Hydrostatic Equilibrium

In honor of Earth Day 2013 on April 22, this week's article will be all about new developments related to the entire Earth. And what an exciting time this is for that kind of planetary science!

Researchers at the Harvard-Smithsonian Center for Astrophysics (CfA) announced last week that they had discovered two planets orbiting the K sized star Kepler-62 that could be completely covered in water. Liquid water.

Why is this such a big deal? Normally the temperatures and lack of atmospheres in space prevent water, should it exist at all on that planet, from melting into its liquid form. For there to be any possibility of sustainable life and possible habitation by humans one day, liquid water must be present. And here are two planets who have nothing but oceans full of the liquid orbiting a sun a little bit smaller and cooler than our own sun. Granted, the size and distances of the planets indicate that there is a huge greenhouse effect in their atmospheres to keep the water from freezing, but it's still awesome.

There are some issues with immediate Earth to planet communications though. For one, the planets are larger than the Earth we love; Kepler-62f is 40% larger and Kepler-62e is 60% larger. Researchers are at this point are unable to determine the mass of the planets because their compositions aren't known. This means we don't know if this planet would have any raw materials needed for technology or even life to evolve, since all the rock and metal would be below the surface. It is possible that some life may exist under the ocean's surface, but there would be no fire or access to metals (the pressure would be too great).

Still, the idea that there are two planets in the habitable zone is very useful information for scientists. For one thing, it's the possibility of other life that drives us forward. Second, it could serve as a second home for us (once we get over the increase in gravity thing). Third, studying other planets is just cool. How often have we discovered a planet completely covered in liquid water? Including these two: twice.

Unfortunately, looking at the planets through the Kepler telescope is probably as close as we'll ever get. The planets orbit a start that is 2,700 light years away from us in the Cygnus constellation, so there's no way to get there quickly. If anything this means that we need to take care of the planet we have now because the closest rescue boat is almost 3000 parsecs away, and that's too far for us to be saved. What would Earth look like with only water?

On that note, we wish everyone a happy Earth week!

Hopkins Baja Team Scores Big

The STS team is no stranger to modeling, but usually we're not the ones building the objects we model. The Hopkins Baja off-road vehicle building team, however, made the leap from computer model to 2D sketch to actual kick-butt vehicle. It's hard to think they do this every year, and even harder to think they have the time to put into this, but it's the payoff at the end of the year and the thrill of racing the vehicle that drives them.

Spending weeks pulling all-nighters in Latrobe and Krieger basements, the Baja team slowly but surely built up their vehicle with no directions and only a chance at glory. The light at the end of the tunnel? A competition kicking off on Thursday, April 18 at Tennessee Tech University, which is the final competition of the semester. The final event of the year is a race at Rochester Institute of Technology in New York. Each competition features a four-hour race over a complete dirt course.

How did the team do it? During the January Intersession, the team bent and molded 20-foot chrome alloy steel bars obtained from an aircraft supply company into a 370 vehicle frame, then added the pedals, wheels, gearbox, gas tank, and a 10-horsepower Briggs and Stratton model engine. They didn't build the tires, seat, engine, or shock absorbers, but everything else is 100% Hopkins engineering made.

The 15 person team worked tirelessly on this design for months, testing, cutting, and measuring every piece of machinery before putting it into the final object. While some teams they'll compete against have Ph.D. students and engineering professors helping them with the design and construction, the Hopkins team received little, if no, input at all. They alone designed the smallest and lightest vehicle ever constructed here, and they have high hopes for the future competitions.

Hopkins typically does well at these competitions, using placing within the top 10 out of over 100 teams. This year, with the improved design and removable gas tank (designed with easy fill-up at pit stops in mind), the team is hoping for a top 5 finish at the race. If it breaks down afterwards, hey, that doesn't matter, the deed is done. The best part is the team can always just rebuild it.

Why are they doing this? It's certainly not for grades, since there are no professors involved here. Andrew Kelly, senior mechanical engineering student and this year's Captain, explains it elegantly: “I do it because I love cars. I love the small details and seeing the whole project come together. It just consumes you.”

We are wishing you luck at your competitions this year! Go Hopkins Baja!

Coursera and You

You may remember reading some Newsletter articles last year about a service called Coursera that had recently joined forces with Hopkins. The article went on to describe how Coursera would open learning up for thousands of people with the click of a mouse button. Johns Hopkins was now part of elite institutions who were making strides to share knowledge with everyone via the internet, and everyone seemed happy.

Yet no one talks about it anymore. Until now.

When arriving at the page of Coursera, thumbnails of available courses jump out at you, and suddenly a Duke course on neuroscience is sharing a space with a statistics class at the University of Nanjing. You can search for classes by topic or by school name. The complete list of participating universities and colleges is under the top tab "Universities" (where else?), and by clicking on any name, the website takes you to the complete list of courses offered by that school.

What isn't readily apparent is the information about what Coursera is. This is a system that partners with universities to offer short courses over a period of a few weeks intended to supplement courses taken for credit at a school. While most schools don't give credit for Coursera classes, a student will receive a certificate of accomplishment upon satisfactory completion of a class. Different standards apply to different classes, of course, but the one thing common to them all is that no class costs any money. That's right: completely free. Plus it looks good on resumes because it shows you pursue independent learning (or so I hope).

The sign up page on the Coursera website.

Signing up for any class is as easy as creating a Coursera account. By doing so you give the usual information about email and such, but you also sign the honor code and general website policy. One of the first policies is each person gets one account, so be careful! After you sign up for an account, you'll be able to register for any or all of the courses. Most require you to watch a short (less than 20 minutes) lecture on the skills you'll need for the next project or the next step in the curriculum, and then you'll be told an assignment for the week. Some of these assignments are graded by the instructor, but most are going to be peer-reviewed. This means that someone from Brazil could be grading a Kenyan's work, which is awesome for global teamwork. So long as you have internet, you can take a Coursera class. It's that easy.

After you create an account, you'll sign in here.

The author has already signed up for a few courses, one of which is on making small games using the Python computing language, but she hasn't yet completed one. When it happens I'll be sure to let you know how it goes. As for the actual technology behind the lectures, it is probably like the virtual classroom environment seen before with Elluminate Live. Nevertheless it is sure to be quite the learning experience for all involved.

The courses that I'm currently enrolled in. Sounds like fun!

What are you waiting for? There are Hopkins (and Princeton and UCSD and...) classes to take! Free, interactive, collaborative, and useful--it doesn't get better than that.