Theory of Relativity quiz

More questions about Theory of Relativity

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   What do you see in a hand mirror while flying near light speed?

   Answer: A normal reflection

   Why: No experiment inside a smoothly moving ship can reveal its speed, so light still races from your face to the mirror as usual.

2. 2 Medium

   What principle says free fall feels like floating in space?

   Answer: Equivalence principle

   Why: Using this idea alone, Einstein predicted that gravity slows clocks and bends light, years before he finished general relativity.

3. 3 Hard

   How much TNT matches the energy in one gram of mass?

   Answer: About 21,000 tonnes

   Why: That's about 25 gigawatt-hours, roughly what a large 1-gigawatt power station generates in a full day.

4. 4 Easy

   How many dimensions does Einstein's spacetime have?

   Answer: Four

   Why: Hermann Minkowski, who had once taught Einstein mathematics, recast relativity as four-dimensional geometry in a 1908 lecture.

5. 5 Medium

   What cosmic-ray particle reaches the ground thanks to time dilation?

   Answer: Muon

   Why: Without that stretch, a muon living about 2.2 microseconds would fly only about 660 m, far short of the ground some 15 km below.

6. 6 Hard

   Which force can an electric force become for a moving observer?

   Answer: Magnetic force

   Why: Einstein's 1905 relativity paper opens with a magnet and a wire, where the current depends only on how they move relative to each other.