Question about time and measurement

[adrian_m]

This is incorrect. The constituent fluid elements making up a macroscopic object need not have the same individual motions, by any means, as the macroscopic object, viewed relative to some inertial frame. Your last sentence has no relevance whatsoever to the rest of your claim.

Take a concrete example. You and I are both traveling inertially at different velocities.

I see your clock's 'second hand' tick over a second, moving at a certain angular velocity. The elapsed time by my clock is different than 1 second, so you have a time dilation with respect to me.

Is it possible that I will not necessarily see the 'atoms' in your second hand move at the same angular velocity, or preserve their positions with respect to each other at any time? That would only be possible if the physical laws in your frame were different than mine.

Unless proportions within a macroscopic object are preserved, it does not make much sense to say that a macroscopic object has 'a' time dilation.

 

[WannabeNewton]

Unless proportions within a macroscopic object are preserved, it does not make much sense to say that a macroscopic object has 'a' time dilation.

This is exactly why your claim above is incorrect. If we represent an extended body by a congruence of time-like curves and have an external observer who intersects a curve in the congruence at a given event on the curve then the external observer can boost to the instantaneous inertial frame of the fluid element described by said curve and the time dilation factors will be attributed on this individual level. Your claim was "If an object as a whole experiences time dilation, then the motion of each particle that makes up the object must undergo the same time dilation.". If you are talking about extended bodies and bringing into the picture the constituent fluid elements then your first clause by itself makes no sense.

A simple example is given by representing a rigidly rotating disk of angular velocity $\omega$ by a congruence of time-like curves. In order to boost from a background global inertial frame to the instantaneous rest frame of each fluid element in the congruence simultaneously, one uses the gamma factor $\gamma = \frac{1}{\sqrt{1 - \omega^2 r^2}}$ which clearly is different for fluid elements situated at different $r$ on the disk.

 

[phyti]

In the 'ideal' rest frame, there is no relative motion of the components, thus the fictional 'center of mass' moves at a constant speed. In the 'real world' rest frame the component motion varies on a molecular/atomic level (even if only due to thermal energy) for extremely short durations. There would be a mean rate of time dilation with small fluctuations. These would be insignificant at small fractions of c. I won't speculate on the significance at high fractions of c.

 

[WannabeNewton]

There is no rest frame for an entire time-like congruence. One can go to the rest frame of a given fluid element in the congruence and in this frame i.e. relative to this fluid element, neighboring fluid elements can have both angular and radial velocity.

 

[phyti]

...
It would seem that, if we were to place a clock somewhere in space, which to us is seemingly not moving at all
that the difference would be something like 1.0000000123 seconds per Earth second get recorded.
This seems like a very small discrepancy.
It should be that we can decrease our velocity and inversely experience 5 seconds our time for every 1 Earth second, and see everything slowly meander about.
...

Two observers A and B with different speeds, do not see time dilation for the other. Clocks are frequencies, therefore they observe doppler (frequency) shifts, positive if approaching, negative if receding. It's similar to the changing pitch of a sound passing by. The aging (accumulation of time) for each clock can only be done by a comparison of the two at a common location, as was shown in post 5 by harrylin.

If you pass by another clock, decreasing your speed each time, the maximum length tick will occur when you stop next to it. You can't go any slower, i.e., moving clocks will run slower, but never faster. In your above example, the difference would be zero, the clock reads 1.00.

 

[questionator89]

Ok I need to catch up a bit,
This is a lot of information...to add.
So firstly, I can't argue because you guys sound like you really know your stuff, But I am going to argue anyways. My lack of understanding can allow this right now.

