Agriculture
Watering the Air
Growing Healthier Tomato Plants
Where Have All the Bees Gone?
Amphibians
Frogs and Toads
Tree Frogs
Newts
Animals
Cacophony Acoustics
Cannibal Crickets
Little Beetle, Big Horns
Behavior
A Global Warming Flap
Chimpanzee Hunting Tools
The chemistry of sleeplessness
Birds
Crows
Eagles
Hawks
Chemistry and Materials
The solar system's biggest junkyard
Earth from the inside out
Heaviest named element is official
Computers
Play for Science
Getting in Touch with Touch
Troubles with Hubble
Dinosaurs and Fossils
Dinosaurs Grow Up
Battling Mastodons
Message in a dinosaur's teeth
E Learning Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
Earth
Slip Slidin' Away—Under the Sea
Coral Islands Survive a Tsunami
Ice Age Melting and Rising Seas
Environment
An Ocean View's Downside
Groundwater and the Water Cycle
Saving Wetlands
Finding the Past
Stonehenge Settlement
Big Woman of the Distant Past
Early Maya Writing
Fish
Sting Ray
Tuna
Great White Shark
Food and Nutrition
Strong Bones for Life
Eat Out, Eat Smart
A Taste for Cheese
GSAT English Rules
Subject and Verb Agreement
Finding Subjects and Verbs
Capitalization Rules
GSAT Exam Preparation Jamaica
Tarrant High overcoming the odds
Preparing for the GSAT Exam
GSAT Scholarship
GSAT Exams Jamaica Scholarships
42,000 students will sit for the GSAT Exam in two weeks
2014 GSAT Results for Jamaican Kids
GSAT Scholarship
GSAT Mathematics
How to Slice a Cake Fairly
10 Common Mistakes When Preparing for the GSAT Math Test
Setting a Prime Number Record
Human Body
Cell Phone Tattlers
Taste Messenger
Hey batter, wake up!
Invertebrates
Squid
Giant Squid
Crabs
Mammals
Lhasa Apsos
Mouse
Tasmanian Devil
Parents
What Not to Say to Emerging Readers
Raise a Lifelong Reader by Reading Aloud
How children learn
Physics
Electric Backpack
Extra Strings for New Sounds
Black Hole Journey
Plants
Tracking the Sun Improves Plant Pollen
Flower family knows its roots
Seeds of the Future
Reptiles
Cobras
Turtles
Pythons
Space and Astronomy
Slip-sliding away
Pluto's New Moons
Black Holes That Burp
Technology and Engineering
Drawing Energy out of Wastewater
Dancing with Robots
Shape Shifting
The Parts of Speech
What is a Preposition?
What is a Verb?
Pronouns
Transportation
How to Fly Like a Bat
Flying the Hyper Skies
Troubles with Hubble
Weather
Earth's Poles in Peril
Polar Ice Feels the Heat
The Best Defense Is a Good Snow Fence
Add your Article

A Butterfly's Electric Glow

The blue-green streaks of a swallowtail butterfly’s wings are more than just beautiful. They’re also a lesson in physics.

The bands of brilliant color on this butterfly's wing are produced from tiny scales on the wing's surface.

The bands of brilliant color on this butterfly’s wing are produced from tiny scales on the wing’s surface.

Image courtesy of Peter Vukusic/University of Exeter

Swallowtails that belong to a group called Princeps nireus actually have fluorescent wings. This means that when the wings absorb a special type of light, called ultraviolet light (or “black light”), they give off a bright blue-green glow. The glow that they give off has a longer wavelength than the ultraviolet light they absorb.

Physicist Peter Vukusic of Exeter University wanted to figure out why the wings are unusually bright. So, he took a close-up look.

Butterfly wings are covered with hundreds of thousands of colored scales, like tiles covering a roof. The scales are made of cuticle, a material that is similar to human fingernails. Vukusic and his colleagues used highly sensitive microscopes to look at individual scales.

Optical microscope image of a single scale from a butterfly wing.

Optical microscope image of a single scale from a butterfly wing.

Image courtesy of Peter Vukusic/University of Exeter

Their pictures show that each scale has three vertical levels. The bottom level is itself split up into three more layers, like an Oreo cookie, with an air space sandwiched between two layers of cuticle. Each layer is about 90 nanometers thick. One nanometer is one-billionth of a meter. A human hair is about 80,000 nanometers wide.

The middle level is a 1.5-micrometer-thick air space, held together by columns of cuticle. One micrometer is one-millionth of a meter, or 1,000 nanometers.

Finally, the top level is made of cuticle arranged in a sort of honeycomb pattern, 2 micrometers thick. The honeycomb holds tiny cylinders of air, measuring 240 nanometers across. The walls of these cylinders hold the pigments that cause the wings to glow, or fluoresce.

The wings seem to achieve their bright glow in two ways, the scientists conclude. First, the pigment-filled cylinders in the top level and the Oreo sandwich in the bottom level cause all of the fluorescence to reflect out of the top of the wing. Second, the bottom level adds even more blue-green light by reflecting sunlight that filters down and hits it.

Peter Vukusic with several different butterflies that have wings covered with special scales that brighten the color.

Peter Vukusic with several different butterflies that have wings covered with special scales that brighten the color.

Image courtesy of Peter Vukusic/University of Exeter

Some electronic devices called light-emitting diodes (LEDs) work in a remarkably similar way. LEDs light up the numbers on clocks and watches and show when appliances are on, among many other jobs.

It’s another amazing example of technology imitating nature, whether intended or not.—E. Sohn

A Butterfly's Electric Glow
A Butterfly's Electric Glow








Designed and Powered by HBJamaica.com™