Monthly Archives: November 2014

Astronomy done right – Chris Impey on the Essentials

Most science documentaries these days are heavy on the kabooms and light on content. Prof. Chris Impey of the University of Arizona reverses this trend in Essential Astronomy – a ten lecture series that works equally well with video or without as a podcast. From past to present with some glimpses of the future, it’s documentary as it should be.

[November 2015:  The original Chris Impey Essential Astronomy videos have disappeared from Youtube.  They have reappeared in different editions with added borders and modified audio but it seems that the original uploads were unauthorized and that these are attempts to skirt Youtube’s infringement detectors.  The playlist now points to a different set of lectures from different sources]

[January 2019: The backup playlist of Impey videos has also disappeared. See below for a playlist of Impey’s office hours for his online students]

Dude, you’re a barista… revisited

Ever wonder why hipsters wind up looking, acting, and talking alike? A fascinating new paper examines this as a physics problem.
“The hipster effect: When anticonformists all look the same”

Jonathan Touboul models a hipster system using statistical physics methods: A hipster looks at a representation of the people around him and based on some interaction probability, decides whether or not to follow the herd. What’s the long-term result? It’s a delightful paper, full of analytic firepower, and not easy to follow.

Jake Vanderplas uses the powerful and friendly Python programming language to explore the problem through computer simulation. He finds “In other words, with enough hipsters around responding to delayed fashion trends, a plethora of facial hair and fixed gear bikes is a natural result.”

Vanderplas’s instructive electronic IPython Notebook is available at

ALMA tell us…

Courtesy European Southern Observatory

Our solar system is thought to have formed when a shockwave from a supernova passing through a cloud of gas caused what’s now our sun to ignite. The remaining material, under the emerging star’s gravity and spin, combined and collected over eons into planets in distinct orbits including one that became capable of hosting life.

A stunning new image from the European Southern Observatory now shows this same system-forming process initiating around a distant young star. The data were collected by the truly gonzo ALMA array of radio telescopes built on a high, dry mountaintop in Chile. Current theories do not expect a star so young to be capable of such things. This is truly a big deal and will cause a lot of headscratching in the astronomy community.

For more on the telescopes that made this possible: