Faster or Slower?

Discussion in 'Physics & Math' started by Motor Daddy, Apr 25, 2022.

  1. James R Just this guy, you know? Staff Member

    You told me:

    Speed of A relative to treadmill = 2 feet/sec.
    Speed of B relative to treadmill = 10 feet/sec.

    The speeds of A and B were both measured in the treadmill frame, there, were they not?

    Why are you saying I'm mixing frames? I just used the treadmill frame - the one you told me about.
    You told me the objects were both moving relative to the treadmill. Is that correct, or not? If not, what were the 2 feet/s and 10 feet/s figures you provided?

    Also, how could the distance between A and B change if neither of them "have a speed"? If you mean to say they are both stationary, with speed zero, then they'll stay the same distance apart at all times, won't they?
    That's what the information you gave me about their speeds relative to the treadmill logically implies!
    10 feet/s minus 8 feet/s = 2 feet/s.

    What's the problem?
    If I stand still on the ground and you run away from me at 2 feet/s, then your speed relative to me is 2 feet/s. I see you moving away from me, and the distance between us increases at 2 feet/s.

    My speed relative to you as you run away from me is also 2 feet/s. You see me moving away from you, and the distance between us increases at 2 feet/s.

    Is there a problem?
    All speeds are relative to something. I may be standing still on the ground, but that doesn't say anything absolute about my speed. It just says my speed is zero relative to the ground. Relative to the Sun, I'm travelling at 30 kilometers per second as I stand still on the ground.

    If you're operating with some crazy notion that you can identify some object in the universe that is absolutely at rest, then why aren't you measuring all speeds relative to that object, rather than talking about the speeds of A and B along a treadmill, and confusing yourself about which one "actually" has the speed?
    Everybody can agree that the car's speed relative to the radar gun was 150 MPH.

    If you want to know the car's speed relative to the Sun instead, the answer is about 30 kilometres per second, plus or minus up to 150 MPH.

    Is there some kind of problem you're having?
    Last edited: May 6, 2022
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  3. Motor Daddy Valued Senior Member


    One more time:

    We are simply talking about closing speed at this point in the discussion.

    There is A and there is B. There is a distance between A and B at t=0. There is a different distance between A and B at a different point in time, which is t=1 second in duration from the start of the time measurement (t=0).

    The distance changed in a duration of 1 second.

    The ONLY thing stated so far is that the distance changed over a duration of time. We are not talking about A or B's speed, we are talking about a distance and a time, that's it.

    The distance changed 8 feet in 1 second.

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  5. James R Just this guy, you know? Staff Member

    Space? I thought it was just you in the box, all by yourself with your ruler and timer. What has space got to do with anything?

    Tell me why the speed of light is different in different directions inside your box.
    Okay. So you have a thought experiment with you in a box in a Newtonian universe in which there's a preferred reference frame that you call "space". Light travels at the same speed in all directions relative to "space", I assume, in your imaginary universe. Moreover, in your imaginary universe, there is universal time and no relativistic effects.

    This would certainly explain why light did not reach both detectors simultaneously inside the box. The box is not stationary with respect to "space", so the apparent speed of light that you measure inside your box will be different in different directions.
    Fine. All good.

    This is all consistent for your toy universe with its absolute reference frame and universal time. I'm happy to tell you there is nothing wrong with your conclusions for this hypothetical universe of yours.

    Are there any remaining issues you'd like to discuss with me?
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  7. James R Just this guy, you know? Staff Member

    Yes. That all sounds fine.

    Anything else I can help you with?
  8. Motor Daddy Valued Senior Member

    GOOD! So you acknowledge that there is no length contraction or time dilation according to my measured distance and times in the box.

    So you agree with my ruler and clock, and that the box is traveling in space a distance per duration of time, and that light travels independently of the box.

    So then you come along and try to tell me that my clock is wrong, my ruler is wrong, and that the box is not moving in space? You are trying to tell me that the light hit all the receivers at the same time in my box?

    Then you go on to tell me my box is not a cube, that it is taller than long?

    Then you claim my clock is ticking at a different rate because my box is moving in space.

    ...and then you wonder why I claim length contraction, time dilation, and relativity of simultaneity is BS, and that Einstein was a CRANK???

    Do you really wonder why I think he was a CRANK? Look no further than the wiki link on Fudge Factor for more proof that he was a CRANK that FUDGED stuff to get an outcome that he desired!
  9. Motor Daddy Valued Senior Member

    Good, so you agree that the distance increased 8 feet in 1 second.

