solovinofly

Yep and we are almost there camrade! There is just this one thing: who was there first: the chicken or the egg?? Nice question for a new thread after this one closes down… Lift in the air is a result of forward movement. Therefore the initial force that causes forward movement can’t be lift. Angular deflection makes you go forwards. And that can create some lift. This lift force (humans falling through the sky) is not strong in relation to the force caused by deflection, drag and gravity though. Say I’m right. Got to catch a plane in a few hours. Byby

OK, you define lift as any horizontal movement, than of course you are right. Atmonauts for sure are covering horizontal distances. I argue that besides the primary movement (obviously downwards) one can move forward, sideways and backwards by only deflecting air (changing the attack angle) and not using (a significant amount of) lift. That’s why I say that lift is not the only condition that can move falling things horizontally. In Atmonauti deflection of air by far outranges the effect of lift in the forward movement. The horizontal movement in atmonauti can be amazing and very efficient, but still its to romantic to relate this sensation to (a significant amount of) lift. In 60-70 sec we go down 3 KM. In my definition you can’t speak of a relevant lift force. It’s quite an efficient deflection of air. Right, lift force works perpendicular to the relative wind. So (diagonal) up, not straight forward or (diagonal) down. Forward movement can also be: only deflection of air or; the result of an external power source (jet)engine. Let me guess: you don’t agree

Regarding Andrewnewell: If you think its just this photo please feel free to check out other smoke atmo photos taken from the side, Im sure that you will see a similar visual each time. Note that smoke jumps in atmo most often are done against the direction of the wind to get better visuals. I don’t mean the relative wind but the (horizontal) wind at freefall altitude. This is to create the (by the way very nice illusion) of more horizontal speed of the atmonauts. In effect the wind blows the smoke in the opposite direction of atmonauti trajectory. So most pictures of smoke jumps are even biased and still you see the effect as mentioned by Andrewnewell. Nice illustration that we can’t speak of significant amounts of lift. Feel like jumping!!!

hihi Yes it is confusing. The thing I said is that the amount of lift being created by a spinning ball or a human body in freefall is not significant. It doesn’t explain moving horizontally in freefall. Deflection of air does. The original explorations of some atmonauts about lift was the foil shape and the negative pressure on top of the flyer (and rigs taking off). That part of the definition of lift is smaller then people used to think. It’s more attack angle. But if you sum the effect of low pressure and angle of attack it is still insignificant because of the relative high weight of a person in relation to the lift force that a human is able to create. Does that make sense?

Allo allo NWPoul. Not ANY body can produce the lift force. A ball can never create lift (check internet for instance NASA). If Vince allows me: There are two explanations for planes to stay in the air. In fact there are two definitions of "lift" (only one is right though). You find them here. The popular explanation, PATH-LENGTH or AIRFOIL-SHAPE: wings do not deflect air, instead they are sucked upwards because the "airfoil" shape has a longer surface on top. Airfoils are curved on top and flat below, and therefore the air follows a longer path above than below. Air that is divided at the leading edge of a wing must rejoin at the trailing edge. Since the upper surface of the wing is longer, it causes the air to flow faster over the upper surface, which (by Bernoulli's principle) creates lower pressure above. Because lift is caused by the shape of the wing, wings can create lift at zero attack angle. They can create lift simply from path length difference which leads to pressure difference, and no air needs to be deflected. After a wing has passed by, the air does not remain moving downwards. (THIS EXPLANATION IS SERIOUSLY FLAWED.) The physics explanation, NEWTONIAN or ATTACK ANGLE: wings are forced upwards because they are tilted and they deflect air (like the kite in the earlier example). A wing's trailing edge must be sharp, and it must be aimed diagonally downward if it's to create lift. Both the upper and lower surfaces of the wing act to deflect the air. The upper surface deflects air downwards because the airflow "sticks" to the wing surface and follows the tilted wing (this phenomena is called "Coanda effect" or "Flow Attachment.") After the wing has passed by, air remains flowing downwards. Airplanes fly because of Newton's 3rd law (action/reaction forces,) the law of Conservation of Momentum, and the Coanda effect. I said earlier that humans in freefall can not produce a significant amount of lift (not without a jet engine in combination with a wingsuite of some type). One can only speak of a significant amount of lift when a body has the potential to up. Two things are important for that: reative low weight compared to (lift)shape of the body and/or high speed (form of trust). That’s way even in atmomauti we primarily go down (in conditions where there is no wind). I think that deflecting air to move forward can give a similar sensation as lift would (at least, the expected sensation of lift since we never experienced it in freefall). Is see now reason to not enjoy this phenomenon. Nobody wants to destroy anybodies dreams. But lift is not a religion , its physics. You are not moving forward because of a significant amount of lift but because of a lot of deflection of air. Like I said, enjoy it anywayzzzz.

I came across your exchange of thoughts and want to contribute to your quest of understanding more about lift. And… to the pilot out there, you should know a little more about the phenomenon called lift and the concept of flied in general. I address this reaction primarily to him. There we go. Think of a kite children play with on sunny and windy days on the beach. The shape of a kite creates to little lift (if any) for it to fly. The wind blows into the front of the kite, which is at an angle. The wind hits the kite and is deflected down. This is what makes a kite go up. No lift involved at all. Of course this only works because a kite is ultra light. Mathematically we can say that lift increases as the downward push of air increases. To be clear, one my ad downward push of air to the effect of lift but it is not the same as lift! It’s equal to flaps on the wing of a plane. Flaps also create downward push of air to allow a plane to fly at low speed (when the amount of lift decreases and can’t keep the plane in the air because of it’s (relative to the amount of lift) high weight). To speak of effective “lift” one has to take weight into the equation. The amount of lift (if any) created by whatever shape of the human body is insignificant because humans are by far to heavy for this “ lift” to have a meaningful effect. So a person moving forward in freefall is actually transforming some of the potential energy (altitude) into kinetic energy by using deflection of air. And primarily a human body is going down isn’t it?? That’s it. Enjoy your flights have fun but if you want to put theory behind it all please don’t be to roman-tic or to emotional, it’s only a sport. By the way, there is a section on Nasas website which explains lift (not the same as downward push of air!!!) to children.