I’ve read that it’s not possible to bias a coin—you can bias a coin toss if you know which way up it starts, but the coin itself will always be fair. But I confess that I don’t know what assumptions they were making, so for all I know you could make something that would be recognizably a coin but that analysis wouldn’t apply.
If one side is heavier, it will land that side down more often. You can see this with a household experiment of gluing a quarter to a circle of cardboard the same thickness, and then flipping it.
So I was thinking of this paper (pdf), which I misremembered somewhat—you can’t make a coin biased for “toss and catch”, but you can make it biased for “toss and let it bounce”. (And for “spin on a table”.) Given that, “can’t bias a coin” is probably too strong, though it’s in the title of the paper.
Props for suggesting an actual experiment! I didn’t feel like doing it though :p
I’ve read that it’s not possible to bias a coin—you can bias a coin toss if you know which way up it starts, but the coin itself will always be fair. But I confess that I don’t know what assumptions they were making, so for all I know you could make something that would be recognizably a coin but that analysis wouldn’t apply.
If one side is heavier, it will land that side down more often. You can see this with a household experiment of gluing a quarter to a circle of cardboard the same thickness, and then flipping it.
So I was thinking of this paper (pdf), which I misremembered somewhat—you can’t make a coin biased for “toss and catch”, but you can make it biased for “toss and let it bounce”. (And for “spin on a table”.) Given that, “can’t bias a coin” is probably too strong, though it’s in the title of the paper.
Props for suggesting an actual experiment! I didn’t feel like doing it though :p