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

[humber]

So Spork's treadmill does not work? It seems to work in the videos.

Roswell is on video.

 

[humber]

I'm still waiting for 'The Great Teacher' to defend even the simplest mechanical problem that underlies his hyperbolic Gallileo/Einstein/Rosencrantz and Guildenstern hypothesis.

 

[jjcote]

I'm curious as to why trains use steel wheels and steel rails. It's pretty clear that the deformation is incredibly small, and the distance that the contact patch is supposedly going to move behind the axle is infinitesimal. Trains must barely be capable of moving. Wouldn't they be much better off to use some other materials that deform more, so that the contact patch can be farther behind the axle?

 

[humber]

I'm curious as to why trains use steel wheels and steel rails. It's pretty clear that the deformation is incredibly small, and the distance that the contact patch is supposedly going to move behind the axle is infinitesimal. Trains must barely be capable of moving. Wouldn't they be much better off to use some other materials that deform more, so that the contact patch can be farther behind the axle?

Woo! Woo!...That's the train you missed.

Naturally under heavy load, both deform and allow the train to accelerate.
When on the move, that load disappears providing a nice low friction drive as the contact patch accommodates itself to the reduced load.
I gave John a description of that, and how early 19th Century engineers did not appreciate that fact, and unnecessarily put gears and feet on their trains to provide traction. Time to move into the 21st Century, jjcote

The benefits of a steel wheels and rails, are that they provide a low friction rolling surface, with high load capacity. Some railed trains, such as found at some airports, use rubber wheels. There are reason for that. You work it out.

Any more feet?

 

[humber]

Where is 'The Great Teacher' or physics?
Perhaps he has gone into hiding?
http://www.infibeam.com/Books/info/...acher-of-Journalists-Kim-Jong/141010124X.html

 

[spork]

Also, because of the synchronized motion of wheel and belt, and in concert with the internal balance mechanism, it can't force it backwards either.

Hey check it out!!! The balance mechanism is back! Just a page ago this thing was not balanced for the first time.

(3) Because of that, there can be no motion relative to the belt.

Now we have the greatest balance mechanism of all - the wheels are rigidly attached to the belt, and the cart is going round and round as the belt does.

Roswell is on video.

Yes, and Roswell actually exists in real life.


What on Earth is wrong with humber!?

 

[spork]

Yes, it is unstable.
...
A number of influences, such as gravity will cause it to travel in one direction or another. Like a pair of scales, a small amount may tip them one way or the other.
...
The rim of the cart's wheels, move at the same velocity as the belt.
...
Because of that, there can be no motion relative to the belt.

So there it is in a nutshell. The cart is both stable and unstable. It moves exactly the speed of the belt, and not at all relative to the belt - at the same time.

The riddle here is clearly not about physics, but rather abnormal psychology.

 

[humber]

Oh - I get it... it's a gay joke.

One intended to trap you. In your narrow view, only men are photographers.
Hook, line and sinker. Still the photo is on angle. Look! a tilted flood plain.

Hey check it out!!! The balance mechanism is back! Just a page ago this thing was not balanced for the first time.

I like to give you a choice of poison. Hemlock is so, like, yesterday.

Now we have the greatest balance mechanism of all - the wheels are rigidly attached to the belt, and the cart is going round and round as the belt does.

No "fully geared" is a standard expression used to say that there is no slip between wheel and road. The belt and wheels are synchronized. That is a real showstopper.

ETA:

So there it is in a nutshell. The cart is both stable and unstable. It moves exactly the speed of the belt, and not at all relative to the belt - at the same time.

It is marginally stable. It does not move with or against the belt, but remains in relatively the same spot until an external force causes otherwise. That may be many things.
The fork does this. The wheels slip, the cart goes backwards because they are no longer at the same velocity as the belt. This condition remains until the momentum from that motion is lost, and once again it begins the process of stuffing some energy back into the rotating mass of the propeller.

