Eccentric Flower talk:201012/Little Green Aliens I

Mmancuso:

God didn't make little green aliens...

-- 20:11, 3 December 2010 (GMT)

Columbina:

Stop that, and go read the link about the direction of time which I posted on Twitter just for you.

-- 20:22, 3 December 2010 (GMT)

ProfRobert:

Green Aliens out in Space will be. Ars'nic eating for their life, you see. Hype spreading out so far and wide, Keep your science and give me that rocket ride.

-- 20:41, 3 December 2010 (GMT)

Peebles:

I cut and paste for you an email that I sent to my class yesterday.

~

I wanted to pass along some breaking news that I thought you might find interesting. There's a NASA press conference going on today during which scientists will announce that they've discovered a bacterium that has learned to replace the phosphorus atoms in its DNA and RNA with arsenic atoms.

The implications are really astonishing. First of all, it's a demonstration of how versatile of a chemist life is. Presented with an adverse environment, these organisms have learned to turn a toxin into a building block of life. This discovery shows that the term "not suitable for life" is much less meaningful than we may have once thought.

Second, it means that the search for life is not a search for life 'like us'. Given the enormity of the universe, if life has the ability to take on such a different form using such different chemical strategies, how likely is it that we are truly alone? Perhaps life is much closer to us than we thought it was, only we had no idea how to go about looking for its chemical traces.

Finally, and perhaps most narrowly, I think this discovery demonstrates a principle we've been telling you about since Chem 103 -- that the periodic table tells us something really fundamental about the properties of the elements. Arsenic is directly below phosphorus in the periodic table, which means it ought to have very similar properties. So there's a chemical logic to this organism's choice to replace the phosphates in its DNA backbone with arsenates that echos what you learned in your very first general chemistry courses. So even as this discovery makes us question what we once thought were basic laws of biology, it's gratifying to know that there are underlying chemical principles that continue to apply.

-- 21:14, 3 December 2010 (GMT)

Rhonda:

Does this mean that the EPA can't clean up toxic lakes full of arsenic can't be cleaned up because that action would destroy the habitat for a rare species?

-- 15:32, 4 December 2010 (GMT)

Rhonda:

Gah. Thought I edited that sentence. It should have been:

Does this mean that the EPA can't clean up toxic lakes full of arsenic because that action would destroy the habitat for a rare species?

Clearly I should go back to bed now.

-- 15:33, 4 December 2010 (GMT)

Ysabel:

Your comment about Mars made me think of this strip: http://xkcd.com/695/

That strip makes me cry.

-- 06:07, 11 January 2011 (GMT)