example_irreversible_video

Part (a) - Irreversible Process:

Original irreversible video: https://www.youtube.com/watch?v=5BTCTooGYPs

Irreversible video reversed: https://www.kapwing.com/e/5e4039d0970a250016b38bc0

This definitely looks funny and is irreversible. The actual projectile-motion fall of the egg looks approximately reversible (ignoring air drag and turbulence), but the breaking of the egg clearly isn’t. This process creates a lot of entropy in a lot of ways. The film that separates the yolk from the white seems to break in at least the far left egg, which means the yolk can now mix with the white, so that creates mixing entropy as the “yolk particle” and “white particle” can mix among each other. When the shell breaks, the volume that the contents are allowed to occupy dramatically changes; they are free to flow and move around. The shell itself must break many molecular bonds when it cracks. This allows the shell pieces to be arranged in many different ways, and released stored energy in the bonds that enters the environment.

Part (b) - Reversible Process:

Original reversible video: https://www.youtube.com/watch?v=ohSGkNsjU88&feature=youtu.be&t=146

Reversible video reversed: https://www.kapwing.com/e/5e403b4ddce786001661986e

This looks pretty reversible to me (I’m focusing on just the few seconds after the time I linked to, during which he is hitting a puck back and forth). A puck sliding basically looks the same forward or backward. If we could look in more detail, however, we could find the small increases in entropy created by this process. The friction (which you can easily hear) among the puck, ground, and air must result in some sort of heat flow that changes the internal energy of these materials. The air also probably gets turbulently mixed to some degree. The man must also be generating heat in his body.