Phyti you are not correct, I do know that. The one thing that is very apparent is that you ONLY see time dilation of another person. not yourself.
But you are correct I think that there is a doppler effect when moving directly away or directly toward an object.
so, I just want to tie in that it is mentioned a bunch in these science papers that, somehow, because light is affected by gravity, then so too is time effected by gravity, and at the center of a black hole time stops, and at the center of a white hole (big bang?)time speeds up.
So when we are looking at a star up in the sky and it is blinking, this is because of the doppler effect, because when it rotates one side moves towards you while the other one away, and in the middle it appears to shrink.
If I got something wrong here let me know.^^

So I mean, I can't be wrong. If we were to stop somethings momentum, it would age. lots.
All the writing says it.
I think what we are forgetting in all this, MAYBE, is that the sun is moving at:
"The sun takes 200 million years to orbit around the centre of the galaxy. It is located 26,ooo light years from the centre so its orbital circumference will be Pi x radius = 22/7 x 26,000 light years. Speed is expressed as distance per unit of time.

Hence, speed equals (22/7 x 26,000) light years per 200 million years. "

I got this off yahoo answers lol.

And I bet by the difference in time (if we could accurately compare clocks) would give us a speed in which our galaxy is moving.

U know.. on this level Einstein always said " when two objects are moving relative to each other, it is completely impossible for one object to tell who is moving. Both objects would assume they are standing still, and the other is moving. And both would be completely correct"

So if this whole thing I am talking about is even REAL, then couldn't we have our astronauts going in circles so they can meet up and compare clocks once in a blue moon?
If we weren't sure who was moving, the clock that counted way less units would definately clear the fog.

Anyways, let's not forget my question is, can we slow something down to make it age drastically?

 

[questionator89]

Phyti I just understood what you are saying lol. But you are still wrong because the seeing of the doppler effect is the same as the seeing of the time dilation I think

 

[ghwellsjr]

Phyti I just understood what you are saying lol. But you are still wrong because the seeing of the doppler effect is the same as the seeing of the time dilation I think

No he's not. There is approximately a two-to-one ratio between the Doppler factor and the Time Dilation factor at high speeds. You can't see Time Dilation, it's the result of taking what you see (Doppler) and applying Einstein's convention and doing some calculations.

 

[questionator89]

Well then does that make him right about his previous post? because I thought how it worked was, Jane on Earth sees Adams clock in his spaceship ticking slow, but to adam his clock is ticking normally and Jane's clock is ticking fast. Does this not imply that you can see time dilation in another object?

In any case we need to make this scenario so that we are using giant magical hourglasses (magical because the sand falls down, and the hourglass grows and accumulates sand at the top) and where our two objects in reference meet up once in a while at the same momentum to compare who has the bigger hourglass.

 

[questionator89]

u know what's interesting while I am sitting here pondering this I am thinking, the speed of light is exactly the speed of time somehow. and because it is constant this is why we experience time dilation?
I said earlier that I do not understand how light and time are connected. and Drakkith said this doesn't even make sense.
But why is light mentioned so much?

Drakkith you say that to any observer that the speed of light is always c. but that would mean if you were traveling at 80% the speed of light then the light you are seeing would have to be traveling at 180% of the speed of light for you to view it normally.

 

[Drakkith]

Phyti you are not correct, I do know that. The one thing that is very apparent is that you ONLY see time dilation of another person. not yourself.
But you are correct I think that there is a doppler effect when moving directly away or directly toward an object.

Of course. You must account for the doppler factor in order to propertly account for time dilation.

so, I just want to tie in that it is mentioned a bunch in these science papers that, somehow, because light is affected by gravity, then so too is time effected by gravity, and at the center of a black hole time stops, and at the center of a white hole (big bang?)time speeds up.

First, you are correct that gravity affects time. But be aware that what happens beyond the event horizon of a black hole is unknown. Most scientists don't believe there is actually a physical singularity at the center, instead believing that we simply don't know how physics works at such an extreme scale. Also, I don't think time speeds up in a white hole, but I'm not sure. Either way, one has never been observed and I don't think most people believe they actually exist.

So when we are looking at a star up in the sky and it is blinking, this is because of the doppler effect, because when it rotates one side moves towards you while the other one away, and in the middle it appears to shrink.
If I got something wrong here let me know.^^

Blinking? I don't know what you're getting at. If you are referring to the "twinkling" of stars in the sky, that's simply because of the light passing through layers of air with different densities. Also, rotating stars do not appear "shrunk", they are actually stretched out into an ellipsoidal shape from their rotation.

