Split Thread The validity of classical physics (split from: DWFTTW)

[spacediver]

If it moves in a circle is it moving? That implies acceleration, and Einstein says that can be detected. Good grief Spacediver. The way you evade, tells me that you do understand what I mean!

Yes, "it's just something you simply pasted..." . That is the problem. These are "soundbites" not the complete idea. Do you think that Huygens knew of relativity or General Relativity?

If it's moving in a circle, it does not have a constant velocity, so of course you can tell the direction of motion over time.

Feynman was talking about a moving system at a constant velocity, not an accelerating system.

If two hobos each wake up in two different box cars, and one is moving with respect to the earth and the other is stationary, there will be absolutely no difference to be found in the motion of objects which are tossed inside each of them.

Do you disagree with this last paragraph?

 

[spork]

So now humber claims that he has offered experiments that can tell the difference between real wind and treadmill wind, but he won't even tell us what those experiments are or where he posted them.

 

[humb]

You may argue, as you have, that the ground does not matter, but when the policeman with his doppler radar gives you a ticket, the clerk-magistrate is not going to care about your assertions of "equivalence". Just because the police car was also in motion does not mean that since you were going only 20 mph faster, you were not speeding. Mark my words! Because the laminar flow under your car will give you away, even if you were traveling the other direction. And if you were, it would be even worse unless you were in the opposite lane! Mothersbaugh and Casale will crawl right back into their hijacked shells and not come to your pitiful defense. Evolving up from little snails indeed! More like larceny!

What does the hobo know? Even a hobo may have GPS, particularly if he has committed a crime and is being tracked by those self-same police. His ankle bracelet will reveal his true velocity.

I have repeatedly shown that it is so, and yet you continue to refuse to retaliate my assertion of the demonstrable non-equivalence. Feynman does not argue with Galileo, and one Greek is not another. When the wind is from the south, I know Archimedes from Aristotle. ("A-A-A, what begins with A?") Would Einstein have dropped two stones from the tower? Ridiculous! He had only one stone!

 

[humber]

If it's moving in a circle, it does not have a constant velocity, so of course you can tell the direction of motion over time.

Feynman was talking about a moving system at a constant velocity, not an accelerating system.

I think is rather the case that you assumed Feynman ws talking about linear motion. You "forgot" about the other possibility.
I am not chasing that point, per se, but to ask why you would offer is as a point. Please understand that I am not interested in that parlour games, I have said that. Spacediver. For me, it is about the way you equate that hobo to the treadmill.

If two hobos each wake up in two different box cars, and one is moving with respect to the earth and the other is stationary, there will be absolutely no difference to be found in the motion of objects which are tossed inside each of them.

Well, if, I suppose, and then again, so what? I am not being sarcastic. I have no idea why you value this attribute of "can't tell". I "get" it, but I think it is inane.

Do you disagree with this last paragraph?

I don't think that will go anywhere, Spacediver. Let me ask you something

You are driving in your car, and you put your hand out of the window and feel the air. The speedometer says 50kph. You now arrange a fan or some other device to slow the wind passing over your window. If you now put your hand out and "feel" 10kph, do you ignore your speedometer and the car ahead as evidence to the contrary?
If you now shut out that information, do you believe the wind? Perhaps if you knew of the fan, no, but if it were to be done without you "knowing" it, would you then believe it, and of what use would that be?

Here is what I think you are supporting. The idea of the "windspeed" cart is born, along with the zero wind. This is conjectured to be the result of the belt. This is supported by appeals to equivalence, allowing the construction of a "hobo". The cart on the treadmill, is then argued from that hobo, rather than from the cart?

 

[humber]

So now humber claims that he has offered experiments that can tell the difference between real wind and treadmill wind, but he won't even tell us what those experiments are or where he posted them.

I can feel the difference in "laminar flow" with my hand. The laminar flow is there, even if the "wind" is not. If the still air is the "wind", then what is the "wind" generated by motion with the belt. Three "winds" I think.

