Rahul Narain @narain@mathstodon.xyz

Wow! A vortex ring created by an exploding meteor
http://fyfluiddynamics.com/post/178481591641/during-the-recent-perseid-shower-photographer

(Not actually fun, not actually a fact)

Spam texts in India are amazing.
"ACCOUNTS IS THE FUTURE OF YOUR CHILD."
wtf

The economic inequality in New Delhi is so stark and so geographically adjacent
It's like a modern metropolis and an impoverished village got into a teleporter accident

Every few weeks I remember this tweet
https://twitter.com/Vordus/status/905321688052719616

What I want for next SIGGRAPH is a paper that takes all these "CNNs for physics-based animation" methods and tells you what low-, mid-, and high-level physical structures they're actually learning from the data.

Guy at the airport with a T-shirt that says

"Love is in the air?
WRONG
Nitrogen, oxygen, carbon dioxide etc. are in the air"

I bet he gets a lot of dates.

Little-known fact: Escalators are named after their inventor, Dr S. Skeletor.

I made a thing.
https://soundcloud.com/user-187050364/all-star-but-its-in-the-style-of-clapping-music-by-steve-reich
I'm sorry.

EVE Online wars are the most cyberpunk thing that exists in real life.
https://www.rockpapershotgun.com/2018/07/23/hundreds-of-pilots-trapped-by-goons-in-eve-onlines-latest-galactic-war/

Counterintuitive consequence: In the limit, an infinitely strong damper is a constraint, and then the system is conservative.

Replace the spring with a damper, so that the system is no longer conservative, and your effort is essentially going to waste. Moderately counterintuitive fact: It's still true that the stronger the damping force, the less work you do.

Take a spring attached to an immovable point, and pull on it with a constant force f for a sufficiently long time t. Mildly counterintuitive fact: The stiffer the spring, the less work you do on the system.

Exciting news about the inverse energy cascade in 2D turbulence!
https://www.quantamagazine.org/mathematicians-tame-turbulence-in-flattened-fluids-20180627/

A musical Jekyll and Hyde situation:
https://www.youtube.com/watch?v=jLvDnRU_ajk vs https://www.youtube.com/watch?v=Oj3-xeX0qeo

I should post the video links, which are the first thing I look at for any graphics paper anyway:
https://www.youtube.com/watch?v=brzmcVNB12w
https://www.youtube.com/watch?v=GmwHFP85Ryc

2. A simple incompressible fluid solver that dramatically reduces the energy loss associated with advection-projection algorithms. This paper was a lot of fun to write; big props to my coauthors Jonas Zehnder and Bernhard Thomaszewski at the U de Montréal.
https://jzehnder.me/publications/advectionReflection/

1. A method to simulate cloth with accurate frictional contact, using an adaptive refinement strategy and an implicit formulation for exact Coulomb friction. Most of the credit goes to lead author Jie Li and to our INRIA collaborators Gilles Daviet and Florence Bertails-Descoubes.
http://www-users.cselabs.umn.edu/~lixx4611/contact_friction.html

Our SIGGRAPH 2018 papers are online! (and have been for a while, I just forgot to post about them)