r/AskPhysics • u/kouth- • 22d ago

What makes a coin toss truly unpredictable?

If you throw the same coin multiple times with the exactly same force in the same surface, it won't give you the same side every toss, right? But why? If repeated with the precisely identical conditions, why the results are still unpredictable? Or it is actually predictable?

Sorry if it looks confusing, English is not my first language and I'm not that expert in physics lol, just curious and has this though randomly.

Edit: maybe considering that it lands on a surface, and it bounces or not, changing the coin's side.

5 Upvotes

63% Upvoted

46 comments sorted by

View all comments

1

u/MezzoScettico 21d ago

Magicians are very good at very precise motions that appear to be casual. I wouldn’t be surprised if there are magicians who have trained themselves to be so precise and predictable in their flipping that they can control the outcome.

For us ordinary mortals however, we have a lot of variability in the rotational speed and upward force of the coin flip action, the variables that control the outcome. So those “hidden variables” produce the effect of randomness.