Could you provide links?
Boltzmann brains were discussed in many places, not sure what the best link would be. The idea is that when the universes reaches thermodynamic equilibrium, after humongous amount of time you get Poincare recurrences: that is, any configuration of matter will randomly appear an infinite number of times. This means there's an infinite number of "conscious" brains coalescing from randomly floating junk, living for a brief moment and perishing. In the current context this calls for time discount because we don't want the utility function to be dominated by the well being of those guys. You might argue we can't influence their well being anyway but you would be wrong. According to UDT, you should behave as if you're deciding for all agents in the same state. Since you have an infinite number of Boltzmann clones, w/o time discount you should be deciding as if you're one of them. Which means, extreme short term optimization (since your chances to survive the next t seconds decline very fast with t). I wouldn't bite this bullet.
UDT is sort-of "cutting edge FAI research", so there are no very good references. Basically, UDT works by counting formal proofs. If your utility function involves an infinite time span it would be typically impossible to prove arbitrarily tight bounds on it since logical sentences that contain unbounded quantifiers can be undecidable.
...I think you mean this procrastination paradox.
Yes.
Is it possible that one's utility function does not discount, but given uncertainty about the future one should kind of behave as if it does?
Well, you can try something like this but for one it doesn't sound consistent with "all parties can achieve arbitrary large amounts of utility" because the latter requires arbitrarily high confidence about the future and for another I think you need unbounded utility to make it work which opens a different can of worms.
What if I maximise measure. or maximise the probability of attaining an unbounded amount of utility?
I don't understand what you mean by maximizing measure. Regarding maximizing the probability of attaining an unbounded (actually infinite) amount of utility, well, that would make you a satisficing agent that only cares about the asymptotically far future (since apparently anything happening in a finite time interval only carries finite utility). I don't think it's a promising approach, but if you want to pursue it, you can recast it in terms of finite utility (by assigning new utility "1" when old utility is "infinity" and new utility "0" in other cases). Of course, this leaves you with the problems mentioned before.
...there is the idea of creating a basement universe to escape into...
If I understand you correctly it's the same as destabilizing the vacuum which I mentioned earlier.
...some form of hypercomputation that can experience subjective infinite time in a finite amount of real time...
This is a nice fantasy but unfortunately strongly incompatible with what we know about physics. By "strongly" I mean that it would take a very radical update to make it work.
...and time crystals which apparently is a real thing and not what powers the TARDIS...
To me it looks the journalist is misrepresenting what has actually been achieved. I think that this is a proposal for computing in extremely low temperatures, not for violating the second law of thermodynamics. Indeed the latter would require actual new physics which is not the case here at all.
AFAIK humanity does not know what the dark matter/ dark energy is that 96% of the universe is made of. This alone seems like a pretty big gap in our understanding...
You're right, of course. There's a lot we don't know yet, what I meant is that we already know enough to begin discussing whether heat death is escapable because the answer might turn out to be universal or nearly universal across a very wide range of models.
Boltzmann brains were discussed in many places, not sure what the best link would be.
Sorry, I should have been more precise - I've read about Boltzmann brains, I just didn't realise the connection to UDT.
In the current context this calls for time discount because we don't want the utility function to be dominated by the well being of those guys.
This is the bit I don't understand - if these agents are identical to me, then it follows that I'm probably a Boltzmann brain too, as if I have some knowledge that I am not a Boltzmann brain, this would be ...
Cross-posted from my blog.
Yudkowsky writes:
My own projection goes more like this:
At least one clear difference between my projection and Yudkowsky's is that I expect AI-expert performance on the problem to improve substantially as a greater fraction of elite AI scientists begin to think about the issue in Near mode rather than Far mode.
As a friend of mine suggested recently, current elite awareness of the AGI safety challenge is roughly where elite awareness of the global warming challenge was in the early 80s. Except, I expect elite acknowledgement of the AGI safety challenge to spread more slowly than it did for global warming or nuclear security, because AGI is tougher to forecast in general, and involves trickier philosophical nuances. (Nobody was ever tempted to say, "But as the nuclear chain reaction grows in power, it will necessarily become more moral!")
Still, there is a worryingly non-negligible chance that AGI explodes "out of nowhere." Sometimes important theorems are proved suddenly after decades of failed attempts by other mathematicians, and sometimes a computational procedure is sped up by 20 orders of magnitude with a single breakthrough.