works on the reality perception differences.

re #28: Nope, Denier, GPS works based on general relativity, and there is no preferred absolute space. It doesn't HAVE perception.

re:27:

An individual point object is capable of holding the information that represents the particles in the standard model and relational data that governs movement probability.

Yes, this is entirely normal classical mechanics, and the beginning of the explanation of why Xeno's paradox gets nowhere in reality. There's nothing there that creates an absolute space reference.

A particle moving at 0.5c would spend half of absolute time

There is no absolute time because that 0.5c would be a speed in reference to a rest frame, for which there is no absolute reference. The particle is not moving in its own reference, and therefore it sees no 0.5c and no time dilation.

An observation from a frame moving relative to it at 0.5c would, but there is no reason to assert some absolute time for that observer: the choice is entirely arbitrary.

YOU WILL NOT FIND WHAT YOU INSIST YOU'RE LOOKING FOR HERE.

re #28: Nope, Denier, GPS works based on general relativity, and there is no preferred absolute space. It doesn't HAVE perception.

re:27:

An individual point object is capable of holding the information that represents the particles in the standard model and relational data that governs movement probability.

Yes, this is entirely normal classical mechanics, and the beginning of the explanation of why Xeno's paradox gets nowhere in reality. There's nothing there that creates an absolute space reference.

A particle moving at 0.5c would spend half of absolute time

There is no absolute time because that 0.5c would be a speed in reference to a rest frame, for which there is no absolute reference. The particle is not moving in its own reference, and therefore it sees no 0.5c and no time dilation.

An observation from a frame moving relative to it at 0.5c would, but there is no reason to assert some absolute time for that observer: the choice is entirely arbitrary.

YOU WILL NOT FIND WHAT YOU INSIST YOU'RE LOOKING FOR HERE.

@eric #26

Gravitational time dilation is just the same movement time dilation described in post #27. I see gravity on a fundamental level as a tweak to the movement probability which introduces a bias of information transfer in the direction of an adjoining point object closer to the center of mass.
If I am deep at a point in a gravity well that the probability of movement is 10 times in every million clock cycles and I am resisting the pull of gravity by standing on a surface then I also have 10 clock cycles spent countering my move towards the center of mass and only perceive 999,980 clock cycles. If you are higher in the gravity well and your probability of movement is only 5 times in every million clock cycles than you would perceive 999,990 clock cycles in the same amount of absolute time. Over the million clock cycles that just occurred in absolute space-time, you perceive my clock to be running 10 ticks slower than yours.

I see gravity on a fundamental level as a tweak to the movement probability which ...

...has no basis in reality, it's just an unspecified deus ex machina to make me insist that I could be right.

Your assertion of "movement probability" is merely wordsalad. The "clock cycle" doesn't exit, there is no standard clock tick. Please stop taking Terry's "Thief of Time" as a physics textbook. And the "particle information transfer" is yet more wordsalad.

You insist on asserting your conclusion. You assert there's a standard clock, then use it to prove there's a standard clock. THERE ISN'T ONE.

Stop it or bugger off to the dump thread with it.

If I am deep at a point in a gravity well that the probability of movement is 10 times in every million clock cycles and I am resisting the pull of gravity by standing on a surface then I also have 10 clock cycles spent countering my move towards the center of mass and only perceive 999,980 clock cycles. If you are higher in the gravity well and your probability of movement is only 5 times in every million clock cycles than you would perceive 999,990 clock cycles in the same amount of absolute time.

I'm going to use a bouncing beam of light as a time piece. If I reflect a light down a gravity well from high point A to low point B and back to A, it must "leave" from both places (leave A to get to B, then leave B to get back to A). Thus it will experience each of your cycle problems once. If I do the opposite and shoot the light up (from point B to A back to B), it must also "leave" from both places, and it will also experience each of your cycle problems once. Thus according to your system the two clocks should record the same time. But this is not true in GR, and its not what we see in reality. In reality, the person at point A see's B's clock moving slower, and the person at point B agrees that A's clock is moving faster, consistent with GR.

Moreover Denier, your probability-based description would not lead to the results you claim it would. P(0.00001) /= 10 in 1,000,000 cycles used doing that thing, P(0.00001) means there will be an average number of cycles and an observed distribution in the clock signal it returns. We don't see that; we see exact measurements of time.

