Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

One of the things that I’ve always found fascinating about humans is their ability to completely ignore the miraculous when it’s commonplace.  Flies walk across the ceiling in apparent defiance of the same gravity that keeps us stuck to the floor.  But we stop wondering about it after about the age of three when the curiosity gene meets the implacable resistance of the surrounding adults.  After the thousandth repetition of “I don’t know” or “Stop asking questions!” curiosity isn’t fun anymore.  I think that may be what distinguishes the true scientist.  They NEVER stop asking “Why?”

But there’s still plenty of wonder in your very own house if you just think about it.  If you’re no longer curious about the flies, just have a look at that gecko on the ceiling.

How does she stay up there?  For a long time, scientists thought it was because geckos had suction cups on their feet, but then they discovered it’s a little more complex than that.  It seems those little wall climbers in your house have a network of tiny hairs and pads on their feet which produce electrical attractions that literally glue the animals down.  With millions of the hairs on each foot, the combined attraction of the weak electrical forces allow the gecko to stick to virtually any surface - even polished glass.  If your hand had the equivalent sticking power, you’ll be able to lift 90 pounds just by clamping on!  (Of course, your arm might object if you tried it!)

Now that scientists have unraveled the secrets of a gecko’s feet, researchers at Rensselaer Polytechnic Institute and the University of Akron have used the information to make some astounding synthetic “gecko tape” with four times the sticking power of standard tape.

They’ve made plastic surfaces covered with carbon nanotube hairs.  These nanotubes are rings of carbon molecules that are microscopically small.  The nanotubes imitate the thousands of microscopic hairs on a gecko’s footpad, which form weak bonds with whatever surface the creature touches, allowing it to “unstick” itself simply by shifting its foot.

For the first time, the team has developed a prototype flexible patch that can stick and unstick repeatedly using the same properties as a gecko’s foot.  They’ve fashioned their material into an adhesive tape that can be used on a wide variety of surfaces, including Teflon.

The material could have a number of applications, including feet for wall-climbing robots; a dry, reversible adhesive in electronic devices; and outer space, where most adhesives don’t work because of the vacuum.

So the next time someone asks you what you’re doing when you’re staring off into space; just tell them you’re contemplating the wonders and the economic possibilities of that gecko on the wall.

PAINT IT BLACK
So . . . . what color do you like your food to be?  We certainly eat foods that are every color of the rainbow, from the white of eggs through red peppers, oranges, yellow squash, broccoli, blueberries and eggplant.

We do prefer our food to be the right color, however.  A famous experiment from years gone by involved taking a juicy, succulent T-bone steak cooked to perfection and coloring it bright green with harmless food coloring.  Nearly everyone it was offered to refused to eat it.  We learned long ago that green meat wasn’t good for us.

But green is the color of life; at least most plant life, and although we humans like to think we’re the epitome of creation, we’re not.  Plants shelter us, feed us (even the carnivores), and create our oxygen for us.  Without plants, all the animals on this planet are but a fading memory.

Did you even wonder why your world is green?  Why green is the favorite color of virtually every plant on the planet? 

Virtually all the available energy on Earth comes from the Sun.  Animals get their energy from eating plants (and animals who eat plants) but the plants get it from the Sun.  All plants contain large chlorophyll molecules that take the energy contained in light photons and convert it into forms the plants can use to run their chemical business.  Then we eat the plants and break down the molecular bonds to obtain their stored energy to run our business.

Chlorophyll is a very efficient energy-converting molecule.  It can use photons of red light, photons of blue light, photons of yellow light.  In fact, chlorophyll can use virtually the entire rainbow spectrum of light to run its energy-converting engine with one significant exception.  Chlorophyll does NOT like green light.  So virtually all the photons of green light that hit the leaves, stems and blades of Earth’s plants are reflected away from the leaf’s surface.  This reflected light enters your eyes and for you, that plant and virtually every other plant is green.  Earth is green because of wasted light.

So . . . what color would your foliage be on another planet?  Well, if that planet’s energy producing molecules had evolved to be more efficient than Earth’s chlorophyll, then the plants would be black.  All energy wavelengths would be absorbed and no light would be reflected.  I’m not sure I’d like a world with black plants, but then, green is what I’m used to!

Of course, plant color would also depend on the size and more importantly temperature of the planet’s parent star.  Humans see the ROY G BIV spectrum of colors because that just happens to be the main radiation wavelengths produced by Sol, our parent star.  If a star is hotter than the Sun and radiates more of its energy at higher wavelengths, its inhabitants would see the ‘colors’ of the wavelengths we call ultraviolet.  If the star is cooler than our Sun, the plants would absorb the ‘colors’ of infrared and any evolved eyes would see the reflected ‘colors’ of infrared.

Life on other worlds would be unbelievably strange.  Although I love Star Trek and other ‘alien’ shows; the aliens will NOT look like humans or humans in alien suits.  Not only will they not ‘look’ like us, they won’t ‘see’ like us either.

Black broccoli, anyone?