Seedling
Well-Known Member
bahahahahahaha.
So which is it, Teach?
bahahahahahaha.
Wrong again, Bucko! When you can explain to me how a light sphere can expand its radius, and at the same time travel along with an object then I will accept that the speed of light is always measured to be c in every frame. Until then you are just blowing hot air. The light sphere is a geometrical fact. SR twists and distorts the truth which is not correct geometry, it's, how you say....illusions!.
I demonstrated my position very clearly in the diagram, which you evidently brushed off. Your inability to comprehend the concept doesn't change the fact that it is correct. Show me the SR equivalent of a light sphere, and a cube in motion. Until you do that I will conclude that SR is not capable of responding to the concept, because SR is only valid when talking about relative velocities, of which we are not talking about. I can add a person walking around inside the cube and create relative velocities too, and could also measure closing speeds between the receivers and the person in motion. I could give the person's absolute velocity in the preferred frame, as I could give the person's velocity in the cube frame. I am speaking about ABSOLUTE VELOCITY IN THE PREFERRED FRAME!!!!
Yes, we build upon the knowledge of others, but is that knowledge always correct? Science has shown over and over again that what it once held true is no longer valid. "It's valid until it isn't" should be the motto for science. It's lived up to that motto since science began
So which is it, Teach?
It's obviously A. When I say that I throw a ball at x velocity it is implied that I mean x speed relative to my own. I am standing on a train not moving. If I throw a ball straight up in the air, it comes straight back down to me. You would see the ball go up, and also continue moving forward at 50 mph, then descending back down to me. If I throw the ball forward, then you will see the ball moving at the speed I throw it, plus the speed I am moving relative to you. If I face the back of the train and throw it 50mph (from my frame) then you will see the ball drop straight down.
My whole point with this example is that this stuff seems very elementary and intuitive. And this stuff is accurate for the speeds we are talking because at such low velocities relative to the speed of light the 1-(v/c)^2 term approaches 0. For very fast moving objects though this intuition is NOT true. Say I have a gun that shoots a bullet at 0.5c, and I am riding on a train that is going .9c according to your measurements. I fire my gun from the front of the train (in the same direction me/train is traveling). How fast do YOU see the bullet traveling?
Intuition tells you that it will be 0.5c + 0.9c = 1.4c because that works for baseballs and trains and cars and everything we experience in regular life. That is not the case though. You will measure the bullet going faster than 0.9c, but less than 1c. I will measure the bullet as traveling 0.5c away from me though.
There were two light sphere's emitted. The point at which they meet is the half way point between the point of origin of each light sphere. The radius of the light spheres are the same when they meet. The radius of the light sphere is inseparable from the time of light travel, by definition.
Since the man on the platform was at the halfway point between where the strikes occurred, and the light spheres simultaneously hit him, that means he had an absolute zero velocity in space. Since he had a zero velocity in space and the lights hit him at the same time, that can only mean one thing, that the strikes occurred simultaneously, and he is correct to state so. The train observer failed to acknowledge that the tracks are at an absolute zero velocity and the train was in relative motion to the tracks, which means the train has an absolute velocity greater than zero. That means since the strikes occurred simultaneously that the radius of the forward light sphere was less than the radius of the rearward light sphere when they impacted the train observer at the center position of the train. So lesson to be learned here, don;t make statements about simultaneity unless you know your frame's absolute velocity. The ol' girl made a fool of herself thinking the strikes occurred at different times. She is living in a world of illusions because she doesn't know here absolute velocity and she is making judgements about simultaneity.
Wait a minute there professor. Slow your roll.
Since he had a zero velocity in space
wait, how do you know he had zero velocity? The video just said he was standing on a platform. How do you know the train is not at zero velocity and the earth and tracks and platform are traveling?
Lets flip it and go from her perspective. A woman is sitting in the middle of a train. The ground (including the tracks and platform) appear to be moving at some velocity. Right as she moves past the observer on the platform she sees simultaneous lighting strikes at the front and rear of the train. She is equal distance from both strikes, and saw them both at the same time, therefore she concludes they were simultaneous.
