What happens in Vegas...well you get the picture.

Guys here's my simple explanation:

If the bird were dead - then it would result in a dead weight.
But, since the bird is alive flying inside the container, it causes turmoil in the air due to its momentum and inertia producing vector forces bouncing downwards/upwards with enough magnitude to give some noticeable fluctuations on the scale display readings.

Conclusion: the measured weight is not constant, but varies with a frequency equal to the number of wing beats per second.

Prove me wrong if you bother…
[8D]

All right! All right! I guess we forgot to ask whether the bottle was a flask, almebic, or retort. And was that retort a riposte to an earlier question. If you don't get it, then you may as well repost to another forum. They may be able to help you form ideas on how things actually work without working (actually). These things get maddeningly silly or inanely insane. Your pick, but not in pique.

Why bother, you are correct.

Well guys, I appreciate your collective knowledge.

However, I must admit that I fully intend to physically test it. It's just one of those things I have to see. I will probably use my electric heli, inside a large, sealed cardboard box with a plexiglass window on the side. I know most of you think this is an expedition into idiocy, but I'm going to try it. If somehow I break the laws of physics, I will make a new post, detailing the feat.

Despite all the facts and knowledge you have presented for me. My brain can't help looping it over and over. For example.. what happens in the box, stays in the box. OK but gravity is acting on the box and its contents. The source of gravity is not inside the sealed box universe, so it is not completely exclusive of the real universe. Also the battery on the helicopter is fully charged. When it begins to hover, the energy is lost in friction, heat, electrical resistance, etc. But what energy finally makes it to the spinning rotors is used to lift the heli. I can't help but thinking the energy of the battery is roundabout converted into some force which acts on the box. I just don't see why it ALL has to go straight down, making the box stay the same weight.

I could go way out on a limb. The way I understand it, a wing doesn't lift because it is blowing particles downward. (toward the bottom of the box) I think battery power is being used in a round about way to make the box lighter.

I now stand alone in the white light of ridicule and say loudly, that until I prove myself wrong. I believe the box will be lighter. And the tomcat in the plane full of chickens will make it lighter as well.

How about this... A rocket in a sealed canister, except for the blue vent holes, which only relieve gas pressure and have symmetrical placement so they offer no overall thrust on the canister while venting. Light the rocket, will the cart roll?

Have a look:

http://i5.photobucket.com/albums/y17...RocketKart.jpg

not the same thing ---not even remotely the same thing
your heli tho -aside from heat losses --should work to see what is happening --if the box is big enough - make one side from Mylar to see it .
Go for it - whenever in doubt --test it.
Just like flat airfoils -- having tested em - for some apps they are the best
Oh yeh -the rocket - as long as it is tied to the cart and the REACTION is unidirectional why should it move ?

Ok then how about this one.

http://i5.photobucket.com/albums/y17...x/PropKart.jpg

Yeah, I can see this one not moving. But the rocket would?

Regardless, I still think the heli in the box is supported by aerodynamic force, created by electrical energy. I will let you know what happens as soon as I locate some precision scales. Probably a few days.

Neither the rocket box nor the second box will move.
The hovering heli, inside a large, sealed cardboard box won't decrease the box's weight.
You'll only may get some fluctuations due to the air moving inside the box.
The magnitude of these fluctuations will be inversely proportional to the box size.

da

How about this - with both hands, grab the underside of the chair you are sitting in and pull upwards with all your might. If you can get yourself to fly around the room like this, then I'll buy into the sealed box stuff defying the laws of physics.

May I just use my bootstraps?

Sure!

NJRCFLYER2,

It worked. I floated up in the air.

Nah I see what you are saying, I am not proposing that you could, for example, roll a pickup truck by standing inside the bed and pushing against the cab.

In the course of this thread, I have brought up rockets, balloons, submarines and other things. It does seem that I am losing focus. I think that instead, I may be closing in on my real point.

I'm not a professional engineer, I'm a cattle rancher with a high school education and an interest in this kind of stuff. The thing that is teasing my mind is this:

These things are obvious...

If I stand inside a box and push against the walls, the box won't slide across the ground.

If I jack a car up in the garage, it won't make the garage any lighter, and pulling on my chair wont make it levitate.

I'm not an idiot, I'm just hanging up on the idea that a helicopter, or bird or flying insect doesn't physically interact with the box in perfectly OPPOSITE directions like all of the previous examples. A helicopter doesnt screw itself into the air like its on a giant auger mounted to the ground. A bird doesn't support itself in the air on invisible blocks, stacked all the way to the bottom of the container.

I am by no means (obviously) an aeronautical expert, but clearly an airfoil moving through the air, driven by a power source, generates lift independent of the ground. (Ignoring ground effect, etc)

The lift comes from the driven airfoil interacting with the air passing immediately over it, not by interacting with the box or whatever else happens to be in the vicinity.

kriegsmacht,
It seems that you don't fully understand the physics laws...
Let's try to explain:
The air, just like any other matter is capable to react against a force applied upon it.
For instance:
When you're standing on the floor, the gravity makes you push on the floor (force), while the floor pushes on you in opposite direction, and - if the both forces are equal - your vertical position won't change.
The principle is the same with a plane in the air (or whatever is flying), but since the air density is much lower than the floor's, you need to move the air molecules downwards in order to get enough kinetic energy to give you enough force upwards (action - reaction).
The heli uses the rotor blades to do that, while the plane uses the wings.

Yes, do let us in on your findings please.

