The Star Trek Art Show at the End of the World

When wondering around central Paris, one may not expect to stumble upon a Geek haven filled with sci-fi merchandise, steam-punk design, a time lord inspired ceiling mural, and plenty of geeks playing games, having fun, and drinking geeky cocktails. Le Dernier Bar Avant La Fin Du Monde (The last bar at the end of the world… anyone get the Hitchhiker’s Guide reference?) is just that place and is located literally a few minutes’ walk from Notre-Dame cathedral. This month, from June 3-30, Le Dernier Bar is hosting a Star Trek art show, where the Trek themed art of local and not-so-local artists is on display and even for sale at only 81€ per piece. Check out some photos of this awesome bar and the amazing work on display below.


The art on display was varied in both style and content, celebrating the old and the new with pop art, caricatures, starships, and galaxies. Here is just a sampling of what was on display.

Old Khan, New Khan, Newer Khan


Even when the Star Trek art show isn’t on, Le Dernier bar is THE geeky place to be. If I lived in Paris, I’d love to call this place my local bar and show up every night for a Samarian Sunset and a game of darts. Get a load of the decorations! The lighting, the metal steam-punk feel to much of the bar and walls, and the overall ambience of the place makes it a totally welcoming venue. The sci-fi music playing overhead and the movie trailers showing on their big TV screen was a welcomed touch, too. It reminded me, just a tiny bit, of a night out at Quark’s.

The bar

Impressive display case of Star Trek goodies just inside the entrance

A closer look at the time lord inspired ceiling

The downstairs seating area where you can chill out and play games

An extended upstairs seating area where you can also play games, or perhaps just sip a latte and relax


Whether you’re on vacation, on business, living it up in Paris, or just passing through, Le Dernier Bar is worth a visit, even if you just pop in for a drink. You’ll find it easy to get to: it’s located just a few minutes walk from the Notre-Dame and the St. Michele and Châtelet Metro Stations.

New Tool for Petrologists: Calculate fO2 Buffer

There’s a simple new excel spreadsheet available on the Tools for Petrologists page. The tool Calculate fO2 Buffer allows you to determine the “delta” of a several oxygen fugacity buffers (for example: ΔNNO, ΔQFM, etc.) when the value of logfO2 is known. Here’s a screenshot of the inputs and outputs:

References: B. R. Frost in Mineralogical Society of America “Reviews in Mineralogy” Volume 25.

Correction to Glass Density Calc in Tools for Petrologists

I’ve discovered an error in the Glass Density Calc spreadsheet, posted on the Tools for Petrologists page. The original version of the spreadsheet, used to calculate the density of a volcanic glass or magma, contained incorrect values for the partial molar volumes of the oxide components and incorrect corresponding dV/dT values. The new version (version 2) has the correct values and has been checked against other density measurements in the literature and found to be within about 10% error.

Please update to the newest version: available here.

New Tool For Petrologists: Link to the Giordano Viscosity Model

I’ve discovered another very nifty tool for you all and it’s posted in the Tools For Petrologists section of this site. The model of Giordano, Russell, and Dingwell to calculate the viscosity of a melt at various temperatures given the melt’s composition and H2O content is available online both as a javascript web applet and an Excel spreadsheet.

Here’s a peek at the excel spreadsheet version:

New Tool for Petrologists – Glass Density Calc

Yet another update to the Tools for Petrologists page this week with the Glass Density Calc tool. This Excel spreadsheet allows you to input the composition of your silicate glass in terms of oxide wt% in addition to the water content in wt% plus the temperature and pressure of your sample and outputs the density of your melt in terms of g/cm3 and g/L.

All of the constants and equations necessary from this tool come from Lange and Carmichael (1990) and Ochs and Lange (1999). The equations are put to further use (and some interesting relationships with viscosity are explored) in Hack and Thompson (2011).

User inputs are in the blue boxes, calculated outputs are in the red.

Connecting to Your Rovio Wi-Fi Robot Ad-Hoc with Linux

As I mentioned in a previous post, I am going to attempt to drive my Rovio wireless robot camera into (or at least near to) a lava lake. Specifically, I want to drive Rovio to the edge of the volcanic crater atop Volcan Villarrica in Chile to get a look at the lava lake churning below.

Setting up the Rovio is not straightforward, and I wanted to be able to use it in the field. That means, no internet connection, and no router. Funnily enough, I found it easiest to set this up on Linux, the one OS for which no installation instructions are included.

Ad-Hoc Connection on Linux

An Ad-Hoc connection means direct from Rovio to your computer, no middle man. No internet connection, no router necessary. I did this on Ubuntu, but it should be fairly similar on most Linux distributions.

Step One: Connect to Rovio’s Network
Click on your wireless connections icon in the menu, and connect to the network “ROVIO_WOWWEE”. I you don’t see this network, make sure that your Rovio is powered up and turned on. The blue lights on Rovio should be illuminated. If you still don’t see this network, try restoring your Rovio to factory settings (page 55 in the Rovio user manual).

Step Two: Edit Rovio’s Network Connection
Now that you’re connected to ROVIO_WOWWEE, click on your wireless connections icon again and this time select “Edit Connections…”

In the Network Connections dialog, select the Wireless tab, select ROVIO_WOWWEE, and click “Edit”.

