By the time I was in fourth grade I had decided what I wanted to be when I grew up, an exobiologist. I was elated by this decision. I felt that the great question of my purpose in life had finally been settled. It didn’t occur to me that it might be less than obvious to the other people in my world why this was such an obvious choice for my vocation, much less that others might not even know what exobiology was. I told my two best friends and received only blank expressions. I gave my most enthusiastic explanation, still blank faces. I thought my fourth grade teacher, Mrs. Bannock, would provide a better reaction. I told her, she was very enthusiastic and I was delighted.
“Dinosaurs are one of my favorite things to study as well!” she said.
I was crushed. In desperation I even told my father, who pointed out that there wasn’t anything, actually, to study yet and probably wouldn’t be for some time. I saw the sense in what he said and ran away to join the circus. So ended my brief career as an exobiologist.
Now days we call the field Astrobiology and NASA has a whole institute devoted to the study of alien life. O.K. we haven’t actually found any yet, BUT in the last twenty years we have found liquid water in the most unexpected places in our solar system and we have found life in some very unexpected places on our planet. Now my eleven-year-old son has got the astrobiology bug (so to speak) and we recently went to listen to a current astrobiologist, Dr. Benner, give a lecture at the museum in Denver.
On the drive there my son and I talked about what life is, exactly, and tried to hammer out a simple definition. To my delight Dr. Benner spent much of the first half of his lecture talking about the philosophy of science and the difficulty of constructing a theory of life without bias. He handed out a number of rocks and asked the audience to determine which ones showed evidence of life. He talked about the human propensity to look for patterns – and see patterns, even if no patterns really exist. He talked about constructive belief and how that influences the design of experiments meant to look for life. He talked about theories that operated under the assumptions that life must: metabolize oxygen or carbon dioxide, fix carbon, be a cell, have our kind of DNA, make protein, have a minimum volume.
Good scientists, he warned, must continually check themselves and each other, examining the sources of assumptions. Thinking outside the box with integrity is very hard work.
The rest of the lecture was filled with wonders. We have made so many amazing discoveries about life just on our own planet, past and present. The quest of astrobiologists has spawned whole new fields: paleogenetics, synthetic biology, computational bioinformatics and the intense study of extreamophiles. Experiments related to the search for life are on board many of the missions we plan to send off into space over the next fifty years. Mars is exciting, of course, but so are moons I had never heard of in my fourth grade enthusiasm: Europa, Enceladus and Titan. What a great time to be alive!
On the car ride home I was waxing philosophical, relating Plato’s parable of the cave and connecting it to the thoughts on the philosophy of science Dr. Brenner had shared. I was really on a roll when my son interrupted me.
“Mom,” he said, “I really like synthetic biology. I think you should help me learn organic chemistry next.”
I didn’t have the heart to tell him that organic chemistry was the only class I ever had to drop in college because I just couldn’t hack it. Isn’t life ironic? I heard my mother’s voice: “I hope you have four just like you!”
I say to my husband “We’ll meet you downtown at 2”
