Martin Krzywinski / Genome Sciences Center / Martin Krzywinski / Genome Sciences Center / - contact me Martin Krzywinski / Genome Sciences Center / on Twitter Martin Krzywinski / Genome Sciences Center / - Lumondo Photography Martin Krzywinski / Genome Sciences Center / - Pi Art Martin Krzywinski / Genome Sciences Center / - Hilbertonians - Creatures on the Hilbert Curve
Lips that taste of tears, they say, are the best for kissing.Dorothy Parkerget crankymore quotes

c: 3

In Silico Flurries: Computing a world of snow. Scientific American. 23 December 2017

data visualization + art

If you like space, you'll love my 2017 Pi Day art which imagines the digits as a star catalogue. Meet the Quagga and Aurochs—the Constellations in this sky are extinct animals and plants.

from an undefined
create (a place)
an account
of us
— Viorica Hrincu

Sometimes when you stare at the void, the void sends you a poem.

Universe—Superclusters and Voids

Universe - Superclusters and Voids / Martin Krzywinski @MKrzywinski
The Universe — Superclustesr and Voids. The two supergalactic hemispheres showing Abell clusters (blue), superclusters (magenta) and voids (black) within a distance of 6,000 million light-years from the Milky Way.

The average density of the universe is about `10 \times 10^{-30} \text{ g/cm}^3` or about 6 protons per cubic meter. This should put some perspective in what we mean when we speak about voids as "underdense regions".

Before you delve into the background material for the map, calm the nerves and awaken the imagination with these space-themed tunes.

Perfect to listen to while perusing the map ... or the terrain.


2 Wicky by Hooverphonic (Live at Koningin Elisabethzaal 2012)

Space walk by Lemon Jelly

Exploration by Karminsky Experience Inc.

100 Billion Stars by Lux

Journey through the Boötes Void by Scott Lawlor

Ok, now let's get to it.

Combined and parsed catalogues

The individual catalogues of objects (stars, clusters, superclusters, voids) shown on the map are available as a parsed single file.

      n TYPE
  ----- ------------
      2 quasar
   1024 supercluster
   2555 void
   5250 abell
   9096 hr
  18707 zwicky

Each element is represented by a single line and all objects start with the same fields:

  radec RA DEC                               
  z REDSHIFT d DISTANCE(Mly)                

For some objects the NAME is blank ("-").

In addition to these fields, each object type has additional information.

Abell cluters have the number of galaxies in them (N) and the IDs of the superclusters to which they belong listed.

abell ... count N mscc/sscc ID1,ID2,...

Superclusters have the number of galaxies in them (N), their size (SIZE) and the two constellation of the supercluster's Abell's clusters (same as CONSTELLATION if the supercluster's Abell clusters are all in the same constellation).

supercluster ... count N size SIZE(Mly) con_compound CON_COMPOUND

Voids have their size void ... size SIZE

The stars, taken from the Yale Catalogue of Bright Stars, do not have a distance or redshift but have a magnitude

hr ... mag MAGNITUDE

Individual catalogues

These are the individual catalogues from Vizier used in the map and to create the single parsed file above.


V/50 Bright Star Catalogue, 5th Revised Ed., Hoffleit+, 1991

Abell clusters

VII/110A Rich Clusters of Galaxies, Abell+, 1989

VII/4A Abell and Zwicky Clusters of Galaxies, Abell+, 1974

Abell redshifts

VII/56 Redshifts for Abell Clusters, Sarazin+, 1982

J/APJ/365/66 Redshifts of a sample of distant Abell clusters, Huchra+, 1990

VII/165A Measured Redshifts of Abell Clusters of Galaxies, Andernach, 1991

VII/177 Redshifts and Velocity Dispersions for Abell Clusters, Struble+, 1991

J/APJS/96/343 Redshifts of rich clusters of galaxies, Quintana+, 1995

J/A+A/310/8 The ESO Nearby Abell Cluster Survey I., Katgert+, 1996

J/A+A/310/31 The ESO Nearby Abell Cluster Survey. II., Mazure+, 1996

J/APJS/126/1 Abell clusters photometry, Quintana+, 2000

J/AJ/126/119 Optical and radio data for rich Abell clusters, Rizza+, 2003

Zwicky clusters

VII/190 Zwicky Galaxy Catalog, Zwicky+, 1968

J/PASP/111/438 Updated Zwicky catalog (UZC), Falco+, 1999


J/MNRAS/445/4073 Two catalogues of superclusters, Chow-Martinez+, 2014


J/APJ/744/82 Catalog of cosmic voids from the SDSS-DR7, Varela+, 2012

J/MNRAS/440/1248 SDSS DR7 voids and superclusters, Nadathur+, 2014

J/APJ/835/161 A cosmic void catalog of SDSS DR12 BOSS galaxies, Mao+, 2017


VI/42 Identification of a Constellation From Position, Roman, 1987

Literature and online references

Good places to start your exploration of the Universe.


Hoffleit, D. & Warren, Jr., W.H. The Bright Star Catalog, 5th Revised Edition (Preliminary Version) (1991)


Roman N.G. Identification of a constellation from a position Publications of the Astronomical Society of the Pacific 99 695–699 (1987)

Constellation list

To determine constellation shapes, I originally started with a list by Marc van der Sluys

BSC (Yale Catalogue of Bright Stars) constellation edges by Marc van der Sluys

However, many of these constellations were not the asterisms sanctioned by the IAU. I therefore corrected all the constellation shapes by manually examining the IAU map and cross-referencing the stars to the Yale Catalogue of Bright Stars. Ugh.

IAU Constellation shapes as edges between BSC stars (Yale Catalogue of Bright Stars) by Martin Krzywinski

For more details about the constellations see my IAU Constellation Shape Resources.


