At One Place

Physics

10 questions in the physics category.

Question Answer Confidence
What would happen if an asteroid hit the Earth? It depends enormously on size — most burn up, a 20-metre one broke windows across a city, and a 10-kilometre one ended the dinosaurs. Established science
What would happen if gravity disappeared? The Earth itself would come apart — gravity is the only thing holding a planet together. Speculative
What would happen if the Sun became a black hole? Earth's orbit would not change at all — the mass would be the same. It would simply go dark and cold. Reasoned extrapolation
What would happen if you fell into a black hole? Into a small one, tidal forces would stretch you apart before you arrived; into a supermassive one, you would cross the horizon without noticing. Reasoned extrapolation
What would happen if you fell into a hole through the Earth? You would oscillate from one side to the other and back, with a one-way trip of about 38 minutes. Reasoned extrapolation
What would happen if you travelled at the speed of light? You cannot — accelerating any mass to light speed requires infinite energy. Approaching it, time dilates dramatically. Established science
What would happen if gravity doubled? You would weigh twice as much, most tall structures would need rebuilding, and no bird larger than a sparrow could fly. Reasoned extrapolation
What would happen if you were shrunk to the size of an ant? The square-cube law would break you: you would freeze, suffocate, and be unable to drink from a surface of water. Reasoned extrapolation
What would happen if the speed of light were slower? Chemistry, nuclear fusion and the mass-energy relationship would all change — stars would not work as they do. Speculative
What would happen if a gamma-ray burst hit the Earth? A nearby one aimed at us would strip a large fraction of the ozone layer within seconds, with the damage arriving as ultraviolet over the following years. Reasoned extrapolation