YouTuber Veritasium uses slinkys and slow motion photography to blow your mind. What slinkys being dropped and even thought the entire slink is in mid-air the bottom of the slinky doesn’t fall towards the ground until the slinky collapses.
The explanation that “it takes time for the bottom of the slinky to feel the change” might work ok, but it isn’t the best.
Then why doesn’t the bottom of the slinky fall as the top is let go? I think the best thing is to think of the slinky as a system. When it is let get, the center of mass certainly accelerates downward (like any falling object). However, at the same time, the slinky (spring) is compressing to its relaxed length. This means that top and bottom are accelerating towards the center of mass of the slinky at the same time the center of mass is accelerating downward.
A domino can knock over another domino about 50% larger than itself. A chain of dominos of increasing size makes a kind of mechanical chain reaction that starts with a tiny push and knocks down an impressively large domino.
Incredibly dorky Redditors took the experiment even further. GeneralConfusion figured out that the 53rd domino would be larger than the Earth’s radius; the 62nd would be nearly tall enough to hit the moon; the 77th would be as tall as the Sun’s distance from Earth; the 90th would be the solar system’s radius; and the 133rd would be the diameter of the Milky Way.