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What has a 1 in a million chance? (2010)

stat.berkeley.edu

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Re: What has a 1 in a million chance? (2010)

#21
“Scientists have calculated that the chances of something so patently absurd actually existing are millions to one. But magicians have calculated that million-to-one chances crop up nine times out of ten.” ― Terry Pratchett, Mort

Re: What has a 1 in a million chance? (2010)

#23
post #4

Picking a random integer between 1 and 1 million.

That depends on the quality of your randomness. If it's a person picking the number that definitely isn't a 1 in a million chance for most numbers. You need to get pretty specialized hardware before you can confidently say it's definitely an equal chance for every number every time.

How bout this guy

https://images.app.goo.gl/aqh2AP5tj7JBkVKZ9

Re: What has a 1 in a million chance? (2010)

#25
post #4

Picking a random integer between 1 and 1 million.

That depends on the quality of your randomness. If it's a person picking the number that definitely isn't a 1 in a million chance for most numbers. You need to get pretty specialized hardware before you can confidently say it's definitely an equal chance for every number every time.

I think true randomness was implied in GP’s comment. A person picking a number “randomly” from a million is not random in the mathematical sense.

Re: What has a 1 in a million chance? (2010)

#26

> "Scientists have calculated that the chances of something so patently absurd actually existing are millions to one. But magicians have calculated that million-to-one chances crop up nine times out of ten." -- Terry Pratchett Making fun of the fact that if someone says "it's a million-to-one chance, but it might just work!" in fiction, you know it's going to work. In _Guards! Guards!_ this is taken to the point that…

See also https://wiki.lspace.org/Million-to-one_chance and more generally https://tvtropes.org/pmwiki/pmwiki.php/Main/MillionToOneChan... .

Re: What has a 1 in a million chance? (2010)

#28
This was a nice read. Takes me back to Probability 101, which was a fairly eye opening experience, not only because of you get to learn the basis of a lot of research (sampling, deviation, etc) but also because of the many counter intuitive behaviors of actual randomness. It was a little bit like learning the physics of math, if that makes sense.

Re: What has a 1 in a million chance? (2010)

#29
post #5

Earlier quoted context omitted.

No, you don’t need specialized hardware. The output of a modern hash for crypto absolutely needs to produce a uniform distribution across a million.

But how do you pick the input for the hash?

You need a seed, and a previous hash. The seed is usually sourced from another random generator, that uses environmental noise and some (salted) hashing as well.

In practice, a precise clock and a few difficult to guess events like keyboard and mouse inputs are enough to get a descent seed.

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