11-15-2017, 02:45 PM | #31 | |
Join Date: May 2010
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
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11-15-2017, 02:46 PM | #32 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
A problem for sapient beings is that brains have limited storage capacity; our learning rates vary significantly with age (the older you are, the slower you learn) and also involve a lot of forgetting. Basically any means for storing immortal memory in a finite brain involves some combination of extremely limited ability to form new memories and extremely aggressive purging of old memories.
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11-15-2017, 02:49 PM | #33 |
Join Date: May 2010
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
The more I think about it, the less sure I am what a conservative design for a von Neumann probe looks like. If the interstellar impact rules in Spaceships 5 are a reasonable approximation of reality, then going faster significantly cuts into your range. The difficulty (impossibility?) of shielding space sails against impact hazards is also a major issue.
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11-15-2017, 03:02 PM | #34 | ||
Wielder of Smart Pants
Join Date: Aug 2004
Location: Ventura CA
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
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At any rate, if this isn't a continuous civilization, the "million years" is meaningless. There is a difference between a civilization that is living in the same habitats they built a million years ago (at least the same in the axe paradox sense) and one that has recently rebuilt habitats after recovering from a global nuclear war and dieback to minimal population a million years ago. Quote:
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11-15-2017, 03:03 PM | #35 | |
Join Date: Dec 2007
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
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https://www.thoughtco.com/why-did-ha...ollapse-195115 Of course civilization collapses rarely destroy more than a few peripheral technologies. The successors rebuild and continue onward, at least preserving if not advancing on the technologies of the former culture. But if if they lasted for a million years with the same civilization and with technological advancement having ground to a halt, then my guess is they went to some trouble to genetically engineer the capacity for original thought and rebelliousness out of themselves. |
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11-15-2017, 04:00 PM | #36 | |
Join Date: Jul 2008
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
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Laser-driven light sails are really simple conceptually - just point a laser array to put extra push on your lightsail, especially at much greater distances from the star than natural light would allow (even if said natural light isn't blocked by a dyson swarm...) Ideally, you also can have a huge collector in-system to catch and recover some of the light reflected back off the sail, but that's cannonball polishing.
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I don't know any 3e, so there is no chance that I am talking about 3e rules by accident. |
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11-15-2017, 04:12 PM | #37 |
Join Date: Feb 2016
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
I doubt that we will reach a Class II civilization ever. That is 3.8e26 W, which is around 2e14 times as much energy as we consume right now (by comparison, we have only increased our per capita energy consumption by x115 over the past two million years). If we assume that the per capita energy consumption will only increase by a similar factor over the next two million years, the population of humanity would need to increase by 1.7e12 in the Sol System to reach a Class II civilization within two million years.
One possible reason why advanced civilizations may not leave their home systems would be due to virtual reality. A TL11 civilization could support a virtual world with a complete cast of realistic characters for every inhabitant for as much expense as it would be to send a small colony to another star system via STL travel. If they have biological immortality and advanced non-volitional AI, they would probably prefer their virtual worlds within a connected virtual galaxy over the boredom and risk associated with STL travel to another star system. With biological immortality, there is also little need for reproduction beyond replacement through cloning, so the alien civilizations would probably cap out at 1 trillion people when their virtual worlds become a reality. |
11-15-2017, 04:14 PM | #38 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
The interstellar impacts issue is mostly about very fine dust that erodes the surface, not larger impacts that punch holes. Sails won't survive that very well. On the other hand, there's no a lot of reason to have sails open after the launch phase, they're kinda useless in deep space and unless there's a laser array at the destination, also useless for stopping, so you'd either fold or discard them.
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11-15-2017, 04:21 PM | #39 | |
Join Date: May 2010
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
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Huh. I didn't realize the end of the Han dynasty coincided with a population collapse. Nevermind then. Note, though, that I'm assuming technological advance grinds to a halt because we're being pessimistic about what's possible in the future, and eventually possible innovations are exhausted. |
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11-15-2017, 04:31 PM | #40 |
Join Date: May 2010
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Re: [Ultra-Tech] Conservative hard SF... but not implausibly conservative
You know, I plucked the 10 million years figure out of a hat, but I just realized at 1% C, you're not actually going to colonize the entire galaxy in that time. Hmmm...
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