Continue reading »]]> 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.

Continue reading »]]> 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:

Continue reading »]]> 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.

Continue reading »]]> 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 192.168.10.5
• Under Addresses, set the Netmask or Subnet mask to 255.255.255.0

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 192.168.10.18. 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.

Continue reading »]]> 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!

Continue reading »]]> 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.

Continue reading »]]> 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.

Continue reading »]]> I travel a lot. Most of the time on airplanes. As a frequent traveller I’ve had my share of good experiences and bad, but what I’ve learned above all else is that you have to have a good attitude. That’s not to say that a friendly smile will ensure that your travel goes picture perfect — it won’t. You will still experience delays, missed connections, and rude TSA agents. But staying positive means that you will save yourself a lot of stress throughout what is more often than not a less than pleasant affair (especially if you’re flying coach, like me).

Take my most recent travel as an example. As I often do, I was checking in at PHX for my flight to London Heathrow, with a connection in San Francisco.

Welcome to US Airways automated check-in kiosk! Please swipe your passport to begin. I went through the motions, opting to not pay $35 to upgrade to a non-middle seat, when suddenly, “We cannot process your request. Please see a ticket agent to complete check-in.” The ticketing agent was happy to help, as they often are but, puzzled, said she’d need to speak to her supervisor.

No problem, I thought. If anything goes horribly wrong, I’ll just demand a First Class upgrade! Every time I travel, I secretly hope that the airline screws up royally and decides that the only way of appeasing me is to upgrade me to First Class free of charge for the trans-Atlantic portion. Hasn’t happened yet.

“Well, you’re checked in,” she said pessimistically, “but you have less than an hour to connect in San Francisco. Who booked this flight for you?” she asked.
“I did. Online.” I explained.
“I don’t know why they let you book this flight. Normally we require two hours for connections onto international flights.”

At this point I needed to get on with the first leg of my journey, so she wished me luck, and on I went. I was probably not as worried as most people would have been. But, there was nothing I could do to make up any more time. The best I could do was hope for an early flight into SFO and short security lines.

Unfortunately, as is typical with airplane travel (especially when you need a break), things didn’t go according to plan. As our aircraft sat on the 112 degree F Phoenix tarmac, its interior heated to more than 90 degrees*, requiring that the crew cool it down before allowing boarding to begin. The plane took off 30 minutes after its scheduled departure time.

The view from the plane as we landed at SFO

Magically, thanks to this new trend whereby airlines seriously overestimate flight times in order to have a better on-time flight record, wheels touched down at SFO just one minute after our scheduled landing time. I still had a chance to make my connection!

Even more magically was that I just happened to be sat next to a woman who worked at SFO and knows the lay of the land. “You’re connecting to Terminal 3,” she informed me, “the international terminal.”
“I have to change terminals? That will take a lot of time! Do I need to take the SkyTrain?”
“Yes, but it’s not far,” she assured me. “Follow me. I’ll show you where to go.”**

One of the flight attendants, Robin***, was also concerned that I wouldn’t make my flight, and was as shocked as the ticket agent that I was even allowed to book it. “I wish there was more I could do!” she said. “You’re connecting with United? Direct to London? Tell you what, I’ll call their gate agent and tell them you’re on your way!”

As soon as the flight began deplaning, woman in 10C and I were on our way. “Take the SkyTrain to G,” she said, “And, good luck!”

Everyone was pulling for me. And, hey, if I missed my flight it’d be the airline’s fault. Grounds for a First Class upgrade? Doubtful, but a girl can dream.

After a not-so-horrible trip through security for the second time that day, I began my sprint down the seemingly never ending corridor that is International Concourse G. Big backpack bouncing against my back and beads of sweat beginning to form on my forehead I hear an announcement come over the loudspeaker.

“This is the final boarding call for flight 930 direct to London Heathrow!”
“CRAP!”
“Again, this is the final boarding call. All passengers wishing to travel on flight 930 direct to London should be aboard the aircraft now!”

I pumped my legs a little faster and ran down the escalator leading to the gate. Passport in hand, I ripped out my boarding pass and began victoriously waiving it in the air.

“Dum da da DAAA!” I announced, “I made it!!”

Flying into London!

The gate agent was not amused. I explained the short connection situation, but he didn’t seem to care. Whatever! I made it! The fact of the matter is, though, I had no control (minus, of course, a gold-medal worthy several hundred meter dash) over whether or not I was going to make this flight. I very well could have spent that night sleeping on a bench in SFO waiting for the next available flight home.

Am I glad I made that flight? Darn right. Would I have been fussed if I’d missed it? Maybe a little. But the thing is that I knew the situation and accepted my fate from the get go. And I honestly believe that my positive attitude was a key ingredient in stirring up sympathy from 10C and Robin, two people who I couldn’t have done this without.

So, after all that, I managed to make my flight. The moral of the story? Stay positive! Oftentimes you’ll be dealt a crappy travel day. Don’t fight it; that’s a losing battle. Know that these things can happen, and hope for the best. And if you get stuck somewhere overnight, hope they have free wifi.

*Fun fact: the magic number below which the temperature of the inside of an aircraft must fall before passengers are allowed to board is 85 degrees F.
**I never did get that woman’s name, but to any high up US Airways staff: she was sitting in seat 10C on flight 409 PHX to SFO on August 16th. Give this woman some free miles or something!
***Robin’s name I did get, as it was on her badge. Hey, US Airways! Give this woman a raise!