how do people live without constantly being afraid. not in an anxiety way or having something concrete to worry about, i'm just constantly scared simply because i am alive and existing.

i know this is a consequence of all the trauma and abuse i went through but it's genuinely wild to me that people exist and go without their day feeling. normal. and not like this.

I'm curious about something: Given the fact that the moon's slowly moving away from Earth, logically there would've been a time in the distant past when annular eclipses never happened, and likewise, there'll be a time when total eclipses will stop happening. Do you have any idea how far in the past and future those events would be?

That’s a really interesting question and one which I don’t know the answer to without looking it up! So needless to say, this reply will be rambly and off the top of my head, with a few easily Googlable numbers involved.

All objects orbiting at radii greater than geocentric orbit (a bit over 42,000 km) are technically unstable and will gradually drift away, but this happens unbelievably slowly. The moon’s orbit, currently averaging about 380,000 km, is increasing by roughly 4 cm every year.

For anyone reading this who doesn’t know, annular and total eclipses happen based on how far away the moon is at the time. The Moon’s orbit is elliptical, so when it’s at perigee (the closest it gets), then a total eclipse would happen because the moon appears larger in the sky than the Sun. On the other hand at apogee (the most distant point in its orbit), it appears smaller than the Sun, so you’d see an annular eclipse.

Giving rough estimates based on these geometries, if the moon was about 36000 km closer, then annular eclipses would never happen even when the moon is at apogee, and if it was about 27000 km further away, it wouldn’t appear large enough to give a total eclipse even at perigee. These are ballpark figures because I’m too lazy to calculate it accurately, but they’re enough to give you a rough idea.

Assuming the Moon keeps moving away at the same rate, this means that around 0.9 billion years ago there were no annular eclipses at all, and in about 0.6 billion years from now there will never be another total eclipse again. I’m also ignoring any changes in Earth’s orbit around the Sun here – Earth is moving very slowly away from the Sun, but only by something tiny like a centimetre each year. Practically nothing when Earth’s orbit is 150 million km!

0.9 billion years ago was sometime during the Neoproterozoic era during the Pre-Cambrian period, around the time multicellular life first developed. So nothing would have seen solar eclipses then, because it was still about 360 million years before eyes evolved – the earliest fossil evidence of complex eyes dates back to the Cambrian Explosion, around 540 million years ago.

It’s hard to say what might be living on Earth in 0.6 billion years time. Something probably will be, but Earth will look like a completely different planet after 0.6 billion years of evolution and continental drift. I can say that by that time, it’s quite likely an Earth day will be a few hours longer, Saturn will no longer have rings, and the Andromeda galaxy will be one of the most noticeable things in the night sky. If we’re optimistic enough to hope that humans still exist in 0.6 billion years, they may be seeing eclipses around other stars by then.

That… was more than I planned on writing. But it was fun, so it’s all good.