why there is no BIG shadows of birds or aeroplane seen?

Question

we all know that shadow of a thing grows bigger as it moves closer to the source of light.Then if the flying birds or aeroplanes should have a bigger shadow falling on earth right?can someone please explain?

Answer 1

Your initial premise is incorrect. There ARE big shadows of airplanes. They are clearly visible on the ground from the viewpoint of someone on the airplane.
They aren't very obvious from the ground for the same reason that a partial eclipse of the sun doesn't seem to appreciably darken the ground .... too much unblocked sun. The percentage change of brightness is small and your eye/brain system is good at accomodating for small changes in brightness.

Answer 2

well the plane/bird is so far away from the ground the shadow would be very light... ie light comes around from other places, such as reflecting of other objects etc to the place where the shadow is supposed to be.
and how big is the sun? lol much bigger than the objects
the shadows are seen on clouds though... just look out of the window on a plane.
if they're low to the ground, the shadow can be seen too

Answer 3

good question,..it is very famous too...
actually what happens is that the sun here acts as a big source of energy not a point one...
but the distance between the bird and the earth is so much that the umbra formed finishes off in the air only.....and the penumbra is very very very big so,the effect is very very very diluted such that it doesnt make a real difference
so u see,...when a bird comes close to the surface ,we do see a shadow,its only when its high up in the air that we dont!

edit: i wud like to add something here....it is NOT related to the size of the objects!...i mean man !look at the aeroplanes!...they are quite big!....its the DISTANCE which matters here

edit:i wud again like to add sumthing here: the shadow that is the UMBRA REGION has FINISHED OFF ON THE AIR...so its growing big doesnt matter
and the PENUMBRA REGION only grows TOO BIG DILUTING IT EVEN MORE,...SO EVEN LESS EFFECT OF SHADOW

i think u now understood,...

Answer 4

hmm interesting, I am only guessing it has to to with the light being blocked out and the distance away from the ground.
Because with lights and things like that the shadow is projected pretty close causing it to be bigger. yet for birds and planes and things like that, they are so far away from the earth that the shadow is relatively small or not there at all, because the actual light being blocked compared to the overall size in very little...I hope this makes as much sense as it did in my head..LOL.

Answer 5

They'd have to appear "big" enough in the distance to blot out most or all of the sun. And the true objects aren't big enough themselves to do that.

It's the same reason that an ordinary lamppost doesn't cast shadows for specks of dust, falling leaves, and so on.

And yes, the scattering of light in the air has something to do with this, as does every other reason that the light "rays" coming from the source aren't perfectly parallel to each other.

Answer 6

Good question. The shadow of birds and planes are mostly not seen because they are mostly in the sky where there is no flat surface for the shadow to be seen.