The riddle here is clearly not about physics, but rather abnormal psychology.

There is no riddle just a set of Russian dolls.

Yes, and Roswell actually exists in real life.

Like this guy?
http://www.engadget.com/2009/02/04/steorn-returns-promises-to-open-orbo-specs-give-you-a-pony/

See how he capitalises on his mistakes to gain credibility by "owning up to them"
http://www.engadget.com/2007/07/07/steorns-ceo-states-the-obvious-we-screwed-up/

What on Earth is wrong with humber!?

Earth?

 

[CORed]

Hey check it out!!! The balance mechanism is back! Just a page ago this thing was not balanced for the first time.



Now we have the greatest balance mechanism of all - the wheels are rigidly attached to the belt, and the cart is going round and round as the belt does.



Yes, and Roswell actually exists in real life.


What on Earth is wrong with humber!?

Pretty amazing how those "rigidly attached" (How?) wheels still manage to roll, but only at a specific speed. They have to slip to turn at anything other than "beltspeed", which is actually negative beltspeed, but, Humber always did have trouble getting the signs right. What exactly causes the wheels to "slip" when not moving at exactly the right speed to "balance" is one of the great mysteries of the Humberverse. Probably one of those strange ground base forces that don't exist in our universe.

This of course, is contrary to numerous videos, and testimony of those who have actually built and tested the carts, which show that getting the cart to "balance" is actually quite difficult, requiring just the right treadmill speed, or just the right incline.

This is the Humberian scientific method: Don't do any actual experiments, and ignore those performed by others that challenge your preconceptions. "Pure reason" is adequate to prove anything, especially when you can deal with any counter arguments simply by refusing to acknowledge them.

 

[Marcus]

My suggestions make up about a third of the list! Yay me!

Should Air Cavitation be left out? I'm pretty sure it's a principal unknown to pre-humberian psychics.

 

[Marcus]

There was also the bit about replacing the prop with a flywheel would make no difference, but I believe he reversed himself on that one.

 

[humber]

Pretty amazing how those "rigidly attached" (How?) wheels still manage to roll, but only at a specific speed. They have to slip to turn at anything other than "beltspeed", which is actually negative beltspeed, but, Humber always did have trouble getting the signs right. What exactly causes the wheels to "slip" when not moving at exactly the right speed to "balance" is one of the great mysteries of the Humberverse. Probably one of those strange ground base forces that don't exist in our universe.

The wheels cannot turn idependantly of the belt, unless powered from an extrnal source. The prop cannot do this because it gets all its power and force from the wheels. Talk of relative velocites is therefore meaningless.

This of course, is contrary to numerous videos, and testimony of those who have actually built and tested the carts, which show that getting the cart to "balance" is actually quite difficult, requiring just the right treadmill speed, or just the right incline.

The videos are evidence that a cart can stay motionless on a belt. The treadmill has nothing to do with real wind performance.

This is the Humberian scientific method: Don't do any actual experiments, and ignore those performed by others that challenge your preconceptions. "Pure reason" is adequate to prove anything, especially when you can deal with any counter arguments simply by refusing to acknowledge them.

Then you agree that your anecdotal evidence is contrary to reason.
I dealt with the "pure reason" of elliptical and square wheels. Why can't you do the same for your case?

 

[John Freestone]

Loads of people have loved this one, so consider it proposed and seconded, Dan?

It [the cart on a treadmill] is capable only of one speed. The wheels can only go slower thant the belt, but not fqaster, so they must be slipping.

@Humber

It moves just faster than the belt? So what?

Go to your supermarket checkout, and with but a small push from your hand, make a can or jar do the most miraculous of things. Move faster than the belt!
Post is on you-tube. Stun and amaze the Crowned Heads of Europe!