So I mean, I can't be wrong. If we were to stop somethings momentum, it would age. lots.
All the writing says it.

No, it does not. It says nothing of the sort. It says that objects with a velocity of zero compared to you does not experience any time dilation due to relative motion as viewed from your frame of reference. Another frame of reference may be moving relative to the first one and would indeed see time dilation for both of you.

And I bet by the difference in time (if we could accurately compare clocks) would give us a speed in which our galaxy is moving.

Moving compared to what? You need something to compare the overall frame of the galaxy against. One of the best frames, but by no means the only frame, is one at rest relative to the CMB.

U know.. on this level Einstein always said " when two objects are moving relative to each other, it is completely impossible for one object to tell who is moving. Both objects would assume they are standing still, and the other is moving. And both would be completely correct"

So if this whole thing I am talking about is even REAL, then couldn't we have our astronauts going in circles so they can meet up and compare clocks once in a blue moon?
If we weren't sure who was moving, the clock that counted way less units would definately clear the fog.

Ah, but you are missing a very important point here. In your situation you do NOT have inertial frames of reference. One has been accelerating, and in that case the rules are different.

Anyways, let's not forget my question is, can we slow something down to make it age drastically?

For the last time, no. It cannot be done.

u know what's interesting while I am sitting here pondering this I am thinking, the speed of light is exactly the speed of time somehow. and because it is constant this is why we experience time dilation?
I said earlier that I do not understand how light and time are connected. and Drakkith said this doesn't even make sense.
But why is light mentioned so much?

Light, AKA an electromagnetic wave propagating through space, is irrelevant. It is the SPEED of light in a vacuum that is the key. You could say that there happens to be a maximum speed limit in the universe and that light happens to travel at this speed because it is massless. But light itself, as an EM wave, has no connection with time. Sorry if I confused you.

Drakkith you say that to any observer that the speed of light is always c. but that would mean if you were traveling at 80% the speed of light then the light you are seeing would have to be traveling at 180% of the speed of light for you to view it normally.

80% compared to what? That's what you need to start thinking about. You MUST consider two frames of reference if you want to really grasp this. Trying to think about SR and time dilation using only 1 frame will NOT work. You have to say 80% c in relation to another frame and then look at what both frames will see and calculate.
Read this: http://en.wikipedia.org/wiki/Time_d...nce_of_time_dilation_due_to_relative_velocity

 

[questionator89]

Of course. You must account for the doppler factor in order to propertly account for time dilation.
First, you are correct that gravity affects time. But be aware that what happens beyond the event horizon of a black hole is unknown. Most scientists don't believe there is actually a physical singularity at the center, instead believing that we simply don't know how physics works at such an extreme scale. Also, I don't think time speeds up in a white hole, but I'm not sure. Either way, one has never been observed and I don't think most people believe they actually exist.
Blinking? I don't know what you're getting at. If you are referring to the "twinkling" of stars in the sky, that's simply because of the light passing through layers of air with different densities. Also, rotating stars do not appear "shrunk", they are actually stretched out into an ellipsoidal shape from their rotation.

When I say blinking I mean one side is red and one side is blue spectrum because of the doppler effect. When I say shrunk I meant just in the middle because when viewing an object in motion this object appears to shrink, but it shrinks so uniformly that if you were inside the object nothing would change inside to you but the world outside would stretch.

No, it does not. It says nothing of the sort. It says that objects with a velocity of zero compared to you does not experience any time dilation due to relative motion as viewed from your frame of reference. Another frame of reference may be moving relative to the first one and would indeed see time dilation for both of you.

Objects at 0 would, by the pattern we are following , experience an infinite amount of time accumulation I think.
and objects at the speed of light do not experience time.
If a photon were sentient and were in a universe of mirrors that ended in a brick wall, the photon would experience hitting all the mirrors and the brick wall simultaneously at the speed of reality.
To us at Earth momentum this photon would take X amount of time to travel this distance. A very long time. Let's not forget that it takes light 1.03 seconds to reach the moon from us and 8 mins to reach the sun. at Earth speed.

