### Archives

### Recent blog posts

- A strong form of König’s lemma October 21, 2017
- 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

### Keywords

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

# 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