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

[Dan O.]

I vote that neither Humber nor 3body have any idea how propellers, wheels, and treadmills work, and therefore are unlikely to ever understand how a wheel and propeller wind interface vehicle on a treadmill can work, no matter what classical physics is applied.

Any seconders?

back of the line newbe

 

[humber]

back of the line newbe

Indeed, cats are hierarchical tail-sniffers

 

[Furcifer]

Well, as a 3000+ hour soaring pilot (with 2 gliding National Championships and a World Championship to boot), please impart some knowledge regarding wind gradients. I'm all ears.

JB

PS: I'm sure hoping your gradient knowledge is better than your prop knowledge or trouble brews.

Oh great, a glider pilot in a dog fight

My prop knowledge? Have you been here? I say "air is compressible and this is an open system" and I get links to to prop data modelled on Ideal incompressible fluids and closed systems.

 

[Furcifer]

I think 3bodyproblem is just vying for attention. He should probably be reported for the personal attacks and put on ignore. Humber is enough entertainment for this thread.

Have you read the thread recently? Humber, Mender, JF and myself are the only ones to contribute to the discussion. The rest created a strawman about creating mass out of thin air in order to derail the thread. They claim to want to help explain things and have yet to address anything.

As I believe this is your thread I will refrain from any further nonsense.

 

[Dan O.]

That looks like an interesting tangent. Thanks.

Don't forget to consider the bow wave.

 

[mender]

It does not really matter if you disagree with the direction or location of the force applied by the wheel to the road.

Braking is different, because efficient motion is not the aim, just loss, so scrubbing and dragging play their part, as does avoiding melting.

Oh, yes indeed, the tire acts completely different when it is "braking" instead of "accelerating". You've done it again, humber!

Here's another picture of the location of the tire patch. It is easy to see the location of the tire patch in this picture. Like the last picture I provided, the vehicle is either accelerating or braking. According to you, both of these cars must be braking.

http://www.gilchristbnw.com/GPC/PS-DDNGallery234.html

Go back to something you can bluff with, humber (you almost had me with the tri-axial accelerometer thing). You're just making yourself look bad.

 

[mender]

So 3body, any problem with the cart moving faster than the wind powered only by the wind?

 

[humber]

Oh, yes indeed, the tire acts completely different when it is "braking" instead of "accelerating". You've done it again, humber!

If you like I will accept that the cart is braking on the belt to stay still. Perhaps you alos thing the suspension behaves the same when accerating or breaking.

Here's another picture of the location of the tire patch. It is easy to see the location of the tire patch in this picture. Like the last picture I provided, the vehicle is either accelerating or braking. According to you, both of these cars must be braking.
http://www.gilchristbnw.com/GPC/PS-DDNGallery234.html

You forget that the car is at an angle to the road...etc.
You could not be sure that what you were seeing as 'breaking' is not just a reduction in the rate of acceleration. Apples and pears, as I said.
ETA: Even at face value, I would say that the maximum force was where the tyre was most compressed. That appears to be to the rear of the axle.

Go back to something you can bluff with, humber (you almost had me with the tri-axial accelerometer thing). You're just making yourself look bad.

Not almost; did. You cannot rebuff it, the runner on the treadmill, nor the wheel drive.

 

[mender]

You forget that the car is at an angle to the road...etc.
You could not be sure that what you were seeing as 'breaking' is not just a reduction in the rate of acceleration. Apples and pears, as I said.

Not almost; did. You cannot rebuff it, the runner on the treadmill, nor the wheel drive.

Oh stop, you're "braking" me up! You forgot to mention almonds and cashews!

Barf Vader voice-over:" You cannot rebuff it, it is your destiny. Join me on the dark side."

Oldie Juan Nofoldy voice-over: "Use the Force - on the other side of the tire."

Toy Yoda voice-over: "Backwards you talk. Stupid you sound."

 

[humber]

Oh stop, you're "braking" me up! You forgot to mention almonds and cashews!

Barf Vader voice-over:" You cannot rebuff it, it is your destiny. Join me on the dark side."

Oldie Juan Nofoldy voice-over:

"Use the Force - on the other side of the tire."

Toy Yoda voice-over:

"Backwards you talk. Stupid you sound."

Sounds like you can't explain your ideas.

 

[mender]

No, I can't explain them to you. Reception seems to be poor.

 

[spork]

Boy this misinformation contest between humber and 3bodyproblem is getting out of hand. They come up with complete nonsense faster than I can ridicule it!

I'd love to get humber to take a bet about his tire patch in front of or behind the axle, but I can't get him to commit to something as simple as 2+2=4, so I know getting him to make a bet is far beyond hopeless.

I think 3bodyproblem is just jealous that we've spent 90 pages pointing out humber's problems with reality and very few on his.

 

[mender]

If the power is available, increased acceleration may be achieved by this means, but not final velocity.

Another gem! A perpetual acceleration machine!

 

[Dan O.]

Humber's "test" for free-fall in a gravity field vs zero acceleration outside of a gravity field qualifies as another statement where he is wrong about the physics involved.

"There is no gravitational field that is indistinguishable from zero-g. It is distinguishable in free-fall or not."​

I do wish humber would proofread what he writes. The first part is just too close to "no gravitational field is indistinguishable from zero-g" which would be true if such a condition existed. I cannot accept it as written.