 

[Dan O.]

Humber is now on Ignore again.
Since he doesn't want my help, I shall no longer waste my time trying to help. And since this thread is only about humber, I have no reason to continue reading this thread. I'll see you all (except humber) on the other threads.

PS: I was going to leave humber a final comment but it's not worth the effort. Let him forever remain the self centered, virtual personality that he is.

Edit to define terms used in the last statement:

self centered - not the dictionary definition but that humber cannot transpose his perception to another frame of reference. There is probably a more appropriate medical term for this.

ignorant - The dictonary definition: lacking knowledge or awareness in general. Since humber may have some knowledge, this isn't the right word but I can't seem to find the right word for someone with specific holes in their knowledge and understanding.

virtual personality - Aren't we all when online. but more so for trolls.
​

 

[spacediver]

Please understand that I am not interested in that parlour games, I have said that. Spacediver. For me, it is about the way you equate that hobo to the treadmill.

When the hell have I ever talked about treadmills? I don't even understand the down wind devices and treadmills - i'm only interested in basic physics here. Again, stop putting words into my mouth.

Humber, I challenge you to dig up ONE quote where I've talked about treadmills.

Here is what I think you are supporting. The idea of the "windspeed" cart is born, along with the zero wind. This is conjectured to be the result of the belt. This is supported by appeals to equivalence, allowing the construction of a "hobo". The cart on the treadmill, is then argued from that hobo, rather than from the cart?

again, I'm not in a position to comment on treadmills and equivalence - i'll leave that to spork and the others. I'd appreciate it if you addressed my concerns independently of your obsession of proving that the treadmill fails equivalence. I'm not at all interested in that since I haven't been following that part of the discussion.

 

[Subduction Zone]

I can feel the difference in "laminar flow" with my hand. The laminar flow is there, even if the "wind" is not. If the still air is the "wind", then what is the "wind" generated by motion with the belt. Three "winds" I think.

Amazing humber has the most sensitive hands in the world. He cant tell the difference in laminar flow between the treadmill and the wind You would have a tough time measuring the difference with most lab equipment and yet humber can do it with his bare hand.

 

[spork]

I can feel the difference in "laminar flow" with my hand.

That's not even a sentence. You can feel the difference between laminar flow and WHAT?

The laminar flow is there, even if the "wind" is not.

I'll bet in your mind that means something - or at least it might have while you were writing it.

If the still air is the "wind", then what is the "wind" generated by motion with the belt.

The gradient or boundary layer.

So still you've failed to even tell us what you CLAIM the difference is. You simply say: I can feel the difference between "A".

Seek help.

 

[ArmillarySphere]

The trouble is that humber's idea about how the world work is pure armchair physics. It is flatly in opposition to what the real world is like, so it is completely useless to try to use real-world facts to describe why his physics are wrong. Humber doesn't just disagree with the theory, he disagrees with the facts.

1) Humber thinks that a canoe leaves a bow-wave when it's floating idly down a river
2) Humber thinks a balloon travels at less than the average speed of the wind
3) Humber thinks he would feel the wind going forwards near the ground when sitting in the cart at windspeed on a road, but backwards when on a cart on a belt.

All these three ideas are in contradiction with reality.
But as someone here likes to quote:
"You're entitled to your own opinion. You aren't entitled to your own facts."

 

[humber]

Humber is now on Ignore again.
Since he doesn't want my help, I shall no longer waste my time trying to help. And since this thread is only about humber, I have no reason to continue reading this thread. I'll see you all (except humber) on the other threads.

That's a very elaborate way of saying 'you are right humber'. The erroneous vectorial translation I mentioned. The cart should be going the other way!

PS: I was going to leave humber a final comment but it's not worth the effort. Let him forever remain the self centered, virtual personality that he is.

