why do tyres of car seem to rotate in the reverse direction when moving at fast speeds?

Answer 1

Feel free to think of it this way. Your brain receives the images in "frames". However at high speeds, your brain only receives a fraction of the frames, or can only process maybe 999 out of 1000 frames, skipping that one vital frame that shows the true direction of the wheel rotation. So you see frames that when put together show the wheel moving in the other direction. Try blinking or imagine the wheel to be moving in the correct direction. It might actually change the way you perceive the "movie".

Answer 2

The eye sees a sequence of stills as a moving image because of eyes tend to retain an image briefly causing a phenomena called "Flicker Fusion". Flicker Fusion is the minimum discernable rate of change by the human eye. In itself it is not a series of snapshots, but it is the slow rate of perception of change that allows a series of snapshots to blend into continuous motion. The fusion rate is different in different parts of the eye (the center reduces strobe more than the peripheral). Certainly its to do with Flicker Fusion rate, but its also to do with perceptions of a moving object. If you look closely, you only notice the "reversing" effect when the rotating object is accelerating or decelerating. You brain sees a rotating object, and interprets the visual siganls so that you see it as rotating. As the object spins faster, there is a lag between you perception an the actual change of speed, so you brain is constantly reinterpreting the incoming stimulus, but at somepoint the the rates of change (of the rotating object, the fixed flicker fusion rate, and the changing perception of you brain) all cause a perception of reversing of the objects rotation. If you look closely, it doesn't occur in a single jump, rather the object seems to slowly starting spinning in the opposite direction and faster and faster in that opposite direction. If the object then slows down is spinning to it original speed, the reversed spinning appear to slow down and then stop (ie eventually the object appears to be spinning in it proper direction). As you might have guessed this fascinated me for ages, so I did some experimenting.

Answer 3

Only in the movies or under florescent lighting. This is a strobe effect. When the lighting, or film frames in a movie, flicker (too fast for us to normally perceive) the tires, at certain speeds, will appear to be rotating backward due to the fact that we are not seeing a continuous motion, but are rather seeing each individual frame repeated quickly - this is especially noticeable in old western movies on the wagon wheels.

Answer 4

Everyone here is correct in their own way. However, I must say I have seen this effect in the daylight while looking at wheels of vehicles which are going rapid changes in rates of acceleration. I live in Daytona FL and during the Rolex 24 Hour race, in the afternoon, when the cars are just coming off of the main tri-oval into the infield track, full throttle to hard brake to full throttle to hard brake to full throttle again, I HAVE seen at times it appear as if the wheels are spinning backwards.

What no one has really explained is why the brain perceives these individual images[which was correctly mentioned as not being able to register faster than 60Hz]. Anyway, we all know of light rays, but light has the duality that it can act as waves or particles. We "see" things because of photons that bounce off of objects and into our eyes. We see everything as still images very rapidly following other still images. Sometimes a photon will hit an object and we register its state in our brain, then when the next photon hits our eye, it looks as if the object--which we know to be in forward motion--has gone backwards. It just depends upon which flash images we register and what order the photons give them to us.
Even our TVs only draw still images. They just redraw them at a rate faster than 60 screens [or frames] in a second. This is why computer monitors that can achieve and maintain 70Hz refresh rate or better are less "tiring" for the eyes to look at for extended periods.

Answer 5

what is ahppening is that you are only seeing a brief glimps of the tire because your eye can't percieve things going that fast. If your eye captures the tire at one point and then the next time it cathes it the tire has rotated 355 out of 360 degrees it will look like it has gone backwards by 5 degrees as well as forward by 355 but it is easier to see the backwards 5 and then when it happens again the tire looks like it is spinning backwards at 5 degree intervals

Answer 6

http://www.sciencenetlinks.com/sci_update.cfm?DocID=51

It has to do with out brain's "sampling rate" we can only register about 40 "frames" a second or so. if it spins faster than that illusions can occur that are explained in detail in the link.

Answer 7

first of all are you seeing this on t.v. or actually on the highway??? tires

Answer 8

i dont know does it have ny connection with inertia?

Answer 9

its optical illusion