Why does the wheels on our car looks like its spining on the opposite direction when we are going faster?

Answer 1

It is because our vision sees in fast alternating pictures, like a movie. Lets say the first picture we see is with rim A at the top pointing up. The next one will be right before it's original spot so that if you were to take these pictures your eyes are seeing you will see that it captures the moment before it reaches it's original spot.

Answer 2

This explanation relates to the same illusion that you see in the movies. But its application in real life is the same.
The wheels are moving too fast for you to continually process the image in the brain and hance you mind subconsciously takes a series of "snap shots" of the motion of the wheel which produces the same effect.


The movie is a series of still pictures that flash on and off 24 times every second. That's plenty fast enough for your brain to think the motion is continuous because your eyes can't see the separate frames. No finite sampling rate, however, is fast enough to capture the true continuous motion.

The wagon wheels can even appear stationary: Suppose the movie camera snaps a frame and the wheel turns just enough in the 1/24th of a second before the camera snaps the next frame so that the next spoke has rotated into the position of the first spoke. Then the camera snaps another frame. The second frame looks identical to the first frame even though the individual spokes are in different positions because all the spokes look alike and they line up with the first-frame positions. At this wagon speed, the wheel doesn't seem to be turning at all in the movie.

If the wheel turns a little faster than this, the spokes seem to slowly move forward. That's because the second spoke, going a little fast, went by the position of the first spoke by the time the camera snapped the second frame. If the wheel turns a little slower, then the spokes appear to move slowly backwards.

Thus, wagon wheels can appear to move backwards, then forwards as the wagon picks up speed. If the wagon slows down, the wheels can seem to change direction again and go backwards. It all depends on how fast the camera snaps frames relative to the wagon wheel speed.

Answer 3

This should only happen if you are looking at the wheels under fluorescent or gas-discharge illumination. Although the light from these sources appears continuous, it is actually going on-and-off at a rate of 120 times per second. That means the wheels are fully illuminated every 1/120 second. Depending on the speed of the wheel, a point on the wheel can make a little less than a full rotation withing that time; when illuminated again, it will appear to be "behind" the point where it was first illuminated, giving the appearance of reverse motion. That is called the stroboscopic effect. The same thing happens in movies and TV for the same reason: you are only seeing the wheel briefly for repetitive periods.

Answer 4

The easiest and best way to explain it is to ask you to have a look at an old, well-made (expensive) record player. On the side you will see a little lighted prism and some notches. Around the 'platter' onto which you place the record are also evenly spaced notches. When the record is moving, you can fine-tune the speed by adjustments which are reflected in the prism on the side. If it's going too fast the notches appear to move in one direction, too slow and they move in the opposite direction. When they appear to be standing still, then the speed is exactly correct.

Just watching this process answers your question; for nothing is really moving forward or backwards except a pattern created by the interference between the notches in the prism and the notches on the 'platter'. The same exact principle is at work with your hubcaps.

Answer 5

fairly the human eye has a refresh value that varies from guy or woman to guy or woman. as a result we don't see the international because of the fact it strikes continuously, yet in discrete chunks. working occasion: Say you're observing a wheel spinning clockwise, and say your eye sees a spoke on the twelve o'clock place, and then your resourceful and prescient refreshes together as the spoke has traveled all a thank you to the eleven o'clock place. even regardless of the undeniable fact which you already understand the wheel is spinning clockwise, your techniques will assume it fairly is spinning counter-clockwise via potential of fact it mentioned the spoke the 2d time basically some levels a techniques off from the placement it mentioned it the 1st time, as a result it fairly is the common assumption. the subsequent time you spot the spoke it is going to probably be interior the ten o'clock place, and you will lower back think of of it fairly is shifting backward. think of of roughly it for a minute, you will get it.

Answer 6

This effect is easy to explain when the moving scene has been sampled - for instance, in a movie (30 frames a second) or say under flickering light (50 times a second for a main powered bulb). The sampling causes adjacent scenes to look advanced or retarded according to how far the wheel has been able to move between frames.

But as you say it also occurs in steady light, and the reason for this is still very hotly debated. One theory is that it is because the brain actually percieves not continuiosly but in discrete samples. See research paper link.

Answer 7

I've noticed this under natural light. Airplane propellors, as they build up speed, appear to have a ghost-image that appears as a slowly animated propellor, as well.

I believe that the human brain is not capable of processing fluid motion, but instead processes still images. The effect is more apparent under lights with oscillating cycles, but not limited as some may believe. When you look at a fan, blink your eyes rapidly. The blur of the fan-blades will be replaced with successive static images. When you stare at the rotating fan, your mind is receiving static images, but combines them quickly into the blurry outline.

Answer 8

It is the visual impact that combines motion (energy), light, speed & time, so by the time we capture the image, our eye sends this signal to our brain, this image (light), with motion (energy), the variance of light, speed (of the wheel), time (rotations) process, is the end result.