That remark leads me to believe that your final comment may not have been too helpful

self centered - not the dictionary definition but that humber cannot transpose his perception to another frame of reference. There is probably a more appropriate medical term for this.

ignorant - The dictonary definition: lacking knowledge or awareness in general. Since humber may have some knowledge, this isn't the right word but I can't seem to find the right word for someone with specific holes in their knowledge and understanding.

virtual personality - Aren't we all when online. but more so for trolls.
[/INDENT][/SIZE][/invisible]

girly-man (noun) -

 

[Clive]

"What is the difference between a duck?"

Is this relevant? Well, one of the more reasonable sounding responses that I've heard to this tricky little question is: "One of its legs is both the same". So, if we can find a way to map this back to the laminar flow, then perhaps some light may be shed on what that was all about.

In any case the question reminds me of a nice quote that I came across not long ago...

"He may look like an idiot and talk like an idiot but don't let that fool you. He really is an idiot."
- Groucho Marx

 

[Modified]

You may argue, as you have, that the ground does not matter, but when the policeman with his doppler radar gives you a ticket, the clerk-magistrate is not going to care about your assertions of "equivalence".

You are utterly and completely wrong. Obviously, you have no idea how police radar works. It measures the speed of the target relative to the device, and the speed of the ground relative to the device, and uses both to compute the upper bound of the possible speed of the target relative to the ground.

Please do a Google search for 'police radar "relative speed"' and read some of the results to correct your misunderstanding. For example: http://www.copradar.com/preview/chapt4/ch4d1.html

 

[humber]

The trouble is that humber's idea about how the world work is pure armchair physics

I flatly deny that. It is garden shed physics.

It is flatly in opposition to what the real world is like, so it is completely useless to try to use real-world facts to describe why his physics are wrong. Humber doesn't just disagree with the theory, he disagrees with the facts.

I do sometimes find facts to be disagreeable.

1) Humber thinks that a canoe leaves a bow-wave when it's floating idly down a river

Please state why not.

2) Humber thinks a balloon travels at less than the average speed of the wind

Humber knows that some people are loose with their terminology. What is the crest factor of that mean?

3) Humber thinks he would feel the wind going forwards near the ground when sitting in the cart at windspeed on a road, but backwards when on a cart on a belt.

Yes. I do believe that is one of the actual differences between real and treadmill.

All these three ideas are in contradiction with reality.
But as someone here likes to quote:
"You're entitled to your own opinion. You aren't entitled to your own facts."

I happen to think that nobody is "entitled" to anything.

 

[John Freestone]

No, that is not correct, John. Your conclusion is the same failure to recognize the nature of flow. Flow has a past and future. The treadmill is a tiny slice of time, and so does not stand scrutiny in that regard. If you were in a car, couldn't you use radar to look ahead of the car in a way that would leave you in do doubt as to which way the flows were going? Doppler radar is used to determine turbulence ahead of aircraft, you know.

"Can't tell" is not seen as a simple statement of fact, or lack of information, but a feature. Wouldn't it be possible to construct a simple air ram so that external air is forced past the observer, so as to make him think that the air is going in the direction of your choice? It's ludicrous.
I doubt that this is what Feynman had in mind.

Which bit of that makes it alright that you measured the wind in the wrong frame of reference, after 'ungluing' your feet from the treadmill belt?

Maybe the 'some reason', is the reason.

Oh we're just hanging on that possibility now, sure, that after 1000 posts and an incredible array of wrong reasons, you've got a mystery right one yet to come. Brilliant.

QED

The thing is, you're supposed to put QED after you demonstrate something logically, not write it next to your answer and back-fill with drivel.

 

[humb]

Originally Posted by humbYou may argue, as you have, that the ground does not matter, but when the policeman with his doppler radar gives you a ticket, the clerk-magistrate is not going to care about your assertions of "equivalence".

You are utterly and completely wrong. [...]
Please do a Google search for 'police radar "relative speed"' and read some of the results to correct your misunderstanding.

Why would I want to do something like that?

 

[John Freestone]

Oh to hell with it.

 

[humber]

"What is the difference between a duck?"

