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

[Tunny]

Seeing Humber act as if KE were a conserved quantity is laughable.
Seeing Humb act as if things can't float locked in with the flow of the water is laughable.

Perhaps you're new to this entertaining thread, but one of these people is apparently quite serious, while the other is a hilarious, over-the-top parody. The fact that it is difficult to tell which is which should be quite telling.

Tunny

 

[John Freestone]

I think humber was talking about gravitational potential energy, which he seems to think will somehow affect lateral movement.

Yes, I gathered that. It's probably another hook he's chucked out to see if it'll catch us arguing over a new topic and move on from the one he's just lost.

I took the bait, questioned whether even that part was correct, and pointed out that whether it was or not, it had nothing to do with the lateral movement of them.

I imagine that if something is floating (like a hot air balloon), we can reverse the direction for it to gain gravitational potential energy: it would need to be pushed down, and would lose that energy by rising again. Even this may be relative, and of course the air is falling round a rising balloon. Anyway, it's just another of those side-alleys humber takes us down - I learn quite a lot from humber, very indirectly.

 

[Modified]

It's pretty "obvious" when you think about it, but perhaps because of the way most of the material is presented at high school level (as I vaguely recall, often using the ground as the frame of reference, and hardly ever looking at the same system using different frames)

That is an interesting point. Even in my intro college physics textbooks, frames of reference are given quick treatment (though at least the concept is introduced before momentum and KE), and the language used most of the time assumes either the earth, surface, or some other frame of reference without specifically saying so. Have things changed since that time (15 years ago), or are there intro texts that don't suffer from this problem? It does seem to be something that needs to be emphasized more.

 

[humber]

I don't normally enter this discussion, but there is something that didn't get said recently:



Drag is the force that drives the paper boat which had been dropped into a flowing river. What other force do you think is accelerating the boat forward?



Let me remind you that , which you have acknowledged twice.

When the paper boat is dropped into a flowing river, u is high initially, and decreases as the paper boat accelerates downstream.

No, there is also momentum exchange with the water driving the item.
If it were a car in air, then the engine would not be needed because, apparently, it is not in the equation
If your argument were correct, all items regardless of drag coefficient, would reach waterspeed.
To make your point, I would ask you to find examples of where this is the case.

 

[humber]

S.

Hot air balloons have an engine. A heat engine. Shut up.

 

[Modified]

I imagine that if something is floating (like a hot air balloon), we can reverse the direction for it to gain gravitational potential energy: it would need to be pushed down, and would lose that energy by rising again.

In the usual description, GPE uses weight and so does not include buoyancy. Buoyant objects are described as gaining GPE as they rise. I suppose you could combine GPE and potential energy due to buoyancy and call it altitude potential energy.

 

[Tunny]

If your argument were correct, all items regardless of drag coefficient, would reach waterspeed.
To make your point, I would ask you to find examples of where this is the case.

Um, all of them?

I'd prefer to say they would all approach water speed, with a more "draggy" item approaching it more quickly, and a more streamlined item approaching it more slowly, but any floating object would quickly converge to water speed.

As a specific example, if I were to place a streamlined model canoe and a squarish barge of similar masses into a river flowing 10 mph, the barge would be dragged downstream ahead of the canoe, quickly reaching 10 mph (or 9.9+, say), while the canoe would take several yards to reach the same speed, at which point they would maintain the same speed and relative distance apart.

I venture to say that any child who has played "Pooh sticks" has confirmed this experiment.

Tunny

 

[Modified]

If your argument were correct, all items regardless of drag coefficient, would reach waterspeed.

By suggesting they don't, you are suggesting that an object pushed and released in still water will reach some fixed speed and keep going. Once again, if an unpowered object starts at some speed relative to the water it eventually slows to effectively zero relative to the water. The speed of the water relative to anything else is irrelevant (ignoring the effect of the air).

 

[humber]

For a third time, you acknowledge that u is the velocity of the object with respect to the fluid it's immersed in.

You also agreed that F_drag=c(u) u², with c(u)>0, and that F_drag is the only force acting.

Third time, yes.

Tell us, humber - what other solution to F = c u²=0 is there other than u=0, given what you just agreed to? Or are you flipflopping yet again?

There are two solutions for U=0 One where the object is still in still water, and the one you cite. There are intermediate values between those cases, that make your solution impossible.

humber, you just agreed that F_drag=c(u) u², with c>0, and that u is the velocity of the object with respect to the fluid it's immersed in. That means at waterspeed, which is u=0, F_drag=0. Even you should be capable of inserting u=0 into that equation.

Capable enough not to fall for a sophism like that.

So please, enlighten us - what have you flipflopped on this time?

You already have my answers to the above. You have put forward the same argument, but more bold text this time.

To make this lucid for you, yes the object is in the water, and driven by that water, so how else could it be?
There are two forces. One driving the object and one retarding it. Let's say that for our given situation, the driving force is linearly related to velocity, and the retarding force the square of that velocity.