Moving compared to what? You need something to compare the overall frame of the galaxy against. One of the best frames, but by no means the only frame, is one at rest relative to the CMB.

I am not sure what you mean by the CMB.
but What would you consider at rest?
our solar system is traveling around the galaxy at an extremely fast rate. We put our hourglass "at rest" behind our Earth orbit, go all the way around the sun, and pick it up on the other side, we will see that this clock has experienced 1.00034 seconds for every Earth seconds.
But don't forget its traveling at the speed our solar system is going.
This is not at rest.
We would have to leave any warp in space time that would drag us along, and really stop moving.
If our galaxy were moving it would probably appear to zoom away from us if we were at rest.

Ah, but you are missing a very important point here. In your situation you do NOT have inertial frames of reference. One has been accelerating, and in that case the rules are different.

what you are saying here is exactly why you believe that when we drop something off in space, but still in our solar system, it appears to be at rest.

For the last time, no. It cannot be done.

I get that you don't have an inertial frame of reference if you weren't accelerating or slowing down.
But close to the speed of light, or maybe not even that close, light is warped,stretched and curved because you are seeing it travel slower.
And i really believe if we had a clock that counted time accumulation rather than a continuous cycle from 1-12, we would be able to compare time accumulation between different momentums
and figure out how fast it is moving compared to a rest point.

Light, AKA an electromagnetic wave propagating through space, is irrelevant. It is the SPEED of light in a vacuum that is the key. You could say that there happens to be a maximum speed limit in the universe and that light happens to travel at this speed because it is massless. But light itself, as an EM wave, has no connection with time. Sorry if I confused you.

Yet it has the connection to time where if you were to reach the speed of light time would stop for you? and at close to the speed of light everything around you ages huge while you feel nothing different than one second per second?
I feel like you don't think I am understanding basic principles about how light slows down when it is passing through a medium, etc. I have read that we can bring sodium gas to close to absolute zero and light will be going only a few miles per hour through this medium.
The questions I am asking are really about momentum and time.
electromagnetic wave speed just happens to be the universal speed limit. for time as well. right?

If we follow the pattern, then at rest you should experience infinite time accumulation.

80% compared to what? That's what you need to start thinking about. You MUST consider two frames of reference if you want to really grasp this. Trying to think about SR and time dilation using only 1 frame will NOT work. You have to say 80% c in relation to another frame and then look at what both frames will see and calculate.
Read this: http://en.wikipedia.org/wiki/Time_d...nce_of_time_dilation_due_to_relative_velocity

K man. when I say 80% of c i mean compared to 100% of c...if you are traveling at 80% of what the max speed is, how much time would you accumulate compared to what we accumulate on an average day here on earth.
There is always a frame of reference that I am using and I don't understand why you keep saying compared to what?
You can't truly believe that at "rest" a clock will only experience slightly over 1 second per Earth second.
So going fast we can easily explain away that a fast person may only experience 1 second for every 10 seconds an Earth person feels.
But you can't believe that a slow person could experience 10 seconds for every 1 second and Earth person feels.
Why would the pattern stop?
Using time accumulation compared to 1 second per Earth second, we should be able to compare something that we can gauge the age of if left alone, and use math to figure out how much slower it would need to go to be at rest

the faster you go the slower time goes, the slower you go the faster time goes.

 

[questionator89]

It can't be true that time goes slower the closer you get to the speed of light, but does not speed up the farther away from the speed of light you get.

 

[Drakkith]

I'm sorry, but you simply don't understand the basic principles of Special Relativity and I don't think I can explain them to you. If you truly would like to understand then there are plenty of resources online. You can even read Einstein's original paper on SR. Everything is explained.

 

[BMW]

Furthermore if i made a bar of copper+entangled duplicate, sent one with the clock, then put an electrical current through the one I kept with me, what would happen to the spaceship copper?
Does this create entangled electrons from a spooky distance?

Why would the electrons introduced by the current get entangled to the distant copper bar? The electrons from the current are not necessarily entangled with anything, so no, it wouldn't create entangled electrons "from a spooky distance."