@eric #33

I want to understand what you are saying but I am not quite getting it. Maybe we can try this one more time.

The person at low point B (999,980 level) sees his clock running at normal speed, sees the the clock at high point A (999,990 level) running ~0.001% faster than what he perceives as normal, and would see a clock running in gravity free absolute space (1,000,000 level) running ~0.002% faster than what he perceived as normal.

The person at high point A sees his clock running at normal speed, but sees the clock at low point B running slower, and would see a clock in gravity free absolute space running faster.

The person in gravity free absolute space would see Mr. A's clock running slower, and would see Mr. B's clock running slower still.

All parties agree on the relative speed of the clocks.

The beam of light spends the exact same amount of absolute time going from Point A to Point B as it would going from Point B back up to Point A. The beam of light itself experiences no time because it is moving every clock cycle.

Maybe the source of the misunderstanding is this: When I'm talking about information transfer from one point object to another, I'm not talking about 2 arbitrary points in space. Information transfer can only happen between adjoining point-objects. If it takes a beam of light 1 million clock cycles to get from low point B to high point A, then the information of that photon was encapsulated in 1 million point-objects and moved 1 million times to get from Mr. B to Mr. A.

@eric #34

If I understanding you correctly, I think that the time scale of the clock cycles and the distances involved are so small they exceed our ability to measure, but if you had the ability perfectly know the position of a thing in space at time intervals that small you would indeed see a distribution in the time scale.

Yup, more post-hoc rationalisation to fix a dream that won't become reality.

@ Denier
"I see space as a matrix of point objects. An individual point object is capable of holding the information that represents the particles in the standard model and relational data that governs movement probability."

the problem then is we are not talking about physics anymore. Not the physics of our universe. Because if we are debating physics and your view is the above one, I have to ask/demand for some theoretical framework and experiments that support it. If there are none, and you still insist on it, then it's religion based on faith and not science based on experiment.

I would ask what are those point objects that hold all the information.. by your description they are some undiscovered hypothetical particles which noone detected. What are their properties? Spin, mass, etc? Then you mention those absolute clock cycles. What are they? How much time is one cycle? How do you measure it? etc etc...

If you don't have support for your view, except " i believe it is so", then you shouldn't write that Mach and Einstein got it wrong, because we have over a century of theory and experiments that confirm SR to an incredible precision. At the least your theory should get same results for those modes and get new results at a quantum level.

On the other hand, you might choose to study these for a while, especially Lorentz transformations, because IMO that's what's confusing you with time dilations.

By Sinisa Lazarek (not verified) on 20 Mar 2015 #permalink

@Denier
p.s.
Ethan, in his new article about "can space expand...." gave a very nice real life example of SR and muons. I find it a great thought experiment which you could apply to your theory. And no "human perceptions of reality".. this isn't a mescaline trip.

You have a muon with a certain half life traveling at near 300.000km/s. You have earth at a certain distance. From muons perspective, it can't reach earth before it decays. Yet detector on earth detect it hitting. Only one rule, you can't accelerate to more than 300.000km/s. Find a model that works.

By Sinisa Lazarek (not verified) on 20 Mar 2015 #permalink

@36: well, we can measure orbital signals to nanoseconds and other signals to femtoseconds. Moreover it would be trivial to detect your sort of physics because another way to do it would be to send lots of timing signals and look for the long tails in the distribution. I.e., the signals that record a significantly longer dilation than what GR would predict. That just takes lots of data collection, which we already do as a matter of standard practice: GPS satellites send out billions of signals a second and have for literal decades, and nobody has seen the distribution you claim exists. This tells me the data does not support your hypothesis.

Sure, you can "distribution of the gaps" it. You can claim that the distribution is always just below our detection limit. But then you aren't really doing science any more, you're doing a sort of woo. At some point if you want to claim to be doing science, you have to show us your hypothesis in terms of equations for number of cycles and probabilities. You have to work out a detection limit. And then when we fail to see the probabilistic behavior orders of magnitude below the detection limit you claim, you have to be willing to abandon your hypothesis.

