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

[CORed]

Sorry Christian, but you know very little. That very reference shows that it is an impedance, a complex frequency dependent impedance, (Z)
These effects are present in flows. Standing waves in water, air?
Also acoustics, again. How do you think a Helmholtz resonator works?

Humber telling somebody they know very little? My irony meter just pegged (I'm an old fart so it's analog).

I still think it's safe to say that "impedance" has nothing to do with a river running over a rock.

 

[Christian Klippel]

Easy, but wrong.

Then explain where it is wrong. Feel free to use your own numbers. Draw a simple diagram showing the airflow and the flow of the slower boundary layer at different observer speeds.

Can you do that, or do you evade that simple request as well?

 

[Christian Klippel]

Lurking Arts grad here...

That was very helpful. Thanks.

Hello D'rok,

thank you too!

Greetings,

Chris

 

[mender]

What do the following have in common?

Understanding a problem when written
Proposing a test to investigate the problem
Observing events and interpreting those events correctly
Making diagrams of those events and/or the original problem
Doing simple arithmetic about those events and/or the original problem
Understanding physics about those events and/or the original problem
Answering point blank questions about those events and/or the original problem

Anyone?

the need to have a clue and some knowledge of the matter at hand, i would say. If the result is expected to be the right one, of course.

I can't decide. Is it "the scientific method", or "things that humber apparently can't do"?

Oh! Me! Me! I know!
Things Humber can't do.

The results of our first question on spork's physics test so far. All are correct so far, except for:

Try answering the question.

A non-response gets you a zero, humbre. But thanks for playing. There will be more questions to come so you can try again.

Just a quick word of explanation, since spork knows that humbre won't answer his questions, he contacted me by PM to ask the first question. You others that have agreed to be tested will be getting your question to ask by PM soon. Spork will let you know how to structure the question in order to get humbre to answer without realizing that he is. I got the easy one but now that humbre is watching for questions, you'll have to be careful how you phrase them.

 

[Christian Klippel]

Hello CORed,

Humber telling somebody they know very little? My irony meter just pegged (I'm an old fart so it's analog).

mine too. You probably have the same model even:

I still think it's safe to say that "impedance" has nothing to do with a river running over a rock.

It is.

Greetings,

Chris

 

[H'ethetheth]

I doubt your capacity to judge, considering that Bainbridge's example could not be more inappropriate. Not even close!

You must not be a very imaginative person; I would think that sound generation in crickets and the dynamics of dishwashing are much more inappropriate.

However, I would be interested in knowing why, rather than the religiously blunt reaction of someone presented with an idea that goes beyond them. Be prepared if you respond.

I told you above. You cannot introduce vertical velocities when modelling a boundary layer, which is necessarily a horizontal phenomenon. Therefore, you are changing the relative velocities of everything involved and your model becomes inherently inaccurate. If you want an accurate boundary layer, use a bigger belt. The flow will become nice and turbulent automatically and the boundary layer thickness will increase until it is no longer different from a wind induced boundary layer.

Also, you are mistaken. Though perhaps "religiously blunt", this was not the reaction of someone presented with an idea that goes beyond them. This was the exasperated reaction of someone faced with a wall of smug ingorance.

 

[jjcote]

The belt-generated boundary layer, is in the opposite direction to that found in the external world ( a.k.a nature, the environment).
In the external world, the boundary layer flows in the direction of what is often called 'the wind', whereas on the treadmill it flows opposite to that expected direction.

humber,
Outdoors, "real" wind coming from behind you. You are traveling at the speed of that wind (e.g. 10 m/s wind from the south, and you are going north at 10 m/s). If you reach down to ankle level, you will feel the air in the boundary layer coming toward you, from in front of you.

Agree or disagree?

 

[CORed]

Was his face on the back of his head?

Based on his bizarre prose I think the prison library must be pretty heavy on the 18th century English literature - and that's where humber first learned to read and write. I guess there aren't a lot of physics books in there....

Oh there are physics books. Unfortunately, they are translations of Aristotle and Ptolemy.

 

[Christian Klippel]

Somehow humber's silence to my request to show me the flaw in my little, simple ASCII diagram is telling. Usually he is really quick to spout his nonsense.

May it be that he knows that the diagram is correct, and now tries really hard to come up with some twisting and goalpost moving to cover up?

 

[jjcote]

Easy, but wrong.