 

[questionator89]

yah i was told this about 60 posts ago BMW but thanks
what we are talking about in this thread is much different

 

[ghwellsjr]

Well then does that make him right about his previous post? because I thought how it worked was, Jane on Earth sees Adams clock in his spaceship ticking slow, but to adam his clock is ticking normally and Jane's clock is ticking fast. Does this not imply that you can see time dilation in another object?

I don't see anything wrong with phyti's previous post (#35). As I mentioned, the Doppler factor can be close to double the Time Dilation factor when objects are receding from each other and as they are approaching each other, the inverses apply. So as an object approaches and passes an observer, its observed Doppler factor will start high (positive, as phyti says) and end up low (negative as phyti says) which means at some point it will be equal to the Time Dilation factor for the rest frame of the observer. If the object is in "orbit" around the observer, maintaining a constant distance from him, the Doppler factor is equal to the value of the Time Dilation factor in the inertial rest frame of the observer but in other inertial rest frames they are not equal. As I keep saying, Time Dilation is a frame dependent effect and observers can't know what frame you are choosing to put them in. The Doppler factor is not frame dependent and is the same no matter what frame you use to describe a scenario.

In any case we need to make this scenario so that we are using giant magical hourglasses (magical because the sand falls down, and the hourglass grows and accumulates sand at the top) and where our two objects in reference meet up once in a while at the same momentum to compare who has the bigger hourglass.

What is magical about an hourglass in which the sand falls down? Or is it magical because it works in the absence of gravity the same as it would on the surface of the earth?

 

[questionator89]

Yeah I mean magical because of the absence of gravity.

I have found yet another conundrum with this theory.
I was using a time dilation calculator and found out that moving at 98.4% the speed of light you will experience a time dilation difference of 2.7 seconds. meaning that you just counted one second, but a "stationary object" ( this is the word the calculator used) experiences 2.7 seconds.
The other time dilation calculator I used came up with a much different answer.0.10903 seconds pass at this speed for every 1 second for a stationary object.

K fine, but here's what's weird with that.

at the speed of light time stops? this means that a photon could travel in one direction for infinity years and never experience one second pass.
Don't u think that at 99% of the speed of light time would barely barely be passing at all?

Instead we see that it passes 1/3 as fast or 1/10 as fast?
Is there some exponential loss of time accumulation after 99%?

It seems like either time dilation must be much more extreme than our math allows
Or to stop time we would have to be going much faster than the speed of light.

 

[Drakkith]

Yeah I mean magical because of the absence of gravity.

I have found yet another conundrum with this theory.
I was using a time dilation calculator and found out that moving at 98.4% the speed of light you will experience a time dilation difference of 2.7 seconds. meaning that you just counted one second, but a "stationary object" ( this is the word the calculator used) experiences 2.7 seconds.
The other time dilation calculator I used came up with a much different answer.0.10903 seconds pass at this speed for every 1 second for a stationary object.

Yes, because you are traveling, with respect to that frame, at 98.4% c, and thus are time dilated.

at the speed of light time stops? this means that a photon could travel in one direction for infinity years and never experience one second pass.

Trying to imagine what time is like at c is pointless. Our math does not allow us to set a frame of reference at c, and thus we cannot try to make predictions about what will happen. Any answer would be pure guesswork/speculation. If you really want to, feel free to imagine that time stops at c. It makes no difference.

Don't u think that at 99% of the speed of light time would barely barely be passing at all?

Instead we see that it passes 1/3 as fast or 1/10 as fast?
Is there some exponential loss of time accumulation after 99%?

Here's the graph:

As you can see, the amount of time dilation (the Y axis) increases rapidly when we get very close to c. (X axis is in fractions of c)

 

[Dale]

lets not forget my question is, can we slow something down to make it age drastically?

No. The slowest it can go is 0, and then it ages normally.

 

[Fiziqs]

A------------------------------B

Let's say that you have two identical atomic clocks with identical readings at point A. Now clock 1 is moved fast from A to B, and clock 2 is moved slowly from A to B. Then you compare the two clocks at B and you will find that clock 1 is behind on clock 2. In other words, the clock that moved slower will have recorded more units of time than the clock that moved fast.

