Sunday, April 12, 2015

Gigantic Lego Device

I could watch this for hours. So if I'm gonna be unproductive, so will you! Bwaaahahahahha!

Wednesday, April 8, 2015

Another Black man gunned down by the police

From the NYT:
A white police officer in North Charleston, S.C., was charged with murder on Tuesday after a video surfaced showing him shooting in the back and killing an apparently unarmed black man while the man ran away.

Stay tuned for
• White people wondering if Walter Scott is a good enough Black person to warrant anger over his death. He does, after all, have a criminal record, which the police will no doubt remind us of soon
• White people wondering why Black people don't worry more about Black-on-Black crime (85% of white people are killed by white people)
• A call for Black people to remain calm and follow the law, ignoring the fact that this country was founded based on outrage turning to violence and then revolution. But those people back then were heroes right? Black people now need to settle down, as we'll soon hear
• Arguments among white people about whether this shooting is in any way related to the shooting of Michael Brown, or Eric Garner, or John Crawford, or Ezel Ford, or Dante Parker. Surely this is an isolated incident involving a bad apple. Right? Anyone?
• Even though the cop has been fired, we still have the suspense of the jury's decision in the murder case. You just never know how things go when someone gets shot on camera in the middle of the day with a bunch of witnesses are around...and when the shooter is a cop.
Here's Jay Smooth on the need for every individual to be a "blackbox recorder," so when the airplane called our society crashes on yet another Black head, we'll at least have some clue as to what really happened. You know, like when other crimes and disasters resulting in the loss of life occur, yet totally unlike when police commit crimes that result in the death of (Black) citizens.

Sunday, April 5, 2015

Rules for the Black Birder

When you envision a typical bird watcher, you probably don't think about a Black man. However, there are a few Black birders out there. And as with most things that Black people pursue in a white world, there's a separate set of rules. Not anything huge, per se, but definitely a distinct rule set that few white people ever have to think about when spending time in nature. This is privilege vs. the lack thereof. This is the way it is in our country, and to pretend otherwise while chanting "post-racial" is like a bird sticking its head in the sand.

Joyful white guys finish ahead of struggling woman and black man in this university’s catalog

 Image in the brochure for the University of North Georgia. In this accurate analogy for the hiringand tenure process at most HWCUs, we can see a white male, in this case Bill, winning. Thosediversity hires never seem to come in first. The reasons are...complicated.
From an article describing the brouhaha around the image above, via the Facebook Diversity in Astronomy and Physics page:
The University of North Georgia apologized and agreed to stop distributing a course catalog that shows white men winning a race while a woman and black man lag behind.
Because...because of course. Because white, male privilege. Because this is the most honest take on University policy ever distributed by a Historically White College or University (HWCUs as I all them). I hear a picture of the starting line was considered for the brochure, but removed simply because the development office "needed more space for buzz words like 'cross-cutting' and 'diversity'." Fortunately, I was able to locate the infographic showing the starting line:

Monday, March 16, 2015

Research Summary: Searching for binaries in calibration spectra

Today's blog post is by Juliette Becker, a first-year astrophysics graduate student at the University of Michigan working with Prof. Fred Adams on exoplanet dynamics, among other topics. While her work is mostly focused on theoretical astrophysics at the moment, Juliette has extensive experience as an observational astrophysicist from her time as an undergraduate at Caltech (see e.g. Muirhead, Becker et al. 2014). At Caltech, Juliette was also the captain of the track and cross-country teams, setting school records in the 3000 steeple chase, as well as the 6k and 10k distance events. In today's post, she describes her latest paper, which summarizes the work she started with me as an undergrad and saw through to completion, with her paper accepted to ApJS last week. Like reaching the finish line in a 10K event, publishing cutting-edge research requires pacing, endurance and patience!

When I was a sophomore at Caltech, I took the introductory astronomy class, Ay20, with Professor John Johnson. His enthusiasm and approachability inspired me to ask if I could work on a research project with him during the following summer as part of the Summer Undergraduate Research Fellowship (John was a SURF researcher in 1999!). Not only did he say yes, but he also told me about a really exciting prospect. There were years of calibration spectra for the California Planet Survey sitting unused on disk. The targets are rapidly rotating, extremely hot ($T_{\rm eff} > 9000$~K) B-type stars, which were used as nearly featureless "blackbodies" in the sky to illuminate the spectrometer optics the same way as a program star.

These calibration spectra had been used to calibrate the radial velocity spectra of smaller target stars, but since the calibrators were rotating so rapidly, there was not much immediate use for them beyond this humble, utilitarian purpose. If someone could extract radial velocity information from these spectra, they could potentially do a search for binary (stellar) companions around these massive rotating stars, as the radial velocity of a star with a companion changes over time as the companion "tugs" its host star around. My first task was to do an order-of-magnitude calculation of the precision attainable from a star spinning at 200 km/s. I found that thanks to the high signal-to-noise in these spectra, we could expect a radial velocity precision of greater than 1 km/s, which is more than enough to detect binary companions all the way down to red dwarfs! (This calculation is in the Appendix of my paper).

The difficulty in extracting these radial velocities arises from the fact that massive, rapidly rotating stars have very few spectral lines, each of which are nearly as broad as the spectrometer's orders (wavelength regions recorded by the spectrograph). While normal CPS targets have thousands of spectral features, a calibrator might have only 10-15 spectral lines. The attached figure taken from our paper for an example of what the comparison looks like for a single spectral order.

To extract the radial velocity data from spectra of rapidly rotating stars, we cannot use traditional methods of fitting the Doppler shift in small chunks of a spectrum and deriving the true radial velocity from a distribution of these shifts. To make maximal use of the few spectral features we have, we fit the entire spectrum – all pixels and orders – simultaneously. This allows the orders without any spectral features to serve as ‘anchor’ orders, setting the continuum level of the fit even as the wide spectral features could otherwise result in an artificially low continuum level.

Our method is described in our paper (details below!), which has been accepted to ApJS and is posted on the arXiv today. As a bonus, not only do we present our functional method for extracting radial velocities from echelle spectra of rapidly rotating stars, but we give absolute radial velocities and rotational velocities ($V\sin{i}$) for each star in our sample (more than 200 stars in all, some of which did not have prior literature measurements).

Here's the preprint of our paper. Enjoy!

Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra
Juliette C. Becker, John Asher Johnson, Andrew Vanderburg, Timothy D. Morton

Monday, March 9, 2015

Now that's pretty shameful...

"If we can work out out how to climb into metal birds, slip the bonds of this Earth and soar through the air to visit these territories, we should be able to figure out how the 4 million people who live there can be adequately heard."

So why is it that US citizens in Puerto Rico and Guam can't vote?

Sunday, February 15, 2015

Dealing with Winter

Guest post by Erin

So many recent conversations with friends near and far have begun with some variation of these phrases: "How's your family dealing with the weather?" or "I bet you're really missing California/Hawaii right now?!?!?"

There's often a subtle look of disappointment when John or I report that it's not too bad.  Yes, there's too much snow and nowhere to put it. Yes, it's getting old that the kids have missed 6 days of school in the last month.  But then again, there's a strange comfort in our current inability to control what's falling from the sky and piling up on our streets and sidewalks.  EVERYWHERE!  And our kids are really helping us to make the best of it. This morning as I marveled at the accumulation, my little contrarian MJ informed me that "Mom, that's not really THAT much snow."

When asked what he thinks about all of the weather, OJ said, "You know, I like that we get all of the seasons.  If I want sunshine, I just wait until summer.  In winter, we get snow and it's so much fun to play in the snow, and we never got to do that in California"