Butterfly wings and fiber optics: a science update

The butterflies you see all around, and some of the moths at night, get their color on their wings by two very different processes. Some, like the monarchs, have dyes in their wings that give color. But the more interesting ones are the tropical ones that shimmer and glisten — their wing colors are made from structures that they grow, structures that bend, reflect and contain light-like miniature prisms. These structures have been given the name of gyroids and they are about to change the world we all live in — in a good way.

These gyroids are nano-structures. That is, they are very, very small. To make them using the finest tools we have in labs is possible. What is far more exciting is the breakthroughs coming out of government labs and Penn State, where they are starting to grow them, called chalcogenide glass replicas. So far, word is they have not been too successful. Seems butterflies can grow them perfectly, whereas we are clumsy. But our scientists are getting better.

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Now, you may ask, what are we doing this butterfly wing color stuff for? Well, imagine a fiber optic cable, channeling light across the nation. Along the way, it leaks signal through its wall and every 200 miles or so you have to put an amplifier in the line to re-boost the signal.

We just cannot seem to make fiber optic cable perfectly, so that 100 percent of the light in one end emerges out the other. It is kind of like electricity, without the insulation on the outside, some of the juice will leak to the surrounding environment. That is why high-tension wires crackle when it drizzles.

So, by growing these gyroids, chalcogenide glass replicas, to surround the fiber optic cable, it will keep bending the light back into the cable, enabling all the light to reach the other end. How effective is Mother Nature’s insulator? So far, scientists think it could save about $1 billion a year in amplifiers, undersea cable repair, computer installations and other high-tech needs.

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Earth’s gravity is a constant, right? That is what they taught you in school anyway. Well, a new satellite called Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) has just finished mapping the earth and it has discovered that gravity varies all over the place. And it may vary by season as well (the pull of the sun in our summer is higher).

The earth is a sphere (ball) that has a few flat spots. GOCE was designed to sense tiny variations in the pull of gravity over the earth’s surface. Scientists use that data stream from the satellite to build a gravity map of the earth. Using that map, they can see where gravity is less strong and other places where it is stronger.

What is perhaps even more interesting is that GOCE can also theoretically see where magma is building up deep underground as gravity increases beneath a volcano, or where a shift in tectonic plates is about to happen.

In time, they may use GOCE to predict earthquakes and volcanic activity. But for now, the gravity map is helping watch the movement of the mass of water around the globe, better predicting weather and tidal forces. And what also has come out of this is a gravity color map you can find online. It shows the strength or weakness of gravity where you live.

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OK, the differences may seem slight (variation from 9.78m/sec/sec at the equator to 9.83/sec/sec at the poles), but already scientists are exploring the animal capability to detect such changes as part of primordial migration navigation. Which way is north for a tern? Maybe they follow the gravity gradient.

What is most interesting is research into human evolution and culture. Europe, China and Malaysia have almost an equal gravitational pull. It is like they are 250 feet above the surface of the earth whereas in North America and east Africa the pull is like you are on the surface. Except in northern England. There is an anomaly there, where you are 120 feet below the surface level, just like in southern India and Mongolia. It may be what gives us the sense of place, the feeling of being “at home.�

Peter Riva, formerly of Amenia Union, lives in New Mexico.