Abell clusters [Wikipedia]

Abell, G.O. The distribution of rich clusters of galaxies. A catalog of 2712 rich clusters found on the National Geographic Society Palomar Observatory Sky Survey The Astrophysical Journal Supplement Series 3 211–88 (1958)

LC 1101: supergiant elliptical galaxy [Wikipedia]

Abell 2029 galaxy cluster [Wikipedia]


The universe within 2 billion light years. by Richard Powell


Finelli F. et al. Supervoids in the WISE–2MASS catalogue imprinting cold spots in the cosmic microwave background Monthly Notices of the Royal Astronomical Society 455 (2016)

Kopylov A.I. & Kopylova F.G. Search for streaming motion of galaxy clusters around the Giant Void Astronomy and Astrophysics 382 389–396 (2002)

Linder U. et al. The structure of supervoids. I. Void hierarchy in the Northern Local Supervoid. Astronomy and Astrophysics 329–347 (1995)

El-Ad H. & Piran T. Voids in the large-scale structure The Astrophysical Journal 491 421–435 (1997)

List of voids [Wikipedia]

Giant void [Wikipedia]

Boötes void [Wikipedia]

Northern local supervoid [Wikipedia]

Southern local supervoid [Wikipedia]

Eridanus supervoid (CMBR Cold spot) [Wikipedia]


J1120+0641 [Wikipedia]

Mortlock D.J. et al A luminous quasar at a redshift of z = 7.085 474 616–619 (2011)

Bañados E. et al An 800-million-solar-mass black hole in a significantly neutral universe at a redshift of 7.5 Nature 553 (2018)

J1342+0928 [Wikipedia]

Coordinate systems

Celestial coordinate system [Wikipedia]

NASA/IPAC Extragalactic Database: Coordinate Transformation & Galactic Extinction Calculator

RA DEC flexible converter by Jan Skowron


How far out in the universe can we see? by Harald Lang

Redshift and distance calculator by Edward Wright

Wright, E.L. The Publications of the Astronomical Society of the Pacific 118 1711–1715 (2006)

Loeb, A. Long-term future of extragalactic astronomy Physical Review D 65 047301.1–047301.4 (2002)

Bennett, C.L. et al The 1% Concordance Hubble Constant Astrophysical Journal 794 (2014)


news + thoughts

Molecular Case Studies Cover

Fri 06-07-2018

The theme of the April issue of Molecular Case Studies is precision oncogenomics. We have three papers in the issue based on work done in our Personalized Oncogenomics Program (POG).

The covers of Molecular Case Studies typically show microscopy images, with some shown in a more abstract fashion. There's also the occasional Circos plot.

I've previously taken a more fine-art approach to cover design, such for those of Nature, Genome Research and Trends in Genetics. I've used microscopy images to create a cover for PNAS—the one that made biology look like astrophysics—and thought that this is kind of material I'd start with for the MCS cover.

Martin Krzywinski @MKrzywinski
Cover design for Apr 2018 issue of Molecular Case Studies. (details)

Happy 2018 `\tau` Day—Art for everyone

Wed 27-06-2018
Martin Krzywinski @MKrzywinski
You know what day it is. (details)

Universe Superclusters and Voids

Mon 25-06-2018

A map of the nearby superclusters and voids in the Unvierse.

By "nearby" I mean within 6,000 million light-years.

Martin Krzywinski @MKrzywinski
The Universe — Superclustesr and Voids. The two supergalactic hemispheres showing Abell clusters, superclusters and voids within a distance of 6,000 million light-years from the Milky Way. (details)

Datavis for your feet—the 178.75 lb socks

Sat 23-06-2018

In the past, I've been tangentially involved in fashion design. I've also been more directly involved in fashion photography.

It was now time to design my first ... pair of socks.

Martin Krzywinski @MKrzywinski
Some datavis for your feet: the 178.75 lb socks. (get some)

In collaboration with Flux Socks, the design features the colors and relative thicknesses of Rogue olympic weightlifting plates. The first four plates in the stack are the 55, 45, 35, and 25 competition plates. The top 4 plates are the 10, 5, 2.5 and 1.25 lb change plates.

The perceived weight of each sock is 178.75 lb and 357.5 lb for the pair.

The actual weight is much less.

Genes Behind Psychiatric Disorders

Sun 24-06-2018

Find patterns behind gene expression and disease.

Expression, correlation and network module membership of 11,000+ genes and 5 psychiatric disorders in about 6" x 7" on a single page.

Design tip: Stay calm.

Martin Krzywinski @MKrzywinski
Martin Krzywinski @MKrzywinski
An analysis of dust reveals how the presence of men, women, dogs and cats affects the variety of bacteria in a household. Appears on Graphic Science page in December 2015 issue of Scientific American.

More of my American Scientific Graphic Science designs

Gandal M.J. et al. Shared Molecular Neuropathology Across Major Psychiatric Disorders Parallels Polygenic Overlap Science 359 693–697 (2018)

Curse(s) of dimensionality

Tue 05-06-2018
There is such a thing as too much of a good thing.

We discuss the many ways in which analysis can be confounded when data has a large number of dimensions (variables). Collectively, these are called the "curses of dimensionality".

Martin Krzywinski @MKrzywinski
Nature Methods Points of Significance column: Curse(s) of dimensionality. (read)

Some of these are unintuitive, such as the fact that the volume of the hypersphere increases and then shrinks beyond about 7 dimensions, while the volume of the hypercube always increases. This means that high-dimensional space is "mostly corners" and the distance between points increases greatly with dimension. This has consequences on correlation and classification.

Altman, N. & Krzywinski, M. (2018) Points of significance: Curse(s) of dimensionality Nature Methods 15:399–400.