Motor Daddy
Valued Senior Member
Prove yours
I make no assertion.
I've already proved it. It is impossible for the train to have been at rest, because the lights impacted the train observer at different times.
The Relativity of Simultaneity
- Thread starter Motor Daddy
- Start date
I've already proved it. It is impossible for the train to have been at rest, because the lights impacted the train observer at different times.
We agree on that point.
I'm asking you to prove in this mathematical world of time dilation and length contraction, your assertion that the propagation of the signal through the wire is equal in both directions.
But, I can see that we won't make any progress on that front, so let's explore what we have established, shall we?
I'm asking you to prove in this mathematical world of time dilation and length contraction, your assertion that the propagation of the signal through the wire is equal in both directions.
But, I can see that we won't make any progress on that front, so let's explore what we have established, shall we?
Motor Daddy
Valued Senior Member
But James doesn't agree, so which one of you is correct, using Einstein's methods? James seems to think that the train could have been at rest and the embankment in motion, according to Einstein's madness. You say you agree with me, that the embankment had to be at rest and the train in motion, that it isn't possible for the train to have been at rest.
How does your length contraction factor into the length of the ropes and the time they are pulled? Are you saying one rope would be pulled a shorter distance than the other, using just one crank to pull on both ropes?
James is talking about the real world.
I'm talking about the mathematical world I defined for this exercise.
No, I'm thinking of the dynamic analysis of the wave propagating through the rope, not the overall movement.
It's too hard for me to analyse. I really don't know how to approach it.
What if the train observer didn't have such materials available?
Do you see that he can't synchronize his clocks or calculate his velocity using rulers, clocks, and light signals alone?
Don't you find that surprising?
Motor Daddy
Valued Senior Member
So in the real world, lightening can strike A and B simultaneously, and impact a midpoint observer at different times, when the observer was at rest?
The motion at the end of the rope is going to determine the rate at which the force builds. Are you saying the end of each rope travels a different distance per crank?
What if he didn't have a brain, then he wouldn't be able to use Einstein's methods either. What if he didn't know the speed of light was defined.
The point is, that when two clocks are synchronized, I am correct and Einstein is incorrect. It's as simple as that. We are talking about theory, in which clocks are accurate and clocks are sync'd, in order to find out how things really work. In the real world, there are all types of things that can and do go wrong. In the real world, measurements are not 100% accurate, they will never be 100% accurate. That's why we use thought experiments, to eliminate the real world mishaps! The point is, it is possible for two clocks to be absolutely sync'd. When they are sync'd, Einstein's world falls apart, and mine prevails!!!
Motor Daddy
Valued Senior Member
I'm not interested in what, illusions? Correct, I'm not.
You've already admitted that the train observer is wrong to assume the train to be at rest. That is the real world. I'm not interested in illusions in which the train observer assumes the train to be at rest and the embankment to be in motion. That is his illusion, and it is absolutely FALSE!!! No, he is not correct to assume that, any more than he is correct to assume his velocity is 567,978,345,432,593,267,590,346,234,787 m/s!
You don't seem interested in exploring different mathematical worlds.
You also don't seem interested in exploring the real world.
You only seem to want to explore your own particular preferred mathematical world.
In the particular mathematical world of the exercise.
How can you tell?
Does it matter?
If he can't tell the difference, if all his measurements are consistent with the train being at rest, then does it matter that he pretends the train is at rest?
What will be the consequences?
Motor Daddy
Valued Senior Member
I'm all ears, but you are wanting to start with false assumptions. If you want to be the train observer scientist, than you don't start with the notion that the train is at rest. You TEST and MEASURE the train's velocity. You start with a solid foundation of your measurements. You don't start with the assumption that the train is at rest and continue to base everything on that garbage.
Yes it does matter. We are talking about the difference between absolute motion and relative motion, do you understand the difference? One is absolute, which is each object's velocity in the universe, relative to and measured by light. The other is relative motion, based on the motion between two objects, of which you don't know the absolute velocity of either in the universe.
Don't you remember? We worked through several measurements of the train velocity. None were successful.
So, if the train observer has no way of synchronizing his clocks or measuring his true velocity...
What advice do you give him?
Should he use his ad-hoc train standard until he is able to determine his velocity?
So what? What are the practical consequences?
Will his microwave oven not work?
Will his two-way radios need rebuilding?