The maximum velocity is the solution to those simultaneous equations, which I have shown graphically. The object's final speed will be dependent on shape and drag coefficient.

As you can see, to reach waterspeed, (u = 0), would require the driving force be greater than the drag for the entire time to waterspeed. That is impossible.

I'm not going to bother with the rest of the garbage in your post - this is as clear as it gets.

No, I did not expect that you would. I have may answer on that score.
So failing that approach, please show evidence of examples of items traveling at waterspeed when driven by the water alone.

 

[humber]

By suggesting they don't, you are suggesting that an object pushed and released in still water will reach some fixed speed and keep going. Once again, if an unpowered object starts at some speed relative to the water it eventually slows to effectively zero relative to the water. The speed of the water relative to anything else is irrelevant (ignoring the effect of the air).

It does no mean that. No, it slows to be less than the speed of the water.

There are three of you saying the same thing, so I would expect that one of you could find evidence of objects that do as you say. That is, reach waterspeed, when driven only by the water.

 

[humber]

A
Seeing Humber act as if KE were a conserved quantity is laughable.

It's called Kinetic Energy. Do you think that energy is not conserved?
That it is conserved, is one of science's most basic precepts.

 

[Christian Klippel]

There are three of you saying the same thing, so I would expect that one of you could find evidence of objects that do as you say. That is, reach waterspeed, when driven only by the water.

What about a bunch of water molecules? How comes that they can indeed travel at the same speed as water, while other molecules in the water should not? What makes them different? Lighter, heavier? What about molecules with the same weight? And so, what makes a bunch of molecules cobbled together to form a body different from a bunch of molecules cobbled together to form water?

As for evidence, it is you who has not yet shown any supportive links or evidence that backs up any of your claims, except for the "evidence" you made up yourself (that is, your drawings). You said many, many times that you will come up with something, but always failed to do so.

Again, that many people tell you that you are wrong, and that these very people back up their claims with supporting links and evidence should give you a really, really big hint that you are indeed wrong. After all its you against many others. Don't you see what's wrong with that?

 

[humber]

Um, all of them?

I'd prefer to say they would all approach water speed, with a more "draggy" item approaching it more quickly, and a more streamlined item approaching it more slowly, but any floating object would quickly converge to water speed.

As a specific example, if I were to place a streamlined model canoe and a squarish barge of similar masses into a river flowing 10 mph, the barge would be dragged downstream ahead of the canoe, quickly reaching 10 mph (or 9.9+, say), while the canoe would take several yards to reach the same speed, at which point they would maintain the same speed and relative distance apart.

I venture to say that any child who has played "Pooh sticks" has confirmed this experiment.

Tunny

Not my argument. If you look at the mathematical argument put forward, the only discriminator is U=O, for any value of c. That means all objects.
You are right to say that objects reach a velocity dependent upon their drag, and approach waterspeed, but they do not reach it.
Pooh sticks is perhaps appropriate. In this case, it is difficult to asses the real velocity w.r.t. the water, and if one is 5% slower that the other? Surface turbulence and so forth. make that difficult.
If you tow a dingy behind a boat, does it have a bow wave?

 

[Christian Klippel]

As someone who taught a college course in ship stability I would like to point out that you are talking nonsense.

Seeing Humber act as if KE were a conserved quantity is laughable.
Seeing Humb act as if things can't float locked in with the flow of the water is laughable.

Hello Molinaro,

you might also want to read the original "Down wind faster than the wind" thread, or at least what humber wrote there. You will then "learn" that in the humberverse slipping wheels do improve the performance of carts, that small, lightweight propellers can store massive amounts of KE to keep a cart on a treadmill going forever, that you can measure velocity with any measurement system (which would include things like beakers, thermometers, multimeters, etc. Just ANY measurement system, you know), and so on. There must be physics revolution coming

You only get half of the fun in this thread here.

 

[humber]

Hello Molinaro,

you might also want to read the original "Down wind faster than the wind" thread, or at least what humber wrote there. You will then "learn" that in the humberverse slipping wheels do improve the performance of carts,

Yes, that can happen. If you put oil on the road does that stop the car, or make it slide?

that small, lightweight propellers can store massive amounts of KE to keep a cart on a treadmill going forever,

Try calculating that, by the way.
No, it can store some and use it. It can be later replenished. Forever is for pixies.

that you can measure velocity with any measurement system (which would include things like beakers, thermometers, multimeters, etc.

I have a TEK TDS210. With my knowledge, I can measure velocity.
In the 16th Century, Tycho Brahe took some remarkable Astronomical measurements, using only simple tools. He measured the diameter of the Earth within 5%.

There must be physics revolution coming

You missed it.

You only get half of the fun in this thread here.

 

[humber]

What about a bunch of water molecules? How comes that they can indeed travel at the same speed as water, while other molecules in the water should not? What makes them different? Lighter, heavier? What about molecules with the same weight? And so, what makes a bunch of molecules cobbled together to form a body different from a bunch of molecules cobbled together to form water?

