Agriculture
Seeds of the Future
Growing Healthier Tomato Plants
Microbes at the Gas Pump
Amphibians
Tree Frogs
Frogs and Toads
Poison Dart Frogs
Animals
Return of the Lost Limbs
Deep Krill
Moss Echoes of Hunting
Behavior
Internet Generation
Mind-reading Machine
Talking with Hands
Birds
Robins
Falcons
Ducks
Chemistry and Materials
A Light Delay
Heaviest named element is official
Earth from the inside out
Computers
New twists for phantom limbs
Fingerprint Evidence
Galaxies on the go
Dinosaurs and Fossils
Dinosaur Dig
A Really Big (but Extinct) Rodent
Ferocious Growth Spurts
E Learning Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
Earth
Hot Summers, Wild Fires
Deep History
Salty, Old and, Perhaps, a Sign of Early Life
Environment
Swimming with Sharks and Stingrays
Saving Wetlands
Hazy with a Chance of Sunshine
Finding the Past
Decoding a Beverage Jar
Chicken of the Sea
Stone Age Sole Survivors
Fish
Bull Sharks
Lampreys
Manta Rays
Food and Nutrition
The mercury in that tuna
Chocolate Rules
A Pepper Part that Burns Fat
GSAT English Rules
Capitalization Rules
Whoever vs. Whomever
Pronouns
GSAT Exam Preparation Jamaica
2014 GSAT Results for Jamaican Kids
Ministry of Education Announces 82 GSAT Scholarships for 2010
How are students placed after passing the GSAT exam
GSAT Exams Jamaica Scholarships
2014 GSAT Results for Jamaican Kids
42,000 students will sit for the GSAT Exam in two weeks
GSAT stars reap scholarship glory
GSAT Mathematics
Math is a real brain bender
Setting a Prime Number Record
How a Venus Flytrap Snaps Shut
Human Body
Hear, Hear
Remembering Facts and Feelings
Running with Sneaker Science
Invertebrates
Invertebrates
Bedbugs
Dust Mites
Mammals
Porcupines
Sloth Bears
Antelope
Parents
Choosing a Preschool: What to Consider
Raise a Lifelong Reader by Reading Aloud
What Not to Say to Emerging Readers
Physics
Echoes of a Stretched Egg
Dreams of Floating in Space
Strange Universe: The Stuff of Darkness
Plants
Getting the dirt on carbon
When Fungi and Algae Marry
Plants Travel Wind Highways
Reptiles
Tortoises
Komodo Dragons
Sea Turtles
Space and Astronomy
Melting Snow on Mars
A Smashing Display
Evidence of a Wet Mars
Technology and Engineering
Young Scientists Take Flight
Smart Windows
Beyond Bar Codes
The Parts of Speech
Countable and Uncountable Nouns
Pronouns
What is a Preposition?
Transportation
Ready, unplug, drive
Troubles with Hubble
Robots on the Road, Again
Weather
A Dire Shortage of Water
Science loses out when ice caps melt
Where rivers run uphill
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™