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

[spork]

On the treadmill, all of the energy comes from the electric motor. It delivers only so much to the cart but at resonance, it can deliver more, enabling the cart to speed up.

That's a brilliant "theory". I assume you base that on a principle we engineers call "pure B.S."?

Going down wind, there is no reason to think such resonance can be achieved.

EXACTLY - just like the treadmill.

In fact, there is no evidence at all of a cert moving down wind faster than the wind, only a cart moving down wind.

Nope - no evidence at all (unless you understand even the most basic principles of high school physics).

 

[semper]

But at least your mention of the Narrows Bridge shows that you can at least understand how the energy delivered to a resonant object is multiplied. Note, energy itself is not multiplied, it is the amount delivered to something from something else, that is multiplied. On the treadmill, all of the energy comes from the electric motor. It delivers only so much to the cart but at resonance, it can deliver more, enabling the cart to speed up. Going down wind, there is no reason to think such resonance can be achieved. In fact, there is no evidence at all of a cert moving down wind faster than the wind, only a cart moving down wind.

Did you maybe hear about a thread offering a Humber Prize?

I'm glad you clarified the bit about Energy Multiplication, we are glad, but is the delivery multiplied, or just stored effectively rather than transfered? I can see the evidence, the little cart moving along the belt powered by the interface energy, can't you see that? Did you happen to look?

 

[humber]

That's a brilliant "theory". I assume you base that on a principle we engineers call "pure B.S."?

We!

EXACTLY - just like the treadmill.

You have no idea at all, if Christoph's idea is plausible or not.

If the propeller compresses the air, that makes it more dense, so there is an exchange of mass over time. if you want to see it that way.

Nope - no evidence at all (unless you understand even the most basic principles of high school physics).

Drone.

 

[humber]

Did you maybe hear about a thread offering a Humber Prize?

I'm glad you clarified the bit about Energy Multiplication, we are glad, but is the delivery multiplied, or just stored effectively rather than transfered? I can see the evidence, the little cart moving along the belt powered by the interface energy, can't you see that? Did you happen to look?

Resonance does not guarantee efficient transfer nor absorption.

 

[spork]

You have no idea at all, if Christoph's idea is plausible or not.

When there's an 89 page thread dedicated to my complete lack of understanding of physics I guess I can start to worry about that.

humber - clueless for over 2000 posts!

 

[Furcifer]

You're wrongness is truly spectacular.

A) there is only one of me. To my knowledge no one else in the history of the planet has ever offered these carts at any price.
B) I offered them at $40. So you were only off by 100%
C) I'm willing to bet you an amount of your choosing that I understand thrust better than you - certainly better than the nonsense you've spewed here about thrust being the rate of change of mass!

Yup. 671 posts, and you haven't found a blog yet. But keep telling your lies.

Lol, I guess I'd better get one at $40 or wait until they are "mass produced" because they are being offered on the net, in your name, for $80. The word on the net is there were only a few you could do for $40, the next ones were going to cost. I heard the ads were being done by Plastic Spork Productions...

You'd better get that paper proof read before you release it (unless that too is another ineternet myth).

At first I thought you guys were being honest but now I think otherwise. It only takes a little Googling to see you guys are on every forum that will lend an ear going on about these toys. You seem to be peddling "inertial reference frames" as a catch phrase to hide something. You have more than a simple interest in these little carts. And now your not sure what the differential of mass wrt to time has to do with thrust? Strange.

 

[humber]

When there's an 89 page thread dedicated to my complete lack of understanding of physics I guess I can start to worry about that.

That lacks ambition.

humber - clueless for over 2000 posts!

It's what you don't say that speaks volumes.

I was thinking that if I want to run as fast as the belt, I run in the same direction as the belt ,and not hang around while the belt passes under my feet. The cart might the going the wring way.

 

[semper]

And now your not sure what the differential of mass wrt to time has to do with thrust? Strange.

