The issue is not that Bitcoin is invincible to quantum attack it's that the attack is impossible. I am not sure I fully understand nostr:nprofile1qqsrcn632cfyx5j0xpld9m389370ffuzgp8muwshvcrqgwm26sn7uacpzemhxue69uhkzarvv9ejumn0wd68ytnvv9hxgqg4waehxw309ajkgetw9ehx7um5wghxcctwvse30xkv's argument wrt discrete time. (Probably because it is over my head.) But there is a much simpler reason why QC can never threaten Bitcoin (or ECC in general).
There is a hard ceiling on that kind of QM system. All we have done in 40 years is improve isolation to let us get at more of the quantum mechanical system. But once you make the system a little bigger it will decohere on its own.
You can't isolate the system from itself.
Experiments are pushing us asymptotically closer to that ceiling (through heroic isolation) but it's not going to move. It's like trying to break the speed of light. And the ceiling is obviously way below the size you would need to run Shor on a Bitcoin key.
It's a physical limit, not an engineering problem.
We should ignore the FUD or just make fun of it. We can dunk on the fiat QC bubble endlessly when it is over. (And we should.) This is just another fiat mania.