In the Wireless tab, make sure of the following:

  • “Connect Automatically” is checked
  • The mode is set to “Ad-hoc”
  • Everything else should be set to automatic, default, or left blank.

In the IPv4 Settings tab, set the following:

  • Set Method to Manual
  • Under Addresses, set the IP address to
  • Under Addresses, set the Netmask or Subnet mask to

Now, click Save.

Congratulations! Your Rovio should now be accessible!

Step Three: Access Rovio’s Interface
Open up the web browser of your choosing and type in Rovio’s default IP address of You should now see Rovio’s interface and be able to talk to Rovio and give him commands. Note that, since you’ve set up a direct, Ad-hoc Rovio to computer connection, you will only be able to access Rovio when your computer is connection to ROVIO_WOWWEE. You will not be able to access Rovio through the internet or from another computer, like you can with a non Ad-Hoc connection.

New Tool for Petrologists – Oxide to Element Conversion Tool

I’ve just updated the Tools for Petrologists page with a new conversion tool. It’s the Oxide to Element Conversion Tool, an Excel spreadsheet that will convert composition values from wt% oxides (ie. SiO2, Na2O, K2O, etc) to wt% element (ie. Si, Na, K, etc.) and vice versa.

After some googling, I found that some tools like this exist already. But, I made my own that was best formatted to my needs, and hopefully you can find it useful too. Enjoy!

Space Pioneers: A Walt Whitman + NASA + Dubstep Mashup

via Brain Pickings

Driving a Robot Into a Lava Lake – Or, At Least, Taking a Picture of One

The lava lake that sits inside of the crater at Villarrica Volcano in Chile provides a unique opportunity to glimpse the molten top of a lava conduit — the place where the underground volcanic plumbing meets the Earth’s surface and where volcanic eruptions, well, erupt.

It also presents a unique opportunity. Not just for science, but for sheer awesome factor. I want to sample that lake.

Actually getting a sample of the lake is at this stage, let’s say, not likely. My initially ever ambitious goal to simply throw, drive, or dangle something into the lake, allow some lava to glom onto that something, and then to retract said glommed lava to the surface is surely overly-ambitious. But, maybe, just maybe, I’ll settle for getting a video or even a photo of the lake’s surface from above. This…. this is plausible.

Villarrica’s volcanic crater as seen from above

Nial, my typical go-to guy for how to make just about anything work, has less faith in this idea than I do. He’s still making fun of me for my robotic endeavors. But, that does nothing more than spur me on. I just want a picture of the goddamn lava. And, I intend to (try and) get it! But, I still want to use robots! Why? Because, reasons!

My plan? Rovio.

Rovio is a toy robot with a built-in camera that wirelessly transmits video back to the user’s computer, where the user is remotely controlling it’s driving. Yes, yes, it’s a toy. And, as Nial points out, it’s probably not powerful enough to make it over the rough terrain one finds oneself up against while driving around on the inside of a volcanic crater. Nevertheless — it doesn’t hurt to try.

Robotic Rovio. The toy I want to drive into a lava lake.

The plan is to tie a tether (read: rope and maybe a bit of duct tape) to the Rovio and then drive that brave little soul toward the lake, while the user is sitting comfortably at a safe distance. Rovio will brave harsh terrain. When he reaches the conduit, he will slowly inch toward its edge, allowing the video-rover to sweetly tip over the edge and point its camera-head toward the lava lake. WHAT COULD GO WRONG.

Rovio’s trajectory

If successful, this won’t be the first time someone’s videoed a lava lake. This won’t even be the first time someone’s done it at Villarrica (see Goto & Johnson, 2011). But, it will be the first time I’ve ever taken a video of a lava lake! And it will (unnecessarily) use a robot!! Awesome!

I plan to take Rovio out for some test runs around Cambridge soon — although I don’t know that I’ll find truly analogous terrain. Or hills. Or topography of any kind, really.

Science History of the Day: Nobel Award to Haber, Resentment Felt in Allied Countries

In 1918 Professor Fritz Haber was awarded the Nobel Prize in Chemistry for developing what is now known as the Haber Process. In 1920, an editorial piece in the New York Times was printed, which announces Haber’s Nobel win and discusses it in a modern context. The Haber Process allows Nitrogen to be extracted from the air and transformed into ammonia, a chemical that is important today for its use in fertilizers, but one that was even more crucial in 1918 at the end of World War I for its use in explosives. The article is a fascinating insight into what life was like during World War I, and how this piece of chemistry may have affected its outcome.
By 1920, Professor Haber had already received the nickname “the father of chemical warfare” for his development and deployment of chlorine and other poisonous gases during WWI. But, in 1918, ammonia was in high demand for explosives on the battlefield, and the N needed to produce it was hard to come by. Plain old air on Earth is made up of mostly nitrogen (78.1% to be exact), but the extremely strong triple bonds holding together the N molecules make it very hard to extract and essentially unavailable.
The Haber process uses high temperature (300-500 °C), high pressure (150-250 bars), and an iron or ruthenium catalyst to get the job done. It works so well, that the Haber process is still used today for ammonia synthesis.

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