The Relativity of Simultaneity

[Motor Daddy]

I agree that your numbers are correct in the world of no time dilation and no length contraction.
But that's not Einstein's world. Remember the agreement:

You haven't proven that a relativity of simultaneity exists, per the agreement.

We agree on the numbers in your mathematical world.
Do you want to see the numbers in Einstein's mathematical world?

I want you to prove that a relativity of simultaneity exists before you start using the concept in your calculation.

 

[RJBeery]

As an addendum, MD isn't quite a "Newton's World" believer either, although I'm struggling to remember the subtle difference in his views. It interested me enough to tease out his ideas for falsifiability, but after having identified the problem I quickly lost interest.

BTW, I do recall that in MD's world you can travel faster than light and observe events in reverse temporal order. This in itself isn't really proof of anything but it was one of the consequences that I pointed out.

 

[Pete]

I want you to prove that a relativity of simultaneity exists before you start using the concept in your calculation.

Correct, as per our agreement.
I will not use the relativity of simultaneity in my calculations. You will notice that it is not listed in my assumptions.

Are we agreed?

 

[AlexG]

Good luck Pete.

It ain't gonna happen, but go to it Don Quixote.

 

[Motor Daddy]

Correct, as per our agreement.
I will not use the relativity of simultaneity in my calculations. You will notice that it is not listed in my assumptions.

Are we agreed?

Ok, so lay it out step by step for me, one at a time.

 

[Pete]

First, the scenario.

Point A and point B are marked 10 metres apart on the embankment.
Point A' is moving, marked on the back of the train.
Point B' is moving, marked on the front of the train.
An observer M is standing on the embankment, halfway between point A and point B.
An observer M' is standing on the train, halfway between point A' and point B'.

The train passes the embankment at 4,958 m/s
gamma = 1 / sqrt(1-v^2/c^2) = 1.0000000001367545054905367903816

At t=0.000:

• the front of the train is passing point B
• the back of the train is passing point A
• the train observer M' is passing embankment observer M
• M' has a clock with him that reads t'=0.000
• A bolt of lightning strikes the front of the train and point B
• Another bolt of lightning strikes the back of the train and point A

From this, I conclude that:

• the lightning bolts struck simultaneously
• the moving train is 10 actual metres long.
• metre rulers on the train are contracted to 1/gamma = 0.99999999986325 actual metres long
• clocks on the train are dilated, elapsing 1/gamma = 0.99999999986325 seconds every actual second

OK so far?

 

[Motor Daddy]

First, the scenario.

Point A and point B are marked 10 metres apart on the embankment.
Point A' is moving, marked on the front of the train.
Point B' is moving, marked on the back of the train.
An observer M is standing on the embankment, halfway between point A and point B.
An observer M' is standing on the train, halfway between point A' and point B'.

The train passes the embankment at 4,958 m/s
gamma = 1 / sqrt(1-v^2/c^2) = 1.0000000001367545054905367903816

At t=0.000:

• the front of the train is passing point A
• the back of the train is passing point B
• the train observer M' is passing embankment observer M
• M' has a clock with him that reads t'=0.000
• A bolt of lightning strikes the front of the train and point A
• Another bolt of lightning strikes the back of the train and point B

From this, I conclude that:

• the lightning bolts struck simultaneously
• the moving train is 10 actual metres long.
• metre rulers on the train are contracted to 1/gamma = 0.99999999986325 actual metres long
• clocks on the train are dilated, elapsing 1/gamma = 0.99999999986325 seconds every actual second

OK so far?

Nope.

Meter rulers on the train are not contracted, and clocks on the train are not dilated.

1. The meter rulers on the train are 1 meter in length, there is no contraction of rulers. A meter ruler is exactly 1 meter in length. If a stick is 0.99999999986325 meters long, it is not a meter stick, it is a 0.99999999986325 stick!

2. Clocks on the train are not dilated. A second is exactly one second, by definition.

Both a meter and a second are standard definitions of distance and time, they don't change. You are baiting and switching by first saying the train is 10 meters long, and then saying it's actually 9.9999999986325 meters long. Which is it, is it 10 meters long or is it 9.9999999986325 meters long??