The air wouldn't all go straight down. In the case of a heli hovering in a sealed box, there would be a column of air going down under the helicopter, striking the bottom. But the air doesn't stay there, collecting. It spreads out along the bottom, then up the sides to the roof, then toward the center and down toward the low pressure area above the rotors. There is always as much mass flow of air going up as down. All of these air molecules encounter resistance as they rub against each other and the sides of the box. It's this resistance to circulation that will allow the helicopter to hover. Some degree of this type of circulation happens even when a heli is hovering outside a box. If the heli has insufficient power, the heli will not be able to keep up with the accelerating circulation and it will "settle with power". Not too likely with a high-powered electric model heli, but a real concern with full-scale helis trying to hover at high density altitude.

All of this resistance or force transfers to the box and the weight stays the same.

I know you guys think I'm an idiot. It's good of you not to come right out and say so.

MEsae, I was thinking that was called recirculation or something like that instead of settling with power, or vortex ring.

Anyway,

I thought this was the Newtonian principle of flight and was generally not accepted. I was thinking it was based on Bernoulli or Coanda or something like that instead of just whacking molecules down and deflecting the wing the other way.

If this thread is annoying and stupid, just let it die. Otherwise, thanks for your time everyone. I appreciate it.

Settling with power is a helicopter term, and is trained for in full-scale:

From FAAH 8400.10, Chapter 2, SECTION 5. ORAL AND FLIGHT TEST EVENTS IN HELICOPTERS:

E. Settling with Power. The applicant must recognize
and initiate immediate recovery from a critical rapid
descent with power. For purposes of this maneuver, settling
is reached when a perceptible buffet is felt or an
indication of immediate settling is detected. If this event is
prohibited in the operator’s aircraft operating manual, it
shall not be conducted in flight, but shall be tested orally.


Things fly by moving air down. This lift production has several aspects. There is simple deflection off the bottom of the wing. There is also acceleration of air molecules over the top of the wing, creating low pressure above. This also moves air down, since the air molecules are accelerated downwards via a curved path above the wing. There is of course also upwash ahead of the wing as air tries to move into the low pressure area above the aircraft. I believe AdamOne was making the statement in a general sense and was not attempting to limit the production of lift only to deflection. This is well understood now, though casual observers seem to think that one or the other theory is "wrong". They are both different aspects of the same overall lift generation process, and must be understood together to get a more complete picture. Air molecules are accelerated somewhat downward by bouncing off the bottom of the wing, and they are also accelerated downward through encounters with low pressure above the wing.

How kum--
I see lots of lip service given to air being deflected down /low pressures above /high pressure under etc., yet none of the comments are including a rather easily seen characteristic of air (a gas) which is simply --compression.
Look at for example -- a plane going lickety split (fast) which is suddly janked into a vertical attitude -- skidding forward . It can be done and is done routinely now even at full scale airshows .
So - air IS compressed ahead of the skidding craft - call it bow wake , call it watermelon -whatever - it is air being compressed .
Whay not just state the obvious--


planes fly on compressed air ---


a really big plane compresses more air -simply because the air can't get out of the way fast enough.
As the plane slows - the air can get out of the way but to fly - the bubble of higher pressure must be in effect.
Unless -you really believe the low pressure above the wing sucks the plane into the air----

I think something else runs on compressed air too...

kriegsmacht,

I certainly don't think your an idiot, you want to understand something or at least have it expalined so you can wrap your head around it..lots of great inventions have been discovered exactly the same way.

Keep in mind, until 1530 EVERYONE KNEW that the earth was the center of the world and it was not until Copernicus observed that this was not the case and had the cajones to step up and say so did things change.
He also did this without the aid of a telescope, just hours watching the sky, pretty amazing thing really.

Good luck, and for the record, my prediction is that the chopper will bounce off teh side of the box and shear the rotor blades.
At least thats what would happen if I was flying it.

OK --disprove it --
I am sure the textbooks don't say it in this manner but -really - pressure difference is how it all works
and higher pressure IS a standard definition of compressed air.
I think-- many of the terms we use for explaining flight --confuse rather than clarify -
Just a thought ----
I was bored
Nuthin personal
Now I will go to the shop n repair a 42% model a friend brought me which ran afoul of one of mamma natures' laws of motion
actually ; Fig Newtons' third -

The above is not the same thing as saying that "planes fly on compressed air ". I agree with your pressure difference statement. It's really all about action/reaction and pressure differences. Sometimes I think you make some statements just to cause controversy. And you suckered me right in again! [sm=crying.gif]

Sure the pressure is higher near the "bottom" of the wing during a positive wall, but it's quite a bit lower near the "top". This causes air to MOVE in an attempt to equalize the pressure again. It takes energy to get air to move, and that energy is supplied by the airplane's movment. So your "planes fly on compressed air " statement tells only part of the story, so I put my hackles up. You're enjoying this, I can tell.[sm=punching.gif]

A reasonable prediction hehe. I predict that I won't have to completely lift off to detect a weight difference. Just by spinning up and getting light on the skids should = light on the box.

I think I have a triple beam scale located. I will post photos when I am done. If I am proven correct, everyone can be dizzy with awe. If I fail, everyone can laugh at my folly.

You are being thoughtful and open-minded and are willing to test your hypothesis in an experiment, instead of just arguing until everyone is vomiting with incredulity.

I for one, will not laugh and I do not consider you folly-ish. No holes in the box!

Do you intend to video the experiment? I would hate to try to fly a heli in a box AND read a scale at the same time. Besides, I'm dying to see how you do it.

Lol me too!

I would love to see that as well.