Let's say Bob's terminal value is to travel back in time and ride a dinosaur.
It is instrumentally rational for Bob to study physics so he can learn how to build a time machine. As he learns more physics, Bob realizes that his terminal value is not only utterly impossible but meaningless. By definition, someone in Bob's past riding a dinosaur is not a future evolution of the present Bob.
There are a number of ways to create the subjective experience of having gone into the past and ridden a dinosaur. But to Bob, it's not the same because he wanted both the subjective experience and the knowledge that it corresponded to objective fact. Without the latter, he might as well have just watched a movie or played a video game.
So if we took the original, innocent-of-physics Bob and somehow calculated his coherent extrapolated volition, we would end up with a Bob who has given up on time travel. The original Bob would not want to be this Bob.
But, how do we know that _anything_ we value won't similarly dissolve under sufficiently thorough deconstruction? Let's suppose for a minute that all "human values" are dangling units; that everything we want is as possible and makes as much sense as wanting to hear the sound of blue or taste the flavor of a prime number. What is the rational course of action in such a situation?
PS: If your response resembles "keep attempting to XXX anyway", please explain what privileges XXX over any number of other alternatives other than your current preference. Are you using some kind of pre-commitment strategy to a subset of your current goals? Do you now wish you had used the same strategy to precommit to goals you had when you were a toddler?
Experience.
I was once a theist. I believed that people were ontologically fundamental, and that there was a true morality written in the sky, and an omniscient deity would tell you what to do if you asked. Now I don't. My values did change a little, in that they're no longer based on what other people tell me is good so I don't think homosexuality is bad and stuff like that, but it wasn't a significant change.
The only part that I think did change because of that was just that I no longer believed that certain people were a good authority on ethics. Had I not believed God would tell us what's right, I'm not sure there'd have been any change at all.
Learning more physics is a comparatively small change, and I'd expect it to correspond to a tiny change in values.
In regards to your Bob example, if I had his values, I'd expect that after learning that someone in the past is by definition not a future evolution of me, I'd change my definition to something closer to the "naive" definition, and ignore any jumps in time so long as the people stay the same when deciding of someone is a future evolution of me. If I then learn about timeless quantum physics and realize there's no such thing as the past anyway, and certainly not pasts that lead to particular futures, I'd settle for a world with a lower entropy, in which a relatively high number of Feynman paths reach here.
Funny you should say that. I, for one, have the terminal value of continued personal existence (a.k.a. being alive). On LW I'm learning that continuity, personhood, and existence might well be illusions. If that is the case, my efforts to find ways to survive amount to extending something tha... (read more)