What we’re about

Cosmic Variance is a group blog by people who, coincidentally or not, all happen to be physicists and astrophysicists: Mark Trodden, Risa Wechsler, Sean Carroll, JoAnne Hewett, Julianne Dalcanton, John Conway, and Daniel Holz. Our day (and night) jobs notwithstanding, the blog is about whatever we find interesting — science, to be sure, but also arts, politics, culture, technology, academia, and miscellaneous trivia. We have similar outlooks on many things, widely disparate opinions about others, and will do our best to keep the discourse reasonably elevated.

A blogroll and some physics-related links can be found on our links page, as well as in pull-down menus on the sidebar at right. We have included a long, although by no means complete, listing of physics/astrophysics-oriented blogs; if you know of any such sites (including your own) falling into this category that we have missed, please let us know. We do not promise to list every blog, but we hope to be fairly inclusive. Our former co-blogger Clifford Johnson has now gone on to blog at asymptotia.com. Various guest bloggers join the fun from time to time.

We have:

• A Facebook group.
• A goodies store. (Wider selection forthcoming, hopefully.)

If you want to use LaTeX to write formulas in your comments, instructions are here.

“Cosmic Variance”

Physical theories occasionally make predictions that are statistical rather than deterministic. An example is the small deviation from perfect smoothness that characterizes the large-scale structure of the universe — our theories attempt to predict the distribution from which such deviations are drawn, but say nothing about the specifics of a particular fluctuation. When comparing such predictions to observations, we are limited by the fact that there are only a finite number of fluctuations at each scale that we can possibly observe.

The irreducible uncertainty that comes from the fact that we live in a single universe is cosmic variance.

Comments policy

We love comments and aim to cultivate a lively and enjoyable space for discussion. To this end, we will not hesitate to delete comments or ban commenters who are excessively impolite or who otherwise derail the discussions. Disagreement with anything we may say is welcome, so long as it is civil and constructive. We’re all about light, not heat.

Picking and choosing

You can choose (for reasons that escape us) to read only one blogger, or any combination of bloggers, either directly or via our syndicated feeds. Instructions are given in this post.

Technical details

Cosmic variance is powered by WordPress open-source blogging software, with web hosting by InMotion Hosting. The theme was designed by Risa and Sean, based on K2.

The banner image is an altered version of the Wilkinson Microwave Anisotropy Probe map of the cosmic microwave background, the relic radiation left over from the Big Bang. Tiny irregularities in the CMB, produced when the universe was one-thousandth its current size, indicate the kind of density perturbations that have grown into the galaxies and large-scale structure we see today.

Disclaimer

Opinions expressed in posts and comments at Cosmic Variance are those of the individual author, not necessarily those of any other authors. Views expressed here do not reflect those of our funding agencies (the Department of Energy, the National Science Foundation, the National Aeronautics and Space Administration, the David and Lucile Packard Foundation, the Research Corporation) or our employers (Syracuse University, Stanford University, the Stanford Linear Accelerator Center, the California Institute of Technology, Los Alamos National Laboratory, the University of Chicago, the University of California at Davis, the University of Washington).

Contact

Write to admin [at] cosmicvariance.com, or to any of the authors at the email addresses on their individual pages above.