Today we have an interesting story available about potentially habitable planets in the Galaxy. It would be interesting to do a compare and contrast with part of a discussion between Ryder, Miss Li and other members of the fictional class in the first volume of the Demeter series (chapter 3). The news article is available at http://www.vox.com/2015/1/2/7474501/exoplanet-simulator
“Our best estimate is three hundred and forty billion stars. Just in our region of the Milky Way there are over a billion planets. Of those, the habitable planets…” Miss Li hesitated. “Well, we assume that there are many planets that would be habitable.”
Cynthia interjected. “I thought they didn’t know if any of the planets were habitable.”
“Well, Earth scientists do not have any clear evidence of habitability, but statistically there is a strong likelihood that some of the planets could support life, especially for different life-forms.”
Randy replied defensively. “My uncle says that Earth is the only planet with life on it, and that all the stories we hear about UFOs and stuff are just somebody’s imagination running wild.”
“Yes, many people believe that, Randy,” Miss Li responded. “Can you explain how all one billion planets are devoid of life, while Earth has such an abundance and variety of life?”
Randy sat pondering, but his brother Joel jumped in. “Well, God created the universe, the galaxies, the solar systems, and the planets. He created it all for us.”
“Interesting idea,” said Miss Li. “Cynthia Flores, what do you think?”
Cynthia seemed to be caught off guard for a moment, but Ryder could tell she was thinking because she always furled her brow when she was considering something challenging. He’d first noticed that pattern on a science test just a couple of weeks earlier. Cynthia began hesitantly. “I believe in God, and my family goes to church every Sunday, but it seems to me that God would not create something so vast just for us. I think he created it for us, and probably other…” She seemed stuck for the word she was looking for. “People, creatures, whatever,” she stammered at the end.
“Ryder, what are your thoughts?” Miss Li inquired.
Ryder was ready for this one. “Miss Li, I don’t know. I’m still trying to figure out how you know there are a billion planets. Last I heard, we had only been able to verify a few hundred. But, if there are a billion planets, considering that there are various types of stars, various different rotations around respective stars, and various life forms, it seems to me that the odds of one supporting life would be roughly eight hundred and fifty to one, which would work out to….one million one hundred seventy-six thousand four hundred and seventy-one.”
Miss Li gave Ryder a pleased look. “Actually, Ryder, our best estimate is between one-point-four and one-point-five million planets in this galaxy that can support life.” She frowned and paused. “In any event, it seems likely that there are some habitable planets even in our galaxy. Now multiply that by thousands of galaxies.”