Planes Flying in the Sky Seem to Move So Slow....Why????

Question

Why, when we lift our eyes to the skies and see a plane flying, does it seem that the plane moves really slow, when in fact at that moment the plane might be flying at 800, 900 or even 1000 km per hour?

Answer 1

Its an optical illusion, as the distance to the plane and the curvature of the earth. You see a wide view of the sky and there is no reference for movement unless there is a cloud or two. The wide view makes it seem that the plane moves slowly.

Answer 2

Planets are so far away that if you see them move even a little bit, it really corresponds to a large distance. Think about how when you look, you can see more things further away than you can see up close. Right next to your eyes you can see maybe a few inches across, so anything moving slow there would be moving really slow. Now consider something a trillion light years away (I know, our planets are closer but you get the idea), your field of view encompasses a much greater distance, so something at the distance that seems to be moving slow would actually be moving very fast.

Oh wow... some of these answers are horrible... Just know that it there's nothing wrong with your eyes, and it isn't much of an illusion.

The only thing behind this is the distance of the object from you.

Nothing about it's orbit, nothing about hte curvature of Earth, just it's distance from you.

Answer 3

Because what you are measuring is the angular change in the location of the plane with regards to your reference points. So when a plane is far away, moving at 800 kph, it forms a small angle, while that very same plane, flying 500 meters over your head at the same speed, will show a very large angular change.

It is the same with the stars in the sky -- they are moving at much, much greater velocities than any aircraft on Earth, yet they hardly seem to move at all because they are so far away, that their movement doesn't make enough of a change in angle to be noticed. Or the moon for the same reason -- the moon moves much faster in its orbit around the earth than any plane flies, yet is seems to crawl across the sky.

Answer 4

There are two different cases here.

When a plane is far away, it seems to be crossing a very small amount of your visual field in a given amount of time. This gives the impression that it it moving very slowly.

Ironically, when a large plane is fairly close, it can also appear to be moving very slowly. I was driving by San Francisco airport yesterday and a huge jumbo jet was landing ... especially compared to the cars that were whizzing by, the plane seemed to be almost floating in for a landing until its wheels touched down and you could see how fast that sucker was moving.

This latter is called the 'looming effect' (Google it, it's interesting). It has to to with the illusion that a very large thing seems closer to us than it is, so we subconsiously expect it to be moving faster across our visual field.

Both effects have to do with subconscious comparisons with other things that we know move very fast (like cars and trains) and that we are much closer to and cover a large part of our visual field very quickly.

Answer 5

Because of the perspective. Since the plane is far away, the distance it moves seems tiny to you when in fact it is kms.

Answer 6

Perspective - the further away an object is, the slower it seems to move.

Look at a spinning disc - focus on a point 1 inch from the centre, it will spin very quickly. Now focus on a point on the edge - it will seem to rotate at a slower speed yet all of the disc is spinning at the same rate.

The moon seems to move quite slowly yet it is travelling at several throusand miled an hour.

Answer 7

Simply because you are so far away.

So the plane may be traveling at several hundred kilometers an hour but it will be up to 10,000 feet above you so the distance it travels each second looks much smaller because you are so far away.

Answer 8

It is because of the height they are flying,if they were nearer the ground they would look to be flying faster,Even though the speed of the aircraft is the same.Hope that makes sense.

Answer 9

There are no objects to compare to so your ee cannot see if it is going fast or slow it can just track one location to another. Say if a car goes past a lampost you can see the speed bit if no shape at all is behind or in front how can you see the spped??

Answer 10

it's a matter of triangulation, the father the moving object is from the viewer the slower it appears to move.