Kliq movie is live

I’m amazingly lucky to have only hobbies, even though I work constantly. The Kliq movie is live! I am extremely proud of the work myself, and my cofounder Michael Craig have done thus far and where we are taking it next, making it easier than ever to interact with people, friends, acquaintances, and potential new best friends, business partners, etc. at events you are already RSVPing to. Read More …

pv-astro poster, simulating the Milky Way, and supercomputer lovefest

I gave a short presentation Friday about pv-astro at the Swiss National Supercomputer Center’s User’s day. We also got to hear a few talks, including about Lucio Mayer’s recent work on a realistic simulation of a Milky Way type galaxy similar to our own. Finally we got an update about the machines at the center being upgraded in October. Some people like fast cars, motorcycles, and airplanes. Me however, I like big machines, with lots of cores and an obscene amount of RAM. Read More …

So a neutrino runs into a tachyon in a bar….

So a neutrino runs into a tachyon in a bar…. HHere’s a collection of interesting twitter snippets from physicists I follow on twitter about today’s neutrino webcast announcing the surprising, and frankly unbelievable, results that the OPERA collaboration observed superluminal neutrinos. I haven’t watched the webcast myself, nor read the paper beyond the abstract yet so can only comment that I believe it must be systematics. That said it would be insanely interesting to be proven otherwise. Finally, the following highlighted tweets are in reverse chronology, because, well… I’ve been here since the day after tomorrow, said the tachyon. What took you so long? Read More …

Galaxy clothing

I splurged and bought two galaxy printed items of designer clothing the other week from the lovely http://www.blackmilkclothing.com/. Some colleagues and I couldn’t help but think about possibilities of extending this further: what about layers of astronomy themed clothing each featuring the same image taken in a different wavelength? Interested seamsters and seamstresses or people with an idea how to print high resolution images on fabric, please contact me! Read More …

Fault tolerant computing

As a first step to writing my own simulation code while attempting to do something useful, a few days ago I started writing a code to explore failure and recovery from failure in a distributed computation. By failure in this case, I mean when one of the computation units goes down. My test system is N harmonic oscillators on N nodes (or processes on a shared memory machine). Read More …

The Intersection of Productivity and Joy (over the past months)

Since last we spoke a couple of months ago, I had a hell of a time personally: I moved house, went from one location to another too often, had a major and very stressful financial crisis and had some rough times with friends which rocked the emotional boat. Although there are many things which didn’t Read More …

Probing the dark matter issue in f(R)-gravity via gravitational lensing

A few days ago in gr-qc  journal club we discussed an interesting paper by a member of our own institute, Probing the dark matter issue in f(R)-gravity via gravitational lensing.1. Background Dark Matter We theoretically expect dark matter to exist based largely on  extensive observations of both dynamics (rotation curves and objects such as the Read More …

Halos gone MAD

I have previously blogged about Structure finding in cosmological simulations and the Haloes Going Mad conference in Madrid this past spring–there you will find the basic background if you are unfamiliar with the subject and I’ll skip that in this post. The result of this conference was a Halo-finder comparison project and its findings were recent posted on the physics arxiv in the paper Haloes gone MAD: The Halo-Finder Comparison Project. I’ll summarize them here.

The paper concentrates on comparing codes on given test data, not comparing the results of various codes to observations, provides a standard test suite and proposes a standard methodology of comparison, both on test, isolated, halos and on a simulation of cosmological volume. Read More …

Locally Cold Flows from Large-Scale Structure

Walls, filaments and voids: it is thought that the large scale distribution of matter is a complex network of galaxies and galaxy clusters connected by elongated filaments and sheetlike walls, outlining vast underdense regions known as voids and meeting at dense and compact regions known as haloes. Aragon-Calvo et. al. in [1] build upon the SpineWeb framework outlined in [2] , which has the capability of identifying these walls, filaments and clusters in cosmological simulations to examine the effect of environment (namely whether a galaxy is “living” in a wall or a void) on the dispersion of the Hubble flow around the Milky, which is significantly lower than theoretical expectations. They show that the measured dispersion could be a result of the fact that Milky Way resides inside a wall of radius around 10Mpc, which is supported by data. Read More …