Sorry 3body, can you just remind us what your idea of thrust is. What does "differential of mass wrt to time" mean in this context. I thought thrust was a force and could be calculated as the rate of change of linear momentum wrt time, or rate of change of mass flow rate. So like the tensile or compression force on a propeller shaft as a reaction to its accelerating the air it is engaging, not flowing mass into another dimension, or directly to energy or anything like that. Do we need to argue the definition of thrust, force etc. I suppose so...

 

[spork]

Wow, when it comes to being absolutely wrong on everything at every level, you're really beginning to steal humber's thunder.

Lol, I guess I'd better get one at $40 or wait until they are "mass produced" because they are being offered on the net, in your name, for $80. The word on the net is there were only a few you could do for $40, the next ones were going to cost. I heard the ads were being done by Plastic Spork Productions...

I guess you hear a lot of things on the net. In fact people probably read your B.S. and then spew it elsewhere. I've sent about 10 out at $40 and that's it. There are no more. And I don't intend to make any more. You got tired of lying about me blogging, so now you need to make lies about me providing carts for $80.00?

At first I thought you guys were being honest but now I think otherwise.

That's the first comforting thing you've said. So far you've been wrong on every single point. If you thought I was honest I don't know if I could live with the implication.

You seem to be peddling "inertial reference frames" as a catch phrase to hide something.

Excellent work. If only there were something to hide.

And now your not sure what the differential of mass wrt to time has to do with thrust? Strange.

Actually I'm quite sure what it has to do with it - NOTHING. Why won't you take my bet on this? Obviously you understand thrust at a deep and philosophical level.

 

[Furcifer]

Sorry 3body, can you just remind us what your idea of thrust is. What does "differential of mass wrt to time" mean in this context. I thought thrust was a force and could be calculated as the rate of change of linear momentum wrt time, or rate of change of mass flow rate. So like the tensile or compression force on a propeller shaft as a reaction to its accelerating the air it is engaging, not flowing mass into another dimension, or directly to energy or anything like that. Do we need to argue the definition of thrust, force etc. I suppose so...

For an open system like this ("open" means mass can enter or leave the system) thrust is the exhaust velocity of the air relative to the cart times the differential change in mass wrt to time.

The cart is getting thrust by pushing more air (mass) out the back of the prop than it takes in the front of the prop. This is a differential in mass occuring over time. You've set the velocity of the wind as constant, it's a scalar quantity, big deal!

If you want to get an idea of what I think is happening I found this

Granted, this is based on single particles, but the idea is the same. If you consider the air as a point particle (well two joined) and the regions on either side of the blades as the bifurcating point it makes more sense.

 

[fredriks]

The flow around a propeller (or wind turbine) is pretty well known. There is at least not any chaotic behaviors (that make any difference) based on compressibility. The force resulting from a propeller is pretty constant if the wind field is uniform.

 

[Furcifer]

I guess you hear a lot of things on the net. In fact people probably read your B.S. and then spew it elsewhere. I've sent about 10 out at $40 and that's it. There are no more. And I don't intend to make any more. You got tired of lying about me blogging, so now you need to make lies about me providing carts for $80.00?

Your semantics are irrelevant. There is a Web log of your thoughts, ideas, experiments etc., too numerous to count. You blog. You are blogging now, you are a blogger.

Actually I'm quite sure what it has to do with it - NOTHING. Why won't you take my bet on this? Obviously you understand thrust at a deep and philosophical level.

Stick a spork in it, you're done.

 

[fredriks]

Your semantics are irrelevant. There is a Web log of your thoughts, ideas, experiments etc., too numerous to count. You blog. You are blogging now, you are a blogger.

Why do you care so much about semantics? Why are your definitions necessary correct?

I don't consider is blogging when I write this and it make no sense whatsoever to argue if it is or not.