    So you agree that in EVERY FRAME that distance increased 8 feet in 1 second?
  10. James R Just this guy, you know? Staff Member

    My mistake. I was assuming you wanted to talk about what would happen in our real universe. In reality, our universe obeys the laws of relativity, not Newtonian absolutism. If you're only concerned about your imaginary toy universe, there's no issue.
    You've heard of length contraction, right? I agree that there is no length contraction in an imaginary Newtonian universe.
    No, relativity doesn't say anything about clocks ticking at different rates due to something to do with "space". It just says that observers who are in relative motion will each observe the other's clocks to be ticking slower than their own.
    I do wonder why you claim those things, because so far you have done nothing to show that anything in relativity is BS or that Einstein was a crank. Do you think you've disproven relativity, somehow, by making some faulty assumptions about a thought experiment? Let's face it: you don't even understand relativity. How could you possibly start to try to disprove it?
    Nah. I'm not going to chase down another crackpot who thinks for some reason that he has proven Einstein wrong and made a web page about it.

    Even if, miraculously, it were to turn out that Einstein was stark raving mad, that wouldn't alter the fact that his theory of relativity has been found to accurately describe reality in experiments conducted for 100+ years. Ad hominem attacks on Einstein can't change that.
  11. James R Just this guy, you know? Staff Member

    Everyone in every frame can agree that the speed of A relative to B was 8 feet/s, if that's what you mean.
  12. Motor Daddy Valued Senior Member

    In my box? NO! I have one ruler, and it fits perfectly between the center of the box and each receiver. They are exactly the same distance to the center.

    For you to claim that distance is different is a CRANK CLAIM, because I know for a FACT that in reality the distance is exactly the same.

    What you are claiming is that the box can be different dimensions in reality because your clock messes up at high velocity.

    Your clock changing rate does not mean that my box changed size! The distance is THE SAME from center to each receiver, and you traveling real fast past my box does not change that FACT!
  13. Motor Daddy Valued Senior Member

    Good, so we all agree what 8 feet means, and we all agree what 1 second is. We all have the same clocks and the same rulers, and they all measure the EXACT SAME THING!

    So where is your "length contraction"?

    If I travel at .866c past A and B, do I measure the distance between A and B to change at a rate of 8 feet per second?
  14. James R Just this guy, you know? Staff Member

    Obviously not in your box, in your imaginary Newtonian universe.
    That's all fine, even in the real world. The ruler in the box won't stop fitting perfectly just because the box moves.
    Which distance? Measured by whom? In which frame? How do you know?
    No. I haven't mentioned different dimensions.
    Well, the two things do sort of go together, in reality. But you needn't worry about it, if you're only doing hypothetical drawings in an imaginary toy universe.
    You failed to specify a reference frame, again. As a result, you're half right and half wrong. Try to be more careful in future.

    Your attempts to bluster your way through this by a process of argument by assertion are entertaining enough, but they aren't really getting you anywhere, in terms of making an actual argument against relativity. You do realise that, don't you? The force of your outrage can't win this for argument you, on its own. You'll need to bring some real-world evidence or something if you want to disprove relativity.

    Another approach, which doesn't require you to do any actual experiments, would be for you to try to show that relativity is not consistent within itself. For example, you could try to show that relativity contradicts itself somehow. Good luck with that, if you want to go down that path. Many have tried, none have succeeded so far, but maybe you'll be the first! If you are going to go down that path, however, make sure that you understand the theory you're trying to bring down, first. Otherwise, you might end up looking like a bit of fool.
  15. James R Just this guy, you know? Staff Member

    Bear in mind that different measurements of distance and time can end up with the same speed value. 16 feet/2 seconds is the same speed as 8 feet/1 second or 4 feet per 0.5 seconds.
    Length contraction is an effect whereby "moving rulers appear shorter" to those who are watching them move past, roughly speaking. If length contraction was not real, many other results in relativity would not hold. But, like I said, relativity has been overwhelmingly supported by real-world experiments for 100+ years now.
    In your imaginary Newtonian universe, yes.
    In the real, relativistic universe, no.
  16. Motor Daddy Valued Senior Member

    My intentions are not to disprove relativity. That would be like trying to disprove religion. That's just a waste of time. I'm not that motivated and I couldn't care less if people to continue to believe in BS.

    I am merely showing you WHY it's wrong. I am not going to write a paper and submit it. I am not gonna make a YouTube video. I am not going to make a movie. I am simply trying to show you the error of your ways.
    If you refuse to acknowledge what I am saying, and continue to believe Einstein's madness, more power to you. Don't expect me to go along with the BS when I see it.

    I specifically claim that the second postulate is BS, and I presented my proof. "You can lead a horse to water but you can't make him drink."
  17. Motor Daddy Valued Senior Member

    The distance is 8 feet and the time is 1 second.

    Sure you can do some math and claim that is 16 feet in 2 seconds, but we both know that is a measured 8 feet in a measured 1 second in reality, right? 2 seconds did not elapse, and the distance did not increase 16 feet.

