31–40 of 78 posts
Last week I was in the field digging dinosaurs in Montana, when one of the dig leaders mentioned there was no grass back then, just lots of ferns, because grass hadn't evolved yet. It kind of blew my mind that for most of dinosaurs, there was just a lot of leafs and ferns. Here's some pictures for context ( https://imgur.com/a/rE5wwc4 ), when you're out where most dino bones are found, you forget that it may have bee…
Earlier quoted context omitted.
The problem is the wavelength of light puts a hard limit on angular resolution, its the same reason why a spy satellite cannot read your newspaper, or microscopes can not see atoms, its physically impossible. https://en.wikipedia.org/wiki/Angular_resolution
It is my understanding that you can mitigate this to an extent by making larger scopes or employing techniques like interferometry. I haven't found an absolute 'hard limit', only a limit based on the size of the resolving device. I'm generally a moron in this area though so I'm certainly missing large swaths of information.
Awesome! It's great to see India move northward between 50m and 35m years ago, and smash into the Eurasian body, creating what is now the Himalayan range.
Here's a curious question, India merged into Eurasia ~40 million years ago, Dinosaurs became extinct around 66 million years ago. When dinosaurs were around India was still an island. We know for sure about the presence of Dinosaurs in ancient India through fossils records https://en.wikipedia.org/wiki/Rajasaurus . So how did the dinosaurs populate an isolated island? Or did they evolve independently of each other in…
https://news.ycombinator.com/item?id=17286770 (59 comments, some from the author)
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But using OP's idea, they could be reflected back at the earth, such that 2018 - 1942 = 2 x numLightYears away from the scattering object. I agree, you wouldn't be able to go "in front of the waves" but you might be able to go to a point in space where they'd eventually arrive through scattering. I think it's very unlikely anyways since the solid angle for them to be reflected right back at a certain point is super s…
Very unlikely indeed. I wish I was smart enough to do the math but I'm sure it's more difficult than resolving a planet 50k light years away. Probably more like resolving a planet in another galaxy.
Last week I was in the field digging dinosaurs in Montana, when one of the dig leaders mentioned there was no grass back then, just lots of ferns, because grass hadn't evolved yet. It kind of blew my mind that for most of dinosaurs, there was just a lot of leafs and ferns. Here's some pictures for context ( https://imgur.com/a/rE5wwc4 ), when you're out where most dino bones are found, you forget that it may have bee…
Somewhere outside the Schwarzschild radius of every black hole is a region in which the path of incoming photons is 'bent' 180 degrees and they are sent back roughly in the direction from which they came. In my mind this means that some infinitesimally small portion of the photons that fall on the earth every day were reflected from the earth ~50K years ago and sent in the direction of the black hole at the center of…
The problem is the wavelength of light puts a hard limit on angular resolution, its the same reason why a spy satellite cannot read your newspaper, or microscopes can not see atoms, its physically impossible. https://en.wikipedia.org/wiki/Angular_resolution
I had no idea flowers evolved so late. The first flowers were 100 million years after the first dinosaurs!
The majority of flora we see now also evolved very late. The dinosaurs probably saw and fed on Conifers, Cycadophytes and Ferns. Grass and Modern leafed flora evolved much later.
I looked up Scotland and 750 million years ago and there is a range of mountains to the North West. :-)
Incidentally, one of the cool things about the North West of Scotland is that the original landscape that was buried by the sandstone has been exposed in places.
Edit: I also seen to remember reading that the Brownstone buildings of New York are actually made from the same stone deposited on areas that ended up on the other side of the Atlantic when it split.