@ Sinisa Lazarek #39

I can see that I’m doing a horrible job explaining the concept. Except for the concept of absolute space, I’m not saying that Mach and Einstein are wrong. In a weird way, I understand what they were saying better now than I did before. I just believe what they are describing is perception and not reality.
The high speed muon is a perfect example. To the muon practically no time elapses before hitting the ground. To the person on the group a small amount of times elapses. The difference between the point of view of the muon and the point of view of the ground observer is the point of view. I totally get Lorentz Transformations, in fact I think they were originally proposed to support the concept of aether.
To me the idea that absolute space can’t exist because entities can’t perceive beyond their inertial frame is tantamount to saying tress that fall in the wood don’t make noise unless someone is there to hear it. It is ridiculous. If two friends synchronize watches before one gets on a super-high-speed vehicle for some time and then they meet up after the vehicle returns to the starting point, the watches will not be synchronized but that doesn’t mean they are at different times in the universe. Friend A can’t occupy the same space where Friend B is standing because the universe really doesn’t care if Friend B and his wristwatch perceived less time elapsing. Perception is not reality.

The point objects are not particles. Perhaps the term I am using is confusing the issue. They are locations and together they are the fabric of space. What I am describing is on a fundamental level how something, anything moves from point A to point B, why that effects its perception of time, why nothing can move through the universe faster than light, and how gravity works.

A clock cycle is a single tick of Planck Time, about 10^-43 seconds.

A point-object is a discretely addressable location in space that measures 1 Planck per side.

Here are some of the crazier thoughts that I have with this model that may bring the whole concept crashing down:

1 – On the most fundamental level there is no possible velocity for matter above absolutely stationary and below half the speed of light. For things on a macro scale to move slower it means smaller pieces are moving back and forth to cancel out some of the aggregate motion of the collective whole.

2 – If a particle is absolutely stationary in absolute space, then it is unaffected by gravity. It could be right next to the strongest gravitational source in the universe and not move unless something bumped into it to give it motion.

3 – There is no such thing as a singularity. Things in the middle of a black hole compress down to planck density and no further. Space itself doesn’t compress, or bend, or warp, or anything like that.

4 – If a SINGLE fundamental particle of matter was moving through empty space at half the speed of light, the particle you see on odd numbered clock cycles is a different particle than the one you see on even number clock cycles. On a slightly larger scale over time it would appear to be a single particle that was zig-zagging as it moved in a straight line.

5 – A fundamental particle moving half the speed of light is always a 2 particle formation. A fundamental particle moving 66% the speed of light is always a 3 particle formation. A single fundamental particle in a 4 particle formation always goes 75% the speed of light. This is the root cause of inertia. Until something alters the number in the formation, the formation will continue on at the exact same speed.

As for conducting experiments, that is beyond me but so many people are conducting experiments that someone is bound to be looking at something relevant. My whole reason for putting this crazy stuff out there is so the criticism I receive in response will help me know where to look. Religion or science, I’m not trying to convince you I am right. I’m trying to learn from what you know by having you poke holes in such a way that I know where I am wrong.

Perhaps the term I am using is confusing the issue.

They're unscientific.

They are a way to get the assumption that there is an absolute space in without it looking like an assumption that makes the conclusion.

As Sean T pointed out ages ago, but you weren't listening because it's devastating to your case.

For your Hanlon's razor breech I submit Hitchen's razor. I suggest everyone consider the same response until Denier can start thinking as a scientist, not a New Age woomancer.

Remember: the FIRST step of science is to be skeptical of your own ideas before sending them out.

The following steps are not necessary if you do that one right.

Denier, if perception is not reality, what is reality?

I propose that perception is the all of reality. Indeed a result of relativity is just that.

@ Denier #41
"I just believe what they are describing is perception and not reality."
No, they are describing physical laws and properties that govern EVERYTHING in the universe, NOT how humans perceive reality. Particles and fields don't have eyes or ears, thus they don't perceive anything. They just are, and they behave according to laws of nature, not their perception of it. You keep on insisting on this human observation of things, and I said to forget about people. When we talk about a particle or two particles or a detector.. there is no perception in that picture.. only interaction of inanimate fields, and SR works, despite there is no human to perceive it. So in essence it's completely the opposite of tree in the wood example.