    I measure a distance of 100 miles and a time of 1 hour and you claim that is only 10 miles in 6 minutes??? So you think I drove 10 miles in 6 minutes when in reality I drove 100 miles in 1 hour?

    Your math tricks are not reality. IN REALITY I drove 100 miles in 1 hour of time. To claim that I only drove 10 miles is ABSURD! You know how far a mile is, right? I drove 100 of them, not 10 of them.
    Last edited: May 6, 2022
  18. James R Just this guy, you know? Staff Member

    For you, maybe. Scientists and mathematicians tend to go about disproving things in rather more rigorous way. Argument by repeated assertion, for example, doesn't count for much in science or mathematics.
    Well, you had me fooled. All that time you've spent coming up with and posting scenarios that you think disprove relativity (or, at least, show that it is absurd, to your way of thinking). All the time spent arguing about it and railing against it on this forum. And now you want us all to believe that you don't really care. Okay. Whatever you say, I guess. I'm skeptical.
    No. You've never shown why its wrong.

    All you have shown is that if you throw out the postulates of special relativity and imagine a hypothetical world in which they do not apply, then you can arrive at different results than the theory of relativity would predict for various thought experiments. That does nothing to show that relativity is wrong.

    It's like me imagining a world in which pigs have wings. Then I construct a thought experiment in which a pig has to reach some cheese on a high shelf in the kitchen. You say the pig can't get the cheese. I say it can, and I show you how it can flap its wings and fly up to the cheese, in a clever thought experiment of my own devising. You complain that pigs don't have wings in the real world, and I tell you that I think the idea that pigs don't have wings is BS concocted by some mad guy that you all like to follow, for some unknown reason. I tell you that anybody who claims pigs don't actually have wings is a crank, and my thought experiment with the cheese proves it.

    Can you see the problem with your approach?
    I have acknowledged everything you have said, and have even agreed with parts of it.

    I don't expect you'll play along with relativity. That would require some expenditure of effort on your part, to learn about the theory. But you've had more than 10 years to do that, and it seems clear that you've done nothing useful in that time (regarding this). I don't expect you to suddenly turn over a new leaf and become open to new ideas or to be suddenly willing to look at the theory with an open mind. You seem very set in your ways.
    What you presented doesn't come close to being a disproof of the postulate that the speed of light is constant in all inertial frames.

    Your supposed "proof" merely begs the question. You start by assuming that the postulate does not hold, then derive some consequences for your thought experiment, based on that assumption. Which would be fine, if you then went on to test your predictions in a real-world experiment. But, of course, you'll never do that, so you'll never find the definitive proof that your assumption was wrong and your "proof" amounts to no more than "garbage in, garbage out".

    Look, don't worry about it. It's all good. You had 10 years to come up with something new and useful, and you failed to do either. No skin off your nose, though. It's not like you care about trying to convince anybody that you're right. Right? Yourself included, it seems.
  19. James R Just this guy, you know? Staff Member

    Who measured the 100 miles? Who timed the hour?

    While you keep ignoring such questions, or just assuming without justification that it doesn't matter, you'll keep making the same stupid mistake, over and over.
    100+ years of experiments say the opposite. Too bad for you!
    Apparently, the university doesn't give a damn about whether you think it is absurd.
    It's fine. Don't let it hurt your head. Relax.
  20. Motor Daddy Valued Senior Member

    The distance between the center of a circle to the outer boundary is the radius. I don't need to tell you how much distance that is, all I have to do is take a stick the same length of that radius, and move it around in different directions from center to edge. I can do that in any direction and the distance is the same.

    You come along and try to tell me that in one direction the distance is shorter. I show you that the stick fits perfectly in all directions. You claim that isn't the real world, that there is such a thing as length contraction.

    I scratch my head for a while, and then reply to you, BS!
  21. Motor Daddy Valued Senior Member

    I did! I invented a unit of measure called a mile. I made a stick the length of that mile. I laid 100 of those sticks end to end, and that is 100 miles.

    You come along and tell me that is only 10 miles.

    I lay 100 mile long sticks end to end and show you that is 100 mile long sticks, not 10 mile long sticks.

    You continue to claim there are only 10 sticks, even when shown to be 100 of them. Count them yourself, there is 100 of them!

    What you are claiming is that my 100 apples are only 10 apples. You DO NOT know how to count!
  22. billvon Valued Senior Member

    And in fact has been for years.

    But fear not. In another few posts he will say something like "You claim my car is going backwards when it is going forwards. You do not understand math!"
  23. exchemist Valued Senior Member

    We're at page 6 I see. Only 9 to go before we match his previous record for posting shit: The Motor Boat.

    There's a chance we could get there, if everyone makes an effort to feed the troll.

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