This book was originally Glasgow University Gifford Lectures for the theme The Search for Who We Are in 1985. Sagan does a great job explaining difficult concepts clearly and with compelling evidence. Unfortunately, in several places I also knew about the contrary evidence which undermines his position. That they were not addressed very much disappointed me.
I mentioned this book in my Evidence blog post a few days ago. The search for proof is never ending because new information leads to new questions not satisfactory answers. So why do we continue to search? Because we want to know. Maybe we even feel entitled to know. (I also mentioned it in my Missing Hydrocarbons when I learned the point methane condenses is way out near Saturn not Earth, so why does Earth have life?)
Cosmology, origin of life, and astronomy are topics about which I read quite a bit. Any NASA and JPL discovery makes me stop whatever to read more about it. This is not something new as one of my school science fair projects was on O-Rings and Challenger. Before that I even attended Space Camp. (This was all so I could post this cute photo.)
Carl Sagan discusses the presence of hydrocarbons other than Earth in The Varieties of Scientific Experience. Materials vary in the distance from the Sun at which they condense. Water condenses at the distance of Earth. Methane condenses out at the distance of Saturn. This makes perfect sense for Titan, Saturn’s largest moon, who has lakes of methane. How hydrocarbons formed on Earth if they are not readily available is the problem.
Then I made the mistake of seeing this, Life Could Have Hitched a Ride to the Moons of Jupiter and Saturn, which discusses the idea that lithopanspermia, microbes catching a ride on meteoroids, could have helped life on Earth or Mars reach the outer planets or their moons. Perhaps it worked the other way around? I have heard similar ideas that comets or panspermia from Mars or planets outside the solar system could be the origin of life on Earth. The latter is an extraterrestrial.
If one finds Earth-style cellular life forms on Europa, then how does one determine whether it came from Earth to Europa or from Europa to Earth? Successful colonization on Earth usually means the colonies having larger populations than the parent. Look at how many people in the world speak English as their primary language compared to the population of England. Or French vs France. That analogy suggests Earth could be the colony of somewhere else in the solar system. I hope we do find life near the outer planets as the amount of speculation and journal articles will be very entertaining.
P.S. The Varieties of Scientific Experience was originally Glasgow University Gifford Lectures for the theme The Search for Who We Are in 1985.
Evidence is often portrayed as the collection of facts who neatly prove a conclusion. Just follow the arrows. Several things of late hurt my brain as others second guess and respond to the sad truth evidence rarely is so neat.
Kendrick Johnson was found dead in a school gym. The local sheriff processed the scene. The Georgia Bureau of Investigations did an autopsy. The ruling was humans are not designed to be upside down so while trapped in an wrestling mat for a long period of time, the brain suffocated as oxygenated blood could not reach it. The family did not buy the result. Trayvon Martin was at the time still a hot topic. The family exhumed the body and got a second autopsy who said he was murdered. CNN got the surveillance footage with gaps. This situation is insanely mess with no where along the line there being all the evidence there ought. Because this is real life not a crime drama, I guess.
The Varieties of Scientific Experience: A Personal View of the Search for God by Carl Sagan talks about various situations such as the search for alien life as allusions for how the lack of evidence is hard. So we keep looking. He also seemed pretty skeptical of the existence of God. As a self-described person who follows the evidence, this should not be too surprising. Because it really means no evidence really will be good enough.
Facts are facts until they are disputed. Not so much the what as the meaning. (Though sometimes the what in order to change the meaning into a desired one.) One person’s rock solid data point is another’s fuzzy meaningless drivel.
Any time we look at facts or data, our experience also looks at them. They shape the meaning for us. These leaps of intuition are our experience drawing inferences. Sometimes for the good. Sometimes for the bad. Only later do we really discover.
The scientist in me never likes my first answer. I want to prove it wrong. And the second, third, and nth. I want the correct answer and spend as much time as it takes to get there.
The pragmatist in me realizes sometimes I do not have time for the correct answer. Sometimes my best guess will have to do. This disappoints me every time, but I try not to let it get to me.