Science Made Cool

Nanotubes: What Can't They Do?

Nanotubes have been in the news lately. What's a nanotube? It's a single cylindrical molecule of graphite rolled up into a little tube about a nanometer across. That's a billionth of a meter. They can be several millimeters long.

By themselves, nanotubes are just ("just!") a cool piece of organic chemistry, part of the generally megaboss fullerene family. But lately chemists have been coming up with lots of really amazing applications for nanotubes.

First of all, there's the nanotube radio -- a tiny, functional radio made of a single carbon nanotube.

Next up, carbon nanotubes can attack bacteria and other germs, fighting biological wars down at the molecular level.

And, finally, someday people may be able to ride up to space aboard an elevator climbing a 50,000 mile cable made of nanotubes.

From the very big to the very small, nanotubes do it all. Plus they make great Christmas stocking stuffers, if you have really really tiny stockings.

WHOOSH!

Modes of transportation tend to go through periods of rapid improvement followed by long periods of roughly steady performance.  Railroads were invented in the 1830s, and by the 1870s trains hit speeds of more than 60 miles per hour -- which is where train speeds remained for nearly a century.  Then, in the 1960s and 1970s the Japanese Shinkansen and French TGV trains kicked up the speeds to more than 100 miles per hour.

Similarly, within two generations after the Wright Brothers, propellor planes had maxed out at about 500 miles per hour.  That's where things remained until jets pushed the limit up to the speed of sound.  Once the "sound barrier" was broken, jet speeds increased rapidly . . . until they stopped.  The fastest plane in the world is the SR-71 spy plane, which set the record of Mach 3.3 on its retirement  flight.  The plane first flew in 1966, which means no faster plane has been built during the lifetime of a middle-aged game designer.

That may change soon.  Researchers at Pratt & Whitney are testing hypersonic engines capable of shoving a plane up to Mach 6 -- or possibly as fast as Mach 15!  This Popular Science article discusses the matter in more depth. 

Having recently flown to Tokyo on a subsonic jetliner, I think the idea of making the voyage in two hours or less has a great deal to recommend it.  And if you're tooling along at Mach 15 anyway, you're almost halfway to orbital velocity, which means a hypersonic scramjet plane is a big step toward a true "spaceplane."  So NASA likes the idea.  Naturally the Air Force likes anything which makes planes and missiles go faster, and of course the deranged geniuses at DARPA are involved because hypersonic ramjets are just totally wicked.

Friday Parasite #52: Hooking Up

This is the human hookworm Ancylostoma duodenale,   an intestinal parasite that takes a long and roundabout journey to its final home. Most intestinal parasites get in through the front door, so to speak -- entering their hosts through contaminated food or water. Hookworms are different. They get in through your feet.

Hookworm larvae are found in soil that has been in contact with contaminated fecal matter. When the larvae find the warm bare skin of a new host, they burrow in and wend their way through its body. But they still don't head for the intestines -- they use the circulatory system as a highway to the host's lungs.
to the lungs. Once they're inside the lungs, they crawl up the trachea toward the mouth, where they can get swallowed and finally reach their warm, dark, intestinal home.

B-Movie Biology: The Course

From January 14th through January 18th I'll be teaching a course at Smith College as part of their Interterm Faculty Film Series. It's called "B-Movie Biology," because I'll use popular science-fiction films as a jumping off point to discuss important biological concepts. One film and one concept each night, for five nights, starting at 7:30 p.m. in Seelye 106 each evening.

Here's the plan:

Monday, January 14
To discuss: How does size affect the physiology of living organisms?
Them!
Nuclear tests in the American Southwest result in gigantic mutant ants that threaten cities as a team of investigators and the Army search for a way to control their spread in this Cold War-era monster film.  (Gordon Douglas, director.  1954)

Tuesday, January 15
To discuss: What is a parasite, and how is its ecology different from a free-living organism?
Alien
A commercial space vehicle heading back to Earth picks up an SOS from a nearby planet. When the crew investigates, some of them leave the ship to explore the area when they come across an egg hatchery of some unknown creature.  Unbeknownst to the exploring team, the ship's computer deciphers the message to be a warning, not a call for help.  When a crew member disturbs one of the eggs, the parasite inside attacks him, and so begins the living nightmare.  With Sigourney Weaver, John Hurt and Harry Dean Stanton. (Ridley Scott, director. 1979)

Wednesday, January 16
To discuss: How do genes control animal development?
The Fly
A brilliant scientist offers up his latest research on matter transportation to a journalist in an attempt to impress her. While his research has so far been successful, there is one last problem he discovers when attempting to teleport himself.  Best line from the movie: “Be afraid. Be very afraid.”  With Jeff Goldblum and Geena Davis.  (David Cronenberg, director.  1986)

Thursday, January 17
To discuss: How does cloning work?
Jurassic Park
Huge advancements involving DNA extraction from ancient samples embedded in amber have enabled scientists to create an island theme park full of living dinosaurs. When the director of this island park invites a small group of scientists to visit, T. Rex and his Velociraptor friends get a little out of hand.  With Laura Dern, Jeff Goldblum and Samuel L. Jackson. (Stephen Spielberg, director.  1993)

Friday, January 18
To discuss: Do genes matter when it comes to human behavior?
Gattaca (1997)
A genetically inferior man, one of the last “natural” babies born into a genetically-enhanced society that discriminates against imperfect genes, assumes the identity of a once-perfect specimen in order to remain a viable candidate for space travel with Gattaca Corp.  Required to pass periodic gene tests, he must be diligent in his use of DNA samples from his assumed identity’s hair, skin and blood to remain undetected.  How long and to what extremes must he go to continue the charade?  With Ethan Hawke, Uma Thurman, Maya Rudolph and Gore Vidal.  (Andrew Niccol, director.  1997)

If anyone is in the Northampton, MA area that week, you should check it out.

Friday Parasite #51: Trypanosomes

                           

Trypanosoma brucei (in blue) cavorting among the red blood cells they infect. This particular trypanosome causes sleeping sickness in humans, and is carried from person to person by tsetse flies.

Photo by Jürgen Berger and Dr. Peter Overath, Max Planck Institute for Developmental Biology.

Iron Science Teachers

For the past 9 years, the Exploratorium has been running an ongoing competition for science teachers inspired by the ever-popular Iron Chef program. Teachers get a secret ingredient (though the museum admits that it's only secret to the audience -- the teachers have had a little time to prepare), then have 5 minutes to prepare a science or math lesson to teach to the studio audience. The results are on the Iron Science Teacher website. There are 80 or 90 webcasts to choose from, showing teachers working with materials ranging from sticky tape to fruitcake.

News From the New Millennium V

A scientist at the University of Arizona has created a robot controlled by the brain of a moth. Pretty neat, eh?

Now of course this has spawned a certain amount of humor about deadly animal-brained cyborg killing machines. Slightly nervous humor, maybe.

But what I find more interesting is that the mothbot demonstrates just how far computer science has yet to go. After all, we tend to think of moths as pretty simple creatures. They fly around, they run into lightbulbs, somewhere along the way they make more moths, and that's about it. Yet apparently a moth's brain is still much better at spatial navigation than the best electronics. A cruise missile, for instance, has a guidance system weighing several kilograms and dependent on inertial gyrocompasses and GPS satellite signals, and it manages to do what a moth does with a brain smaller than a grain of rice.

Computers are smart and getting smarter, but they've got miles to go before they're as good at basic real-world tasks as even the simplest animals. So there's no nead to be stocking your basement to survive a robot uprising just yet.

The moth cyborgs will get you first.