Wrong? How so? Wrong in what way? "Wrong" is not an adequate comment. State what is wrong in the diagram, and ideally state what the correct version would look like.

 

[humb]

Some ASCII art to visualize it, just for you humber.
Is it really that hard to grasp, humber?

Tag team! I can step in here.

Real wind over road, as seen in the ref.frame of the road:

  >>>>>>>>>>    Wind, 10km/h rel. to observer
  >>            Boundary layer flow, 2km/h
 |----------    Road
 +--Observer stationary on the ground

Difference Wind vs. boundary: 8km/h

Fine so far. Yes, it is as it was.

Real wind over road, as seen in the ref.frame of someone moving at 5km/h:

       >>>>>            Wind, 5km/h rel. to observer
    <<<                 Boundary layer flow, 3km/h opposite
      |----------       Road
      ^--Observer at 5km/h

Difference Wind vs. boundary: 8km/h

No, no, no. First of all, when you start backing up like that, you will cause turbulence. Then all hell breaks loose.

Real wind over road, as seen in the ref.frame of someone moving at 5km/h:

       >>>>>            Wind, 5km/h rel. to observer
 <@<@<@                 Boundary layer flow, all swirly
      |----------       Road
      ^--Observer at 5km/h

Difference Wind vs. boundary: 2km/h less the energy lost to the eddies.

Real wind over road, as seen in the ref.frame of the wind:

                         Wind, 0km/h rel. to observer
<<<<<<<<                 Boundary layer flow, 8km/h opposite
       |----------       Road
       ^--Observer at 10 mk/h windspeed

Difference Wind vs. boundary: 8km/h

Now this is really ridiculous. How can something be reversed from zero? The resultant direction is undefined! Therefore it might as well be:

Real wind over road, as seen in the ref.frame of the wind:

          ^
          ^
          ^
          ^
          ^
          ^
          ^
          ^
          ^           Wind, 10km/h rel. to observer going sideways
      ><><><><><      Boundary layer flow, every which way
      |----------    Road
       ^--Observer at 10 mk/h windspeed

Difference Wind vs. boundary: all backwards and fershimmelt

QED

 

[sol invictus]

An impedance mismatch causes reflections in transmission lines for example and has a mechanical counterpart.
http://en.wikipedia.org/wiki/Mechanical_impedance

As I said, systems described by linear wave equations have an impedance. Rivers flowing around rocks do not.

Incomprehensible. Do you or do you not agree that an anemometer carried by someone standing on a moving belt, as in John's figure, would read as I said? If not, what will it read?
That's a direct and simple question - answer it or look like a fool yet again.

I don't have to.

So you take the latter option, as expected.

(1)In nature, the boundary layer flows in the direction of the wind, but slower.

In the frame of the ground, yes. In the windspeed frame it flows in the opposite direction.

(2)On the treadmill, the tailwind is said to flow up the belt, to drive the rear ofthe cart.

The boundary layer, moves with the belt, and so in the opposite direction of the tailwind.

In the frame of the ground the treadmill rests on (which is equivalent to windspeed frame), the boundary layer moves in the opposite direction, just as with "real" wind. In the frame of the treadmill belt, it flows in the same direction, just as with "real" wind.

(3) It is not possible to reconcile this situation in a manner that makes them equivalent.

Manifestly false.

Patently obvious. 10 seconds though for me, if not immediate.

Yes, you're completely wrong in no time flat.

 

[Christian Klippel]

Tag team! I can step in here.

Gahh, humb invasion

Fine so far. Yes, it is as it was.

And as never should be. Or did you forget about Led Zeppelin?

Real wind over road, as seen in the ref.frame of someone moving at 5km/h:

       >>>>>            Wind, 5km/h rel. to observer
 <@<@<@                 Boundary layer flow, all swirly
      |----------       Road
      ^--Observer at 5km/h
Difference Wind vs. boundary: 2km/h less the energy lost to the eddies.

OK, an obviously stoned boundary layer. No wonder, i would feel stoned as well if subjected to humberphysics.

Now this is really ridiculous. How can something be reversed from zero? The resultant direction is undefined! Therefore it might as well be:

Real wind over road, as seen in the ref.frame of the wind:

          ^
          ^
          ^
          ^
          ^
          ^
          ^
          ^
          ^           Wind, 10km/h rel. to observer going sideways
      ><><><><><      Boundary layer flow, every which way
      |----------    Road
       ^--Observer at 10 mk/h windspeed

Difference Wind vs. boundary: all backwards and fershimmelt

Uhum. I see you have an obsession with phallic symbolism. But hey, it's ok. Lot's of stoners get a hard one
Besides, where have the kinetic balls gone?

