We mark our years by how long it takes the Earth to complete a cycle around the Sun, so the end of a year is a great time to contemplate how our orbit has some advantages for life on this planet. The big one is that it keeps us from slamming into the Sun and burning up, points out Aatish Bhatia at his Empirical Zeal blog at Wired.
Bhatia explains that since orbit is like falling around the Sun, if we stopped we would fall into the Sun. This would take about 64 days, but we’d all die before then. Here are some highlights:
- By day 21, the average global temperature has climbed to about 95 degrees Fahrenheit and crops are failing.
- By day 35 most of the Earth is hot, hot, hot. "[E]ven the Saharan silver ant, one of the most heat resistant land animals on Earth, can no longer survive the heat," writes Bhatia. The Sahara desert ant however "can survive surface temperatures of up to 70 C [158 degrees F]. As scavengers, these ants feed on the corpses of other creatures that have died from the heat, and there’s now plenty of food to go around." Humans survive only if they still have air conditioning.
- By day 47, the Earth’s oceans are boiling. Most life is extinct. Tardigrades, the legendary survivors, are still OK, but they’ll die by day 54.
- By half-past noon on day 64, after reaching temperatures that melt all Earth’s rocks, the tidal forces of the Sun pull the planet apart.
In the highly unlikely event this catastrophe happens, it will at least force the approximately 1 in 4 Americans currently unaware that the Earth orbits around the Sun to quickly get up to speed and realize the importance of that fact. (To be fair and very technical, the Earth doesn’t orbit around the Sun. It actually orbits around the center of mass in the solar system. That isn’t quite at the center of the Sun, but it’s usually nearby.)
Overall, it would be much better, but still bad news, if the Earth simply stopped spinning—but kept orbiting. The Moon would eventually get us rotating again.
Alternatively, we could just keep everything as is, merrily spinning and orbiting. Let’s do that.