Maths problem

[pErvinalia]

It's not a matter of saying so. It's how the dynamics of sound waves work. So if the clock is open to the surrounding air, then you have to subtract/add the appropriate amount to the speed to determine how long a sound ping will take to traverse the distance between emitter and receiver.

[Brian Peacock]

I have done just that. Surely this is clearly shown by the relative difference in the circle's radiuses (radii?) depending on the angle and the send and return angles displayed on completion? Are you not saying that the a ping returning from a reflector directly behind the clock will return at the speed of sound + the speed of the train even while you acknowledge that the speed of sound is a constant?

[pErvinalia]

Yeah your animation shows it. But you have repeatedly stated that you can't add/subtract (you mistakenly called it "multiplied") the speed of the train from the speed of sound.

A "reflector directly behind the clock" implies to me that the clock is at the back of the train and pointing 180 degrees to the direction of train travel. In that case the return ping will be the speed of sound minus the speed of the train, relative to the clock. It will of course be the constant speed of sound in the frame of the still air.

By the way, my equation that I linked above at the wolphramalpha site was wrong. As usual. I've since corrected it. It's working for the outward journey of the ping. Just need to come up with the algorithm for the return journey and add them together.

[Brian Peacock]

More knitpickery. It doesn't matter if the clock is at the front or the back of the train - one assumes the train is moving in a straight line - if the reflector is directly behind the clock does the speed of the returning ping travel at the speed of sound + the speed of the train or the speed of sound - the speed of the train? I have only ever 'repeatedly stated' that the speed of sound is constant regardless of the speed of the train and that the clock's timing, it's periodic interval or cycle, is a function of the total distance the ping travels from the clock, to reflector, and back to the clock, and that that distance is dependent on the angle of the reflector to the direction of travel: slower as the reflector tends towards +/-0|180° than at +/-90°, which is the shortest possible cycle.

Geometry for the win.

[pErvinalia]

More knitpickery.

Where?

It doesn't matter if the clock is at the front or the back of the train - one assumes the train is moving in a straight line -

Of course it does. If it's at the back then the reflected ping is moving at a slower relative speed towards the emitter than if the clock was at the front of the train.

if the reflector is directly behind the clock

This doesn't even make sense. The reflector is part of the clock. It can't be "behind" the clock.

I have only ever 'repeatedly stated' that the speed of sound is constant regardless of the speed of the train and that the clock's timing, it's periodic interval or cycle, is a function of the total distance the ping travels from the clock, to reflector, and back to the clock, and that that distance is dependent on the angle of the reflector to the direction of travel: slower as the reflector tends towards +/-0|180° than at +/-90°, which is the shortest possible cycle.

That's not anywhere near what you "have only ever 'repeatedly stated'". You've sated reams of nonsense and ignored replies pointing out why it is nonsense in a fashion that would make 42 proud.

[Brian Peacock]

I don't want to fall out with you, and quibbling over simple terminology like 'behind' is as pointless with me as comparing me to people you disfavour. But if you'd been a little more charitable you would have caught my drift ages ago, that Doppler nonsense aside.

[pErvinalia]

Fair enough. But "behind" isn't simple. That's the point. It makes no sense. I'm only trying to work out what you are on about.

[Brian Peacock]

I said 'directly behind', in the sense that someone in the back of a bus who is sitting directly behind the driver is 'directly behind' the driver.

[pErvinalia]

Again, the reflector is part of the clock. How the hell can it be behind itself?!? I suspect all the problems you've had in this thread are possibly due to the fact that you don't have an accurate picture of how such a device would be constructed. Can you describe how you think this device is constructed and operates?

[Brian Peacock]

Yes, the reflector is part of the clock, and the clock is on the train which is also part of the clock, and the train is on the track which is also part of the clock... You know I was talking about the reflector's position relative to the sound source, surely? Construction specifics aren't important - the idea's the thing, so why not stop the quibbling over terms, apply a little charitable imagination, and rather than challenging me to provide design specs - which you'll probably take a pop at for not matching your own conception - how about you just explain what you think is important about the construction, why, and what bearing you think it has on the system?

[pErvinalia]

I've already described how the whole thing would work with two separate constructions. You've barely addressed anything I've said. And I've asked you multiple times to clarify whether your conception of the thought experiment involves the clock open to the air or a closed unit. Why won't you answer this question??

And it's not "quibbling". You have got the basics wrong in this debate time after time after time. It's not unreasonable for me to posit that you don't get how the thought experiment works, as an explanation for why you keep posting stuff that is irrelevant or flat out wrong. Indeed, your first animation in this thread shows that at least then you didn't understand what the concept was that MM was describing. And you've done nothing since to remove any doubt. Yawn is right. Your contributions to this thread have amounted to little more than a pretty animation. If you aren't willing to define the assumptions you are making in your own conceptualisation, then what do you want from me? I've tried to address the best interpretation of what your cobbled together model is trying to convey, but you singularly refuse to address virtually every point I've raised, instead handwaving it away with disingenuous accusations of "nitpicking" or "quibbling". Your model makes no fucking sense. It's not my problem. If you are unwilling to clarify whatever the fuck it is you are trying to convey, then that's your business.

For mine, I'm going to work on an equation to give the answer for every angle in an open-aired clock system.

[pErvinalia]

Yes, the reflector is part of the clock, and the clock is on the train which is also part of the clock,

No it's fucking not.

and the train is on the track which is also part of the clock...

No it's fucking not. What universe are you inhabiting?

You know I was talking about the reflector's position relative to the sound source, surely?

Well that was my first attempt at parsing your word salad, and I described how it would work, and then you accused me of quibbling again, without even addressing what I said.

Construction specifics aren't important

Of course they fucking are. If it's open to the air it will perform TOTALLY DIFFERENTLY to if it was a closed unit.

[pErvinalia]

Jesus Christ! Did 42 take over your account? Does this explain why we haven't seen him (as 42) for a while now?

[Brian Peacock]

God, you've really got one on you today.

[pErvinalia]

Yes, that's right it's my fault you've been repeatedly wrong in this thread, refused to address critiques, and thrown disingenuous refrains around as a means to avoid addressing the problems in your model.