Today's Google doodle is a Finacci mirror to commemorate the 218th anniversary of the birth of Joseph Joseph Antoine Ferdinand Plateau in Belgian physics.

Prato studies the phenomenon of visual parking, and uses this phenomenon to design a simple animation device such as Finacci Mirror. Looking at the rotating disk through a narrow slit, you can see that the pattern on the disc becomes a small circular animation.

it is also said that this is the first time that Google doodle has tried to display different patterns on different device platforms, and the graffiti will look different from the mobile end and the Google App.

the following is the version seen on the phone:

Finacci Mirror has many different designs. What should be shown here is a version of looking in the mirror, like this:

people look at the mirror image of the pattern through the narrow slit on the disk, and only when looking through the narrow gap can the rotating pattern become a clear small animation. The purpose of the slit is to ensure that the viewer can see the next frame pattern only when it reaches the same position as the previous frame. For example, if it is an octagonal pattern, the difference between the two slits is 1x8 laps, and the same is true between the two patterns, so every time you can see the pattern in the slit, there is a difference of 1ppm 8 laps between the previous frame and the previous frame. At this time, the next pattern is transferred to the position of the previous one. In this way, under the effect of visual retention, people will feel that the pattern is moving in place.

but modern versions of Finacci mirrors don't have to be seen through narrow slits. For example, you can use the flicker of the lighting light to match the rotation speed of the disk, illuminating the device only when the next frame is transferred to the previous frame position, and some people have made a Finaci mirror that can be seen with the app of the mobile phone to achieve a narrow gap to "control the frame rate".

the animation displayed by Finacci Mirror can only be a very short cycle, and the method of observation is also very limited. although it is still created, it has no obvious use value. However, the subsequent animations and films are also based on the principle of visual temporary.

the following are two previous versions of Finacci Mirror DIY tutorials. You can also design your own circular animation

disk version

Look perfectly ravishing in long sleeve blush wedding wear. Look at the catalogue to get the best fitting cloth.

another cylinder version

Source: https://www.google.com/doodles/joseph-plateaus-218th-birthday