the lichen knowledge iceberg i have constructed on request.
jhanettesticle replies:
we cant make lichen happen in a lab? have we tried taking the parts that make up a lichen and throwing them together in a petri dish?
bogleech replies:
The deranged fucked up dark sided thing about lichen is that the exact species comprising it don't even necessarily determine the type of lichen. You can have what seems to be the same lichen in two different locations using different symbiotes, or two different looking lichen turn out to have the very same symbiotes. So it's not even that they form when the right component species meet up, because that doesn't always have a predictable result. Something in the environment tells them to build a lichen. Something that makes sense to them but has no meaning to us yet. Whatever it is cannot be imitated by us, in fact if you move a lichen indoors - or move it at all, really - it's all but guaranteed to stop being a lichen or just due, even if you try to recreate the climate you found it in!
For anyone else who was curious about lichens covering "a not insignificant amount" of the earth's surface, a quick google tells me it's about 7% (according to e.g. new york times, scientific american, etc)
Edit: oh and estimating the age of an exposed surface by lichen diameter is called lichenometry. I'm seeing stuff about it being used in geological contexts but it makes sense that it could work for old buildings too
i imagine alien hivemind organisms looking at earth and our cities upon it and thinking "what are these growths and why aren't the samples we collect producing them?"
For anyone interested, I really recommend the book / audio book Entangled Life by Merlin Sheldrake.
I liked the book so much that I later on bought the audio book. It's entertaining, filled with facts, but not overly scientific to a degree where it can't be enjoyed by a layman.
It's a thing that grows on trees and rocks mostly, but can and does grow on basically anything in the goldilocks conditions. They feel like crispy moss if you touch them.
So, I opened this without looking at the source community. I'm on an RPG meme community as well. I was actually predicting a pun on a certain phylactery-using undead. Only as it was loading did I realize I had a chance for the science memes sub instead.