The can would almost certainly go faster than the supermarket checkout belt without slipping, particularly if you let your pushing contact slide over the surface as it accelerates. But once you stop pushing, any slip that you might have given it over the belt would almost immediately stop as the friction acts. This idea of the cart wheels slipping has always been quite ridiculous, but the can at the checkout is a good way to begin to catch up. You could quite easily propel a can at - what, 5 mph, 10 mph?, 20 mph? I'm not sure, a darn good speed - on a supermarket checkout belt going about 1/4 mph (I'm guessing, you get the idea). But a wheeled cart - well, just spork's wheeled cart - isn't allowed to do that. Besides, these aren't the correct analogous relative directions anyway. What the Crowned Heads of Europe would be midly impressed by is a can rolling backwards towards the end of the queue (that's against the motion, geddit?) up a few degrees of incline, whether its slipping or not.

Again, this crazy objection is totally stupid anyway. If spork's cart for some reason goes DDWFTTW by flying a bit of the way, that would be even more interesting than the trick it already does. If it did it by somehow secretly being a heat engine or a balance transcender or harnessing the morning dew from nearby ley-lines, then quite frankly I, and the bunnies with anemometers playing in the real wind at the bottom of my garden, will be even more delighted.

If the wheels are in good contact with the belt, then they must move at the same speed as the belt.

Where they contact it, yes.

The propeller is directly geared to the wheel, so it cannot turn any faster than the wheel.

With a 1:1 gearing, yes.

Therefore,

Now, ah, but you see, when you say "Therefore"....

when it does move forward, it must be sliding to some degree.

And to think that I spent time discussing the complexities of contact areas of tyres, when you don't understand that wheels go different speeds. It is that simple: you do not understand that wheels go at different speeds. The above "flow" of "logic" demonstrates it. The intervening propeller statement is in fact irrelevant. The bare bones of this masterful piece of genius goes:

1. Consider a wheel that isn't slipping, with its centre moving w.r.t. the surface it is travelling on at velocity v.
2. If it that velocity is then found to have increased to v + c, where c is any positive constant, the wheel must no longer have good contact, and be slipping.

The unspoken rule (which hopefully only applies to spork's cart) is "It can only go at one speed."

IT'S A FRIKKIN WHEEL!

There are several mechanisms at work.

Well you should really harness one and see if you can squeeze it through your ear.

How can the cart make linear progress from a standstill?

By increasing velocity!

The wheels either slip, or turn at exactly beltspeed.

My car is the same. The wheels only go at roadspeed. Whatever damn speed I make the middle bit go at, the bottom bit just goes at roadspeed. I've complained, but they tell me they're supposed to do that and to get over myself.

Woo! Woo!...That's the train you missed.

Naturally under heavy load, both deform and allow the train to accelerate.
When on the move, that load disappears providing a nice low friction drive as the contact patch accommodates itself to the reduced load.
I gave John a description of that, and how early 19th Century engineers did not appreciate that fact, and unnecessarily put gears and feet on their trains to provide traction. Time to move into the 21st Century, jjcote

I wonder if they had the idea that the force of the wheel had to push back against something to the rear, this being a time of fairly innocent thoughts about mechanics. Catch up with the 20th Century, humber.

 

[CORed]

The wheels cannot turn idependantly of the belt, unless powered from an extrnal source. The prop cannot do this because it gets all its power and force from the wheels. Talk of relative velocites is therefore meaningless.


The videos are evidence that a cart can stay motionless on a belt. The treadmill has nothing to do with real wind performance.



Then you agree that your anecdotal evidence is contrary to reason.
I dealt with the "pure reason" of elliptical and square wheels. Why can't you do the same for your case?

I agree to nothing of the sort. Do not put words in my mouth. I demand that you retract the damn lie in your last paragraph that I agree to anything of the sort

I further assert that the "anecdotal" and video evidence offered in support of the performance of the propeller carts, while not up to the standards that would be required for a peer-reviewed scientific publication, are far superior in quality to unsupported assertions contrary to well established scientific theory, backed by no experimental evidence, and, for the most part, not even logically consistent, are not evidence at all, except possibly evidence of your delusional thinking.

