The Swing of a Pendulum

Motor Daddy said:
In the end all that matters is that I understand it. It would be nice if everyone understood and agreed with it, but that is not gonna happen. I understand it and that is the important thing. I tried to teach people but they didn't listen. Oh well, I tried and I'll keep trying.
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Actually, I listened. What I tried to establish is whether or not your worldview was falsifiable; I cannot remember the issue but I do remember that there was one. Most people here just read "absolute velocity...oh Motor Daddy is a CRANK!" but you had some defenses for it which I had not seen before (such as explaining redshift by counting the waves, using the baseball analogy). If you worked on a mathematical formalism for your worldview I suspect you'd get more interest in it, and possibly discover where the problem lies on your own.
 
Say one car was traveling 20m/s faster than the other car. Then they both accelerate about the same amount. The pendelum would swing at the same rate in both cars. This is because there is no absolute frame of reference. You can't know which one is really going faster, so then the force of acceleration would be the same for the car going 0 m/s relative to the Earth and 20 m/s relative to the Earth. To say otherwise implies an absolute frame of reference. You would have to know that one was actually going faster so then it would feel more force from the same acceleration, this is not what happens.

It just seems like it is harder to accelerate in a car because the wheels just have to spin faster relative to the ground that stays at the same speed. So it is just harder to get the wheels going a faster speed on the ground that doesn't change speeds with the car.
 
Motor Daddy said:
That's what I said, the only thing you have is the relative velocity between the two rockets. That is one velocity not two.
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Sorry, then I misunderstood. With your mention of 40 m/s and 60 m/s it sounded like you were saying there had to be an absolute velocity. I agree that the relative velocity is all you have.
 
Motor Daddy said:
How would you know that without an absolute velocity?
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The difference between the speed of the two cars would be 20 m/s relative to each other. I don't think the term absolute velocity has even been defined or exist.

If I was to guess I would say it was alphanumerics Ph.D. view of acceleration, where objects that are moving faster then feel a greater force of acceleration even though they are accelerating at the same rate. The absolute velocity would then the velocity something traveled without any extra forces of acceleration felt. That is a totally bogus viewpoint because there is not supposed to be a absolute frame of reference. He must have used his commen sense instead of just his maths to figure this. Good indication he should stick with just doing the math.
 
billvon said:
Sorry, then I misunderstood. With your mention of 40 m/s and 60 m/s it sounded like you were saying there had to be an absolute velocity. I agree that the relative velocity is all you have.
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Ok, so back to square one, how do you know that one rocket is moving 20 m/s faster than the other rocket, when there is only one velocity?
 
Prof.Layman said:
If I was to guess I would say it was alphanumerics Ph.D. view of acceleration, where objects that are moving faster then feel a greater force of acceleration even though they are accelerating at the same rate. The absolute velocity would then the velocity something traveled without any extra forces of acceleration felt. That is a totally bogus viewpoint because there is not supposed to be a absolute frame of reference.
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Lousey guess, but then not surprising.

I can't see how you get anything like this from AN's posts.
 
Motor Daddy said:
Ok, so back to square one, how do you know that one rocket is moving 20 faster than the other when all there is is one velocity?
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The one velocity is 20 m/s. The second rocket can observe the motion of the first rocket, and it is 20 m/s.
 
For that matter, the first rocket can observe the second rocket, and see a velocity difference of 20 m/s. That's the one velocity, the RELATIVE velocity between the two rockets.
 
Motor Daddy said:
Right, so how does the "one rocket is 20 m/s faster than the other rocket" come into play?
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One rocket can look at the other rocket and see a difference of 20 m/s. What is it about this you don't understand?
 
Why. One rocket moves away from the other rocket at 20 m/s. That's the one velocity. What would the other velocity be?
 
AlexG said:
Why. One rocket moves away from the other rocket at 20 m/s. That's the one velocity. What would the other velocity be?
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The relative velocity is 20 m/s. How does the "20 m/s faster" come into play? Is it 100 m/s-80 m/s? Is it 392 m/s 372m/s?? What are the two velocities of the two cars?? There must be two different velocities if one car is 20 m/s faster than the other car!!
 
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