But hey, don't be too stoned to get the German language right. It is "verschimmelt", you know?

QED

So shall it be!

 

[Christian Klippel]

I must say that humb really made my day with his post. I would almost nominate that one. Almost too god to be true

 

[ThinAirDesigns]

Almost too god to be true

And that's pretty damn god. :^)

JB

 

[spacediver]

No sale, I will not be led. Live in ignorance if you wish. I have given enough information, for anyone with adequate intelligence to see what is actually an incandescent error
You insistence on "math" shows that all of you, do not have the insight or native intuition to see that error.

You need to be shown. Take it or leave it.

well we're not convinced, so obviously we all have inadequate intelligence.

Why not stoop to our level so you can show us the error of our ways?

You've not accomplished anything so far in convincing us of anything yet, so your current strategy is inadequate.

Solve our high school physics problems for us Humber. Step up to the challenge.

 

[humber]

I'm sure you can tell us what mechanical structure a rock is, can you? And how a flow consists of complex frequencies, can you?

It's a rock. More dense than water, immovable perhaps. Notice how waves develop on the surface? See, frequencies. Waves.

Ah, i see. Again you are moving the goalpost and switch the topic. No one talked about acoustics, let alone a Helmholtz resonator. But then, it's your usually way of the "look, there is elvis!" strategy, just to try to distract others from pointing out your obvious errors.

Elvis has left the treadmill.

 

[humber]

Humber telling somebody they know very little? My irony meter just pegged (I'm an old fart so it's analog).

I have a digital irony meter.

[/QUOTE]
I still think it's safe to say that "impedance" has nothing to do with a river running over a rock.[/QUOTE]

Means, I don't know, but...

Of course not. There is a complete set if laws, just for rocks.

 

[John Freestone]

It is blindingly obvious that the flow is moving with the belt. This is because the belt powers the "wind", whereas a road does not power the real wind, and even then, it is going the wrong way, because without air flow to represent the wind, it cannot stay on the belt, let alone travel.
It is fundamentally flawed. This boundary example is rock-solid proof of that claim. No more games.

Hard to figure out what that means, because although it follows the rules of English syntax, beyond that it's just muddle. (What does power the real wind, by the way?)

Let's simplify the question of the "a-h" windspeeds. Forget the speed, just tell us the direction at each level. Finding this to be misleading because of the perspective that it's viewed from? Fine, pick any perspective you like, tell us what it is, and tell us the direction of the airflow at each level. This is a question. If you feel that we have the wrong answer, then you have to tell us what the right answer is, not just claim that the question is wrong.

That is another fine plan, jjcote, just getting the directions from humber, with a single and unchanging frame of reference.

Humber wrote:


Let me solve this tricky syntactical conundrum for you .


Even a layman should appreciate that the boundary layer is viscously attached to the belt, so will flow with the belt.

Agreed

The boundary layer is associated with the belt, because the belt is the only source of power for the treadmill "winds". However, it is not the case that roads power the wind or boundary layer in the external world ( a.k.a nature, the environment).

Agreed, as far as makes no odds.

The belt-generated boundary layer, is in the opposite direction to that found in the external world ( a.k.a nature, the environment).

Agreed, at least in the sense of "I understand what you're trying to say."

In the external world, the boundary layer flows in the direction of what is often called 'the wind', whereas on the treadmill it flows opposite to that expected direction.

Agreed.

This suggests that the cart is actually traveling the wrong way and should be traveling with the belt, in which case, the boundary layer would be in the appropriate direction.

No, because if it travelled with the belt, it would be travelling into a belt-generated headwind, and it is a dDWfttw vehicle. For Christ's sake, please try to understand that for the treadmill situation NOTHING is going the wrong way. EVERYTHING is shifted 10 m/s. It is as simple as that. That statement is virtually the whole explanation of the velocities. Where once a cart would have been going 10 m/s to the right to match the 10 m/s tailwind, it is now at 0 or around there (a shift of 10 leftwise). Where the ground was still, it is now going 10 to the left (a shift of 10 leftwise). Where a person was standing measuring the windspeeds at different heights at 0, he is now doing so at 10 m/s to the left (a shift of 10 leftwise). Where once he measured a windspeed of 10 m/s to the right as he stood still, he now measures a windspeed of 10 m/s to the right - what? no change, no shift of 10 leftwise? No. Why? Because the wind has shifted 10 leftwise, but he has also (along with the belt) undergone a shift 10 leftwise.