Looks like you answered your own question, then contradicted yourself.

As for evidence, it is you who has not yet shown any supportive links or evidence that backs up any of your claims, except for the "evidence" you made up yourself (that is, your drawings). You said many, many times that you will come up with something, but always failed to do so.

Shocking eh? My ideas. I do that sometimes, because posts in between suggest that I should do otherwise. Also, I don't always have the time.

Again, that many people tell you that you are wrong, and that these very people back up their claims with supporting links and evidence should give you a really, really big hint that you are indeed wrong. After all its you against many others. Don't you see what's wrong with that?

Think so? The links are usually attempts to bluff, or evade.
See if you can find some evidence. And while your at it, see if A journal will publish your results. Strangely, academia thinks not.
Good point, though. Physics by the lowest common denominator. Press your button now. If you took the time to study this yourself, you would not be so dependent upon the opinions of others.

 

[Christian Klippel]

Yes, that can happen. If you put oil on the road does that stop the car, or make it slide?

And this does improve the performance exactly how?

Try calculating that, by the way.
No, it can store some and use it. It can be later replenished. Forever is for pixies.

And it replenishes it how exactly, without making the cart go backwards first to take up the energy?

I have a TEK TDS210. With my knowledge, I can measure velocity.

And you do that how by using the DMM only?

In the 16th Century, Tycho Brahe took some remarkable Astronomical measurements, using only simple tools. He measured the diameter of the Earth within 5%.

And the diameter of an object has to do what exactly with it's velocity?

You missed it.

No problem since there is nothing noteworthy anyways.

See, you only spout out "i can", "i know", etc... but never give examples and evidence of it. You talk a lot but mean nothing in the end. You demand evidence and backup's for claims of others, but you constantly fail to do that for your own statements. And still you think that people should take you serious? That's laughable.

 

[Christian Klippel]

Looks like you answered your own question, then contradicted yourself.

Where did i answer my question, and where did i contradict it? This is again you reflecting yourself onto others. Nothing new here.

Shocking eh? My ideas. I do that sometimes, because posts in between suggest that I should do otherwise. Also, I don't always have the time.

Given the amount of time you have to post your nonsense here, lack of time can't be the problem at all. And yes, your ideas are indeed shocking. Shocking to every sincere and sane person.

Think so? The links are usually attempts to bluff, or evade.

Same could be said for every thing you hand out here, it works the other round as well. Only problem is that you are the only one defending your nonsense, while all the others agree that you spout nonsense. Still you don't see the pattern here?

See if you can find some evidence. And while your at it, see if A journal will publish your results. Strangely, academia thinks not.
Good point, though. Physics by the lowest common denominator. Press your button now. If you took the time to study this yourself, you would not be so dependent upon the opinions of others.

Why me? Many links have been giving to lots of evidence, many explanations have been given, but still you reject it. You asked if somebody can find someone else to confirm his views, that person did, and immediately you dismissed it. You try to put yourself above everything else, as if you were the one only source of truth.

What scientific paper have you published so far? You make demands of showing what other have done or tried, and can't give the same for yourself? Talk about hypocrisy.....
Edit: And what should i try to get them to publish? That KE is relative? That velocity is relative? Do you really think they would publish stuff that is know for centuries by now? You should try to get some of your nonsense published. And in a respected journal, of course. So far, what you have given could only end up in crackpot journals at best. You know, the guys that propose free energy and stuff. Because the level of quality of your statements is the same as the quality of articles in those "journals". The yellow press of physics.

And, studying you is way more fun. You never depend on others to explain or to learn things? Do you want to say you were born and already knew everything? If not, how can you be sure that the person who told you stuff wasn't wrong? See, your arguments just backfire to you all the time. I call that poor reflection of yourself onto others. You might think that what you say is clever, but in reality it's plain stupid. After all, you are the only one here thinking that you are clever. That really should give you something to think about.

 

[humber]

And this does improve the performance exactly how?

Do you think that if the wheels are retarding motion, it may be useful to decouple them from the road?

And it replenishes it how exactly, without making the cart go backwards first to take up the energy?

Backwards is not the opposite of spinning.

And you do that how by using the DMM only?

If you buy a ruler, do you look for the instruction leaflet?

And the diameter of an object has to do what exactly with it's velocity?

Oh dear. He was an example of a man who knew how to measure things, even though he didn't have a meter with "Earth Diameterometer" written on it.

No problem since there is nothing noteworthy anyways.
See, you only spout out "i can", "i know", etc... but never give examples and evidence of it. You talk a lot but mean nothing in the end. You demand evidence and backup's for claims of others, but you constantly fail to do that for your own statements. And still you think that people should take you serious? That's laughable.

You could be looking for those waterspeed objects.

 

[humber]

<snip>

I find the time. You don't.