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

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How right you were. I guess that's why he can't tell me which direction the wind moves relative to my little man on a treadmill. It must depend where each molecule has been throughout its entire history. We can't discern the velocity of anything with a mere instrument, we have to ask the object where it was created and what has happened to it since.

Don't put your little man on the treadmill, John

As, I suggested, the history is metaphorical, it is how the object got to be there. How else? This contrasts with your ideas that things need to be kept in frames, or they will run wild. Nothing happens until some thing acts upon it. As far as the molecules go, I was not suggesting some strict from of determinism.
 
This reminds me of Humber, for some reason.

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I wrote up a short paper on basic newtonian physics. It's about 50 pages long. I ended up writing it all up after trying to remember all my basic college physics stuff while trying to deal with the DDFTTW thingy.

Go to my website and replace "tumbleweed" with "newton" and you'll be there. Most of it is basic units stuff, but there is a page or so about inertial frames.
 
I ended up writing it all up after trying to remember all my basic college physics stuff while trying to deal with the DDFTTW thingy.

What you mean is you had to go re-study up on all the basic college physics stuff you got wrong the first times -- those times you called us frauds and perveyers of perpetual motion etc. The time you produced this document?

(Yeah, we know you deleted that document from your website in embarassment after we tested the device you designed and proved it to actually BE a fraud, but we saved it just so we could roll it out as you go around peddling more of your wrongness)

For history buffs, Greg called us every name in the book over on BoingBoing for hundreds of posts and then produced his above linked document *proving* that we didn't know what the heck we were talking about and show how easy it was to design a DDWFTTW device with no moving parts (show pics and all in his .pdf).

Of course there was absolutely no need whatsoever to test it as he understood it perfectly and his line of work requires "scientific rigor or people die". Well, we just had to build it and show that not only did it not work, but that for it to work it would have to defy the laws of physics (just the thing he accused us of).

The test:
http://www.youtube.com/watch?v=axoflkkwwyI

Needless to say, we don't sit on our hands when Greg decides he wishes to explain DDWFTTW to the world. And yes, his current documents are absolutely riddled with wrongness.

JB
 
humber, with 2000 posts, there's no way I"m catching up. Is your issue with the treadmill tied to whether the propeller cart can go DDFTTW? Or do you believe the cart works, and the issue with the treadmill is a tangential discussion?
 
humber, with 2000 posts, there's no way I"m catching up. Is your issue with the treadmill tied to whether the propeller cart can go DDFTTW? Or do you believe the cart works, and the issue with the treadmill is a tangential discussion?
In Humber's absence, let me try a very quick summary of his position for you Greg:

"A belt is not a road."

Expanding on that slightly, I understand that Humber has said he doesn't have any problems with the general concept of a vehicle travelling directly downwind faster than the wind, although he may think that a steady state situation is problematic, and I'm pretty sure he has also said that the spork/JB cart is not one of the vehicles that could actually achieve DDFTTW. I don't recall hearing his views on your tumbleweed device.

But the really big issue is that he doesn't agree that testing/demonstrating the cart on the treadmill can be said to be equivalent to the cart running downwind over a real road at the same speed as the "real wind". This is nothing to do with anybody faking videos, just the physics. From memory, for the last 1500 posts or so the main topic has been something to do with which direction some parts of the boundary layer above the belt of the treadmill may moving relative to the belt, and how that could differ from the situation with "real wind" moving over a road. Once that is resolved, I suppose it is possible the "discussion" may move on to whether this boundary layer actually has any significant effect on the cart's behaviour or not. At this point I really wouldn't like to estimate how many thousands of posts that might consume.

Hmmm. Maybe I am exaggerating slightly, because I've just recalled that a decent chunk of the last 1500 posts might have been more about a hobo in a boxcar and whether he could tell whether he was "moving", and whether that was to the left, or clockwise. What is really needed (hint!) is for someone to create a giant map and index so newcomers to this interesting place can explore more easily. Don't forget to read the even longer parent thread! Much important background information and earlier discussions are only to be found there.

Possibly the best place for you to start (if you don't mind me making a suggestion) would be by posting your thoughts on the validity or otherwise of using the treadmill (as shown in the spork/JB videos on youtube) to test/demonstrate the cart's behaviour when it is moving directly downwind at the same speed as the wind (or very close to it).

