Welcome to the Robot Zoo!

by Eric  Bender

Harvard Microrobotics Lab’s Robobees, MIT Personal Robot Group’s Dragonbot and Olin Robotic Team’s Damn Yankee

The Science Carnival that kicks off at noon on Saturday April 18 at Cambridge High School's field house is sort of like the Big Apple Circus of Science, except that it's way bigger and free.

Okay, there are no trained horses and probably no clowns, but you can walk inside an inflatable gray whale and a 300,000-times-scale model of a human white blood cell at the Carnival. You can also check out demonstrations of everything from deriving your own DNA to 3D-printing your own trinket and from superconducting magnetic levitation to walking a glider.

But be sure to save time for the Robot Zoo, which will draw a diverse population of robots and their builders.

You can elbow your way through the crowds in the Zoo to find the pioneering firm iRobot and a few of what it describes as its “cool, practical” robots. You can watch videos of robots at work, as in the exhilarating demo reel from Above Summit, a “drone-focused multimedia production studio”. Or you can cheer on robots themselves at play, and chat with their builders at educational groups such as US First Robotics and Play-Well TEKnologies.

Moreover, you can talk to researchers who are building strange and wonderful new robots.

Among them, some of the most ambitious projects are underway at MIT's Personal Robots Group, which will bring kid-friendly research robots. Dragonbots are intriguing little animals stuffed with clever electromechanical parts and an Android phone that acts as a brain and presents a face to the world. “Tega is a new robot platform designed to support long-term, in-home interactions with children, with applications in early-literacy education from vocabulary to storytelling,” says the group. Tega incorporates a camera, the ability to run on batteries for up to six hours, and even higher levels of cutely anthropomorphic behavior than its predecessors.

You'll find a different set of tough robot design challenges under the tall blue sails of the Damn Yankee, a two-meter-long model for the Olin Robotic Sailing Team’s quest to build an autonomous sailboat that eventually can voyage across the Atlantic Ocean. “You can tell this guy where to go and it will go there—give it a GPS coordinate and it determines everything else,” says co-team-leader Amanda Sutherland. Olin College's student-run team is now modifying a small daysailer with technologies tested on the Damn Yankee, and aiming to send the boat across Massachusetts Bay from Gloucester to Provincetown this fall. “The point is to prove that sailing is a robust enough platform to be used for sustainable research on the water,” says Sutherland.

“We also hope that our program will get more people in elementary schools and middle schools excited about working in teams,” she adds. “You can pull together everybody’s skills so you end up with something awesome.”

Harvard’s Microrobotics Laboratory “makes robots in ways that other people don’t necessarily think of making robots,” including printable robots and robots made of soft materials, says graduate student Michelle Rosen. “That raises the question, what is a robot? I like to ask that question to visitors at our booth, which is interesting to them and to me.”

Maybe most engagingly at the Zoo, the lab will show its insect-inspired, insect-size robots, which eventually may swarm in with sensors that aid in search and rescue or other tasks in challenging environments. Look for the flapping-wing Robobee, the beetle-like Harvard Ambulatory MicroRobot and a centipede-imitating millirobot. Look closely, because they are tiny. “It's exciting for kids to actually touch and get close to these robots,” says Rosen.

Countdown to the Festival!

Bottled Water vs. Tap Water -- Who Wins?

...Is there a difference? Should you prefer one over the other?

Well, let’s start with this fact: some of the bottled water you buy is actually tap water. That’s right, tap. While bottled water may come from more pristine-sounding places like natural springs and wells, other bottled water is simply dressed-up tap water. Sure, it might have undergone some extra treatments, such as dechlorination and some tweaking of mineral content, but it is still tap water placed in a fancy and portable plastic container.

Let’s do some math first. Water from the tap is dirt cheap. Water from the bottle is much less so. Typically, buying a bottle of water at a vending machine or convenience store costs you at least $1 per half-liter bottle. That’s $2 for a liter of bottled water, and there are about 3.8 liters in a gallon. This puts us at $7.60 for a gallon of bottled water. Now compare that to current gas prices of around $2.75 per gallon. Makes bottled water seem like a rip-off, doesn’t it?

Water doesn’t have to be that expensive, even with purification treatments. When you’re buying bottled water, you’re paying less for the water and more for the cost of bottling, packaging, shipping, marketing, and of course, company profit. Not to mention, buying bottled water means producing more waste in the form of plastic containers. The more tap water and less bottled water you drink, the better you are being to the environment.

Why do people bother with bottled water then?

For many, it’s a matter of hygiene. Whether the source of the water was from a spring or a tap, bottled water comes with a reputation for being cleaner and thus healthier; but is that actually the case?

