Agriculture
Cleaning Up Fish Farms
Treating peanut allergy bit by bit
New Gene Fights Potato Blight
Amphibians
Toads
Newts
Salamanders
Animals
Fishy Cleaners
A Microbe Nanny for Young Wasps
Mouse Songs
Behavior
The Smell of Trust
The nerve of one animal
Talking with Hands
Birds
Cassowaries
Ospreys
Cranes
Chemistry and Materials
Revving Up Green Machines
Meteorites may have sparked life on Earth
Graphene's superstrength
Computers
Computers with Attitude
Toxic Dirt + Avian Flu = Science Fair Success
Look into My Eyes
Dinosaurs and Fossils
Tiny Pterodactyl
A Dino King's Ancestor
Did Dinosaurs Do Handstands?
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
Detecting an Eerie Sea Glow
The Pacific Ocean's Bald Spot
A Volcano Wakes Up
Environment
Acid Snails
Fungus Hunt
Catching Some Rays
Finding the Past
Of Lice and Old Clothes
Early Maya Writing
Prehistoric Trips to the Dentist
Fish
A Grim Future for Some Killer Whales
Lungfish
Barracudas
Food and Nutrition
How Super Are Superfruits?
The mercury in that tuna
Symbols from the Stone Age
GSAT English Rules
Whoever vs. Whomever
Finding Subjects and Verbs
Subject and Verb Agreement
GSAT Exam Preparation Jamaica
Preparing for the GSAT Exam
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
10 Common Mistakes When Preparing for the GSAT Math Test
GSAT Exams Jamaica Scholarships
GSAT Exam Preparation
GSAT Scholarship
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Mathematics
Math of the World
Detecting True Art
Secrets of an Ancient Computer
Human Body
Hear, Hear
Kids now getting 'adult' disease
Speedy Gene Gives Runners a Boost
Invertebrates
Dust Mites
Walking Sticks
Grasshoppers
Mammals
Bloodhounds
Siamese Cats
Bison
Parents
Raise a Lifelong Reader by Reading Aloud
Choosing a Preschool: What to Consider
How children learn
Physics
Strange Universe: The Stuff of Darkness
Echoes of a Stretched Egg
One ring around them all
Plants
Plants Travel Wind Highways
The algae invasion
Assembling the Tree of Life
Reptiles
Black Mamba
Tortoises
Sea Turtles
Space and Astronomy
An Icy Blob of Fluff
A Great Ball of Fire
Return to Space
Technology and Engineering
Model Plane Flies the Atlantic
A Satellite of Your Own
Bionic Bacteria
The Parts of Speech
Problems with Prepositions
Adjectives and Adverbs
What is a Preposition?
Transportation
Morphing a Wing to Save Fuel
Ready, unplug, drive
Flying the Hyper Skies
Weather
Weekend Weather Really Is Different
The Best Defense Is a Good Snow Fence
In Antarctica watch the heat (and your step)
Add your Article

Supersonic Splash

Supersonic means faster than the speed of sound, which is about 760 miles per hour in air. Thatís a speed limit that can be broken ó by jets and bullets, for example, or by the space shuttle as it returns to Earth. Now, a scientist named Stephan Gekle has found that you can make air move faster than the speed of sound by doing a simple little trick: throw a rock in a pond. Gekle is a scientist at the University of Twente in the Netherlands who studies the physics of fluids. Physics is the study of forces and motion, and Geckle investigates how forces act on liquids, like water. In a recent study, he and his colleagues showed that after a rock drops into a body of water, a tiny jet of air shoots upward faster than the speed of sound. This isnít the first time Gekle has explored what happens when a rock sinks through water. In an earlier study, he and his team showed that as a rock falls into a flat surface of water, like a pond, it carves out a tiny tube of air. This tube connects the sinking rock to the air above the pond. The tube doesnít exist for very long, though ó almost immediately, the surrounding water pushes on the sides. This pressure is stronger in the middle than at the ends. As a result, the tube looks like an hourglass, where the middle gets smaller and smaller as the water forces the air out. Thereís not room in the hourglass for water and air, so as the water comes in the air escapes upward ó and fast. These tiny jets of air can blast faster than the speed of sound, Gekle found. To measure these air jets is trickier than it may seem. Gekle and his colleagues had to do more than stand at the edge of a pond with stopwatches. A careful science experiment requires a scientist to take multiple measurements of the exact same thing, to check and double-check the results. In this case, it would have been almost impossible for Gekle and his colleagues to throw a rock in a pond in the same way over and over again. Instead, the scientists created a lab experiment that acted like a rock falling through water: They dragged a circular disc down through water at the same speed, over and over again, and watched what happened. But there was another difficulty: Itís hard to see and measure air. To solve that problem, the scientists filled the air above the water with smoke and illuminated the smoke with a laser, which made the moving air easier to see. (To make the smoke, Gekle said, they used a smoke machine like the ones that provide the dramatic effects seen onstage at theaters.) Finally, because everything happens so fast when the rock moves through water, the scientists had to find a way to slow down time. As the disc moved through the water, the scientists took pictures with a camera that captured 15,000 frames every second. (Thatís faster than most movie cameras.) After the experiment, the researchers could slow down the movie and, aided by computer simulations, calculate the speed of air as it blew out of the hourglass-shaped tube. But thereís one aspect of supersonic air that Gekle and his team didnít observe. When a jet exceeds the speed of sound, the air around it produces a noise like thunder, called a sonic boom. So far, however, Gekle says the tiny air jets arenít making even a teeny, tiny boom ó but the researchers will keep listening. POWER WORDS (adapted from the Yahoo! Kids Dictionary) speed of sound About 760 miles per hour, through air at sea level. supersonic Faster than the speed of sound. physics The science of matter and energy and of interactions between the two, grouped in traditional fields such as acoustics, optics, mechanics, thermodynamics and electromagnetism, as well as in modern fields including atomic and nuclear physics, solid-state physics, particle physics and plasma physics. force The capacity to do work or cause physical change. pressure Force applied uniformly over a surface, measured as force per unit of area.

Supersonic Splash
Supersonic Splash








Designed and Powered by HBJamaica.com™