Roberto Canogar

Associate Professor of Mathematics.
Universidad Nacional de Educación a Distancia (UNED)

[Keenan Crane @keenanisalive]

A standard way to draw planar graphs is to draw nodes as dots and edges as line segments.

But the Koebe–Andreev–Thurston theorem also shows that any planar graph can be visualized by drawing nodes as circular disks, which are tangent if they share an edge:

[Joyce Karam @Joyce_Karam]

Wow. This quote from Jacinda Ardern’s resignation: ‘Hope I leave New Zealanders with a belief that you can be kind but strong, empathetic but decisive, optimistic but focused...that you can be your own kind of leader, one who knows when it’s time to go’..

[Robin Houston @robinhouston]

Mathematical education gives a really misleading impression of the state of our mathematical knowledge.

[Alex Kontorovich @AlexKontorovich]

What humans will do with their time and talents is limitless!

[aliceinbo @aliceinbo1]

El mal genera mal. El daño genera daño.
Es lo que percibo a diario con las personas privadas de libertad con las que trabajo.
Muchas de ellas provienen de historias personales durísimas que a su vez generan daño a otros.

[Steven Strogatz @stevenstrogatz]

My favorite part of this email is Gmail‘s three suggested replies.

[CHEMA PONZE @Chema_Ponze]

¡¡El tema de "Superman" de John Williams interpretado con órgano de iglesia!!

[Nao Casanova @NaoCasanova]

Este CANDADO "comunitario" de un garaje se desbloquea así que se abra uno solo y cualquiera de sus candados individuales.
(Miradlo con cuidado.)
Matemáticamente es un ENLACE BRUNIANO.

[Robin Houston @robinhouston]

In 2016, Jeffrey Shallit wrote in a comment on https://t.co/qCiNNGknfg:

> apparently it is not even currently known whether or not 9 multiplications are needed to compute the determinant of a 3x3 matrix

Does anyone know if this is still open?

[Randall Munroe @xkcd]

Selection Bias https://t.co/mcALp3vjGX

[Frank Dellaert @fdellaert]

SO(3) materialized and visualized.

[Robin Houston @robinhouston]

omg @tszzl what have you started‽ https://t.co/tsV3FRGMzt

[dave @beesandbombs]

:)

[Roberto Canogar @RCanogar]

@NSalmoria @TCutrofello 10 years! Time does fly. Great news that you are working on a new version Nicola 👏😊. I would love to play too.

[Matt Henderson @matthen2]

bouncing from the focus of one parabola to another

[Robin Houston @robinhouston]

At first I thought this was a joke and they were going straight in hyperbolic space or something. But no, they actually are going straight in the ordinary sense (i.e. giving up a life of crime)

[Akiyoshi Kitaoka @AkiyoshiKitaoka]

Horizontally aligned rows appear to tilt alternately.

[dave @beesandbombs]

:)

[dave @beesandbombs]

:)