Why don't simple admit that you have a different understanding of blogging compared to spork? Spork could also admit that you two use the same word in different ways. I believe that spork's use is more common though.

 

[Subduction Zone]

For an open system like this ("open" means mass can enter or leave the system) thrust is the exhaust velocity of the air relative to the cart times the differential change in mass wrt to time.

The cart is getting thrust by pushing more air (mass) out the back of the prop than it takes in the front of the prop. This is a differential in mass occuring over time. You've set the velocity of the wind as constant, it's a scalar quantity, big deal!

If you want to get an idea of what I think is happening I found this

Granted, this is based on single particles, but the idea is the same. If you consider the air as a point particle (well two joined) and the regions on either side of the blades as the bifurcating point it makes more sense.

You do not understand how propellers work. It does not push more mass out the back than comes in front. Where does this mystery mass come from? It changes the momentum of the air that it is moving through. The momentum of the air it moves is "higher" after it goes through the prop (actually higher with respect to the cart since momentum is a vector). Now I can see how you might have been confused since momentum is mass times velocity, but it is not the mass that is increased, that would be a neat trick, it is the velocity that goes up relative to the propeller. spork's cart works by slowing down the wind relative to the ground, though since it is pushing it back it seems on the cart that it is now going faster to the rear after it goes through the propeller.

 

[John Freestone]

Shall I wikki wikki, or will you?

You.

I did and I was wrong and you were right.

This concerned the question of whether more massive and less massive bodies fall towards Earth (say) at the same rate of acceleration. I could have sworn I saw a full and very clear refutation as per my own posts earlier, but either it was wrong or I imagined it, apparently, and everything I've turned up seems to support Galileo and humber...

...except one, which anyway relates to when two bodies are dropped together, making three bodies with the earth: http://paias.org/Science/Newton/Newton.htm ...wherupon the lesser mass falls very, very slightly faster, yes, you read that right, the lesser mass. I haven't read the detail yet, but how ironic if true!

However, I meant in the situation of a small mass falling to Earth and a large mass falling towards Earth, separately, without considering them as a triad.

I mistook the force, for m1 and m2 masses at distance r from Earth of mass M, as:

F = G.m1.M/r^2 and
F = G.m2.M/r^2, like a complete idiot. In fact, I didn't bother with m2 at all. I went on to the acceleration:

a = F/m1 (which is ok, except that I assumed) ...

a = F/m2 in the second case, when of course I should have had F1 and F2 and substituted from the Law of UG above, hence, as you said, they cancel:

For m1,

a1 = F1/m1
= G.m1.M/m1.r^2
= G.M/r^2

Similarly for m2, m2 disappears from the equation,

a2 = G.M/r^2,
a1 = a2 (er, QED, )

Not only that, but where I had before calculated the acceleration of Earth towards m1 as F/M, again it should have dawned on me that the object mass didn't appear in the equation at all, and hence the Earth would accelerate towards everything at the same rate! It should, of course, be

A1 = F1/M
= G.m1.M/M.r^2
= G.m1/r^2 ... and, in the case of m2

A2 = G.m2/r^2

Whatever we consider the object, its mass cancels out. The acceleration of it depends entirely on the other mass.

I notice you physics experts (sorry, humber, although you won that one, I'm not considering you an expert without further evidence) sat there and let me perpetrate that heresy and make a complete twit of myself into the bargain!

Right, let's see that triad situation...any thoughts anyone on whether the lesser mass falls fastest?

 

[RossFW]

Whatever we consider the object, its mass cancels out. The acceleration of it depends entirely on the other mass.

John,

Whilst that is correct, because acceleration is absolute, remember we are talking about Humber here.

Whilst the acceleration of one body is dependent the mass of the other, the aceleration of that OTHER body is dependent of the mass of the first.

Thus, while a body accelerating towrds the earth will do so at a fixed acceleration regardless if it's mass, the EARTH will accelerate towards a larger mass at a larger magnitude than it will towards a smaller body.

