I'm trying to sort this out so I can add it to the collection of cryonics fermi calculations. Do I have this right:

Either we get FAI first (3%) or WBE (97%). If WBE, 60% chance we die out first. Once we do get WBE but before revival, 88% chance of catastrophe, 2% chance of FAI, leaving 10% chance of revival. 50% chance heads are still around.

If at any point we get FAI, then 50% chance heads are still around and 50% chance it's interested in reviving us.

So, combining it all:

 (0.5 heads still around)*
((0.03 FAI first)*(0.5 humans useful to FAI) +
(0.97 WBE first)*(0.4 don't die first)*
((.02 FAI before revival)*(0.5 humans useful to FAI) +
(.1 revival with no catastrophe or FAI))))
= .5*(0.03*0.5 + 0.97*0.4*(0.02*0.5 + 0.1))
= 2.9%

This is less than your 4%, but I don't see where I'm misinterpreting you.

Do you also think that the following events are so close to impossible that approximating them at 0% is reasonable?

• The cryonics process doesn't preserve everything
• You die in a situation (location, legality, unfriendly hospital, ...) where you can be frozen quickly enough
• The cryonics people screw up in freezing you