Hey I love your blog dude. There should be more like yours, harboring curiosity and a spirit of exploration in people :) It's great! I was wondering if you had thoughts on this 'astrobiology' movement? Half the stuff you hear about astronomy in the media now seems it has to do with other life forms, and you seem like the type of person who would be interested/know more than I do about it! Give my blog a look if you want :)
Astrobiology/xenobiology or whatever you want to call it – it’s a pretty awesome thing to think about. Life on Earth essentially represents a single data point. We literally don’t know how similar life on other planets might be to life on Earth, or even if it’s similar at all! In fact, defining what we mean by life is a pretty tough question, which I’ve tried to answer in a blog post here.
This summer I’ve been involved in a research project in an area of computational biology that tries to answer questions like: what aspects of life we see around us are specific to life on Earth, and what are its fundamental properties abstract to observed biology? What kinds of chemistry are required (and in which regions of parameter space) for the emergence of life-like properties?
Being a physicist, I take two opinions. Firstly, living organisms are nothing more than entropy pumps. That is, a metabolism enclosed within some membrane. Secondly, I subscribe to the 'metabolism-first' school of abiogenesis - in other words, there needed to be some kind of entropy-lowering/free-energy-raising chemical cycle in place before the first replicator can emerge.
I think it’s perfectly possible to think up abstract (conceptual or computational) chemical models that lead to the emergence of something that looks like life. These are called artificial chemistries, and they’re what I’ve been researching this summer.
However, can the chemistry of our universe be responsible for different kinds of life altogether? Or is the sugar-phosphate-base DNA that we’re used to the only convergent genetic material that this universe is capable of breeding? I think this question is quite open, and I can’t decide which I think.
I had been meaning to write to Neil for awhile, but I guess that opportunity is gone now. I have a signed picture of Mr. Armstrong with my grandparents at a Golden Eagles conference in San Diego over 10 years ago. The Golden Eagles are the elitest group of aviators in the U.S. military. I sat on…