I'm wondering if this is indeed correct. As you have described the thought experiment, clock 1 moves quickly from point A to point B, but it then it has to stop and wait for clock 2 to catch up, so that we can compare them. So for a period of time clock 1 is the faster moving clock, but then it stops and clock 2 becomes the faster moving clock. Do these two effects cancel each other out such that the two clocks will actually read the same time when clocks 1 and 2 reach point B? Or is the effect of increased time dilation exponentially greater as speed increases such that the faster moving clock will have actually experienced less time when both clocks ultimately reach point B?

 

[questionator89]

Yes Fiziqs.
To make it simpler I try to make these two objects in the thought experiment traveling in circles so that they just meet up on there own orbit every few orbits or something.
If the fast object has to stop (and i am trying to figure out why when we "stop" we don't just age ininiftely by the pattern of time dilation) wait for the slow object I would assume that when they met they would actually have experienced the exact same amount of time.

Just like with the astronaut returning to Earth to see everyone age dramatically, the Earth doesn't speed up to catch the astronaut, and the astronaut doesn't slow down and wait for the earth. He, in most cases, will turn around and head back to earth.

Drakkith that is a good graph.

But I still do not understand why we can STOP the accumulation of time, but we can only speed up the accumulation of time by slightly over one second per Earth second.

And you keep saying to me there is no point in trying to understand what it would be like to travel at light speed, because we have no idea.

Yet we have made the assumption that time stops?... right. So if it clearly shows time stopping at the speed of light you must agree.

It is pretty easy to understand time stopping.
You will experience one second per second, but the next second will never come, and you will never take the time to have this thought, and your spaceship would never take the time to fire out rocket fuel or ions or whatever.
Best way to really grasp it is that you are dead for a moment because you are frozen in time.

And I would much rather talk about why time cannot speed up according to you.And other physicists. (im assuming your a physicist?)

If you were to reach 0 speed, then why would you only experience 1.000004 seconds per Earth second.
you are barely aging any faster at all, but we are assuming you are not moving?

I should mention that if you were in a 0 rest frame, you would just experience one second per second, while anything at the speed of light would perceive you to age to infinity.
Maybe this is where I am getting confused.
Maybe I am correct, but we are already going so slow that our accumulation of time is almost at its maximum speed.
Things moving fast already see us aging at an incredible rate.

But this being said I know that our planet is traveling very fast around a star that is traveling very fast around a galaxy that is traveling very fast (maybe).
We could probably go a bit higher than 1.0000004 seconds per Earth second by going slower.

 

[questionator89]

HHHMMMMM u know what.
at the speed of light you would perceive any slower speed to age to infinity.
Maybe this is where I have not understood this?

an object at rest is already aging to infinity.
but we are barely moving so relative to us, it seems to be just ticking slightly faster.
we are already accumulating time at almost the maximum rate.But still, to add to this, could we not judge how fast an object has moved over its journey compared to us by how much more or less time it accumulated?

Einstein says when two objects are in motion relative to each other they have no idea if one they are still and the other object is moving toward them...

Our spaceships could flash a little signal to the other spaceship to start a clock,

and the one that was moving would be like " dude, i barely felt any time at all, you must have been waiting for soo long"

So can't we gauge how fast an object is moving, by how much time it accumulates, in comparison to another object?

 

[questionator89]

I think I answered my own question maybe.
We are already ALMOST experiencing the fastest rate of time we can accumulate.

 

[harrylin]

I'm wondering if this is indeed correct. As you have described the thought experiment, clock 1 moves quickly from point A to point B, but it then it has to stop and wait for clock 2 to catch up, so that we can compare them. So for a period of time clock 1 is the faster moving clock, but then it stops and clock 2 becomes the faster moving clock. Do these two effects cancel each other out such that the two clocks will actually read the same time when clocks 1 and 2 reach point B? Or is the effect of increased time dilation exponentially greater as speed increases such that the faster moving clock will have actually experienced less time when both clocks ultimately reach point B?

