Tuesday, February 16, 2010

Random Cont.


The fact that atoms and molecules make random movements in gas and liquid affects how they interact. There is a theory called "Collision Theory" (Wikipedia entry HERE) which describes the interaction of molecules to form various substances. It is not hard to visualize, as shown in the picture. The random movements are accounted for in the calculations, related to the Maxwell-Boltzmann statistics as discussed in the previous post. It's not necessary to know all the mathematics to understand that atom and molecule interaction is random in nature. And, as the caption of the picture notes, the concentrations of the atoms can affect how much they interact. A higher temperature can affect the movements so that more particles collide when they are hotter, but higher temperature does not give more order to the movements. The properties of the atoms and molecules can affect how they interact, but as we proceed we can see how we can narrow down our focus so that we can eliminate some of the factors which would make it impossible to figure.

For example, the pre-life ocean and atmosphere may have changed from their compositions at the very start of things to what they are now. We may never know what the beginning concentrations of various atoms and molecules were. This limits our knowledge in certain ways. We don't know how many carbon atoms were available to interact with hydrogen atoms. But there are ways to theorize about these things, and many scientists for years have been trying to figure out how molecules could form into life.

Just recently a new paper came out saying that it doesn't look good for pre-life replication and biological-type behavior of atoms and molecules. This is what I've been saying--that chemistry rules at this level, while biologists were trying to impose biological laws on chemistry. They are not the same. The new research is Vasas et al., "Lack of evolvability in self-sustaining autocatalytic networks contraints metabolism-first scenarios for the origin of life," PNAS 107, 4 (Jan. 26, 2010): 1470-1475.

The randomness we are talking about is what we usually mean with the term "chance." We are talking about nature and not the supernatural. Now there are laws that govern the planets, such as gravity, but gravity is not going to make atoms form into proteins. Atoms of different elements have different chemical properties, such as charges and types of bonds between them. I will get into that more next time.

And, we can still apply probabilities in some cases. We know what the cell has now, so we can look at what needed to take place to get us to the present composition. No one has a realistic scenario of how that could have taken place.

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