In America, where the public water infrastructure is quite good, the answer is no. Experts trusted by the bottled water industry agree. According to a report by ABC News 20/20, “Even Yale University School of Medicine's Dr. Stephen Edberg, the person whom the International Bottled Water Association told ‘20/20’ to talk to, agreed that bottled water is no better for you. ‘No, I wouldn't argue it's safer or not safer.’” Moreover, the safety of tap water is supported by studies: one 4-year study by the Natural Resources Defense Council (NRDC) found that tap water is often subject to even more stringent regulation and testing than bottled water. Not much to fear from tap water then.

Conclusion: in the U.S. it is not necessary to buy bottled water out of health concerns.

However, there are those who claim that bottled water just tastes better. Is that actually the case too? Blind taste tests of bottled vs. tap water have been favorable towards tap water, but why don’t you taste the results yourself at this year’s Cambridge Science Festival?

At the Science Carnival on Saturday, April 24 between noon and 4pm, the Cambridge Public Library will be holding the event Bottled Water v Tap Water, where you can learn more about the differences and similarities between the water from the bottle and from the tap—all while sipping on a refreshing cool drink of water.

This event is sponsored by CDM.

Image Credits:
• Bottled water image modified from Brett Weinstein’s photograph.
• Tap water image modified from Alex Anlicker’s photograph.

The “Coolest” Way to Make Ice Cream

What is the secret to delicious and quick homemade ice cream? Liquid nitrogen.

Don’t believe me? Stop by the Cambridge Public Library between noon and 4pm on Saturday April 24--the Science Carnival is hosting an event called “Liquid Nitrogen Ice Cream Making!” where YOU not only get to witness the amazing spectacle of making liquid nitrogen ice cream, but also get to consume the delicious final product.

It’s a pretty cool looking process. Here’s a photo from the first time I made liquid nitrogen ice cream:


Nitrogen is readily found in our atmosphere, but only in its gaseous state (incidentally, nitrogen gas makes up 70% of our atmosphere). Liquid nitrogen, on the other hands, does not occur naturally on Earth. Liquid nitrogen only exists under super-cold conditions. I’m talking -321°F cold, way colder than any place on Earth. By comparison, room temperature is around 70°F, and the coldest recorded air temperature on Earth was “only” -129°F (that honor went to Russia in 1983).

If liquid nitrogen hits any temperature above -321°F, it boils immediately into nitrogen gas. That’s why the ice cream looks like it is steaming in the above picture. Liquid nitrogen “steams” into gaseous nitrogen as it boils, just like how water steams into water vapor when it boils. Same concept and same process, except liquid nitrogen boils at a much lower temperature, and thus its “steam” is correspondingly much cooler. Colder things are denser than warm things, so while steam from water rises, the “steam” from liquid nitrogen sinks. (You can see this in the photo and at the festival!)

Due to liquid nitrogen’s coldness, you must handle it carefully with proper equipment, like gloves and specialized cold storage containers, and such matters will be properly taken care of at the Science Carnival.

But why use liquid nitrogen for making ice cream? It’s not necessary to have liquid nitrogen to make ice cream, but it certainly makes the task much easier (provided that you don’t have trouble acquiring liquid nitrogen).

Making ice cream sans liquid nitrogen is a slow process, one where you must churn the ice cream a lot while it is being cooled. This is the usual approach of ice cream making machines you find at factories and in home kitchens. Why the churning? For texture! We love ice cream not only for its flavor but also for its texture. Churning ice cream while it cools prevents it from solidifying into solid blocks--after all, eating rock-hard ice cream would be no fun. Churning also whips the ice cream, aerating it to the fluffy and smooth consistency we love. Like any recipe that involves a lot of aeration (ever tried making whipped cream or meringues, for instance?), this takes a while, but liquid nitrogen turns ice cream making into a snap.

The secret lies in the extreme coldness of liquid nitrogen. Boiling at about 400°F below room temperature, the transformation of nitrogen from liquid to gas form is incredibly violent. Think about a pot of boiling water on a stove. If you turn up the temperature on the stove, the water boils more violently. Same concept applies for liquid nitrogen (just at much cooler temperatures), thus liquid nitrogen boils with extreme ferocity: it fizzles and sizzles and immediately turns into vapor, like water splashed onto a very hot pan. This intense bubbling action serves as a whipping and aerating mechanism. All you need to do is create an ice cream base (a combination of milk, cream, sugar, and flavorings) and pour liquid nitrogen into the base while stirring, cutting down on the amount of work you need to do churning. Moreover, all of the liquid nitrogen evaporates, leaving you only with delicious ice cream.

Without a doubt, the “coolest” way to make ice cream is with liquid nitrogen.