 

[CORed]

I think, in addition to the list of things the Humber is obviously wrong about, perhaps we should compile a "Whiskey Tango Foxtrot" list. A list of the thousands of sentences of pure, incomprehensible gibberish, for which it is impossible to decipher any meaning at all.

 

[CORed]

My car is the same. The wheels only go at roadspeed. Whatever damn speed I make the middle bit go at, the bottom bit just goes at roadspeed. I've complained, but they tell me they're supposed to do that and to get over myself.

Well, I've found that with sufficient application of power, I can get the bottom bit to go backwards wrt the road. This is especially true on ice, snow or wet roads, but sometimes happens even on dry paving, especially when accelerating around a corner. Curiously enough, this doesn't seem to work very well. Although it can generate an impressive amount of noise, and on dry paving, smoke and black marks on the pavement, the car doesn't move as fast, if at all, as when the bottom bit is at roadspeed, and the car often ends up pointing in a direction other than the one I am trying to steer it.

Interestingly (and apparently quite counter-intuitive for some drivers), the best course of action when this happens seems to be to reduce the amount of power applied so that the bottom bit returns to roadspeed.

ETA: I think I should also mention that I can get the bottom bit to faster than the road (at least on a car without antilock brakes) by a zealous application of the brakes. Again, this doesn't seem to work as well as when the bottom bit is going at roadspeed. The surest way to spot a driver who hasn't a clue how to drive in winter conditions: Front wheels sliding, and cranked all the way to the lock in a futile effort to steer with the sliding front wheels, until he hits the curb (if he's lucky) or another car. It seems that Humber is not alone in not knowing how wheels work.

 

[humber]

Loads of people have loved this one, so consider it proposed and seconded, Dan?

The can would almost certainly go faster than the supermarket checkout belt without slipping, particularly if you let your pushing contact slide over the surface as it accelerates. But once you stop pushing, any slip that you might have given it over the belt would almost immediately stop as the friction acts. This idea of the cart wheels slipping has always been quite ridiculous, but the can at the checkout is a good way to begin to catch up. You could quite easily propel a can at - what, 5 mph, 10 mph?, 20 mph? I'm not sure, a darn good speed - on a supermarket checkout belt going about 1/4 mph (I'm guessing, you get the idea). But a wheeled cart - well, just spork's wheeled cart - isn't allowed to do that. Besides, these aren't the correct analogous relative directions anyway. What the Crowned Heads of Europe would be midly impressed by is a can rolling backwards towards the end of the queue (that's against the motion, geddit?) up a few degrees of incline, whether its slipping or not.

At point of contact of wheel and belt, both the belt and wheel circumference are moving in the same direction. Therefore, the cart should go with the belt.
An external force will prevent this, allowing the wheel axle to remain stationary, and so inhibit the motion. This force is low, being total friction to the belt, so a light touch of the finger, or drag from a propeller, will easily hold it in place. The prop does not move the cart relative to the belt, but simply prevents is from moving back with the belt.

The wheel and so the propellor can not move at any other velocity than directly determined by the belt, unless the wheels can rotate slower than the belt. Faster is not possible, as no matter what the grearing, the propellor cannot drive the wheel faster than the wheel that drives it.
It is not possible for a cart to move at say 2m/s slower than a 4m/s belt, while 'traveling up the belt', because then the wheels must spin at half the velocity of the belt.
The cart is brought to speed by operator influence, so that it may balance in place.

Again, this crazy objection is totally stupid anyway. If spork's cart for some reason goes DDWFTTW by flying a bit of the way, that would be even more interesting than the trick it already does. If it did it by somehow secretly being a heat engine or a balance transcender or harnessing the morning dew from nearby ley-lines, then quite frankly I, and the bunnies with anemometers playing in the real wind at the bottom of my garden, will be even more delighted.

