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How to make a mind—part3 Take life, put it in the right environment, and give it between 3.5 and 4 billion years. We take the time to review what we’ve covered since “How to make a mind—part1,” episode 35; and “How to make a mind—part2,” episode 59. This sets us up nicely to talk about …
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Death There are creatures that do not seem to have a natural limit on their life span. They only die when they are killed by accident or the action of sickness parasites and pathogens. Other creatures are apparently programmed to die at a given time, and under a given set of conditions. So why do …
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Sex This episode turned out to be both long and hard. Feel free to snicker at this point. It was long because I couldn’t resist the numerical pun. To match this episode’s number with its subject, I had to squish together the development of eukaryotes with the development of sexual reproduction. Fortunately, they may both …
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An environmental catastrophe Sometimes, a new species will come into being, and explode across the planet. The population increases drastically within a short time period as they learn to use new materials and new forms of energy. Sometimes, they produce material that is poisonous to forms of life that previously hadn’t encountered such substances. Many …
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Don’t let the headlines fool you. Nobody knows how life started This is probably the least coherent episode to date. Though the precursors of life can apparently be produced by processes taking place anywhere from the deep sea to deep space, how to get from those starting chemicals to a living cell is still unknown. …
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When worlds literally collide It is theorized that our moon was formed when our planet was struck a glancing blow by an object roughly the size of Mars. The notion is known as the giant impact hypothesis. If such a large impact happened to our planet, what about the other planets. How common are giant …
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Our big, beautiful moon According to the rare Earth hypothesis, see episode 59, a large moon is needed for the development of complex life. Our moon isn’t the biggest moon in our solar system; but the moons that are bigger are orbiting much larger planets. Our moon is the largest as a percentage of the …
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Why do big ones orbit so strangely? Today, we consider all the large planets orbiting stars other than our sun, and their tendency to adopt eccentric orbits. The possible reasons include close encounters with other stars, interactions between the planets themselves, and different ways the large planets may have formed. Here’s an article on the …
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Let’s keep it round According to the “rare earth” hypothesis, see episode 59, one of the requirements for the development of complex life is a stable, and nearly circular orbit. If the orbit is too eccentric, the planet would be cooked during one part of its year, and frozen most of the rest of the …
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not quite a star, not quite a planet, not quite life After a somewhat disjointed primer on organic chemistry, we talk about how the radiation of a protostar, bathing the protoplanetary disk, See the previous episode, can create the early chemical building blocks of life. This has happened in laboratory experiments, and the chemicals have …