If the clocks travel at the same speed then the two clocks will be equally retarded, so that they are in synch wiht each other. Instead, we compared a clock that was transported rapidly from A to B with a clock that was transported much more slowly from A to B. See §4 of http://fourmilab.ch/etexts/einstein/specrel/www/

 

[questionator89]

Harrylin, that is what Fiziqs was saying though.
We can't go from A to B and have this effect work. Ill explain what I mean.
If both clocks have to travel the same distance, this means they experienced the same time rate if they have to meet up.
The fast clock must go much farther and return to the other object for this to work. So the fast clock does a continuous loop and checks back in once in a while. Or the fast clock zooms away from the Earth turns around and zooms back. The fast clock could even zoom past the Earth and turn around and just do a back and forth guitar string pattern over the earth. something.

If we are sending two clocks from A to B, one going slow, one going fast, we would need Buddah to be the 3rd observer and count a certain amount of time, maybe after the fast clock is halfway through the journey or something, and check both the clocks at the same time and see which one has accumulated more or less time.

Its much better to comprehend if the fast clock makes the effort to get back to the slow clock for the comparison.

once the fast clock reaches point B, to compare clocks he would have to wait. and all of the extra anti aging he would have would be completely canceled out while driving miss Daisy meanders through the journey

 

[Fiziqs]

We can't go from A to B and have this effect work. Ill explain what I mean.
If both clocks have to travel the same distance, this means they experienced the same time rate if they have to meet up.

Actually questionator89 I think harrylin is correct, even if clock 1 has to stop and wait for clock 2 their clocks will not read the same. The reason that I think this is true is that the time dilation effect is not linear. In other words both clocks would end up reading the same time if going twice as fast simply meant experiencing half the passage of time. But time dilation isn't linear, going twice as fast will cut the passage of time by more than half.

Thus if clock 1 travels at just under the speed of light it will experience very little time at all, and if clock 2 is traveling at exactly half the speed of clock 1 it will nonetheless experience much more than twice the time. Going faster for a shorter period of time will have more of an effect than traveling slower for a longer period of time.

At least that's how it appears to me.

 

[questionator89]

Right. But isn't it all related to what distance you went through space time to give you this dilation?

At the end of the road with object one they measure the time. But then it takes the other object much longer to reach the end of the road. But once it reaches it they measure this time.
Under this scenario I can understand a discrepancy.

But if they measure both clocks at the same time, they would have to wait while the other object finishes the journey and the faster object sits not moving, which means the object which reached it faster is now experiencing the maximum accumulation of time that any object can experience because it is at rest. the slow moving clock is still moving towards it and experiencing slightly less time accumulation.
It is not linear it is an exponential increase, but it continues both ways.
To sit and wait for the other clock to arrive would take just as long as the entire journey that the slower clock perceived.

 

[questionator89]

Harrylin,
Could you explain one section in that link that you shared?
The part where the light particle is bouncing off a reflector and they are determining the difference in force between the light that hit the surface and left, and determining what force was enacted upon the surface (or "work done")?
I can't follow the math here. are they saying that the reflector feels the photons bounce off and moves?

I have heard of the solar sails that we are considering using for spacecraft , and ionic propulsion, but I do not understand how this works.

If a photon was massless how can it apply any force?
I thought that light bent with gravity only because gravity is warping the straight line that light would have normally travelled. What is the weight of an electron?

 

[harrylin]

Harrylin,
Could you explain one section in that link that you shared?
The part where the light particle is bouncing off a reflector and they are determining the difference in force between the light that hit the surface and left, and determining what force was enacted upon the surface (or "work done")?
I can't follow the math here. are they saying that the reflector feels the photons bounce off and moves?
[..]
If a photon was massless how can it apply any force?
I thought that light bent with gravity only because gravity is warping the straight line that light would have normally travelled. What is the weight of an electron?

That's a completely different topic; anyway in §8 he uses the concept of light waves and not photons - no light particles. Light pressure is already known from classical optics, compare https://en.wikipedia.org/wiki/Radiation_pressure.
Light energy is the square of its amplitude. By definition the work done on an object equals the energy that entered it minus the energy that was given back. if you want to discuss it further, please start it with a new thread.