@ #42 most of this is simply not physics of our universe i.e.

"On the most fundamental level there is no possible velocity for matter above absolutely stationary and below half the speed of light." - blatantly wrong.. look at any i.e. accelerator on earth.. it's accelerating matter to speeds of 99.999% of c..

" If a particle is absolutely stationary in absolute space, then it is unaffected by gravity." - absolutely wrong, I don't even understand where you got this from.. or based on what theory you think so. The rest of your points get even worse.. it's just daydreaming.. not physics. Give one example why you think so (physics based).. but I'm pretty sure there are none.

In the end.. what I think is somewhere there in your mind is close to what Loop Quantum Gravity is trying to do. A plank scale net of relations. But what arises is poles apart from your view. In LQG space and time are no absolute, they are emergent. Meaning... in some sense and in some scales.. it doesn't even exist..

By Sinisa Lazarek (not verified) on 24 Mar 2015 #permalink

@Sinisa Lazarek #46

What I saying has NOTHING to do with human perception. NOTHING. I've never said it has anything to do with humans or consciousness or anything even approaching those ridiculous metaphysical concepts. I use people and time perceiving muons in the examples to convey a point in a way I think can be more easily grasped, but I am obviously falling flat.

The base concept I am trying to convey is this: Two people get on separate trains that each travel in a giant loop. One loop is 1000 times bigger than the other loop, but the train on that track goes 1000 times faster. Special/General Relativity describes perfectly what is experienced by the travelers, and their non-human, non-conscious, totally-completely mechanical wristwatches that are influenced in no way by the presence or non-presence of people living or dead. Hooray for Einstein!

Reality is that when the two travelers get off their respective trains they can shake hands. They may disagree on how much time has elapsed between embarking and hand shaking, but the universe doesn't care. (The caring or lack thereof was a personification and not intended to mean I believe the universe has feelings).

@Sinisa Lazarek #42 part 2

On particle accelerators: I don't know the particles of the standard model are fundamental, but either way 99.999 is not a number between 0 and 50,

On the crazy idea of motionless particles not being effected by gravity, it is basically throwing zeros into the relativistic energy-momentum equation and seeing what that does to the mass value.

@ Denier

I was, like others, genuinely trying to help you get a better grasp on SR because you said "I'm lost again." I gave a reply and quotes to sentences written by you. I don't know what you think, I only know what you write. So couple of things.

1. PERCEPTION - Is a word which means a certain thing. And IMPLIES a LIVING thing. There are other words like interaction, detection, reflection, deflection etc. which would mean a different thing depending on usage. I don't know if you meant something else, I know what you said over and over. And it's doesn't work.

2. "Reality is that when the two travelers get off their respective trains they can shake hands. " - No! The reality is that one will be alive and one dead if enough time passes. The Reality IS that time passes differently in different parts of space/universe depending on certain factors. And the ONLY clock that CAN tick absolute time is one that is outside of it and stationary to the whole of it.

3. "... but either way 99.999 is not a number between 0 and 50," - Seriously? ROFL! Jeez man.. that one reminded me of certain Chelle guy here a few years back.

By Sinisa Lazarek (not verified) on 25 Mar 2015 #permalink

On the crazy idea of motionless particles not being effected by gravity, it is basically throwing zeros into the relativistic energy-momentum equation and seeing what that does to the mass value.

Relativistic Lorentz transformations for objects with mass typically involve factors of SQRT[1-(v/c)^2]. "Throwing zeros" into them for velocity does not do anything like what you imagine, instead it just makes objects have m's, t's and other behavior equivalent to Newtonian mechanics. Thinking it would do something like make them unaffected by gravity is a pretty enormous and basic error that nobody would make who actually worked with the equations.

There are in fact mathematical discontinuities in relativistic equations, but they occur when an object with mass is taken to have a velocity of c, not when their v = 0.

@Sinisa Lazarek #50

I appreciate you putting time in and your tidbit on Quantum Loop Gravity is a fascinating direction to explore.

