### Archives

### Recent blog posts

- Prikry forcing may add a Souslin tree June 12, 2016
- The reflection principle $R_2$ May 20, 2016
- Prolific Souslin trees March 17, 2016
- Generalizations of Martin’s Axiom and the well-met condition January 11, 2015
- Many diamonds from just one January 6, 2015
- Happy new jewish year! September 24, 2014
- Square principles April 19, 2014
- Partitioning the club guessing January 22, 2014

### Keywords

Rado's conjecture Cardinal Invariants Partition Relations Fast club Diamond projective Boolean algebra Almost-disjoint famiy very good scale Fodor-type reflection Axiom R Singular Density P-Ideal Dichotomy OCA Martin's Axiom Nonspecial tree Club Guessing coloring number Stevo Todorcevic polarized partition relation PFA Reduced Power Kurepa Hypothesis S-Space Whitehead Problem reflection principles Microscopic Approach Cardinal function Chromatic number Forcing stationary reflection Hereditarily Lindelöf space Shelah's Strong Hypothesis Ostaszewski square Forcing Axioms free Boolean algebra Absoluteness Almost Souslin Almost countably chromatic Slim tree Successor of Singular Cardinal L-space Sakurai's Bell inequality Prevalent singular cardinals Prikry-type forcing Erdos-Hajnal graphs Ascent Path Cohen real Uniformization Generalized Clubs ccc Coherent tree Postprocessing function PFA(S)[S] Foundations Selective Ultrafilter square principles Distributive tree approachability ideal Luzin set Uniformly coherent Hedetniemi's conjecture Antichain middle diamond Weakly compact cardinal Chang's conjecture 05A17 Rainbow sets Parameterized proxy principle Hindman's Theorem sap Aronszajn tree Small forcing Rock n' Roll xbox Large Cardinals Commutative cancellative semigroups square 11P99 20M14 Jonsson cardinal Mandelbrot set Universal Sequences Singular cardinals combinatorics Non-saturation stationary hitting incompactness Singular coﬁnality Square-Brackets Partition Relations Erdos Cardinal Successor of Regular Cardinal weak diamond Dushnik-Miller Souslin Tree Knaster Poset weak square Constructible Universe b-scale diamond star super-Souslin tree tensor product graph HOD Fat stationary set Minimal Walks

# Tag Archives: Mandelbrot set

## A natural Mandelbrot set

Chris Hadfield is a Canadian astronaut, with a very high-profile twitter account. He posts there beautiful photos everyday, and I (plus half a million followers) enjoy it very much. Today, Chris posted the following picture: and I find it quite … Continue reading