Motor Daddy
Valued Senior Member
If he has no way of syncing clocks then he has no way to measure velocity, which means he has no way to measure length using light travel time. So I suggest that he stops making assumptions about one's motion. If he wants to make statements about distance and time, according to the proper definition of the speed of light and the meter, then he needs to conform to the standards. If he wants to make his own standards, fine, but he has no business pretending those standards are correct according to the definition of the meter.
If he wants to make false statements about when lightening strikes occurred and the simultaneity of the strikes, yes, he should assume whatever make believe BS he wants to, and he can be happy in his own little imagination. Ignorance is bliss, you know?
His microwave will work, and his radios will work, but his dictionary will be different, so that won't work. His dictionary is BS, and he doesn't even know it. See, I told you ignorance is bliss!
One needs to include an energy balance if the goal is reality. If we assume the embarkment or the train are in relative motion, we can do a simple energy balance for each and compare. They won't be the same. If we still want to assume relativity and pick the wrong energy balance, as the stationary reference, we can alter the universal energy balance to create perpetual motion.
Let me give an example. We have a moving train and a person standing at the station. If we assume relative motion, the standing person sees energy proportionsl to the mass of the train. The person in the train sees energy proportional to the mass of the station, plus all the mass in the background scenery. Depending on which referece we pick, since it is relative, we can add magic energy to the universe for perpetual motion tricks.
Let u sapply the idea of simultaneity. Instead of focusing on space-time and relativity, one needs to think in terms of an energy balance for the system. We can't have simultaneity with relativity, since we can violate the universal energy balance so they can never add properly. But if we maintain an accurate energy balance for our system, then we know what each is doing, allowing us to know simultaneity.
The reason I had enough sense to see through the relative reference illusion, was because of art. In particular, it is work of art by Escher that is called Relativity. Each reference appears to valid when looked at separately apart from the whole; relative. But if we look at all of these relative references together, the assumption creates an illusion that can not exist in 3-D, but can only exist in 2-D. We don't live in a 2-D universe.
In other words, assume the painting is a plot of all relative references in a group of reference. Instead of a smooth curve, for the data plot, we get this complex abstraction. The math that defines the curves allows us to create illusions (cause and effect) that look real in 2-D, but onlu if we focus on one reference. But when you extrapolate into 3-D, these all can't exist in 3-D (using a spatial principle such as the universal energy balance).
Let me give an example. We have a moving train and a person standing at the station. If we assume relative motion, the standing person sees energy proportionsl to the mass of the train. The person in the train sees energy proportional to the mass of the station, plus all the mass in the background scenery. Depending on which referece we pick, since it is relative, we can add magic energy to the universe for perpetual motion tricks.
Let u sapply the idea of simultaneity. Instead of focusing on space-time and relativity, one needs to think in terms of an energy balance for the system. We can't have simultaneity with relativity, since we can violate the universal energy balance so they can never add properly. But if we maintain an accurate energy balance for our system, then we know what each is doing, allowing us to know simultaneity.
The reason I had enough sense to see through the relative reference illusion, was because of art. In particular, it is work of art by Escher that is called Relativity. Each reference appears to valid when looked at separately apart from the whole; relative. But if we look at all of these relative references together, the assumption creates an illusion that can not exist in 3-D, but can only exist in 2-D. We don't live in a 2-D universe.
In other words, assume the painting is a plot of all relative references in a group of reference. Instead of a smooth curve, for the data plot, we get this complex abstraction. The math that defines the curves allows us to create illusions (cause and effect) that look real in 2-D, but onlu if we focus on one reference. But when you extrapolate into 3-D, these all can't exist in 3-D (using a spatial principle such as the universal energy balance).
Motor Daddy
Valued Senior Member
...another idea for the sync of clocks.
Place a light transmitter and a receiver a distance apart from each other on a table, inline with the train from front to rear, roughly an arm's length apart from each other. Make a steel wheel that is a circle, roughly an arms length in diameter. Place steel tabs sticking out 180 degrees apart from each other on the wheel. Install a bearing in the center of the steel circle. Find the center of the distance between the transmitter and receiver on the table. Mount the wheel on a shaft at the center in such a fashion that when the wheel rotates, the tabs come in contact with the actuator on the transmitter and receiver. Rotate the wheel so the tabs are almost touching the actuators. Calibrate each actuator so that when the wheel is spun the tabs contact the two actuators simultaneously.