Perhaps you are right in that 'perceive' is the wrong term to use. Other terms I can think of also have similar problem. 'Experience'? "Is subjected to"? It is just that time (the dimension) and time (the thing described in SR/GR) seem to be closely related but distinct. It may very will be that nothing in space can tell the difference between SR/GR time and dimension time but they shouldn't be conflated.

It is just that time (the dimension) and time (the thing described in SR/GR) seem to be closely related but distinct.

SOLELY because you want there to be absolute space or time, and that view doesn't gel with the reality shown by GR/SR therefore you HAVE TO "[deem them] closely related but distinct.

YET AGAIN you're assuming the result you want to prove with your claim.

I note that you could not bring yourself to answer what is reality if it's not perception.

Is it because your perception is that there MUST be an absolute velocity frame of reference and that if you can't prove that perception is not reality, you have just thrown away the reason for your assertions?

@ Wow #53

I am not trying to prove anything to anyone. I know only enough to be dangerous and don't pretend otherwise. That being said, things make the most sense to me if there is a quantized space, an example of which is central to Loop Quantum Gravity. I may be a nutball, but there are actual smart people who also believe in discrete planck sized pieces that make up an absolute space.

The problem I have with SR/GR time is that it is meaningless. As mentioned previously, two guys jump on separate trains traveling in different sized loops and going different speeds. The get off their trains and shake hands. Mr. A thinks 10 minutes has elapsed. Mr. B thinks an hour has elapsed. The clock at the train stations says 3 hours have passed. They all started in the same place and time, and all ended at the same place and time, but the SR/GR time elapsing between the two meetings can be almost anything. If it can be anything then it is meaningless.

I am not trying to prove anything to anyone.

Then stop posting your attempts to not prove this not-a-claim-at-all so that all the nobody can not read it at their leisure.

Or admit that was a load of bollocks and you ARE trying, just failing, therefore "cannot be trying" because you cant be allowed to fail.

The problem I have with SR/GR time is that it is meaningless.

The problem with that is that the claim is meaningless. And unsupported. It doesn't make a meaning YOU LIKE. That is all.

As mentioned previously... blah blah blah

Which is going to prove what? You're not here to prove anything to anyone, remember?

but the SR/GR time elapsing between the two meetings can be almost anything.</blockquote

Yup, it can. So what?

If it can be anything then it is meaningless.

No, it still means everything happens one after the other, causation occurs and we all go through time forwards, looking back,

What other meaning should there be and why?

Oh, but I forgot: you're not trying to prove anything to anyone, right?

wo guys jump on separate trains traveling in different sized loops and going different speeds. The get off their trains and shake hands. Mr. A thinks 10 minutes has elapsed. Mr. B thinks an hour has elapsed. The clock at the train stations says 3 hours have passed.

No, "thinks" is absolutely wrong. They and everything in their frame of reference(s) have all experienced in every way the time on their clocks. They aged that much. All physical interactions in their frame of references have occurred within that time frame. If you could watch every single atom, every single interaction in those various frames, you would see that they all interacted and interactions occur within those time frames.

the SR/GR time elapsing between the two meetings can be almost anything.

No, the various time dilations etc. are quite constrained by the equations. True, the variation can be extreme if one object is going near-c and the other is not (or one object is experiencing extreme gravity and the other is not). But its not arbitrary; its not like the theory could be made to fit any possible conclusion.

Its not meaningless because it provides an accurate and useful model of a part of our observable reality. Until folk like you come up with a more accurate and more useful model of that same part of our observable reality, science will continue to use it. As far as I can tell, you personally denier are stuck at the "words-only hypothesis" stage. You don't have math to describe your alternative idea, so it's basically untestable at this point. That makes it neither accurate nor useful.

eric, it's not even "words-only hypothesis", it's not even thought out that well. It's blather. It's the result of directed unreasoning.

It's making a based on wishful thinking.

Denier,

Then by your own logic, measurements of distance are similarly meaningless. In your example, suppose Mr A, Mr B, and the train station are all equipped with an accurate instrument for measuring distance travelled, say an odometer. Mr A and Mr B both board different trains, travel in a loop and return to the station. Mr A says that he travelled 50 km. Mr B says he travelled 100 km. The odometer at the station reads 0 km. Does that make distance measurement meaningless?

