MASS

Episode 7 The Backbone of Night

When Carl romances about what the ancients knew, it is humbling to recognize that people 2500 years ago were pretty smart. The Ionians believed things were made from atoms, humans sprang from simpler forms of life, diseases were not caused by demons, Earth was a planet going around the sun and stars were far away. I wasn't sure where Ionia was but a map in the "Cosmos" book showed that it was the western side of modern day Turkey and just across the Aegean Sea from Greece. He attributes their forward thinking to the lack of a strong civil government and no controlling religion.

Eventually more mystical thought and oppressive governments overtook the Ionian way of thinking. It took the Enlightenment of the 1600's to rediscover many of these early truths. Imagine how much more science might have advanced if we didn't take the 2000 year detour.

There was no 1995 update by Carl on this episode. Probably because he had the exoplanet search and size of the universe pretty up-to-date. He mentions that the Milky Way contains a few hundred billion stars and that there are about 100 billion galaxies. These numbers are what scientists today think are accurate. I've seen within the last year that they estimate that there are 300 sextillion stars in the universe (3 followed by 23 zeros). There are more stars than grains of sand on all the beaches of Earth!

The exoplanet count is now up to 755. The vast majority where discovered by spectroscopic studies where they follow how the stars move toward us and then away from us as the planets revolve around them (blue-shifting and red-shifting of spectral lines). The Kepler satellite used the method of  rhythmic star dimming due to planets passing in front of the star, to find planet candidates.The number of Kepler unconfirmed candidate planets is 3470. I've seen a recent estimate of 33 billion habitable-zone earth-like planets in the Milky Way. I'm sure that statistic would have brought a smile to Carl's face.

Let us support space and science endeavours so that we can fulfill his final comment that, "Man is ready to set sail for the stars." I think he'd frown a bit to see how little we have advanced since 1980 in some areas.