I have just finished listening, for the second time, to a set of 48 lectures called “Big History: The Big Bang, Life on Earth, and the Rise of Humanity” given by David Christian of Macquarie University . The lectures are available for purchase from The Teaching Company and are described here. Christian explains the history of the universe, life and humanity in terms of increasing complexity of the most complex thing in the universe. The listener is taken through 8 thresholds of increased complexity. The first is the big bang, the next is the formation of stars, then the creation of solar systems and planets, then the beginning of life on Earth, and so on. The last threshold is the dawn of the modern era of in the 1700s. The focus on increasing complexity makes the discussion coherent and delivers terrific insights. Christian is careful to clearly define what he means by complexity and thresholds of new levels of complexity.
The most striking aspect of the lectures for me is the compression of time between the levels of complexity. From the creation of the universe to the appearance of life on earth is 10 billion years. From the appearance of life to the appearance of Eukaryotic cells and multi-celled organisms is 3 billion years. Evolution of hominids takes 600 million years. Evolution of humans takes 7 million years. Then humans take 200,000 years to develop agriculture, then 5,000 years to develop agrarian civilisations, then 5,000 years to reach the scientific revolution and the enlightenment. Then 300 years to develop our modern, global society.
Well educated listeners will be familiar with much of what is discussed, although it filled in a lot of gaps for me. Nonetheless, regardless of familiarity, when the whole story is laid out and discussed just in terms of increasing complexity, it is quite shocking. It seemed to me that a graph of complexity against the log of time is not linear. The level of complexity is convex in the log of time, meaning that complexity is growing faster than an exponential rate. It really gave me the feeling that we are living in the final hour for humanity. We will either destroy ourselves or reach a level of complexity that is beyond our biological hominid origin in a very short time compared to the 200,000 years between the evolution of homo sapiens and the development of agriculture. Short even compared to the 10,000 years since the development of agriculture. I know this is all well rehearsed, but Christian’s lectures are clarifying on this.
After 45 fabulous lectures the last 3 are a bit silly and soppy in parts because they turn to speculation about the future, which as Christian himself notes, a historian shouldn’t do. I had to skip through these last lectures because they became too annoying. At one point Christian states that it is likely that there is life on other planets. That is a dumb statement. The evidence of life outside the earth is the empty set. The idea that there are a large number of planets, therefore there must be life, which is what he argues, is silly. He also states with certainty that since the universe is expanding at an increasing rate, the universe will expand forever and ultimately go cold, with the loss of all complexity. Again, a dumb statement. If you don’t know what is causing the universe to expand at an increasing rate then you cannot make statements about the ultimate fate of the universe. At one point he describes one idea as anthropo-centric, meaning that the idea takes only the human perspective — as if some other perspective exists? That is what I mean by being a bit soppy.
Nonetheless, overall, the lectures are terrific and I am sold on the idea of big history. I think a version of ‘big history’, focusing on the increasing growth of complexity should be taught in our schools, for two reasons. First, students need to have a sense of how much the world will change in their lifetimes. They need to prepare for that rate of change by committing to life long learning and embracing of change. Second, students need to realise how much danger we are in. We have already seen some bad outcomes from developing systems that are two complex to understand — think of nuclear energy or the GFC. They are just the beginning of our problems with developing complexity that is too great for us. The only way we can navigate the growth of complexity without destroying ourselves is to co-operate at a global level. Again, this is an often stated idea. But it would be good to get it across to our to the next generations, in a convincing way, that without global co-operation we will compete in an unregulated way to create ever greater complexity, and the unintended consequences may consume us.