Thomas comments on Open Thread, September 1-15, 2012 - Less Wrong

6 Post author: OpenThreadGuy 01 September 2012 08:13AM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (353)

You are viewing a single comment's thread. Show more comments above.

Comment author: JoshuaZ 01 September 2012 04:32:56PM *  10 points [-]

It has become increasingly clear over the last year or so that planets can in fact form around highly metal poor stars. Example planet. This both increases the total number of planets to expect and increase the chance that planets formed around the very oldest stars. (Younger stars have higher metal content). One argument against Great Filter concerns is that it might be that life cannot arise much younger than it did on Earth because stars much older than our sun would not have high metal content. This seems to seriously undermine this argument.

How much should this do to our estimates for whether to expect heavy Filtration in front of us? My immediate reaction is that it does make future filtration more likely but not by much since even if planets could form, a lack of carbon and other heavier elements would still make formation of life and its evolution into complicated creatures difficult. Is this analysis accurate?

Comment author: Thomas 01 September 2012 06:00:55PM 2 points [-]

Several times more planets could increase the probability of a distant civilization several times, at the most. That is not a lot, if the initial probability is already tiny.

A rocky planet with no metals have a much weaker magnetic field. A civilization without iron and other metals is more difficult as well. Without heavy radioactive isotopes, volcanoes and tectonics is also different or non existent.

May be some other factors, not all against aliens.