The treadmill has nothing to do with a cart in wind.

Where they contact it, yes.

With a 1:1 gearing, yes.

Now, ah, but you see, when you say "Therefore"....

And to think that I spent time discussing the complexities of contact areas of tyres, when you don't understand that wheels go different speeds. It is that simple: you do not understand that wheels go at different speeds. The above "flow" of "logic" demonstrates it. The intervening propeller statement is in fact irrelevant. The bare bones of this masterful piece of genius goes:

Gearing is two way. 'Up' from the wheels, is 'down' from the propellor. Gearing makes no difference,
The belt and wheel do not go at different speeds. The only other option is for the wheel to completely slip on the belt, and so go slower then the belt, but that means motion down the belt.

1. Consider a wheel that isn't slipping, with its centre moving w.r.t. the surface it is travelling on at velocity v.

Look up the defintion of 'slip'. A wheel without slip cannot travel.

2. If it that velocity is then found to have increased to v + c, where c is any positive constant, the wheel must no longer have good contact, and be slipping.
The unspoken rule (which hopefully only applies to spork's cart) is "It can only go at one speed."
IT'S A FRIKKIN WHEEL!
Well you should really harness one and see if you can squeeze it through your ear.
By increasing velocity!
My car is the same. The wheels only go at roadspeed. Whatever damn speed I make the middle bit go at, the bottom bit just goes at roadspeed. I've complained, but they tell me they're supposed to do that and to get over myself.

You contradict yourself, and do not notice that in your case, both the axle and tyre move relative to the road.
There are other errors. The wheels on the front and rear of a car are often at different angular velocities.
The average diameter of the driven wheel is actually smaller than an undriven wheel. That is how thrust develops. On a tire, this causes the tread to 'slip' to make up the difference. The cart does no have structured pneumatic tyres, so comparisons to a disk are more appropriate.

I wonder if they had the idea that the force of the wheel had to push back against something to the rear, this being a time of fairly innocent thoughts about mechanics. Catch up with the 20th Century, humber.

Quite wrong again. They were aware that the contact is to the rear, but did not fully understand the process, and concluded that a steel wheel could not pull a load greater then static friction would allow. That is why the unnecessarily added the feet. So, a few centuries later, it's your turn to learn how wheels work.

 

[humber]

Well, I've found that with sufficient application of power, I can get the bottom bit to go backwards wrt the road. This is especially true on ice, snow or wet roads, but sometimes happens even on dry paving, especially when accelerating around a corner. Curiously enough, this doesn't seem to work very well. Although it can generate an impressive amount of noise, and on dry paving, smoke and black marks on the pavement, the car doesn't move as fast, if at all, as when the bottom bit is at roadspeed, and the car often ends up pointing in a direction other than the one I am trying to steer it.

When that happens, you don't move. Just like on the treadmill. DOH!

Interestingly (and apparently quite counter-intuitive for some drivers), the best course of action when this happens seems to be to reduce the amount of power applied so that the bottom bit returns to roadspeed.

That will be of use when you can show that it has anything to do with the cart.

 

[humber]

I agree to nothing of the sort. Do not put words in my mouth. I demand that you retract the damn lie in your last paragraph that I agree to anything of the sort

Yes you did.

I further assert that the "anecdotal" and video evidence offered in support of the performance of the propeller carts, while not up to the standards that would be required for a peer-reviewed scientific publication, are far superior in quality to unsupported assertions contrary to well established scientific theory, backed by no experimental evidence, and, for the most part, not even logically consistent, are not evidence at all, except possibly evidence of your delusional thinking.

It meets no standards, other than your willingness to believe.

 

[sol invictus]

The treadmill has nothing to do with a cart in wind.
<snip>
Look up the defintion of 'slip'. A wheel without slip cannot travel.

spork, your sock puppet shouldn't say things this unbelievably stupid - it's too obvious.