Recently I was sitting at St. Kilda Beach with a few friends and we got to talking about the upcoming Easter holidays. I happened to make the innocent comment: "Isn't it silly to have a holiday to celebrate a God who doesn't exist? But a few days off from work is still very nice." One of my friends piped up and said "God that doesn't exist? Are you one of those people that believes we all descended from chimps?" Usually such a comment would get me into an argument, but it was such a lovely Melbourne day so I subtly I suggested we all go to Acland street and have a few drinks. But I got to thinking about how important Charles Darwin's theory of natural selection has been. Even if you believe that God created the Earth and the heavens, Darwinian thought has given science a new and powerful perspective on how to view things.
In a recent post, I described how viruses evolve resistance to antibiotics - using Darwinian principles of natural selection. Natural selection occurs in our own bodies in other ways. One example is in our immune systems. In our bodies we have proteins called antibodies, which can recognise foreign molecules, bacteria and viruses, and bind to them. Any foreign body or antigen injected into the body will stimulate the production of a complementary antibody that is instrumental in the immune defence. The antibody genes of each individual lead to the production of a huge number of different antibodies. Exposure of this huge repertoire of antibodies to a foreign molecule - e.g. a virus - is followed by the selection and growth of the cells which have only the antibodies that fit the invading foreign molecule sufficiently well.
Even our own brain development can be seen from a Darwinian point of view and, indeed, it has been. Neural Darwinism is a term first used by Nobel Prize winning scientist Gerald Edelman. At the early developmental stage of the brain, synaptic connections between neurons are established. Then, these connections are weakened and strengthened according to their individual activity. Then, with the individual's experience, changes in the strengths of the synapses occur favoring some pathways over others. The most-used connections are kept and strengthened, while the least-used ones are dissolved.
Scientists have invoked Darwinism to explain many diverse phenomena; we have Social Darwinism, which attempts to apply Darwin's principles to explain social behaviour, and Evolutionary Psychology, which attempts to explain mental and psychological characteristics as useful products of natural selection. Charles Darwin himself would never have dreamed that his ideas would be taken so far.
It's all well and good to be able to apply Darwinian philosophy to our own flesh-and-blood bodies - after all, natural selection belongs in the realm of biological science. But how about applying it to the big picture - the universe. The religious fundamentalists of our world say that life on Earth is a miracle that can only be attributed to God - not by a "series of chance mutations" - and I guess they would say the same about the universe - the planets, the stars, the galaxies. Our universe exists thanks to the laws of physics being "just right"; it appears that "by sheer coincidence or act of God", the laws of physics are just perfect to allow life to exist. For example, the electrical force between 2 protons is 10^38 times stronger than the gravitational force between 2 protons. If, instead, the electrical force was 10^37 times stronger than gravity (i.e. gravity was 10 times stronger than it is), a star the size of our sun would live for only 10 million years instead of 10 billion years ... certainly not enough time for intelligent life to evolve on Earth. Another coincidence arises due to the relative masses of electrons, protons and neutrons. A neutron outweighs a proton by about the mass of an electron, and the size of an electron is much smaller than that of a proton. If this were not the case, it would not be possible to form atoms, which means that there would be no stars and no chemistry.
Our universe is large enough to accommodate stars; why is it not smaller - say, the size of a pin head; is it another coincidence?
It can't be just a mere coincidence; surely there is a God that who kindly set up the conditions and the physical laws so that we could exist. Or maybe it is just a coincidence and we exist only due to a series of improbable events.
Well, again, Darwinian thought has been used to attempt to explain this "accidental universe" of ours. I recently read a book called "The Life of the Cosmos" by Lee Smolin. Smolin attempts to use Darwinian philosophy and black holes to explain our existence. It's a speculative attempt at an explanation, but very interesting and it's backed up by a lot of logic and data. Here's how it works:
It is said that the Big Bang - the birth of our universe - came from a singularity. Singularities are also said to occur in black holes. A black hole is basically a star that has collapsed into a singularity in our universe's spacetime. One theory tells us that any material that falls into this singularity will emerge as an expanding singularity in another spacetime - i.e. in another universe. It is as if our universe has given birth to a baby universe using a collapsing star as a vehicle. Our universe would be connected to its offspring via a "wormhole". If one universe can be born from a black hole, then there may be an infinite number of universes connected by a vast network of wormholes. Of course, this also means that our universe was probably born out of a black hole in another universe.
Lee Smolin's idea is that every time a black hole collapses into a singularity and a baby universe is born, the laws of physics are slightly different in the new universe ... just the same as a human child is genetically slightly different from his/her parents. If the laws of physics in the new universe allows the creation of a lot of stars and a lot of black holes - thus giving birth to more baby universes - this new universe would be a successful universe. If, on the other hand, the baby universe does not expand very much, it will die without leaving any progeny, and it would be an unsuccessful universe. Also, there is competition as the many universes jostle for room in the multidimensional spacetime. The successful universes - the ones that have the laws of physics which encourage the formations of stars and black holes - will be the ones that have the potential to evolve life. It's reminiscent of successful/unsuccessful species on Earth.
2007 is the 125th anniversary of Charles Darwin's passing, but it seems that his legacy - one of the great achievements of humanity - will never die.
Thoughts about science, human nature and other stuff.
