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

Status
Not open for further replies.
Hi Brian. Surely you're not trying to explain the physics of this to humber at this stage are you? Mind you, I was trying to do that very recently. If anyone else tries to explain to humber why objects immersed in fluids generally reach fluid speed, they need a profoundly different approach.
Brian-M said:
YES! When it's travelling at wind speed you could think of it (in a way) of being held in a "pocket" of air travelling at the same velocity... except that this "pocket" constitutes the entire body of air.

If the balloon is travelling at less than windspeed, then the air pushes the balloon to a faster speed as the air passes by. As such, the balloon cannot remain below windspeed because the wind keeps pushing it faster.
Click to expand...
No, humber has explained that that is not the case. A balloon goes slower than the wind, faster than the wind, and at the mean speed of the wind, but not at windspeed. That's a ridiculous idea. Er, when I say 'explained', I mean 'asserted'. I asked about five times what force of resistance balances that push of the passing air, but to no avail. He ignores it, or doesn't understand it, or is lying about it. He pretends that 'drag' is different from 'force' and somehow thinks that since fluids have drag that's only going to slow down the balloon. I have explained it several times from the orthodox position - drag accelerates it - much as you are doing here.

However, if it is travelling at windspeed it can remain at that speed indefinetly, because the wind is no longer exerting a net force on it, and objects in motion tend to remain in motion unless acted upon by an outside force.
Click to expand...
No, humber has, er, explained that Newton was wrong about forces and motion generally. Bodies travelling at constant speed require a constant force to overcome their coupledness (I'm not sure if that's the right term) to the innertial frame of the Earth, which is the only valid frame of reference. You really should keep up. If we keep harping on about centuries old physics we'll never develop transport systems.

"Wind" is the relative motion of the air. The air is moving relative to the surface of the treadmill (which is acting as the ground).
Click to expand...
Sightly off topic, but again he's explained: The treadmill is nonsense. That is not rhetoric. It is stupefyingly wrong. Which is kind of funny if you read it right. Humber is a genius. That is not rhetoric. It is stupefyingly wrong.

If wind is the relative motion of the air, and the air has motion relative to the surface treadmill, then for something on the treadmill, there is wind.

Every critic of the treadmill test forgets this.
Click to expand...
Ah, but not 'real wind': although he hasn't defined that, there's obviously a difference. He could use a balloon, BTW, to show us that the treadmill is wrong. Just before Christmas, I think it was, he promised 'unambiguously clear' information that would show us that the treadmill was wrong, and designs for his 'generic windcart', whatever that is. I have one myself, a cardboard box I've mounted on castors. You should see it go!
 
spork said:
So now we have Mark Drela on one side (with his PhD in Aero, prof. of Aero at M.I.T. and generally thought to be one of the sharpest aero minds in the field), and on the other we have humber (a guy who can't construct one sentence without changing his mind twice midstream).
Click to expand...
Ah, but do you know what that midstream speed is? If you dipped a hydrometer into humber's mind...
 
spork said:
spork brilliantly and against all odds predicted the future as follows:



So now we have Mark Drela on one side (with his PhD in Aero, prof. of Aero at M.I.T. and generally thought to be one of the sharpest aero minds in the field), and on the other we have humber (a guy who can't construct one sentence without changing his mind twice midstream).

If anyone for a moment thought there was some hope of putting humber on the right course - I hope this puts that to bed for you.

humber is to be used for entertainment purposes only. Any other use is not covered by warranty.
Click to expand...


Actually, I Googled and could not find this reference,so perhaps we should see how many other comments there are that are not quite what you would like. Link.
I can contact Dr Drela, even if you can't.
I look forward once again to the opportunity to show that you are a fraud.
 
spork said:
This is brilliant. I've been flying hang gliders and sailplanes for almost 15 years now. When I want to ride a thermal I have to first FIND the thermal. 99% of the time this requires me to move relative to the air mass I happen to be in. Then if I want to make use of that thermal I have to dwell in it. I fly slower in lift than I do in sink (yes - if there's lift there's also sink), and I circle in that lift while I speed through the sink in relatively straight lines. I can't wait to hear how the balloon "operator" manages this!
Click to expand...
Done that too, Spork. The rest of your remark is a result of your low IQ.
Hot air balloons have an engine. As probably all academics have told you, that makes a difference.
Balloons are raised avoid you talking about failures of your treadmill, which when I ask you, you do not answer. You have done that at least three times, and then talk once again about balloons. I bet you do that to the academics that you court.