In GR, time measurement is not distinct from distance measurement. Just as each observer travelled a different distance through space, each observer travelled a different "distance" through time as well. It's no more meaningless to talk about different passage of time for each observer than it is to talk about different spatial distances that they travelled.

@Sean T #58

Thinking of time as distance is exactly why I have a problem with GR. Mr A and Mr B shake hands, mark the spot on the platform where they shook hands, jump on their trains, get off their trains, shake hands again, and mark the spot on the platform where the second hand shake took place. The distance between the first mark on the platform and the second mark is exactly 10 meters.

Mr A's train traveled 50 km, but Mr A sees the two spots on the platform and confirms the two handshakes took place 10 meters apart.

Mr B's traveled much farther and faster but it is completely irrelevant because the two spots on the platform are 10 meters apart. The distance between the spots on the platform is not effected in any way by what Mr A and Mr B did between handshakes.

With time, that is not the case. Mr A says one amount of time has passed, while Mr B says another amount of time has passed, and the station agent says yet a different amount of time transpired. Unlike the two spots on the platform that can be measured with a tape measure, the two points of time could only be measured by a measuring device that was outside of time-space and stationary to it.

Because such a measuring device is not available to us, the true universe-centric time doesn't exist and all we can do is calculate the way time passes to our own reference frame. I just really don't like that answer and want to treat time like a dimension rather than an experience.

Again, you are mistaken, Denier, if you think that distances are any more absolute than times in relativity. The reason that the observers in your example, and the only reason, is that both observers are at rest with respect to the marks when they measure the distance between them. They are in the same inertial reference frame. If Mr A measures the distance between the marks while on the platform and Mr B measures the same distance while on a train moving with respect to the marks, the observers will NOT agree that they are 10 meters apart. You may object that a measurement made while moving is not as valid as one made while at rest, but that objection is not founded. ALL reference frames are equivalent; no measurement made in one is preferred to a measurement made in any other.

Your comparison is akin to observing that Mr A and Mr B go on their trains and return to the station. They look at the clock at the station before and after their trips. They agree that the clock at the station says that one hour has passed since they left. When measurements are made by two observers in the same inertial reference frame, the observers will agree on the measured values; that's not surprising, and certainly not evidence for either absolute space or absolute time.

The real fact is that Mr A and Mr B will not agree on how far they travelled through space. Why should they? They did, in fact, travel different distances through space. That's not particularly difficult to understand. What is more difficult to grasp is that they travelled different "distances" through time as well. The reason that's more difficult is that no human has actually ever travelled noticeably different "distances" through time than any other human. To do so would require travel at near light speed. We can, and do, however, measure such distances using precise atomic clocks. An experiment was actually performed in which two such clocks were synchronized and then one was flown on an airplane at known speed for a known distance. The travelling clock indeed came back showing less time to have passed than the stay-at-home clock. Relativity, whether you like it or not, has been experimentally verified.

"Relativity, whether you like it or not, has been experimentally verified."

Bizarrely Sean T, I don't think Denier disputes that. As I understand his position, he is happy to concede that the mathematics of SR/GR perfectly model observed phenomena whilst baring little relationship to the underlying physics. Where he seems to have a problem is accepting the fact that as motion though his absolute time and space has, in all cases yet examined by experimental physics, required equal terms on both sides of the SR/GR eqations. thus putting his hypothesis into the "not even wrong" category.

I understand the disruptions of space-time caused by the station-keeping flappings of the infinite column of turtles cancel out in a very simlar fashion.

He does, however, Dave. he says it's not real, that it's false because there IS an absolute space and time, which is the antithesis of Relativity.

Just saying "Oh, I agree with the results, but they're wrong in the conclusion" is NOT agreeing with the theory, it's avoiding the evidence supporting the theory.

@Sean T #60, 61, 62

If time the way you are using it is simply another dimension then give me an example of what an observer would have to be doing or where an observer would have to be to measure the 2 spots marked on the train station platform as infinitely or asymptotically close to infinitely far apart.

I can think of 2 ways to do that with the "time" between handshakes.

