Sciencespeaking topic
To have weight you need a surface to stand on. Astronauts on the space station aren't falling upward; they're in constant free fall around the Earth, which is why they're weightless. Is 'weight' not a property of matter but a relationship?
— free fall / weightlessness
practice with this topic
Set the timer (5-30 min), take 20 seconds of prep if you like, start talking. Jot your thoughts onto the sticky-note board.
similar topics
- The base rate fallacy: even a very accurate test for a rare disease usually misleads when it comes back positive. Why does a test being 99 percent accurate not mean you're 99 percent likely to be sick?
- A honeycomb is hexagonal not because bees know geometry; the wax naturally settles into the shape that covers the most area with the least material. Can flawless design emerge without a designer?
- In a neighborhood, if everyone can tolerate their neighbor being only slightly different, the city eventually splits into sharply segregated areas, even if no one is racist. How do small, innocent preferences create the sharp divisions no one wanted?
- Grid cells: the Mosers discovered brain cells that encode space in a hexagonal grid. If the brain measures space with a mathematical coordinate system, is our sense of place innate?
- A human can only truly maintain close relationships with about 150 people; our brains can't handle more. While we live in cities of millions, are we still designed for a small tribe?