Now spin the wheel. As soon as the tabs make contact, the transmitter sends a light pulse to the receiver, and at the same time the receiver starts a clock. So when the light arrives at the receiver the clock is stopped and the elapsed time is shown.
Now repeat the test in the opposite direction.
Mind you, the distance between the transmitter and receiver is still unknown, but the two one-way times are known.
Use the equation L=(2cTt)/(T+t) to find the distance between the transmitter and receiver.
Use the equation v=(ct-L)/t to find the velocity of the train.
No sticks required.
... and no suspicions, illusions, assumptions of convenience, or pretending involved! Just straight up measurements of distance and time!
Place a light transmitter and a receiver a distance apart from each other on a table, inline with the train from front to rear, roughly an arm's length apart from each other. Make a steel wheel that is a circle, roughly an arms length in diameter. Place steel tabs sticking out 180 degrees apart from each other on the wheel. Install a bearing in the center of the steel circle. Find the center of the distance between the transmitter and receiver on the table. Mount the wheel on a shaft at the center in such a fashion that when the wheel rotates, the tabs come in contact with the actuator on the transmitter and receiver. Rotate the wheel so the tabs are almost touching the actuators. Calibrate each actuator so that when the wheel is spun the tabs contact the two actuators simultaneously.
Now spin the wheel. As soon as the tabs make contact, the transmitter sends a light pulse to the receiver, and at the same time the receiver starts a clock. So when the light arrives at the receiver the clock is stopped and the elapsed time is shown.
Now repeat the test in the opposite direction.
Mind you, the distance between the transmitter and receiver is still unknown, but the two one-way times are known.
Use the equation L=(2cTt)/(T+t) to find the distance between the transmitter and receiver.
Use the equation v=(ct-L)/t to find the velocity of the train.
No sticks required.
... and no suspicions, illusions, assumptions of convenience, or pretending involved! Just straight up measurements of distance and time!
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Motor Daddy
Valued Senior Member
Are you saying the train observer thinks the lights hit him simultaneously?? If the train observer says the lights impacted him simultaneously (which is impossible), what makes him believe the strikes occurred at different times at A and B (of which he is still clearly wrong). There is no way out of it. The situation is NOT reversible!
Neddy Bate
Valued Senior Member
No, this is not correct. The light rays reach the train observer at different times. Given that the train observer is located at the midpoint of the train, and given that the speed of light on the train is the same in both directions, the train observer concludes the lightning strikes must not have been simultaneous.
When JamesR said the light reaches the ends of the train simultaneously, he was talking about light from a single light source at the center of the train.
Neddy Bate
Valued Senior Member
Motor Daddy,
What I'm about to say is going to blow your mind. The apparatus you describe above will work for synchronizing two clocks, but the clocks will only be synchronized in the frame in which the transmitter and receiver are at rest. For example, if you do this procedure on the embankment, the clocks will only be synchronized on the embankment.
Here is what it will look like from the train's point of view: The steel wheel on the embankment is distorted such that the two steel tabs are no longer exactly at opposite sides of the circle. The reason is because one side of the wheel is "ahead" in time, and the other side of the wheel is "behind" in time. The steel itself does not bend, its just that those parts of the wheel are in different "time zones" so-to-speak. This means that the train observer will say that the embankment started his clocks at different times, because the tabs on the wheel were not located exactly opposite each other.
Motor Daddy
Valued Senior Member
Which again, would be impossible for the lights to reach the end of the train simultaneously from a single source at the midpoint of the train.
Say the train observer flashed a light from the midpoint when A and B on the train lined up with A and B on the embankment. It is simply impossible for the light to reach the front and back of the train simultaneously. That's like saying it takes the same time for light to reach you from a lamp post if you run towards it when light is emitted, and when you run away from it when light is emitted. It's simply impossible for light to travel the same distance in both scenarios.
Motor Daddy
Valued Senior Member
Do you actually believe that crap? Neddy Bate, You sound like an intelligent person. Why do you believe that garbage? You may as well be saying the clocks are different because a pink fairy is in between the embankment and the train, and she is waving her magic wand, and throwing magic dust in the air, which causes one to have massive illusions about space and time.
What a load of garbage!!!
Who cares what illusions appear to be, we are talking about measuring distance and time in the universe!! Illusions are for magic shows! Measurements are not magic.