Quote from: DannyHamilton on March 17, 2017, 03:27:58 PM

Quote from: suredoood on March 17, 2017, 03:58:00 AM

But, to be pedantic, it is still possible to create an address that is not unique. It is just EXTREMELY unlikely.

To be pedantic...

The quotes I was responding to weren't whether or not it is possible to create a non-unique address. They were whether we would "run out of unique wallet address" and the fact that it would "take so many years before that could happen".

Furthermore, as long as the private keys are generated randomly, it is effectively "impossible".

When the average person hears or says "EXTREMELY unlikey", they take it to mean that it does occasionally happen (such as it is extremely unlikely to win the lottery or to get struck by lightning, or for the earth to get hit by an asteroid big enough to eliminate all life).

That isn't the kind of "extremely unlikely" that we are talking about here. We are talking about the type of "extremely unlikely" that the average person means when they say that something is "impossible".

For example...

If you press your hand up against a wall, there is an EXTREMELY unlikely (but non-zero mathematically) chance that all of the particles of your had will simultaneously quantum tunnel to the other side of the wall. The average person understands that this is "impossible" for all intents and purposes, but mathematically the chance isn't literally 0.

All the air molecules in a room are bouncing around RANDOMLY. Any and every random arrangement of those molecules is possible. There are far more arrangements that result in enough oxygen being near the mouth and nose of every person in the room so they can all continue to live, and so those are the "likely" arrangements. However, it is EXTREMELY unlikely (non-zero chance mathematically) that the oxygen molecules could all bounce around into one small corner in the room suffocating everyone in the room to death until the molecules happen to bounce around back into a more even distribution. The average person understands that this is "impossible" for all intents and purposes, but mathematically the chance isn't literally 0.

These are the type of "EXTREMELY unlikely" you are talking about when you are talking about address collisions with randomly generated addresses. The average person needs to understand that this is "impossible" for all intents and purposes, but mathematically the chance isn't literally 0.

Classic!

I love to read your posts @DannyHamilton ! It is really pleasure to have on this forum someone who can so clearly write about Bitcoin!

I'm also interested what gonna happen with wallet addresses when they make BU fork/Segwit?

Sorry for little off top - did you already write somewhere about Segwit/BU + BTC and what do you think about all this situation with pools and which chain they will choose?

Edit: I found something here: https://bitcointalk.org/index.php?topic=1827814.msg18197544#msg18197544