Oh, last thought, in some other tangential discussion I think it was also established that "a kite is not a treadmill". I can't remember if Humber actually agreed with that, but Humb probably did.
 
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Let me post a better summary:

This thread isn't really about DDWFTTW, that was covered elsewhere, and this thread was split off because the discussion was degenerating to humber's ludicrous misuse of basic scientific principles and language. So we all retired over here to occasionally delude ourselves into thinking that we can get through to humber, but usually we just wait for him to outdo himself in terms of how preposterous a post he can make, and then we quote it in our signature lines (which I haven't bothered to figure out how to do). It would be a far more productive use of your time to read all of the preceding posts for purposes of amusement than it would be to waste your time trying to make a reasonable argument that he'll pay any attention to. There's plenty of goofy stuff there, and if you do want to stick around for more of the show, you'll probably want to have the background. Don't worry if it takes a while to catch up, there isn't any progress that's going to be made here any time soon.

(And I'd say ThinAirDesigns is quite justified in feeling the way he does after the situation you caused back on BoingBoing, Greg.)
 
Clive, thanks for the summarization.

he doesn't agree that testing/demonstrating the cart on the treadmill can be said to be equivalent to the cart running downwind over a real road at the same speed as the "real wind". This is nothing to do with anybody faking videos, just the physics.

Hm. Guess I don't know where he's stuck.

There's a really great video that shows the cart as a "gear" between air and ground and then shows that it doesn't matter if you move the "air" or move the "ground", the cart moves the same. Someone posted this, I assume. It's really, really straightforward. and shows different inertial frames.

I'll send it to you in a private message if I can. I can't seem to post URL's yet.

the boundary layer above the belt of the treadmill may moving relative to the belt

hm. Dunno bout that one. I suppose one could argue that a wind tunnel used for automobile design isn't accurate if it has a stationary floor, that the floor should move at the same speed as the wind so that any "boundary layer" between the ground and air shows up in the currents. Or that it isn't accurate if the wheels on the car dont turn. I suppose that might be technically correct, but I don't think that dismisses the entire results of a wind tunnel though.


Possibly the best place for you to start would be posting your thoughts on the validity or otherwise of using the treadmill

I think a treadmill is good enough, like the video I linked to above, the concept of the propeller cart is that it acts like a "gear" betwen the air and ground, so it doesn't matter if the "air" or the "ground" moves, the cart always moves the same.

the speed of the cart is some function of the difference between the speed of the "air" and the speed of teh "ground", that function determined by the gear ratio. And it doesn't matter if you move the groudn or move the air, the difference between them is what determines the speed of the cart.
 
Don't put your little man on the treadmill, John

As, I suggested, the history is metaphorical, it is how the object got to be there. How else? This contrasts with your ideas that things need to be kept in frames, or they will run wild. Nothing happens until some thing acts upon it. As far as the molecules go, I was not suggesting some strict from of determinism.

Yes, the history is metaphorical, I see. Yes, also, there's no need to keep everything in frames so it doesn't run wild. Things do what they do.

We can perhaps forget inertial frames of reference for now. Please, also forget the DDWFTTW cart for now, and help me understand what you are saying, one last time. I presented the idea of just a person on the ground, then on a treadmill precisely so we could forget the complications of wheels, gears and props, and deal just with a surface and the wind (and an observer just to 'take measurements'). Numbers (not my strong point) and cart mechanics crept in again and confused me.

I find your mathematical descriptions impossible to follow, perhaps partly because you tend to use some sort of shorthand notation, and it has left me still unsure whether (as I would put it using frames) - w.r.t. the person on the belt - you consider there to be a down-belt wind or not. I know that there is one w.r.t. the ground, but we seem unable to reach an understanding that way about the thing I'm interested it.

We can probably forget frames of reference altogether (whew!) by just discussing what would happen in certain circumstances. Instead of a man, let me posit a small device, like a child's toy ladder for a doll, about 40 cm high, with rungs at 4 cm intervals, which I fix vertically to the ground, then to a moving surface. To each rung, I attach a small, light piece of tissue paper by its top edge like a miniature cat-flap, to indicate to an observer which way the wind is going past it, because it will move to the left or right.

I will keep the same directions as before - in 'real wind' the wind blows from left to right - and the moving surface (avoiding the t-word) will move right to left under a stationary mass of air (with the ladder attached).

