61–70 of 75 posts
To see life evolve from algae, one would have to live 7.5 million lifespans, assuming one has a lifespan of 100 years. Ancient Egypt is just 50 lifespans away in comparison. That's the most mind-boggling fact I learnt today.
For much of human history 50 years is probably a lot closer. Anyway… https://xkcd.com/2608
How much of that topology is speculation? I get that geologists can estimate the latitude of a location at a given time because of climate and chemical signals, plus some contemporary tectonic shift vectors. I don't get how paleomagnetism is reliable when the magnetic field can wander in the timespan of some thousand years. I'd expect the resulting equations to yield a multitude of solutions or even be unsolvable.
Pretty much all of it.
Earlier quoted context omitted.
The map goes back less than a billion years. We don’t know much about the shape of the Earths continents for the first few billion years.
Movement of plate tectonics started probably 750 million years ago. https://www.youtube.com/watch?v=DI6SemRT2iY
> The further back we look into the geological past, the more obscured the view, masked by an increasingly fragmentary geological record. This has resulted in a controversy on whether plate tectonics operated the same way, or even at all, during early Earth history.
How much of that topology is speculation? I get that geologists can estimate the latitude of a location at a given time because of climate and chemical signals, plus some contemporary tectonic shift vectors. I don't get how paleomagnetism is reliable when the magnetic field can wander in the timespan of some thousand years. I'd expect the resulting equations to yield a multitude of solutions or even be unsolvable.
How much of that topology is speculation? I get that geologists can estimate the latitude of a location at a given time because of climate and chemical signals, plus some contemporary tectonic shift vectors. I don't get how paleomagnetism is reliable when the magnetic field can wander in the timespan of some thousand years. I'd expect the resulting equations to yield a multitude of solutions or even be unsolvable.
On a related note, I heard both of those coastlines were formed by glaciers in the last ice age. But wouldn't that also have been true during every ice age? Or did they just get more dramatic each time? ;)
It would be so incredible if you could hit a Play button and see the plates move (or even just step through the existing snapshots slide show style while centered I your city).
This is awesome. I like how it goes from 20 million years ago to present in one jump, which is sort of interesting on the timeline. We had a warm period without ice ages 3-5 million years ago, then had the onset of ice ages 2 million years ago(and that cycle might have been terminated by current fossil fuel use). Just a blip in time from this perspective.
Just so we’re clear—the most recent ice age was already ending before the industrial revolution. Unless you believe like a couple did in the 70s that there was a coming ice age which we completely stopped and reversed. I would love to hear the steelmanning for that.
We've very much curbed out aerosol, but increased our greenhouse-gas pollution. I very much doubt that their analysis was correct to begin with, and I doubt had we not curbed the aerosol pollution, we'd be facing an ice age today - but I'm just some jerk on the internet - I could easily be wrong! Right or wrong, the first paragraph above is how I understand the argument to have been made at the time.
[0] https://arstechnica.com/science/2016/06/that-70s-myth-did-cl...