Interesting that a man who likes to call academics idiots and lacking intuition, should so often look for their approval. The thing that you really crave, academic credibility, is the one thing you will never get.

Hopefully humb will take a crack at this one too. I'm going to dial 9-1 and keep my finger over the 1 when I read the response. Whether we get humb or humber I'm likely to die of laughter either way.
Click to expand...
You will giggle, yes.


For the record:

1) I honestly can't follow that sentence, but I'm sure it says something wrong.
2) I've never been face to face with Mark Drela, and I didn't pose the question. I did enjoy the fact that he just happened to dispose of both of humber's claims (balloons that can't keep up with the wind and carts that can tell the difference between inertial frames) all in one go.
Click to expand...
No, that is right, but Mender used that term. Dr Drela's remarks have nothing to do with support for your treadmill. It denies it when he uses "windmass"
That is right, windmass is missing from your treadmill. As you have been told many times.

The rest is again about balloons, again. Professor Whiteman did not agree with your ideas about the speed of those objects, and denied so in a reply to me. There is no support for you in Drela's remarks, either.
So, perhaps you can find another source to misrepresent, though I will need the link.
Relative velocities are not frames of reference. He labels your idea, a "misconception". For you, differential velocities are a magical wonder.

No oyu dis not. His answer was not to you, or about the treadmill.

HEY! That's two questions. And besides, you're just poking at the side show freak now. You're clearly just giving him fuel to entertain us. Why else would you ever think to ask him a question more subtle than "what does 2+2 equal?".

n fact I'm going to make a point here. And this is in all seriousness. humber - I claim 2 + 2 = 4. What do you think of that?
Click to expand...

I told, I know what you think.
 
RossFW said:
Which they use to alter the density of the air in the envelope in order to provide buoyancy and for no other purpose. It in no way provides thrust for lateral movement. Hydrogen balloons do NOT have an engine, and move at the speed of the wind, as do hot air balloons.
Click to expand...
This contains at least tow errors RossFW. Firstly, a balloon can raise its altitude, and gain potential energy. When descending, that energy is converted to lateral velocity. Aslo, the air is heated, so the air is less dense than the surrounding air. There is a difference of buoyancy over a passive balloon.
Hydrogen balloons are less dense than air. A windcart is not.

No, they don't. They work just fine in still (lateral AND vertical) air.
Click to expand...
[/QUOTE]
Yes, because the engine heats the air to make the balloon buoyant. Windspeed is a different matter.
 
spork said:
Including professors of Physics, Aero, and M.E. (yes I can name one of each - and I'm sure there are MANY more). It makes me want to cry.
Click to expand...
Classic. All those academics who don't agree with you. Hilarious that you think Drela does. Let's see the full list of Professors that do not agree with you. Go on.

I didn't just post Drela's post to this list. I also emailed it to a professor that swears the treadmill and the wind over a road are unrelated.
Click to expand...
Of course they are unrelated.

This seems brutally obvious to me. But I hoped maybe this guy would budge from his humber-like position if he heard it from another PhD. I'm making myself sad just typing this.
Click to expand...

You would need a baseball bat to get an academic of any standing to agree with you. Save your tears.

So, despite one desperate attempt to twist Drela's words to your advantage, academia thinks you are completely wrong.

I told you, I know what you think. No, once you've missed the boat, it's too late.
 
Last edited:
When descending, that energy is converted to lateral velocity.
Click to expand...

That will come as a suprise to several of my friends who are competition balloon pilots. Exactley how the hell is it suposed to do that??
 
So here's the current status:

humber claims that Drela's statement does NOT support the case that the balloon goes the speed of the wind or that it supports the treadmill being equivalent to a road with a tailwind.

BUT..... He is also sure Drela never said what I quoted directly (as a cut and paste). humber thinks the statement supports his own argument, but is now on a mission to prove Drela never said it.

