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

[humber]

Very generous interpretation of the comic.

Miine: "If a kite falls in a vacuum because a Dog headed God on a treadmill let it go, does it make a sound?"

That's 'Lord Anubis' to you.
The kite won't fly in a vacuum, so the answer is, doh.
.

 

[Michael C]

[qimg]http://www.internationalskeptics.com/forums/attachment.php?attachmentid=12801&stc=1&d=1232929514[/qimg]

Anubis is angry. He wants to take his inertial frame of reference back to Walmart.

From the Walmart customer service department:

Dear Lord Anubis, We are sorry to hear that you are having problems with your frame of reference. Our technicians have tested the frame you returned to us and we can assure you that it is working exactly as advertised. We suggest that you should try not to hover on the treadmill. In respectful devotion, Customer service, Walmart Stores Inc.

 

[humber]

The annotated wisdom of semper;

BTW Humber, I am sorry it has been so long since you have been outside.

You have a curious way of expressing sympathy.

There is no further use for your ramblings Humber, but your drawings are cool as long as they do not purport to be technical and are considered only as art. Also, there may be a job for your rabbit, if she can spare some time from looking after you.

I am afraid that the rabbit does not indulge in the practices that you have in mind.

Does humber really understand physics more than is apparent in this thread?
Yes, but not much.
I think we are all going to miss that guy.

Doubtful, considering you hit the barn door.

Oh Humber, it has been backed up, it has been shown, there is no point doing it anymore. All the king's rabbits, nor all the king's Anubis can put you together again.

Well Humpty Dumpty, perhaps you can show me where, and we shall see who cracks first.

Just accept that you are unable to function in our world, and we can only view your's through theatrical device. If you ever need to work a problem such that it can transcend into broader reality, please give your rabbit full and proper authority, sign the power of attorney.

Yeah. Like physics is like, you know, all cosmic, and "nobody" can say what's real. You do seem unnaturally fond of my rabbit.

 

[humber]

Ooo, I haven't done that since '72


[qimg]http://www.internationalskeptics.com/forums/imagehosting/15144497d3301994d8.jpg[/qimg]

There you go. Now it's the right way up for you.

 

[semper]

Yeah. Like physics is like, you know, all cosmic, and "nobody" can say what's real. You do seem unnaturally fond of my rabbit.

Please, don't be jealous, it is just that your rabbit provides your only tangible connection with reality. Through that medium, we can connect whereas all your writing and diagrams appear meaningless. I'm not the only one, your rabbit has struck a chord with many here, who I'm sure believe as I do, that she really wants to help.

Sure, "nobody" can say what is real. Everything is perception, a construct of the mind, a matrix. That is why we rely on consensus, I can only assume that the pain experienced by another if we crash our cars is real. I do feel empathy, and I resort to honesty in trying to avoid that collision, the most honesty I find for that situation is in properly defined physics. It may be a matter of faith, but why do you argue? The rabbit is crying Humber, don't make the rabbit cry.

 

[fredriks]

Why doesn't Lord Anubis kite fly humber? Is he running forward on the belt? Is he floating on the belt (still relative to the room)?

O I see the answer now, The kite doesn't fly because humber says it doesn't fly.

I ques we have to talk to all pg, hg and sailplane pilots that are using a winch, static line etc to get into the air that that method is not possibly in zero wind so please stop doing it in zero wind. It is just an illusion that you guys get into the air.

Parasailing simple don't work either.

 

[fredriks]

Humber don't know more physics than it seems to but it is possibly that he to some extent know that everything he says is incorrect but that he like to write nonsense on the internet anyway.

 

[humber]

So I see you've never flown a kite, either.
If you fly a kite in "Real" wind and let go of the string, it accelerates to wind speed, thus losing relative airflow and lift, and begins to descend. If it is high enough, it wil reach wind speed and drop vertically wrt the air aound it.

This must be the 'Hamburg Interpretation' of kites. Kites do not need a string to fly, but to stop the from being carried away; to restrain them so they can be observed at "windspeed", like on a treadmill if you wish.
The cart is also "restrained", but in a different manner.
Some kites, because they are aircraft, may reach windspeed, but that is not important to the point of course.

If you run with a kite (or are on a long enough tredmill) and let go of the string, EXACTLEY the same thing happens wrt the air around the kite.

No, when released, the kite will continue to travel in the same direction, while losing its KE to friction with the air, and beginning to fall when the velocity is inadequate to keep it airborne. Very noticeable difference between real and treadmill.

It will look like a decelleration from the ground, but the kite is simply changing it's velocity to windspeed (which is zero WRT the ground), an acceleration vector with exactley the same direction and magnitude as if the wind was real (excluding boundary layer effects if it's only you running, but IDENTICAL if you were on a big enough treadmill).