Denier,

I highly doubt that you can do that WRT the time between handshakes, assuming that you use a time that is analogous to the distance that you deal with in your example. The analogous time would be the time recorded by a clock at rest on the platform. Suppose that the clock made a printout showing the time any time someone pushed a print button on it. If that button is pushed each time Mr. A and Mr. B shake hands, nobody will dispute the time between their handshakes as measured by that clock.

What is in dispute is the notion that this clock is somehow the one that is absolutely correct and that other clock readings are somehow invalid. The clocks on Mr A and Mr B's trains will certainly show different times between handshakes. Why should we believe that these clocks are wrong? Similarly, if Mr A and Mr B measure the distance between the two spots on the station platform while their trains are moving through the station, they would not agree that the distance is the same as the one measured by them while they were stationary with respect to the platform. Why should we consider the stationary distance to be correct and the other distance measurements to be wrong?

It may seem obvious that the stationary reference frame is special and that the moving ones are different, but that is an illusion based on the fact that we, in our ordinary lives, have a commonly accepted reference frame to define what "stationary" means, namely the surface of the earth. For everyday matters, this works quite well, but is unsatisfactory for doing physics. The earth's surface is in fact not stationary with respect to pretty much every other object in the universe. When dealing with universal physics, why should we regard the earth as stationary and everything else as moving?

Consider also a spaceship in an area where there is nothing visible or detectable around. How would you determine whether that spaceship is moving or stationary? If that's not possible (which it isn't) how could you determine if the clocks on that spaceship are giving "correct" times? It makes the most sense to say that ALL clocks are giving correct times, and that the nature of time is just such that time is not consistent between reference frames, that is, relativity is correct.

@David L #63 & Wow #64

I'm saying that any successful Grand Unification Theory is going to include an absolute space. I find Loop Quantum Gravity interesting because it is one such theory.

All of the talk of Lorentz Transformations is fun to mentally play with, but it doesn't prove or disprove absolute space. It predates SR/GR and was originally thought up to support Aether. As such, it works nicely with absolute space.

I think that SR/GR are completely valid, but the time they describe is closely related but distinct from dimensional time. A photon from the CMB hitting our detectors today, because it travels at c, would not have been subject to the passage of time. If the photon has a wristwatch, not a single second would have passed. I'm saying the photon is wrong. I may not know the true answer to exactly how much older the universe is since the CMB because I am subject to the constrains of my own frame, but I know the photon isn't right.

@Sean T #66

You ducked the question so I am going to ask it again: If time the way you are using it is simply another dimension then give me an example of what an observer would have to be doing or where an observer would have to be to measure the 2 spots marked on the train station platform as infinitely or asymptotically close to infinitely far apart.

The 2 ways I can think of doing it with regards to Relative time are as follows:

Option #1

Mr A and Mr B shake hands and board their respective trains. Mr A, Mr B, the station, the trains and their loops all descend into a black hole. To an observer outside the black hole the trains would slow and the second handshake would never happen. The time between handshakes would be infinite.

Option #2:

Mr A and Mr B shake hands and board their trains. The spaceship the trains are built on is then accelerated to a velocity asymptotically close to c. To an observer not traveling at c.....

So if Relative time is just another dimension, show me how to do that same trick with two points in X-Y-Z space.

It may seem obvious that the stationary reference frame is special and that the moving ones are different,

Only and solely because it was defined as stationary. If you define something as "absolutely stationary" then claim that it must be the true time and therefore there must be an absolutely verified reference, then you've only claimed the result that the assertion asserts.

There is no special stationary clock that is absolutely correct.

There is no way to know that Mr A is "absolutely correct" and it is instead the station clock that is moving fast and therefore showing the wrong time.

Or that Mr B is incorrect making the same claim.

Or that someone else with a different time is "actually correct".

Because there is no special stationary reference frame, only inertial ones moving with respect to each other, each claiming their clock is right.

To an observer not traveling at c….

Why is that observer not the one moving at nearly c away from Mr A and Mr B?

"Why is that observer not the one moving at nearly c away from Mr A and Mr B?"

And is the speed limit in absolute space 2c not c?

@Wow #70

Because acceleration can't last forever

@ David L #71

The absolute speed limit of data propagation in the universe is c. Matter and energy are just data.

@Wow #70

Because acceleration can’t last forever

Whutdafuq?

Why is that observer not the one moving at nearly c away from Mr A and Mr B?