As such the relative velocity between the larger body and the Earth will always be more than that between the smaller body and the Earth.

As Humber uses the earth as his absloute reference, it would appear that the larger body has a greater acceleration.

 

[John Freestone]

Really? Got a Wikki link?
[this is the "contact patch" argument about wheels]
You have it front to back again, humber.

Yes, I thought that, admittedly without checking other sources. If we just increase the - what should it be called, fluidity?, deformability? - of a wheel, it's fairly easy to imagine. It helps also to imagine a high inertia or some resistant force on the machine. Imagine wheels of a jelly-like substance; then, if these are driven by an engine or whatever, they will try to turn forward against the resistance. If the vehicle didn't move at all, the wheel would deform, twisting, and pile up its mass in front of the axle. A simple demo would be to push a piece of soft rubber over your desk, similarly it is dragged backwards w.r.t. your push; the wheel below the axle pushes backwards on the ground (obviously) w.r.t. the vehicle's intended motion, so the rubber of the tire or jelly piles up on the backward side of that backward push, i.e. the front.

Interestingly, the cart is pushed by the wind over the ground and the ground drives the wheels, so that's all backwards anyway! Not only that, but the treadmill also drives the wheels. Or, I wonder, does that relationship change at different windspeeds?

Perhaps less interestingly, I have joined the consensus and started discussing the frikken cart on this thread, when I was about to post and remind everyone that there is another thread (now sitting idle) for DDWFTTW cart discussion! Bother!

Ah no, I'm just discussing wheels, a valid part of classical physics since the stone age.

 

[John Freestone]

John,

Whilst that is correct, because acceleration is absolute, remember we are talking about Humber here.

Still not got my head round what that means yet, but...

Whilst the acceleration of one body is dependent the mass of the other, the aceleration of that OTHER body is dependent of the mass of the first.

Thus, while a body accelerating towrds the earth will do so at a fixed acceleration regardless if it's mass, the EARTH will accelerate towards a larger mass at a larger magnitude than it will towards a smaller body.

Wow! Like this just gets better and better. So the answer (ignoring the triad problem), is "They accelerate at the same rate, Sir, but the Earth accelerates upwards at the more massive object faster"! Love it.

As such the relative velocity between the larger body and the Earth will always be more than that between the smaller body and the Earth.

So you mean the heavier body will LAND first in ideal conditions?

I'd like to see a multiple-choice question setter set that one unambiguously! (I'll let you off with 'larger' this time )

As Humber uses the earth as his absloute reference, it would appear that the larger body has a greater acceleration.

Passing swiftly on ... can we just add accelerations, if they're towards each other? It would seem that's what you're saying, or that the effect is the same?, like A1+a1, which if my math holds up,
= G (m1 + M)/r^2
=/= A2+a2

We can add velocities that are towards each other, but there I mean velocities w.r.t. something else (a frame of reference). Perhaps even then I should say the difference, but one is in the opposite direction. Jeez, no, a vector can't be negative, so all of that was crap. Never mind, I'll go back to school again!

Thanks Ross.

 

[RossFW]

Purely a laymans understanding, John. I think I have the record for being corrected here aprt from, well, you know....

 

[Furcifer]

You do not understand how propellers work. It does not push more mass out the back than comes in front. Where does this mystery mass come from? It changes the momentum of the air that it is moving through.

I don't? Really. Well how about I put a 10 Hp Mercury in a 50 gallon drum, a closed system. No water (mass) can pass into that drum.

It doesn't matter how fast you spin that prop and change the momentum of the water, you're not going to move that drum.

You need mass moving out of the drum to produce thrust. The velocity of the mass exiting is just a scalar.

In order to produce thrust on the cart (move up the belt), it has to exhaust more air mass than it takes in. This means the density of the air is higher on the backside of the prop than the front or "compressed".

When we're looking at compressed things, we talk springs.