The ground? Are you a Groundian?
From the belt observer's point of view, the kite will still move towards him after release, but since it is now decelerating, its average velocity will be less than belt's over that same time period, so increasing the distance between kite and observer. It will fall, to remain at a fixed distance from that observer.

If you were still on the treadmill and looked back, you would see the kite getting smaller (as it's distance from you is increasing) and it following a curved path, followed by a vertical path to the ground.

EXACTLY the same thing you would see in a "REAL" wind looking at the kite after you let go of it's string.

No. In real wind, the kite will remain aloft.

 

[humber]

It is a bit of a poser, is humber as incredibly stupid as he actually seems, or is he some sort of sick troll who really gets off on all of this attention that he is getting? Either way he is a big loser, and I think it is time to quit feeding this fool. Personally, I have to agree with spork, only a true believer would keep this nonsense up for 65 pages and over 2,500 posts.

Funny SZ. The number of times you refer to belief. It seems that the treadmill is a religious icon.
BTW. If your 'rocket scientist' brother wants to give an opinion, please invite him to do so, even if he disagrees with me.

 

[humber]

A real physicist doesn't have to make things up to be entertaining. This I believe shows that humber doesn't have the background to be faking it
PS: Don't use this poll to bash humber because that would be against the forum rules. Say what you think but be polite.

Maybe he can afford to be.

 

[humber]

Poll update:

Does humber really understand physics more than is apparent in this thread?

And the results:

Yes:
Clive: He Understands Much But Excludes Reason.

NO:
spork: his confusion is legit
subduction zone: only a true believer would keep this nonsense up for 65 pages and over 2,500 posts.
mender: I believe that humber is presenting things as he understands them.

Yeah, verily, do I walk in the shadow of Spork.
I have challenged you time and time again, yet you have not managed to refute one single point. When there is the opportunity, you are nowhere to be found, but make a triumphal return to count the dead.
You would not have a chance, and you know it.

 

[humber]

From the Walmart customer service department:

Dear Lord Anubis, We are sorry to hear that you are having problems with your frame of reference. Our technicians have tested the frame you returned to us and we can assure you that it is working exactly as advertised. We suggest that you should try not to hover on the treadmill. In respectful devotion, Customer service, Walmart Stores Inc.

Dear Walmart,
Thank you for your response. However, Lord Anubis remains angry. It was his intention to fly kites indoors, so that he could remain close to his concubines. It transpires that the product is unsuitable for this purpose, and indeed many others. However, it does seem to be useful as an exercise machine, and that may be the more appropriate way to market this product.

Regards,
Imhotep

 

[humber]

Why doesn't Lord Anubis kite fly humber? Is he running forward on the belt? Is he floating on the belt (still relative to the room)?

O I see the answer now, The kite doesn't fly because humber says it doesn't fly.

It falls to the ground because there is no wind, Fredriks.

I ques we have to talk to all pg, hg and sailplane pilots that are using a winch, static line etc to get into the air that that method is not possibly in zero wind so please stop doing it in zero wind. It is just an illusion that you guys get into the air.
Parasailing simple don't work either.

Can you spot the difference, Fredriks. They use wind to fly.
Why do they not work in what is said to be a windtunnel?

 

[fredriks]

It was his intention to fly kites indoors,

Are you suggesting that it is impossibly to fly a kite indoors (in zero wind)?

Lord Anubis clearly needs a larger home and a longer treadmill. A home and treadmill was not included in the package from Walmart.

 

[fredriks]

Can you spot the difference, Fredriks. They use wind to fly.

Here are some facts. No airplane, pg, hg or sailplane needs a wind to fly (ask your bunny). It is possibly to winch any airplane, pg, hg or sailplane in zero wind.

We have a couple experts about this on the forum at least the following persons. I am a hg and pg pilot, Spork and JB are a HG pilots and might fly something else. I am sure that all of us have winched or aerotowed in zero wind and flown in zero wind. And RossFW is of course also an expert.

Can you spot your error humber?

 

[RossFW]

This must be the 'Hamburg Interpretation' of kites. Kites do not need a string to fly, but to stop the from being carried away;

So you HAVE never flown a kite.

Some kites, because they are aircraft, may reach windspeed, but that is not important to the point of course.

If they are at windspeed, they have no relative airflow, so what are they using to produce lift?

I used to own a glider, humber. Are you suggesting on a windy day I could just climb in it and fly away? You see, we used to attach them to a "String" (a winch) and tow them up.

No matter what the horizontal movement of the air, unless there was some vertical somewhere (Thermal, ridge, wave) you couldn;t stay up.