We both agree - I am sure - what happens if this is standing up on the ground in a 'real wind' from the left. All the flaps will be pushed to the right by the wind. We also agree about the effects of friction - there will be a gradient of windspeed, slowest at the bottom, higher at the top, hence we can expect the greatest movement of the top flap, down to almost none perhaps at the bottom.

Please tell me what you would see if this contraption was then put on a moving surface (or indeed, it could have been on that very same surface already, but there is means to move it). The ladder is now moved with the surface, in still air.

As you will note, this, while completely familiar in essence, gets rid of specific measurements, calculations, moving observers, anemometers, frames of reference, and other complications. We can contrive whatever optics etc. are required to observe the paper. Could you please tell me which way the bits of paper flap at different heights? Thanks.
 
Hey spacediver - I'm curious, did you click on the 'Explain this image dot com' button - what did it say?

Oh wait, it's not like that is it. They are unexplained photos there. D'oh!
 
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The depth of crazy-levels in this one is amazing, the nested nuttery: "No object can sustain zero KE, without permanently staying at the same velocity."

You get 5 bonus points for "nested nuttery". Although I can't decide if I prefer "nested nuttery" or "nested nuttiness". It's a tough call, and at least as worthy of pursuing as the other matters in this thread. :D

I think my version is much neater, but I'm worried it may have lost some of the incorrectness of the original.

Now that is just friggin' brilliant! That's one of those truisms you normally have to go to Yogi Beara for.
 
Dutch? Yep! That'll do it!

Worst aircraft accident in history was caused by a Dutch Captain who wouldn't listen when his First Officer told him he wasn't cleared for take off.

700ish people dead 'cause he was right and everyone else was wrong.....

Was that the runway collision between two 747's in the Canary Islands?
 
I wrote up a short paper on basic newtonian physics. It's about 50 pages long. I ended up writing it all up after trying to remember all my basic college physics stuff while trying to deal with the DDFTTW thingy.

Go to my website and replace "tumbleweed" with "newton" and you'll be there. Most of it is basic units stuff, but there is a page or so about inertial frames.

Welcome to our little discussion of reality.

I think you will soon find that everybody here already understands the basics of newtonian physics. Many have build their own carts and would have little difficulty explaining the concepts to any stranger on the street.

However, all have totally failed to transfer any of that knowledge to humber despite the valiant and courageous efforts. With no hope of achieving 100% acceptance our spirit is crushed.

But now that you are here with new illumination to show the way and a steady breeze to propel our carts we cannot fail.
 
Was that the runway collision between two 747's in the Canary Islands?

Indeed. Tenerife. Several aircraft had diverted there due to fog at the other airport on the island. There was minimal visibility at THIS airport, too, but sufficient for operations. There was also a closed taxiway which meant aircraft had to taxi on the runway for part of the taxi.

The KLM aircraft was commanded by a VERY senior Captain, known for being opinionated. It was also tight on time as the amount of time a crew can stay on duty was regulated. As it reached the end of the runway, a Pan AM 747 was still taxiing on the same runway as it had missed the turn-off back onto the taxiway.

The KLM guy went to takeoff, but his FO told him he didn't have a Clarence. He obviously didn't like having this pointed out to him and barked some order at the FO to get one. The F/O radioed the tower and received an Airways Clarence which is a set of instructions regarding routing after take-off. It is NOT a Clarence to takeoff. The Captain said something like "RIGHT!" and started the takeoff. The FO had used up his quota of Cohones and simply radio "We are at takeoff!!".

The resulting collision involved loss of all life on the KLM aircraft, and most on the Pan Am.

All because an intransigent personality wouldn't acknowledge the better knowledge of another.
 
I think a treadmill is good enough, like the video I linked to above, the concept of the propeller cart is that it acts like a "gear" betwen the air and ground, so it doesn't matter if the "air" or the "ground" moves, the cart always moves the same.

Oh, this will be good!!!

Wecome to the Humberverse!!

You see, according to our friend Humber, the cart isn't moving at all. Just look!! It's not going anywhere!!

This is variously artuiculated as "The cart has no meaning" "The cart has no KE in any frame" and my personal favourite- "A car may appear to be moving backward WRT you, but it isn't. You can tell by the way it's wheels are turning".

No, I'm not kidding.

And disturbingly, neither is he....:boggled:
 
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