She predicts her friend on the platform will have a different view. Since the strikes happened simultaneously, and equal distance from him, he will continue to travel along with the ground and the tracks, all getting pulled toward the rear of the train. Therefore he will be pulled toward the rear strike and away from the front strike. Therefore he will see the rear strike before the front strike.
Since the woman on the train was at the halfway point between where the strikes occurred, and the light spheres simultaneously hit her, that means she had an absolute zero velocity in space. Since she had a zero velocity in space and the lights hit her at the same time, that can only mean one thing, that the strikes occurred simultaneously, and she is correct to state so. The platform observer failed to acknowledge that the train ise at an absolute zero velocity and the tracks/ground/platform was in relative motion to the train, which means the tracks/ground/platform has an absolute velocity greater than zero. That means since the strikes occurred simultaneously that the radius of the rear light sphere was less than the radius of the front light sphere when they impacted the platform observer at the center position of the platform. So lesson to be learned here, don;t make statements about simultaneity unless you know your frame's absolute velocity. The ol' man made a fool of himself thinking the strikes occurred at different times. He is living in a world of illusions because he doesn't know his absolute velocity and he is making judgements about simultaneity.
You didn't use the same scenario from her perspective you created a different scenario. In the original scenario the woman on the train was struck by the lights at different times. That is reality. She was not struck by the light simultaneously in the original scenario, so it wasn't a change of perspective you illustrated in the "flip," it was a entirely different scenario.
Good, so you understand your mistake. Now do you understand that in the second scenario it is the woman on the train that has the absolute zero velocity and is correct about the simultaneity of the strikes, and the platform observer is clueless as to the simultaneity (or lack thereof) of the strikes? So what you have learned is that it is utterly foolish to make assumptions about the simultaneity of events unless you first know your absolute velocity, because a light sphere is a clock, for all intent and purposes. Furthermore, you've also learned that the relativity of simultaneity is complete nonsense, that it only exists in the mind of people that don't have a clue as to their absolute velocities and make incorrect statements about simultaneity or lack thereof.Yes, the youtube video already showed both POV for the scenario. I presented an entirely different scenario. Who is correct in the second scenario? Did the lighting strikes indeed occur simultaneously? She thinks they did, he thinks they didn't.
EDIT: To clarify what I meant by "Lets flip it and go from her perspective" Is I meant let's pretend we are her, sitting in a train, and we see simultaneous lighting strikes.
Ok so lets go with a third scenario. It combines both of these scenarios. We will call them scenario A (youtube vid) and scenario B (my example).
The train passenger does not know if she is moving, or if the ground is moving. She doesn't know and cannot tell. It appears that the ground is moving past her.
The observer on the platform does not know if he is moving, or if the train is moving. He cannot tell. It appears to him that the train is moving past him though.
I have not made any definite statements about any velocity other than each observer thinks they are at absolute rest.
Train passes observer on platform and scenario A happens. Man on the platform thinks strikes are simultaneous. Woman in train thinks they were not simultaneous.
At this point the platform observer runs faster than the train and stops at the next platform.
Train passes observer on platform and scenario B happens. The woman thinks THESE strikes are simultaneous, and the man thinks they were not.
Which strikes were in fact simultaneous? The first set? or second? Who has the zero velocity reference frame, and why?
In scenario A the embankment observer was at an absolute zero velocity.
Because he was at the midpoint between where the strikes occurred, and the lights hit him at the same time. That means light traveled the same distance to get to him, which means light traveled the same time to get to him, and since the lights hit him simultaneously that means the strikes occurred simultaneously. The only possible way that the embankment observer could have been equal distance from where the strikes occurred, the light traveling the same distance to reach him, and the light hit him at the same time, is that he had an absolute zero velocity in space. Each light sphere had the same radius when they hit him simultaneously.
This is simply Chapter 9 which I mentioned much earlier in this thread. http://www.bartleby.com/173/9.html
Seriously, go back and reread chapter 9. You do not understand what it is saying.