[Bored chemist]

If it is adequately lit,  you can see a single atom at a million miles.

[Just thinking (OP)]

If it is adequately lit,  you can see a single atom at a million miles.

I believe that is true. It is very interesting to me as to how light can reveal its self on such a fin level but it certainly can. I think some of the brighter stars are at that level of scale and we can see them with the naked eye.

[Just thinking (OP)]

Here's my little bit, too, JT:

Thanks for that CC. yes we can get lift in many ways these days the fighter jet planes are more like rockets the way that they can fly. You make some interesting points regarding wing shape and the main reason for a plane with conventional wing design being able to fly inverted as you pointed out it is done by increst angle of attack and adequate engine power just don't forget that your elevator control is also reversed when inverted.

[Bored chemist]

I think some of the brighter stars are at that level of scale

They are bigger than an atom.
Oddly, they may not look like it.
The well lit single atom, and the distant star are both diffraction limited dots.
The image you would see would be the limits of your eye rather than anything to do with the object.

[Just thinking (OP)]

The well lit single atom, and the distant star are both diffraction limited dots.
The image you would see would be the limits of your eye rather than anything to do with the object.

I think I understand what your saying a star five light years away is like a golf ball at the distance of the moon we can never see the golf ball at that distance but if it was as hot as a star we will see its light. That is its diffracted and distorted light.

[alancalverd]

But/t, I have seen aerobatic biplanes fly just above the ground
perfectly horizontally, with no angle of attack!?

The angle of attack is the angle between the wing chord and the vector of motion. Not to be confused with the angle of incidence, which is the angle between the wing chord and longitudinal axis of the aircraft.

Most modern aerobatic planes are "taildraggers" with a small (maybe zero) angle of incidence but a high angle of attack when they start moving. This configuration is lighter than a tricycle undercarriage but is more difficult to handle on the ground.

A symmetrical aerofoil will generate the same lift either way up if the angle of attack is the same. Most explanatory diagrams show large AOAs to emphasise the contributions of the upper and lower surfaces and the effects of turbulence, but level flight may only involve a couple of degrees, so the aerobatic demonstrator may be flying with the wing chord very close to horizontal when inverted.   

[Just thinking (OP)]

Planes normally do fly upside down Down Under.

And we drive on the wrong side of the road upside down. The U.S. fly right side up and they drive on the right side of the road.LOL.

[chris]

This may help: https://www.thenakedscientists.com/articles/science-features/how-does-wing-work

[Just thinking (OP)]

This may help: https://www.thenakedscientists.com/articles/science-features/how-does-wing-work

Thanks, Chris this article goes a long way to explain the nature of lift and flight. I find it very interesting how the paper aeroplane can fly without the aid of aerofoil but this can be explained by the nature of weight to air density ratio with forward velocity even a ball can be projected the paper plane is aided by the curvature of the wing even if it is by slite change of forward and rear edge deformation. There are so many variations in aircraft wing design as there are so many variations in propulsion and power.

[alancalverd]

the paper aeroplane can fly without the aid of aerofoil

Not true! A flat plate is an aerofoil, just not a very good one. At any nonzero angle of attack the leading edge develops turbulence over the upper surface, so it makes sense to smooth it into....well, a curve like a wing seems to work pretty well.....

[Just thinking (OP)]

Not true! A flat plate is an aerofoil, just not a very good one. At any nonzero angle of attack the leading edge develops turbulence over the upper surface, so it makes sense to smooth it into....well, a curve like a wing seems to work pretty well.....

I guess there are many paper plain designs but the standard type works quite well with a tiny bit of slat and a little upward flap..