NEVER asked you about acceleration.

(forget that the claim you've made is bollocks: acceleration lasts forever if it continues. There's no maximum duration for acceleration, moron.

SO ANSWER THE FRIGGING QUESTION:

Why is that observer not the one moving at nearly c away from Mr A and Mr B?

@Denier #72: You are clearly ignornant of basic physics, whether willfully or not.

1) There is no limit to acceleration: momentum and kinetic energy may increase without bound, which is what acceleration does.

2) The fact that 'c' is a limiting speed is a _consequence_ of special relativity, not a separate physical law. Since you have already demonstrated (despite your ironic denials) that you reject relativity, your claim now that it is a limiting speed is either ignorant or disingenuous.

By Michael Kelsey (not verified) on 01 Apr 2015 #permalink

@Michael Kelsey #74

You are of course right in there being no limit to acceleration. That is my fault due to a lack of completeness in my answer so it could be taken out of context. The question was why I chose party A in my hypothetical scenario instead of party B. I needed time to pass almost infinitely faster for one frame than the other. I did not believe acceleration time dilation would be adequate before velocity time dilation became dominant. So I chose party A.

...And all of that was an effort to not answer the question I asked in #65 and again in #68

@Denier: Your question in #65 is ill-posed, and reflects an ignorance (either willful or not) of special relativity. You asked, "what an observer would have to be doing or where an observer would have to be to measure the 2 spots marked on the train station platform as infinitely or asymptotically close to infinitely far apart."

Nothing. What you pose is impossible, by construction. The two marks on the platform are there simultaneously: observers are measuring a _spatial_ separation, a distance of 10 meters, for example. An observer at rest in the train station will measure that distance as 10 meters. An observer moving through the station will measure that distances as being _shorter_ by an amount proportional to sqrt(1-v^2/c^2). Since the scale factor is a function of v^2, it doesn't depend on direction, and is ALWAYS smaller than 1. It is impossible for a moving observer to observe a spatial length larger than the rest length.

If you understood the mathematics of special relativity, you would know that.

By Michael Kelsey (not verified) on 01 Apr 2015 #permalink

The question was why I chose party A in my hypothetical scenario instead of party B.

Is the error in your eyesight or your brain, denier?

The question WAS NOT about why you chose A since you never chose A *or* B as your observer.

You chose another observer that you said was "not traveling at c", why you chose that observer and why could they NOT be traveling at nearly c.

Why is your observer stated to be going slowly? Why can't they be going fast?

@Michael Kelsey #76

The question was perfectly posed and of course I knew the answer. The whole point was to draw a distinction between relativistic time and distance.

@Deiner #78: The question was ill-posed. You stated a false premise. If you don't know what that means, I propose you find out.
All the rest of us having this "discussion" with you understand perfectly well the difference between time and distance, and how they appear in the metrics of both special and general relativity. We also understand the invariant interval and transforms between different inertial coordinate systems, and how to compound transforms when dealing with test particles undergoing non-internal motion. None of which you appear to have any inkling of whatsoever, as demonstrated by your repeated incorrect assertions.

By Michael Kelsey (not verified) on 01 Apr 2015 #permalink

@Michael Kelsey #79

You don't like the way the question was set up. Fair enough. Let me ask you another one.

To an observer some distance from a black hole it appears that something falling towards a black hole slows down, gets redder, and dimmer as it falls toward the event horizon, but to the observer the falling thing never gets to the event horizon. Is that reality? Is time really stopped at the event horizon where space is NOT infinitely curved? Or is it an illusion caused by the intense gravity effecting the propagation of information near the event horizon?

It's not that he doesn't like it, but that the set up is wrong. It doesn't do what you purport it to do.

"Is that reality?"

Which that?

They are both reality.

It isn't an illusion. They both really do what happens. Not imagining it.

Moreover, this STILL doesn't make your case.

Which are yet more things people don't like about your contentions. We don't like that they OUGHT to be coherent, reasoned and explicative, but they are none. We would LIKE you to make sense, but you're not. We do not LIKE to see people make asses of themselves, but you are, so we;d LIKE you to make a better effort at making your case.

Because we'd LIKE to see someone do well.