[*] "Two standard mass-sensing accelerometers, one on each end of a bar. Spun in zero-g, they would show a constant output as a result of that acceleration. In free-fall towards the Earth, each acclerometer will either be moving with gravity or against it, with each revolution. Easily detected." #3361​

Accepted.

 

[humber]

Boy this misinformation contest between humber and 3bodyproblem is getting out of hand. They come up with complete nonsense faster than I can ridicule it!

Do let me know when you start.

I'd love to get humber to take a bet about his tire patch in front of or behind the axle, but I can't get him to commit to something as simple as 2+2=4, so I know getting him to make a bet is far beyond hopeless.

The bluff bet of an empty hand.

A vehicle propelled along a road by wheels, cannot be simulated by that same vehicle driven from the wheels by a belt.

The reason is obvious. If a car is on a moving belt, then neither it nor the driver "can tell" that the belt is moving. From the ground, an unpowered car would appear to move as if attached to the belt, but of course it appears motionless when viewed from the belt. Therefore, there is no reason to expect that the belt would turn the wheels.
The model and reality are not equivalent, meaning that the premise of the treadmill is false.
Only if the car supplies the power can it move along the belt. There is no video of the cart showing that expected behavior.

I think 3bodyproblem is just jealous that we've spent 90 pages pointing out humber's problems with reality and very few on his.

How about one more then?

 

[humber]

"There is no gravitational field that is indistinguishable from zero-g. It is distinguishable in free-fall or not."​

I do wish humber would proofread what he writes. The first part is just too close to "no gravitational field is indistinguishable from zero-g" which would be true if such a condition existed. I cannot accept it as written.

[*] "Two standard mass-sensing accelerometers, one on each end of a bar. Spun in zero-g, they would show a constant output as a result of that acceleration. In free-fall towards the Earth, each acclerometer will either be moving with gravity or against it, with each revolution. Easily detected." #3361​

Accepted.

Good. Then you also accept that free-fall is not zero-g. The other one makes sense.

A commercial patent:
HDD be in a read or write mode at the instant the fall begins. The second approach is to employ accelerometers to detect a drop and then generate a signal that causes an HDD head to be recalled to a safe zone. If this can occur before the product hits the floor or other stationary surface, a collision between head and platter will be prevented. This approach was first used commercially in a notebook PC released by IBM in October 2003.
There is a difference between detecting the acceleration of your "frame of reference" and having an instrument with you.

 

[fredriks]

Oh great, a glider pilot in a dog fight

My prop knowledge? Have you been here? I say "air is compressible and this is an open system" and I get links to to prop data modelled on Ideal incompressible fluids and closed systems.

Ok, ignore all relevant theories about propellers. You already know that you know everything that can be known.

You are a genius and I can't see that people claim that you are arrogant at all.

Do you get a lot of calls from Stockholm?

More serious, go and read a very basic physics book instead of making a fool of your self on the forum.

 

[Dan O.]

Wow - what nonsense!

You just have to insert the words that humber leaves out...

"For a vehicle driven by a solid axle, the wheels must exhibit 'slip'."​

We could make this a contest. Go through the list of "Where humber is wrong"^tm and add the minimum number of words to make each statement correct.

More complete nonsense. But at least this isn't the usual gibberish nonsense. This is nice clear nonsense.

In the case of forward motion, the contact point with the road - the friction that provides the reaction to the driving force - must lie behind the axle.​

Can humber be accused of plagiarizing himself? This repeated claim is already on the list.

 

[semper]

So far. No evidence that you understand how a belt drives a wheel, the idea of power transfer..., just the usual catch-cry, again.



A runner standing on the belt, so as to go back with it, will have KE due to his velocity w.r.t the ground. A ground observer would confirm this.
If the runner runs up against the belt, he will arrive at beltspeed with zero velocity w.r.t the ground. A ground observer will agree with this.
However, there also is no KE w.r.t the belt.

Nice one Humber, you just can't see how KE is relative do you. You just can't figure it out can you? You are just unable to understand. So if you were on a large massive treadmill, maybe the belt and associated mass in the movement weighs 1 tonne. And it has sand paper as a surface texture, right. And you are running flat out wrt the belt, but have no velocity wrt the room you are in. What you are saying is that if you trip over, you won't need to worry about anything more than if you fell over while standing still on the floor of the the room with its sandpaper floor. Well Mr Humber, what i say is, please, please set up that experiment and have a go. You may need more than a little bandaid though. Right?

Lol, what is so hard to understand. The cart gets pushed to windspeed, prop or no prop. With a prop, at wind speed, you have a diffential, the standing air in front of the prop accelerated by the prop producing thrust.
I'm astonished at the lack of knowledge on gradients here. Well not really, too many engineers

And you Mr Pbody, you have learnt alot from Humber, but in this particular post, you almost get it right, almost. So I am astonished by your lack of knowledge, why did you bother writing it, why not make it correct.

 

[humber]

You just have to insert the words that humber leaves out...

"For a vehicle driven by a solid axle, the wheels must exhibit 'slip'."​

The solid is implied. I did not mean axles made of jello.

We could make this a contest.

Very risky on your own.

Go through the list of "Where humber is wrong"^tm and add the minimum number of words to make each statement correct.

Only the minimum? Go on, spoil yourself.

In the case of forward motion, the contact point with the road - the friction that provides the reaction to the driving force - must lie behind the axle.​

Can humber be accused of plagiarizing himself? This repeated claim is already on the list.

If you want to do something other than plagiarize and misrepresent me, you may like to show me where that one is wrong. Hint; It isn't.