### 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

Poset PFA(S)[S] Antichain Microscopic Approach Singular cardinals combinatorics Aronszajn tree Hindman's Theorem Knaster Coherent tree Jonsson cardinal Chromatic number Erdos-Hajnal graphs Hereditarily Lindelöf space Selective Ultrafilter Almost-disjoint famiy Forcing Axioms Souslin Tree Stevo Todorcevic 05D10 Sakurai's Bell inequality Universal Sequences b-scale Singular Density Rainbow sets Reduced Power Fast club reflection principles S-Space Dushnik-Miller Cardinal function Hedetniemi's conjecture Parameterized proxy principle Mandelbrot set Weakly compact cardinal 11P99 Square-Brackets Partition Relations Non-saturation P-Ideal Dichotomy Cardinal Invariants Singular Cofinality Cohen real Successor of Regular Cardinal Commutative cancellative semigroups Chang's conjecture Slim tree incompactness Constructible Universe OCA square PFA free Boolean algebra Almost Souslin approachability ideal Small forcing Rock n' Roll Rado's conjecture Diamond very good scale coloring number Foundations ccc Prevalent singular cardinals tensor product graph Uniformization stationary hitting Martin's Axiom Fat stationary set L-space Whitehead Problem HOD Large Cardinals polarized partition relation Generalized Clubs projective Boolean algebra Absoluteness Erdos Cardinal 05A17 diamond star Singular coﬁnality Partition Relations 20M14 Almost countably chromatic Axiom R sap middle diamond xbox Ascent Path Forcing Prikry-type forcing Kurepa Hypothesis weak diamond Ostaszewski square weak square Successor of Singular Cardinal Minimal Walks Club Guessing Shelah's Strong Hypothesis stationary reflection Fodor-type reflection

# 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