Thursday, August 18, 2011

A Little Bit on Where Humans Came From

     Hey interweb. Today I decided to build a little on some of the notions in the Meteorite DNA post and discuss a little bit about where we come from. I just wanted to share some more knowledge. I promise that this is not a post about aliens altering monkey DNA, or superman pods, or even religion. I also promise to bore you as little as possible with a bunch of physics ramblings (I love my physics classes in college) but there are a few things that I think everyone will find interesting. In the Meteorite DNA post, I shared some evidence that pre-organic compounds like amino acids which are long molecules that link together and form proteins are readily formed and transported through space on meteorites. But you may ask "where did the building blocks of these molecules come from?" Then again maybe you aren't a nerdo like me, but if you are, I have an answer for your question! Scientists believe that not too long after the big bang and after the initial expansion (the part that causes the most problems in the theory), the first atoms began to form. Look at your periodic table of the elements and you will see that hydrogen is the smallest and simplest atom. Hydrogen is also the most abundant element in the universe. So even for simplistic reasons without any math, modern physics, or magic thinking you can come to understand why hydrogen was formed first. Now when you have hydrogen in space, it will clump together due to the laws of gravity.

When enough hydrogen clumps together the gravity in the clump increases forcing the atoms closer and closer together and it starts to heat up (the gas laws). Now once it gets hot and dense enough with enough gravity, the atoms are actually forced to fuse together in a process known as nuclear fusion and they form helium (a "noble" and inert gas) and now you have a star (like our sun). Skip ahead a few billion years and the star starts to run out of hydrogen (star fuel) to fuse into helium. The outward pressure created by the energy released becomes less and a lot of hydrogen (star fuel) falls into the "reactor core" very quickly leading to a supernova explosion (if the star is large enough and this is also the source of black holes.) Our sun is not large enough to supernova just FYI. Now when all of this hydrogen falls into the core, there is a HUGE increase in pressure, gravity, and heat just before the star explodes. This is the time period in which heavier elements are created because the helium and hydrogen are forced to fuse even further because of all the extra "heat and pressure." The elements that I am talking about include carbon, iron, calcium, oxygen, potassium, magnesium, etc. Most of these should sound familiar because they are what make up our world and even OUR BODIES! This is the point that I was leading up to. How amazing is it that we imperfect humans are actually made up of stardust?   


  1. You are not alone Mr. Science Geek. There are others out here on Blogger. Carbon makes four bonds-that's going to be chisled into my tombstone.

  2. And when my 3 year old niece told me she was made of stardust and rainbows, I laughed at her. Turns out the little brat was half right.

  3. Good to know I'm not the only one out here. And I do hate it when little kids are smarter than I am so I always defend my point "No, the sky is obviously purple because of all of the dichlorodiphenyltrichloroethane and the triple integral of the surface area of the conical helix. Punk. Pfft how could you think it's blue?"