Now, if you can understand still air (w.r.t. the room) as a 10 m/s "belt-generated wind" that is "going to" the right, which you grudgingly do (a shift of 10 rightwise), it is only one small step further to recognise a boundary layer flow of 1 m/s to the left (w.r.t. the room) as a 9 m/s "belt-generated wind" that is "going to" the right (a shift of 10 rightwise). That is...and this is the crucial bit...if you have got to the stage in your mechanical and physical knowledge to understand relative motion and frames of reference (and you have enough links to follow).

Similarly, a 10 m/s wind to the left at belt level (w.r.t. the room) is, by switching frames, motionless (a shift of 10 rightwise). What is the new frame in all these second cases? It is that of the belt. That is why I wanted you to say what you thought were the windspeeds recorded by our person going back with the belt, because they are identical to those in the land-based situation where the ground actually is still. Person and wind have both had a shift of the same amount, so the anemometer will read the same values.

However, this would result in the cart simply traveling with the belt as expected of a can of beans, perhaps. (Not very noteworthy.)
Without airflow to represent a tailwind, the cart cannot travel with that belt beyond that limited manner. It is therefore a matter of necessity to the windspeed claim, that the cart be set against the travel of the belt.
(It looks more impressive, but that is all.)

No. You know that if the cart is pushed backwards by the belt into the air behind it, that is a tailwind. The even funnier thing is that if you had a clue how the cart worked, you'd realise that it is impossible to run it that way [ETA: the way you suggested, with the belt], and if you turn it round, it still goes left to right.

Is that not clear? You want maths for that? Walk before running.

What we wanted was a simple number, or set of numbers, or a direction. Your maths was not very helpful, because you were trying to measure different speeds and make your new-fangled paddle spin with them, and because, as always, your frame of ref was all over the shop.

(1)In nature, the boundary layer flows in the direction of the wind, but slower.

YES, you don't need to repeat things we all have agreed.

(2)On the treadmill, the tailwind is said to flow up the belt, to drive the rear ofthe cart. The boundary layer, moves with the belt, and so in the opposite direction of the tailwind.

There you go again, shifting frames. That statement is so monumentally stupid, young children are probably coming here from bebo just to laugh at it.

Look at it this way. You say the b.l. moves with the belt and so is going the opposite way to the tailwind. But the tailwind is at 0 (you said so yourself), so the b.l. can't be opposite to that. What wind is opposite to stationary air? The tailwind you talk of only exists once whateveritis that is your frame of reference is moving to the left, and as your frame moves to the left, miraculously the value of the b.l. changes too, since all motion is relative, and is shifted right by that same amount. Like if you are on a train, and another train seems to be going backwards, but in fact is only going forwards slower than you. You're overtaking it, so it's going backwards from your frame. Jesusss, how long do we have to explain relative motion?

However, you have been precise enough, I think, for my purposes. You do actually seem to have said that when a surface is driven through a fluid, there will be two opposite flows created. The one near the surface is 'reversed' so as to go faster than the surface. Lovely. Let's phone NASA.

(3) It is not possible to reconcile this situation in a manner that makes them equivalent.

(4) The "layers" do not matter, because of that eclipsing error.

The 'two directions of flow at once" error. Yeah, I'd say that was pretty eclipsing.

Patently obvious. 10 seconds though for me, if not immediate.

Less haste, more speed, or just try to go in the right direction.

 

[Christian Klippel]

It's a rock. More dense than water, immovable perhaps.

Indeed. And now, what exactly makes that rock a mechanical structure, so that you could compare it to mechanical impedance?

Notice how waves develop on the surface? See, frequencies. Waves.

You should get yourself familiar with the nature of frequencies. Just because we use "waves" to describe sound doesn't make "waves" as we see on the water the same thing.

Come on, such a superior, kingly know-all like you should have known that, right?

Or are you an example of the emperor with no clothes?

Elvis has left the treadmill.

So did you. Just that your treadmill is what we call reality.