1. This is a gallium, a metal that melts in your hands:
2. This is what getting a tattoo looks like in slow motion:
3. This is how springs are made:
4. This is an app that translates things in real time:
5. This is what happens when a car from 1959 collides with a car from 2009:
6. This is a paper airplane machine:
7. This is what happens when glass shatters:
8. This is what a star being swallowed up by a black hole looks like:
9. This is how trains turn:
10. This is what tonic water looks like with a black light:
11. This is a machine that peels apples for you:
12. This is what it looks like to cry in space:
13. This is a train being crash tested:
14. What happens when a bubble freezes:
15. What 1,000 paintballs being fired at once looks like:
16. What 3D-printed metal looks like:
17. What tape does to frosted glass:
18. This is how big Australia is compared to the United States:
19. This is what Earth would look like with Saturn's rings:
20. This is what snake venom does to blood:
21. This is what a tree full of pollen looks like:
22. This is what happens when you drop a hammer and a feather at the same time on the Moon:
23. This is an app that does your math for you:
24. This is how a Slinky drops:
25. Oh, and how to make chocolate bowls:
ESSENTIAL.