Is this relevant? Well, one of the more reasonable sounding responses that I've heard to this tricky little question is: "One of its legs is both the same". So, if we can find a way to map this back to the laminar flow, then perhaps some light may be shed on what that was all about.
In any case the question reminds me of a nice quote that I came across not long ago...

"He may look like an idiot and talk like an idiot but don't let that fool you. He really is an idiot."
- Groucho Marx

I have another one, Clive. 'What is the difference between a Raven and a Writing Desk?

Anyway,the laminar flow is different in each case, Clive. It is an indicator that something is wrong. Here we go.

Take the F1/BMW wind tunnel. This is a correct model, that uses real wind. The car is also artificially stabilized.
A typical application would be to test the car for 100kph on the road, in still air. This is simulated by the wind from that big fan, blowing as a headwind. The belt could be off, as this is normally an adequate simulation. In F1, they are also looking to simulate the road as the car passes over it. This they do by running the belt backwards.
Ignoring the laminar flow, this arrangement has the correct attributes and relative velocities. Note, though, that the belt speed is not actually physically related to the wind, but only by the calculation. The operator may change that as desired. This may lead to situations where the belt is going faster than the wind, or numerous other combinations. The beltspeed, and so the model, is only correct for one value, that of the speed of the wind.
This means that the beltspeed must follow the wind's speed. If you reduce the wind, you reduce the beltspeed and so on, until zero. That is correct, zero wind, belt off.
Now, what you cannot do, is turn on the belt in still air, and equate that to motion on the road in reality. That is no more than a careless operator may do, but with the wind off. There is no causal relationship between the wind and the belt. It is "really" the road, but is artificially contrived, because for one thing, the car is not moving.
(Also, to make the model good, the wind must have the power, not the belt.)
The same reasoning goes for tailwinds.

If you think of the erroneous beltspeed as a 'reversal', then things become right again, but this means driving up (with) the belt, not against it.
The current problem is that everything; velocity, KE, "wind",force, is backwards, except the cart. That's why the (belt) laminar flow is wrong. It's the one thing relative to the belt, that cannot be metaphorically reversed.

There is a definite difference in the lamina flow in wind and on the treadmill.
The general flow is opposite to the tailwind. If you imagine that you are being dragged back with the belt "wind on back" then yes, you will get a laminar flow coming from behind you, but there is also one coming towards you from the belt, dragged by the belt, towards you. This looks OK, but if you move up the belt, then you will see the relationship of the two laminar flows will change. A hand placed across the belt tells you that this is not the laminar flow of tailwind, but another spurious wind, that is also there if there is nothing on the belt to create the "pushing wind".

If you could run with the belt, (or stand on the belt) and so create your own 'headwind' then the laminar flow from the belt will match up. The mirror is complete.

That the power from the wind comes from the belt, explains the remainder.

 

[humber]

You are utterly and completely wrong. Obviously, you have no idea how police radar works. It measures the speed of the target relative to the device, and the speed of the ground relative to the device, and uses both to compute the upper bound of the possible speed of the target relative to the ground.

Please do a Google search for 'police radar "relative speed"' and read some of the results to correct your misunderstanding. For example: http://www.copradar.com/preview/chapt4/ch4d1.html

Police guns uses the Doppler shift between the gun and the target. Yes. That target can be air mass. There are also Doppler laser devices that can measure real-time flow even in bad conditions.
Ultrasonics could work, I suppose. It's the principle that matters. That the difference not only exists, but can be detected.
Still, a hand across the belt tells you this is not the laminar flow of the tailwind, but of the belt. That is different. Real wind does not have two sorts of laminar flow.

 

[humb]

When the cart he is to the area, if wheels to key have been closed, he will put himself to the back in functioning to and he will feel himself tailwind. S/he leads to front with the speed of the area, nobody will ventilate himself to feel. This is exactly analogous to the travel to the speed of wind. The consequence of the area, or the way, to the air himself and in both cases are such as he are predominated of the cart.