What’s there to explain? It’s all there in black and white.
(The paper posits that the same gravitation interactions that lead scientists to infer the existence of Planet Nine could be explained by “A relatively massive and moderately eccentric disk of trans-Neptunian objects (TNOs)”.
A: 42
I guess what I mean is this like a bunch of asteroids or comets all orbiting each other? About the size of a planet or a lot bigger? And are they in the plane of the ecliptic, or perpendicular or what? I was trying to visualize it and not having much luck.
I’m visualizing it as a much larger, much more massive asteroid belt.
Seems to me that wouldn’t have the condensed gravitational attraction of a single planet - it would be spread out around the ring. But if it were eccentric, perhaps that would do it.
Can a ring be eccentric? Would gravitational forces tend to pull different objects in the same ring or belt into similar orbits, with the same aphelion, or would it tend to push them into different orbits?
The linked paper says that they should be relatively easy to form, and their gravity would resist scattering by procession, with Uranus’s ε ring as an example. That much is a new idea to me. There definitely are eccentric rings around stars, like the lovely one 25 light years away around Fomalhaut:
But as it says, that seems to be unusual, and generally supposed to be maintained by a planet. Even Uranus’s rings have shepherd moons, Cordelia and Ophelia for the ε ring. So not that I am an astrophysicist, but it seems to me finding an eccentric ring existing on its own is at least not the expected case.
Weather turns out to be as predictable as climate.
Wish he could have given a bit of the details of why they’ve gotten so accurate.
They’ve finally put GPS tags on all of the butterflies.
It’s in the linked paper, beginning with this paragraph
Why Forecasts are Improving
Key developments in observation, numerical modeling, and data assimilation have enabled these advances in forecast skill. Improved observations, particularly by satellite remote sensing of the atmosphere and surface, provide valuable global information many times per day. Much faster and more powerful computers, in conjunction with improved understanding of atmospheric physics and dynamics, allow more-accurate numerical prediction models. Finally, improved techniques for putting data and models together have been developed…
One sentence jumps out at me.
Sensitivity to initial conditions varies greatly in space and time, and an important but largely unsung advance in weather prediction is the growing ability to quantify the forecast uncertainty by using large ensembles of numerical forecasts that each start from slightly different but equally plausible initial states, together with perturbations in model physics.
I recently read a profile of a conservative or alt-right bigwig (possibly Robert Mercer or someone else related to Cambridge Analytica ) who did scientific programming before he started a hedge fund. The story he tells is that he got disillusioned with government when speeding up a program by ten times didn’t result in a 90% reduction in costs-- instead, the users simply increased the resolution of their program so as to spend the same amount of money.
and here in this very paper, we have a validation of the maxim-- science is advanced by (intelligently) consuming the available computer power.
That makes cryptocurrency perfect for these greedy thieving scumbags. ALL THA POWR TO MEEEE.
That’s just programming in general. Usage expands to fit the available resources, and programming bloats to do the same. Which is why you now need 16GB of RAM, a 3GHz processor, and a TB of drive space to edit the same text file you used to edit with a 640k RAM, an 8MHz processor, and a 720k floppy drive. Same reason people used to complain that it took a long time to download a song (which you can now download way quicker than it plays) and now they complain that it takes a long time to download a 4k video.
Thanks for the summary! I didn’t notice the link.
Clearly he knows nothing about computer simulation of complex physics, especially when fluid mechanics is involved.
In some circumstances, such as the web, it seems more of a design-push than user-pull though. I certainly didn’t ask for all the “modern (sic) web design.”
“Flat”, for example, doesn’t work for anyone actually doing work in a UI that has at least as much complexity as UIs had in the Nineties. 3D may not be the best way, but making objects look like objects? What a concept!
Where did this flat shit come from? I want to say Gmail.
. . . but it looks so crisp . . . and snappy . . . or something . . .
You had 640k RAM and a 3-1/2" DD floppy drive? Wow! I’ll bet you even had a 10 Mb HDD! 
(My old Corona PC had 512k and 2 x 5-1/4" DD floppy drives, no HDD - lots of fun when writing and compiling C programs: boot up with DOS floppy, swap for a data floppy; insert MicroEmacs floppy in 2nd drive, swap out for compiler. It really was fun in a boneheaded way…)
We were taught in a seminar I attended that skeumorphic and 3d were no longer required because audiences/users were now sufficiently computer literate to not need those conventions to understand a UI.
To which my response is:
Ergo BS, QED.
The teacher was too young to know either of those, and didn’t know his computer history very well either – he mentioned a text game based on another text game, and when I mentioned they were both based on Adventure from the 1960s, he had no idea what I was talking about (and assumed I was confused, grrr).
At work we joke about bevels coming back in fashion next. You never know.
