That's a good point. One thing I forgot to note is why the Silver Millennium isn't much, much older. I think this is pretty unlikely, and the first reason is Doylist: Takeuchi's name with "millennium" in it is telling us to think in terms of millennia, not in millions of years. She thinks about geology a lot, since most everyone is named after some sort of rock, but she doesn't use geological time scales for the story events. Similarly, Crystal Tokyo is definitely on the site of modern Tokyo, because of the Crystal Points and Dark Points; the time scales do not expect radical changes to geography.
Plus, we learn about the ruins of the Dark Kingdom and Silver Millennium both, and if there are actually ruins to be had, it can't be in the multimillion years. The Moon is not really a static place — all those craters you see happened over time. See the Silurian hypothesis, which talks about how hard it would be to detect anything at all from a civilization this old. (I mean, maybe the Earth Kingdom was originally lizard people? Seems kinda unlikely based on what we saw on-screen.)
To me, though, the biggest reason for it to be in the last ten thousand years or so is social. The names of the planets actually relate to the personalities of the Sailor Guardians who represented those planets. The names seem to be partially preserved in Western tradition, while the elemental alignment is preserved in the Eastern traditions. For instance, Jupiter has more to do with lightning in Roman tradition, but in Chinese thought it's associated with the element of wood, which explains her flower power. In Norse tradition, they preserved it as Odin's special association with Yggdrasil, etc. (Well, maybe not in our setting on the last one, because we're using AMG.)
You could reverse that argument though, and say that that ancient people could notice the power of the planets, and each senshi's power comes from their alignment to the planet. Therefore their elemental powers are unsurprising. But it's our setting and we can assume causality however we want!
Can people remember cultural information across multiple millennia without writing? Well, let's head out to Oregon to get our answer, to a place called Mount Mazama. It's more often known as Crater Lake these days, since 7700 years ago Mount Mazama erupted catastrophically, leaving a giant hole with a conical island in the middle. The Klamath people though, still remember the eruption, and talked about what happened there, so long ago. The first person in history to have his name recorded saying that this was the site of a volcano was a Klamath native, not a geologist. Apparently some Australian Aboriginal groups remember volcanoes out to 40000 years (but I haven't been there).
There are other examples, like how people like to link different cultures' narratives about mega floods together, and say they are a memory of that one time the Black Sea flooded. Of course if you're Graham Hancock, you say that there's was actually a global flood event, something something Atlantis. Floods are pretty common, though; people saying that this particular mountain exploded is a precise fact.
Because of cultural memories, including the Tale of the Bamboo Cutter, it is most likely that the Silver Millennium took place in a time within the bounds of oral tradition, which probably has a horizon of around 50000 years. Combined with the things I talked about above, I still believe the sweet spot is three to fourteen millennia before present. This is actually double the amount of time in history at present writing, so it should be enough.
None of this post is on-topic for "Politics" though, which is probably why I wanted to wrap up the last bit fast. Although, as I get into nationalism, maybe it is on-topic? Every nation has to have a national myth.
Plus, we learn about the ruins of the Dark Kingdom and Silver Millennium both, and if there are actually ruins to be had, it can't be in the multimillion years. The Moon is not really a static place — all those craters you see happened over time. See the Silurian hypothesis, which talks about how hard it would be to detect anything at all from a civilization this old. (I mean, maybe the Earth Kingdom was originally lizard people? Seems kinda unlikely based on what we saw on-screen.)
To me, though, the biggest reason for it to be in the last ten thousand years or so is social. The names of the planets actually relate to the personalities of the Sailor Guardians who represented those planets. The names seem to be partially preserved in Western tradition, while the elemental alignment is preserved in the Eastern traditions. For instance, Jupiter has more to do with lightning in Roman tradition, but in Chinese thought it's associated with the element of wood, which explains her flower power. In Norse tradition, they preserved it as Odin's special association with Yggdrasil, etc. (Well, maybe not in our setting on the last one, because we're using AMG.)
You could reverse that argument though, and say that that ancient people could notice the power of the planets, and each senshi's power comes from their alignment to the planet. Therefore their elemental powers are unsurprising. But it's our setting and we can assume causality however we want!
Can people remember cultural information across multiple millennia without writing? Well, let's head out to Oregon to get our answer, to a place called Mount Mazama. It's more often known as Crater Lake these days, since 7700 years ago Mount Mazama erupted catastrophically, leaving a giant hole with a conical island in the middle. The Klamath people though, still remember the eruption, and talked about what happened there, so long ago. The first person in history to have his name recorded saying that this was the site of a volcano was a Klamath native, not a geologist. Apparently some Australian Aboriginal groups remember volcanoes out to 40000 years (but I haven't been there).
There are other examples, like how people like to link different cultures' narratives about mega floods together, and say they are a memory of that one time the Black Sea flooded. Of course if you're Graham Hancock, you say that there's was actually a global flood event, something something Atlantis. Floods are pretty common, though; people saying that this particular mountain exploded is a precise fact.
Because of cultural memories, including the Tale of the Bamboo Cutter, it is most likely that the Silver Millennium took place in a time within the bounds of oral tradition, which probably has a horizon of around 50000 years. Combined with the things I talked about above, I still believe the sweet spot is three to fourteen millennia before present. This is actually double the amount of time in history at present writing, so it should be enough.
None of this post is on-topic for "Politics" though, which is probably why I wanted to wrap up the last bit fast. Although, as I get into nationalism, maybe it is on-topic? Every nation has to have a national myth.
"Kitto daijoubu da yo." - Sakura Kinomoto