Also, one very important point: The front and back of the train are not passing the A and B points on the embankment, they are perfectly aligned with the embankment points, simultaneously. In order for the A and B points on the embankment to be 10 meters apart, and the train's front and back perfectly aligned simultaneously with the embankment's points, the train must be exactly 10 meters in length from front to back.

If you say the train is actually 9.9999999986325 meters long, and the points on the embankment are 10 meters apart, there is no way the front and rear of the train can be aligned with the embankment points simultaneously. No way!

 

[AlexG]

Meter rulers on the train are not contracted, and clocks on the train are not dilated.

Repeated denial in the face of experimental evidence.

Hopeless.

 

[Tach]

Nope.

Meter rulers on the train are not contracted, and clocks on the train are not dilated.

1. The meter rulers on the train are 1 meter in length, there is no contraction of rulers.

With respect to what frame? With respect to the car frame , no. With respect to any other frame moving wrt the car, yes.

2. Clocks on the train are not dilated. A second is exactly one second, by definition.

With respect to what frame? With respect to the car frame , no. With respect to any other frame moving wrt the car, yes.

Also, one very important point: The front and back of the train are not passing the A and B points on the embankment, they are perfectly aligned with the embankment points, simultaneously. In order for the A and B points on the embankment to be 10 meters apart, and the train's front and back perfectly aligned simultaneously with the embankment's points, the train must be exactly 10 meters in length from front to back.

With respect to what frame? With respect to the car frame , yes. With respect to any other frame moving wrt the car, no. If points A and B are attached to the car, yes, otherwise, no.

This is what happens when you don't know what you are talking about, MotorMouth.

 

[wellwisher]

Simulataneity exists, however not all references are in a position to observe it when we use relative reference. To do so you need to include an energy balance.

Special relativity has three equations, one for mass, one for distance and one for time. If you use only space-time ; distance-time, you can't determine absolute reference. Rather reference will appear relatice. You need to include relativistic mass, since energy conservation will not allow a stationary reference to pretend it gained energy, in the same way you can pretent it has motion using only distance and time.

For example, I call this the relative reference work-out. You sit on the sidelines, stationary, and watch someone run. You then say reference is relative, and you are the one that is moving. This allows you to ignore energy conservation, and be the one burning all the calories, since you are the one in relative motion.

On the other hand, if we are forced to do an energy balance by measuring calories, the relative reference trick won't work, because measuring the calories defines an absolute scale that tells us who is stationary and who is moving.

Say we have someone stationary, and someone on a train is moving close to C. If we do an energy balance, you can tell one from the other, even if we decide to begin with relative reference, and define moving as stationary and the stationary as moving.

Since only one reference has the energy needed to complete the energy balance, the question becomes, does the observed distance contraction and time dilation stem from the same mechanism for both, or from two different mechanisms due to an absolute reference based on energy?

If we use the mass equation of special relativity, since only one reference has an actual mass increase, its visual effects are directly connected to its own absolute velocity. The other reference is not generating its own effect, since it lacks energy to make a real space-time impact. One reference is generating the effects for both references. This is an example of simulataneity since there is only one source for two effects.

 

[AlexG]

Simulataneity exists, however not all references are in a position to observe it when we use relative reference. To do so you need to include an energy balance.

Special relativity has three equations, one for mass, one for distance and one for time. If you use only space-time ; distance-time, you can't determine absolute reference. Rather reference will appear relatice. You need to include relativistic mass, since energy conservation will not allow a stationary reference to pretend it gained energy, in the same way you can pretent it has motion using only distance and time.

For example, I call this the relative reference work-out. You sit on the sidelines, stationary, and watch someone run. You then say reference is relative, and you are the one that is moving. This allows you to ignore energy conservation, and be the one burning all the calories, since you are the one in relative motion.

On the other hand, if we are forced to do an energy balance by measuring calories, the relative reference trick won't work, because measuring the calories defines an absolute scale that tells us who is stationary and who is moving.

Say we have someone stationary, and someone on a train is moving close to C. If we do an energy balance, you can tell one from the other, even if we decide to begin with relative reference, and define moving as stationary and the stationary as moving.

Since only one reference has the energy needed to complete the energy balance, the question becomes, does the observed distance contraction and time dilation stem from the same mechanism for both, or from two different mechanisms due to an absolute reference based on energy?