And he refuses to respond to my assertion that 2+2 = 4

You want a link humber? Here you go:
http://www.boatdesign.net/forums/boat-design/wind-powered-sail-less-boat-24669-34.html#post246355
 
Subduction Zone said:
One more question for humber. humber it you jumped at a high altitude, say 20,000 feet, would you fall at, faster, or slower than your terminal velocity? And why?
Click to expand...

The body accelerates until terminal velocity is reached.
If the altitude is great enough, and so the air thinner, the body may exceed the nominal terminal velocity during that time, but will slow in denser air to a velocity that is largely independent of initial height.
 
All powered by the velocity difference between two media". Yes, relative velocities
Click to expand...

Which is to say the difference in velocity between the surface and the air. It doesn't matter which one (or both) is moving, just that there is a difference.

Simple concept, even an idiot could understand......
 
Thabiguy said:
I see a difference there. I think humber has been able to stay relatively polite through all this. I mean, sure, there is an occasional nip here and there, but it's nothing like the vitriolic, burning bile that GMB has been spewing.
Click to expand...

I don't know who he is. Would you like me to associate you with a poster of my choice?
 
RossFW said:
Which is to say the difference in velocity between the surface and the air. It doesn't matter which one (or both) is moving, just that there is a difference.

Simple concept, even an idiot could understand......
Click to expand...

It's not the velocities, that is too simplistic, RossFW.

The idea of differential or relative velocities is demonstrated every time that two cars pass or overtake each other. So, that is blindingly obvious right?

Yet, you think that I, and it seems many others, including all of the academics that Spork has forced himself upon, seem to have problem with that. Why?

Perhaps it's not the relative velocities that are in question, but something else, like airmass. That's just one of many problems with the treadmill.
 
jjcote said:
Um... does this mean that you don't know how to calculate the terminal velocity of the balloon? I don't care what the guy in the meteorology book was trying to do (although I'm completely aware of what he was doing, and you evidently aren't), I just want to use the numbers in his example to ask a simple question.

In a constant 1 m/s wind, what will the "terminal velocity" of that balloon be? Or do you need additional information?
Click to expand...

It seems that you both care and do not care. In that case, there can be no answer. I have given you the answer. The equation is an approximation that will not yield the correct result.

You did not address the remark, that if the balloon travels at windspeed, then it will not show any change in velocity, so how can you see the variations? This balloon does not travel at windspeed. Since you will not take reasoning, or check your text books concerning contemporary ideas concerning fluid dynamics. I will say this.

Some posts ago, I asked "Have you tried tracking a tennis-ball sized object behind a weather balloon?".
Well, I have, and they do not travel at windspeed, though sometimes, the ball gains on the balloon. Radar says so.
 
humber said:
Have you tried tracking a tennis-ball sized object behind a weather balloon?
Well, I have, and they do not travel at windspeed, though sometimes, the ball gains on the balloon. Radar says so.
Click to expand...


Do tell us all about that. That sounds almost like a "job". Were you employed at one time?

And why will you not respond to my assertion that 2+2 = 4 ?

I suspect the terms of your bet don't permit you to say anything that's actually correct.
 
RossFW said:
That will come as a suprise to several of my friends who are competition balloon pilots. Exactley how the hell is it suposed to do that??
Click to expand...

Ask a physicist. And then ask if the hot air balloon is less dense than air, and then ask if the air is constant flow. I don't care about those cases. They are not relevant to a passive object, i.e .a canoe in water, or parachute in air.
They are always raised, in all threads where Spork is concerned, to avoid answering questions about his treadmill. A red herring, as usual .

Anecdotal evidence sucks RossFW. It is the last resort when all else fails. In summer, countless hot air balloons pass over my house at some speed. Are they evidence for me or for you?

Just for the record, and a putative example, friction with the air can be used to convert vertical height into horizontal velocity. Something like this:
http://en.wikipedia.org/wiki/Tractrix
 
That humber likes to single me out as being the most wrong is a great source of pride for me. It almost makes me wish humber were more well known so I could add this to my resume.
 
Status
Not open for further replies.

Back
Top Bottom