And neither can a kite unless something anchors it in order to stop it moving ay windspeed, and thus with no relative airflow.

Amazing that you claim such in depth knowledge, and don't even know how a kite works!!

 

[RossFW]

Here are some facts. No airplane, pg, hg or sailplane needs a wind to fly (ask your bunny). It is possibly to winch any airplane, pg, hg or sailplane in zero wind.

We have a couple experts about this on the forum at least the following persons. I am a hg and pg pilot, Spork and JB are a HG pilots and might fly something else. I am sure that all of us have winched or aerotowed in zero wind and flown in zero wind.

Can you spot your error humber?

err, fred...

I'm a Boeing 777 instructor pilot, former Australian champion Aerobatic pilot, Silver C glider pilot and former Parachuting instructor.

Can I be on your list?

I even know how a kite flys!!

 

[humber]

Okay, I'm willing to exchange answers, humber.

OK. Must be The Commonwealth that makes the difference?

I'm assuming that your diagrams are meant to show a difference between what happens when Anubis releases the kite string outside while standing on the ground with a 10 m/s wind blowing and when he releases the kite string when moving on the now ubiquitous treadmill scenario.

Yes.

First diagram: Anubis releases the string. I'll pick an arbitrary number of seconds that the kite takes to fall to the ground since you didn't specify a height. So the kite takes 3 seconds to fall to the ground. The distance between Anubis and the kite is again unspecified, so I'll say it is 50 m. When the kite is released, it immediately assumes the speed of the wind, moving away from Anubis at 10 m/s. In the three seconds that it takes for the kite to fall, the kite moves 30 m farther away, for a total distance that Anubis has to cover to get his kite of 80 m. He walks the 80 m along the ground, picks up his kite and takes it back to Walmart for a refund.

Yes, no numbers. It is a general case. The time that the kite takes to fall, depends only upon its mass, and therefore KE, and it's area, and so total friction to the air.
At the point of release, the kite will continue in the direction of the belt but decelerate, so its average velocity will be less than the belt, and so that of Anubis.
He will see the kite recede for a short time, after which it will fall to the ground. This is a clear demonstration of the relationship between the belt and the power of the wind. No such relationship exists between the real road and the wind.

Second diagram: Anubis releases the string. The kite takes 3 seconds to fall to the ground. The distance between Anubis and the kite at the time of release is 50 m. When the kite is released, it immediately assumes the speed of the air (which is still) and falls to the treadmill surface (very long treadmill to make sure that everything happens only on the treadmill). Anubis is still on the treadmill moving away from the place that he released the kite string at 10 m/s. In the three seconds that it takes for the kite to fall, Anubis moves 30 m farther away, for a total distance that Anubis has to cover to get his kite of 80 m. He walks the 80 m along the treadmill belt, picks up his kite and takes it back to Walmart for a refund.

Yes, but that can be easily changed. A low mass, high area kite would decelerate quickly, whereas in the wind, that is a condition for a fast accelerating kite. (See the meteorological balloon book that was earlier posted. The basis of the equations are similar)
In real wind, that kite would continue to fly away for some indeterminate time, and not fall inevitably to the ground as on the treadmill.
(The string can be removed of course, by using a second string to allow it do be detached from the kite end.)

In both cases, the kite lands the same distance away from Anubis. I don't think you were meaning for your diagrams to show this particular result, so I'll assume you were in a hurry. Or do you feel that your diagrams somehow show a different result from what I've stated?
When you have a moment, could you go back to my previous post and continue our conversation? Thanks.

Numbers can be added, but the difference os so clear. Yes, I realize I missed a post of yours, Mender, but I will address it.

 

[RossFW]

Can you spot the difference, Fredriks. They use wind to fly.
Why do they not work in what is said to be a windtunnel?

They fly because they have RELATIVE AIRFLOW. It makes no difference to the aircraft whether IT'S moving through the AIR or THE AIR is moving past IT!

I did a flight to Dehli and back last night. The winds at altitude were 100+ knots directley on route. Tailwind there, headwind back, so a 200Kt difference in groundspeed onthe two flights.

Do you know what difference being in a 100kt head or tailwind makes to the way the aircraft flies? Climb performance? Turn rate? Stall speed?

None.

An aircraft flies because of the flow of air over it. It has no connection with the ground and it's speed over it makes no difference to the way it flies.

 

[RossFW]

Sorry guys, I'm out. We are trying to explain Aerodynamics to someone who doesn't understand (and won't learn!!) how a kite flys!

Entertainment value has given way to frustration and incredulity.

See you on other threads.

Humber, enjoy your ignorance- You fought hard to preserve it, so you deserve it!