If we use the mass equation of special relativity, since only one reference has an actual mass increase, its visual effects are directly connected to its own absolute velocity. The other reference is not generating its own effect, since it lacks energy to make a real space-time impact. One reference is generating the effects for both references. This is an example of simulataneity since there is only one source for two effects.

Epic fail.

There is NO absolute frame of reference. There is no absolute velocity. Reletavistic mass is a relative quntity, not an absolute.

This is wrong on all levels.

 

[Motor Daddy]

Epic fail.

There is NO absolute frame of reference. There is no absolute velocity. Reletavistic mass is a relative quntity, not an absolute.

This is wrong on all levels.

...and yet you insist that a frame can be at rest. At rest compared to what? At rest has to be relative to something. What is that something you refer to when you say "at rest?" Answer the question.

 

[Motor Daddy]

Pete, you have the same question to answer that you've continuously evaded. What do you mean when you say "at rest?" Describe your concept of "at rest."

 

[Me-Ki-Gal]

Because you're not the first person to come on here and claim to have demonstrated relativity is flawed using algebra on the level expected in a beginners SR textbook. Your problems and arguments are not new and previously have been retorted and explained away by people here and in the relativity research community as a whole.

Depends your point of view. If you have only just come across relativity and all these weird experiments involving trains and flash lights and light cones then it might seem exciting and novel, even if you disagree with it. For those who have known relativity for years, if not decades, the said experiments and results are old news. More often than not a relativity nay-sayer is new to relativity and is still too entrenched in their Newtonian intuition and thinks that their comments and criticisms are novel or insightful or deep or advanced. Almost invariably they are none of those and the nay-sayer fails to realise just how little they have read and understood of relativity. If you aren't just a sock puppet of Jack_ then I suggest you look at threads he's started. He's the canonical example of what I've just said, someone with little or no knowledge, naive about his level of understanding (especially compared to professional researchers in relativity) and utterly unwilling to accept that perhaps he doesn't understand something he's only just read about.

If you've made an honest attempt to learn some relativity and you're stuck on a few specific things then I'm sure people will be happy to help. If you're denouncing relativity because you haven't looked at it much and what you have looked at you've not bothered to think about then please don't let the door hit you on the way out.

Alpha , Sorry to interrupt. If space time is curved could our universe be circling something else and our rate of constant in the motion is the boundary of light speed ? Except for the influence of massive objects does spacetime all curve the same direction our is it all willy nilly like my messy hair ?

 

[Me-Ki-Gal]

Pete, you have the same question to answer that you've continuously evaded. What do you mean when you say "at rest?" Describe your concept of "at rest."

The constant of expansionism is probably as close to "Rest " in our life time . Speeding up from what I hear . If the universe is speeding up is it in a logarithmic fashion or at some steady constant ? Do we know how much the universe is speeding up in its expansion ? If it is is our frame of reference in flux? Does this influence the speed of light , but unknown to us for it always is the same from our vantage point ?

 

[wellwisher]

Time and distance or space-time is relative. But relativistic mass is not relative, since it equates to energy via E=MC2. We can pretend to be moving relative to a moving reference. But once you do an energy balance, you can tell it is an illusion.

For example, we have someone on a train looking outside. They think they are stationary and the landscape is moving. Someone at the station sees the train moving and themselves as stationary. Without an energy balance, it all seems relative.

But if we add an mass/energy balance the person on the train sees the landscape moving. So we need to calculate the mass of those mountains times the velocity to get an idea of just how much energy there is in that motion. The other person at the station only see the mass of the train in motion. There is two different energy amounts that voids relative, since relative would mean both have the same energy.

The magic trick doesn't work when we add mass/energy, which is why mass is downplayed so much. Some even try to explain mass in terms of space-time, so the magic trick is harder to see. This allows special effects that can make use of perpetual motion.

 

[origin]

...and yet you insist that a frame can be at rest. At rest compared to what? At rest has to be relative to something. What is that something you refer to when you say "at rest?" Answer the question.

You can say that one inertial frame is at rest relative to another inertial frame, but niether inertail frames are at rest in an absolute sense.

Here is an example: Assume there is a space ship moving along at about 25 kph and another heading in the opposite direction also at 25 kph. The first ship can be viewed at rest compared to the second ship which is moving at 50 kph relative to the first ship. The second ship could also be viewed at rest relative to the first ship which is moving at 50 kph. A third ship may be sitting at some distance away at rest compared to those 2 ships and notice that they are both moving at 25 kpm towards each other. A fourth ship may be an even farther distance away at rest relative to the 3 ships and see that all 3 are moving together at 1000 kph. A 5th ship ......

This is hopeless you know, right? MD does not even understand the concept that the speed of light is constant. He thinks the speed of light is a constant like the speed of sound. He stated [from the trains reference]:

If the train has a .5c velocity going down the tracks, and the train turns on a headlight that's located at the front of the train, 1 second later the light will be 149,896,229 meters in front of the train. The light traveled at c (299,792,458 m/s) for 1 second, and the train traveled at .5c (149,896,229 m/s) for 1 second, so the light is 149,896,229 meters in front of the train after 1 second.

He thinks from the trains inertial frame that the speed of the light relative to the train is 149,896,229 m/s. He does not seem to grasp that the speed of light is constant, that is the speed of light relative to the train (or any other velocity frame) will be 299,792,458 m/s.

I have asked him for evidence of this and he has ignored the request - which is not surprising as there is no evidence that this has any basis in fact. His belief also indicates that he has chosen to ignore all of the experimentation over the past 100 years showing that the inertial frame has no affect on the relative speed of light.

Abandon all hope of reasoning with this guy. He is the epitome of willful ignorance.

 

[Motor Daddy]

You can say that one inertial frame is at rest relative to another inertial frame, but niether inertail frames are at rest in an absolute sense.

Here is an example: Assume there is a space ship moving along at about 25 kph and another heading in the opposite direction also at 25 kph. The first ship can be viewed at rest compared to the second ship which is moving at 50 kph relative to the first ship. The second ship could also be viewed at rest relative to the first ship which is moving at 50 kph. A third ship may be sitting at some distance away at rest compared to those 2 ships and notice that they are both moving at 25 kpm towards each other. A fourth ship may be an even farther distance away at rest relative to the 3 ships and see that all 3 are moving together at 1000 kph. A 5th ship ......

You say there is a spaceship moving along at 25 kph. How did you determine the ship is traveling at 25 kph? Did you measure the distance it traveled in a specific amount of time? How exactly did you measure the distance, and what are the points you measured from? Certainly you did not measure from the other ship, , as the distance was closing at the rate of 50 kph. So exactly how did you determine the ship was moving at 25 kph? You don't even understand where you go wrong. You just make up numbers, and then change the numbers in order to fit Einstein's delusional world. Do you understand that in order for you to have measured the velocity of an object that the time must have already elapsed, and that you are looking at a record of the past? The stop watch has already stopped, the test is completed. Why can't you comprehend that??

...and you told me to assume the ship is moving along at 25 kph. Then you want me to assume that the ship can be considered at rest (with respect to what I don't know). Are you now telling me to disregard the first assumption that the ship is moving along at 25 kph, and to assume the ship has a zero velocity? Make up my mind, will you? Which is it?

By the way, even a zero velocity has to have been measured. How did you measure the zero velocity, and how much time did you perform the test, or has the ship always been at a zero velocity? Did it appear out of nowhere instantaneously, or did it come from some other place a distance away? If so, should I disregard that motion in my calculations of distance and time? You're clueless!

 

[AlexG]

But relativistic mass is not relative, since it equates to energy via E=MC2.

Wrong. Relativistic mass is relative, since it depends on RELATIVE VELOCITIES.

There is NO absolute frame of reference.

There is also no arguing with those who believe there is.

Motor Daddy,

"AT REST" with respect to the arbitrarily chosen inertial frame of the observer.

 

[Motor Daddy]

Motor Daddy,

"AT REST" with respect to the arbitrarily chosen inertial frame of the observer.

So basically you just make it up out of thin air? You don't perform any measurements of any kind? So you can just as easily say you have a 29.345 m/s velocity as you can a zero velocity? You say at rest and don't even realize that is a velocity, a zero velocity, which needs to be substantiated by facts, and yet..you can't do that, because you made it up out of thin air!

We are both in the same ship. You say the ship has a 0 m/s velocity, I say the ship has a 325.56743 m/s velocity.