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New LW Meetup: Zurich

1 FrankAdamek 21 October 2016 10:47AM

[Link] The Leverhulme Centre for the Future of Intelligence officially launches.

1 ignoranceprior 21 October 2016 01:22AM

*How* people shut down thought because of high-status respectable halos

6 NancyLebovitz 20 October 2016 02:09PM


A detailed look at the belief that high status social structures can be so much better than anything one can think of that there's no point in even trying to think about the details of what to do, and how debilitating this is.

Discussion of the essay

A problem in anthropics with implications for the soundness of the simulation argument.

5 philosophytorres 19 October 2016 09:07PM

What are your intuitions about this? It has direct implications for whether the Simulation Argument is sound.


Imagine two rooms, A and B. Between times t1 and t2, 100 trillion people sojourn in room A while 100 billion sojourn in room B. At any given moment, though, exactly 1 person occupies room A while 1,000 people occupy room B. At t2, you find yourself in a room, but you don't know which one. If you have to place a bet on which room it is (at t2), what do you say? Do you consider the time-slice or the history of room occupants? How do you place your bet?


If you bet that you're in room B, then the Simulation Argument may be flawed: there could be a fourth disjunct that Bostrom misses, namely that we become a posthuman civilization that runs a huge number of simulations yet we don't have reason for believing that we're stimulants.



[Link] Program good ethics into artificial intelligence

2 XFrequentist 19 October 2016 04:28PM

[Link] AI-ON is an open community dedicated to advancing Artificial Intelligence

3 morganism 18 October 2016 10:17PM

[Link] The Non-identity Problem - Another argument in favour of classical utilitarianism

1 casebash 18 October 2016 01:41PM

Open thread, Oct. 17 - Oct. 23, 2016

3 MrMind 17 October 2016 07:02AM

If it's worth saying, but not worth its own post, then it goes here.

Notes for future OT posters:

1. Please add the 'open_thread' tag.

2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)

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Astrobiology IV: Photosynthesis and energy

8 CellBioGuy 17 October 2016 12:30AM

Originally I sat down to write about the large-scale history of Earth, and line up the big developments that our biosphere has undergone in the last 4 billion years.  But after writing about the reason that Earth is unique in our solar system (that is, photosynthesis being an option here), I guess I needed to explore photosynthesis and other forms of metabolism on Earth in a little more detail and before I knew it I’d written more than 3000 words about it.  So, here we are, taking a deep dive into photosynthesis and energy metabolism, and trying to determine if the origin of photosynthesis is a rare event or likely anywhere you get a biosphere with light falling on it.  Warning:  gets a little technical.


In short, I think it’s clear from the fact that there are multiple origins of it that phototrophy, using light for energy, is likely to show up anywhere there is light and life.  I suspect, but cannot rigorously prove, that even though photosynthesis of biomass only emerged once it was an early development in life on Earth emerging very near the root of the Bacterial tree and just produced a very strong first-mover advantage crowding out secondary origins of it, and would probably also show up where there is life and light.  As for oxygen-producing photosynthesis, its origin from more mundane other forms of photosynthesis is still being studied.  It required a strange chaining together of multiple modes of photosynthesis to make it work, and only ever happened once as well.  Its time of emergence, early or late, is pretty unconstrained and I don’t think there’s sufficient evidence to say one way or another if it is likely to happen anywhere there is photosynthesis.  It could be subject to the same ‘first mover advantage’ situation that other photosynthesis may have encountered as well.  But once it got going, it would naturally take over biomass production and crowd out other forms of photosynthesis due to the inherent chemical advantages it has on any wet planet (that have nothing to do with making oxygen) and its effects on other forms of photosynthesis.

Oxygen in the atmosphere had some important side effects, one which most people care about being allowing big complicated energy-gobbling organisms like animals – all that energy that organisms can get burning biomass in oxygen lets organisms that do so do a lot of interesting stuff.  Looking for oxygen in the atmospheres of other terrestrial planets would be an extremely informative experiment, as the presence of this substance would suggest that a process very similar to the process that created our huge diverse and active biosphere were underway.

[Link] There are 125 sheep and 5 dogs in a flock. How old is the shepherd? / Math Education

6 James_Miller 17 October 2016 12:12AM

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