site banner

Friday Fun Thread for October 14, 2022

Be advised; this thread is not for serious in depth discussion of weighty topics (we have a link for that), this thread is not for anything Culture War related. This thread is for Fun. You got jokes? Share 'em. You got silly questions? Ask 'em.

9
Jump in the discussion.

No email address required.

238km/s is not highly relativistic. Also it would be silly to travel at 99.9% the speed of light when you could travel at 90% for a tiny fraction of the energy and risk and get there less than 10% later. The only reason to do it would be so that less time passes for your travelers -- but if it's a self-repairing box of electronics and robotics, engineered by a galaxy-brain superintelligence, it can probably while away the millions of years without issue. There are no primates on board who are aging, nor even who are consuming energy to maintain.

I'm aware 238 km/s isn't highly relativistic, travelling slightly above that speed just means the probe will spend a painfully large amount of time cruising. And even non-relativistic travel poses issues. For example your probe is going to encounter the harsh radiation environment in space, even if it's not travelling at relativistic speeds (if it is it's much worse). Shielding could be possible if one was willing to add to probe mass, but if it fails to block all of the radiation it's going to be exposed to that for the entirety of the journey. This is fine when your mission duration is short. It's less fine when your mission duration is millions of years and your probe contains lots of delicate electronics that need to work properly.

Self-repair is hypothetically possible, but that requires usable energy and matter, and interstellar and intergalactic space is famously devoid of both of these things. And the longer your mission is, the greater the chance of a critical failure at some point. Even if that chance is small, if you're going to take millions upon millions of years to get there most of your probes might not reach. Travelling slow comes with its own costs and impracticalities.

And yeah, I know every single one of these problems can be solved by invoking [hypothetical future technology], and I'm sure the future will unceremoniously spit in the face of any prediction I make, but I'm not too convinced by any explanation that relies too heavily on handwavium.

And you can send a lot of probes -- depending on how small they can be and how efficient their propulsion is, even a very high loss rate can just be overcome with quantity. Another advantage of not having precious primates on board!

Yes, I agree, even with a high loss rate you could spread your probes as long as there's a nonzero probability of survival. As I said, the idea you posited is not out of the question. Of course, then the Fermi paradox rears its head, since not only are we seeing no sign of alien life from our own galaxy, but also from other galaxies and other galaxy clusters which should hypothetically be able to reach us.

Why would the outpost be dead? Galaxy-brained superintelligences don't seem like likely to be mercurial creatures that might just die off one day from a plague or civil war or something. Once they're established, I assume they're gonna be here till the end of time.

I'm not saying it would be dead, I'm more saying that communicating would be full of latency problems - any information you'd get from it wouldn't be timely at all and would be mostly of little value since it'd be impossible to act on. The point was that for all you know the outpost could be dead and you'd only know 11.4 million years later.

I think humanity is going to let go of our sentimental attachment to meat-based life basically as soon as we have a digital alternative

Personally, I wouldn't do it. Even assuming that you can replicate the phenomenon of consciousness in a non-biological substrate (something that could be the case but that's basically impossible to prove), there's the issue of continuity when you're uploading your brain. Sure, there's another version of myself now, but this is not me and I will not experience the change. I will live and die as meat-based life, and there will not be any "transfer" of consciousness. There will not be any change in my own state except now I possess the knowledge that there is an immortal version of me running around out there.

So this is not because I have any attachment to meat-based life - the benefits of a digital substrate would be very tantalising if I could genuinely transfer myself into it. Rather, I think my experience of being me is so intrinsically linked with my physical body that they basically can't be disconnected from each other. The incentive to digitise my brain kind of starts looking very weak then.

but even if we don't, as you say, presumably your Von Neumann probes could build "human manufactories" on the other side of their voyage, even from digitally reconstituted genomes from our local group, in which case I don't see why they'd be any less "ours" than whatever distant descendants clambered off of a successful million year generation ship after it arrived on the other side of the cosmic ocean.

The issue for me is that you don't actually get to colonise anywhere, nobody leaves, you just make another galaxy cluster full of humans. Maybe this is just an irreconcilable values difference, but I think this solution completely voids the point of the exercise. I don't intrinsically care about creating as many humans as possible and distributing them throughout the galaxy. I care infinitely more about where these humans come from.

Anyway... if I'm right about the trajectory of our species, how much of our light cone do you think we could in principle colonize? That's the interesting question IMO.

Let's assume we can go at, say, 50% light speed (149896.229 km/s). The expansion of the universe is 68 km/s/Mpc, and the value of Mpc that gives us a recession speed of 0.5c (the relevant formula here is 68 x Mpc = 149896.229) is 2204.36 megaparsecs, which translates to roughly 7 billion light years. Everything outside that distance is receding from us faster than that.

It's basically Hubble's law. You can take any speed of travel, divide it by the expansion rate, and find the distance beyond which everything is receding from you faster than your travel speed. There's probably additional complexity created by the aforementioned fact that the Hubble "constant" is not actually constant and is decreasing, but I can't be arsed to factor that in right now.

Personally, I wouldn't do it. Even assuming that you can replicate the phenomenon of consciousness in a non-biological substrate (something that could be the case but that's basically impossible to prove), there's the issue of continuity when you're uploading your brain. Sure, there's another version of myself now, but this is not me and I will not experience the change. I will live and die as meat-based life, and there will not be any "transfer" of consciousness. There will not be any change in my own state except now I possess the knowledge that there is an immortal version of me running around out there.

My typical rejoinder is basically, how do you know this isn't happening every time you go to sleep -- that "you" die and a new "you" comes into existence when your body and brain awake the next morning, a brand new consciousness tricked by your brain's memories into inferring false continuity of self? Or even that this isn't happening thirty times per second as part of your brain's natural operation?

My other rejoinder is, how about a Moravec Procedure, where you remain conscious and lucid the entire time during your gradual upload, in each moment satisfied (and confirming via repeated formal consent) that your consciousness has not changed?

The issue for me is that you don't actually get to colonise anywhere, nobody leaves, you just make another galaxy cluster full of humans. Maybe this is just an irreconcilable values difference, but I think this solution completely voids the point of the exercise. I don't intrinsically care about creating as many humans as possible and distributing them throughout the galaxy. I care infinitely more about where these humans come from.

Indeed, perhaps an irreconcilable values difference, but I think there's something ineffably beautiful about a quest to awaken the dead matter of the universe into sentience.

Fortunately, it's very cheap! The cost of sending von neumann probes beyond the radius of a given civilization sphere is likely to be low relative to the wealth of mass-energy contained within the sphere. That is true even when our sphere is just the earth, and becomes only more true as the sphere expands. Even if 99% of the sentiences or "mind-share" of the civilization agrees with you, the remaining 1% could probably fund the expedition as a hobby.

Let's assume we can go at, say, 50% light speed (149896.229 km/s). The expansion of the universe is 68 km/s/Mpc, and the value of Mpc that gives us a recession speed of 0.5c (the relevant formula here is 68 x Mpc = 149896.229) is 2204.36 megaparsecs, which translates to roughly 7 billion light years. Everything outside that distance is receding from us faster than that.

A 7 billion light year radius is pretty damn good, I'd say! We're well outside our local group and have begun eating superclusters like potato chips at that point!