The improbabilty of total solar eclipses
2024-04-10 06:34:00 +07:00 by Mark Smith
I've listenned to several podcasts covering the recent solar eclipse in the US. One of which was Andrew Keen's interesting interview with author Christopher Cokinos. Amoung other topics they talk about, I was struck by Christipher's description of the science behind the eclipse. Of the shear impossibility of it all.
These days we hear announcements of eclipses every year. We almost take it for granted. But that wasn't always the case. In the years before scientific understanding and modern technology, solar eclipses really freaked people out, which is very understandable. You live your entire life knowing that the sun sets in the evening and rises in the morning. Eclipses turn all that on it's head. Those in the direct path of the eclipse, literally experience for 4 minutes night time recreated in the middle of the day.
So what's so special about it? Well first off, the moon is at a distance perfect for eclipses. It's also perfect in size. It is 400 times smaller than the sun and 400 times closer to the Earth. That means that when it crosses the face of the sun, it's diameter is just such that it can cover it completely. Because if this, total solar eclipses are possible, and have enabled us to see the Sun's corona. This is the area on the surface edges that are much hotter than the rest of the Sun. This distance and size fact alone, leaves me thinking how improbable the situation is, but that's not the only thing.
The solar eclipses we see on Earth happen seemingly randomly because it turns out that the moon orbits the Earth in a non-standard orbit. Though the Earth and Sun move in the plain of the Galaxy the moon's orbit is in fact tilted compared to the plain of the galaxy. The moon is 5 degrees off of 'the ecliptic'. Whereas other planets that do have moons, the moons are likely in a regular orbit. They would have eclipses every single month. Granted these days eclipses are seen as much less random, we understand the science, but that's only happened relatively recently. For most of humanity's existence, eclipses basically happend randomly.
The moon is also strangely big in comparison to the Earth, especially when considering its short distance from the earth. It took a long time for scientists to figure out how it was formed. We think the moon was formed, not by a foreign entity gravity well capture, as is the case with most other planets, but by a collision with a Mars sized planet, causing an enormous part of earth to be ejected into orbit. That eventually, after billions of years, turned into the moon.
Basically this whole setup is very very rare in galactic terms.
This configuration had a massive effect on the development of the planet, the tides, the seasons, and even life. Some believe it might have played a big role in creating the conditions for life itself, since the early Earth would have been impacted by it's forces greatly.
All this got me thinking. In my opinion it might even be responsible for our fear of the unknown, the development of gods and religions etc, because you never knew when an eclipse would happen. It likely created and shaped how we perceive the external world and ultimately the universe. And since most other habitable planets probably don’t have such a moon, I suspect that, should there be life somewhere else in the universe, these civilisations would develop with a very different view of the universe and existence.
The very particular way our solar system has evolved likely has had a big impact on our species at a core level. If there are aliens somewhere in the Universe, how we experienced the moon as we evolved as a species and developed into a civilisation will probably be responsible for many of our deep rooted differences.
Personally I am in awe at all this, I mean seriously, what are the chances? The fact that all these giant entities arranged themselves in such a way that we get total solar eclipses, and random ones, so we never got bored with them, always curious to look for thousands and thousands of years, at what was out there beyond the skies of our planet. It's amazing. #