Agriculture
Middle school science adventures
Microbes at the Gas Pump
New Gene Fights Potato Blight
Amphibians
Salamanders
Bullfrogs
Toads
Animals
Monkey Math
A Seabird's Endless Summer
Pothole Repair, Insect-style
Behavior
Between a rock and a wet place
Fighting fat with fat
Video Game Violence
Birds
Songbirds
Roadrunners
A Meal Plan for Birds
Chemistry and Materials
Batteries built by Viruses
Mother-of-Pearl on Ice
Smelly Traps for Lampreys
Computers
Batteries built by Viruses
Galaxies far, far, far away
Look into My Eyes
Dinosaurs and Fossils
Message in a dinosaur's teeth
Downsized Dinosaurs
Fingerprinting Fossils
E Learning Jamaica
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Earth
Recipe for a Hurricane
Drilling Deep for Fuel
Surf Watch
Environment
Ready, unplug, drive
Fishing for Fun Takes Toll
Bald Eagles Forever
Finding the Past
A Volcano's Deadly Ash
Stonehenge Settlement
Settling the Americas
Fish
Tiger Sharks
Barracudas
Skates
Food and Nutrition
The Color of Health
In Search of the Perfect French Fry
Allergies: From Bee Stings to Peanuts
GSAT English Rules
Whoever vs. Whomever
Subject and Verb Agreement
Finding Subjects and Verbs
GSAT Exam Preparation Jamaica
10 Common Mistakes When Preparing for the GSAT Math Test
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
How are students placed after passing the GSAT exam
GSAT Exams Jamaica Scholarships
GSAT Scholarship
Results of GSAT are in schools this week
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Mathematics
Prime Time for Cicadas
Deep-space dancers
A Sweet Advance in Candy Packing
Human Body
Sleeping Soundly for a Longer Life
Fighting Off Micro-Invader Epidemics
Nature's Medicines
Invertebrates
Crabs
Flatworms
Bees
Mammals
Blue Whales
Bulldogs
Mongooses
Parents
Raise a Lifelong Reader by Reading Aloud
Expert report highlights the importance to parents of reading to children!
Choosing a Preschool: What to Consider
Physics
One ring around them all
IceCube Science
Black Hole Journey
Plants
Flower family knows its roots
Cactus Goo for Clean Water
Plants Travel Wind Highways
Reptiles
Copperhead Snakes
Boa Constrictors
Snakes
Space and Astronomy
A Moon's Icy Spray
Icy Red Planet
A Smashing Display
Technology and Engineering
Smart Windows
Young Scientists Take Flight
Roll-Up Computer Monitors to Go
The Parts of Speech
Adjectives and Adverbs
Pronouns
Countable and Uncountable Nouns
Transportation
Middle school science adventures
Robots on a Rocky Road
Seen on the Science Fair Scene
Weather
The Best Defense Is a Good Snow Fence
The solar system's biggest junkyard
Earth's Poles in Peril
Add your Article

Supernovas Shed Light on Dark Energy

It's mysterious. It's so dark that it's invisible. And, boy, is it repulsive! Still, astronomers who study dark energy in the universe keep learning new things about it. Scientists came up with the bizarre concept of dark energy 8 years ago to explain mysterious data that they were collecting from outer space. The data appeared to show that, about 6 billion years ago, something began pushing everything in the universe farther and farther apart at an ever-faster rate. Scientists called this something "dark energy" and suggested that it supplies a repulsive force that causes the universe to expand outward with increasing speed. Most experts now agree that dark energy exists, but they still have a lot to learn about it. To find out more, an international team looked at images taken by the Canada-France-Hawaii Telescope on top of Hawaii's Mauna Kea. The astronomers identified 71 supernovas of a certain type known as "1a." These are very old stars that explode when they die. We see the light that they emit a few billion years later. Looking at type 1a supernovas is a good way to learn about the expansion of the universe because the explosions are all roughly equal in brightness at the source, just as all 100-watt light bulbs are equally bright. The farther away they are, though, the dimmer they look. So scientists can look at the brightness of supernovas and figure out how far away they are from Earth. Also, each supernova gives off a spectrum, or combination of wavelengths, of light. This spectrum shows how quickly the star's galaxy was moving away when the star exploded. Using all of this information, the researchers were able to figure out how long ago each of the 71 supernovas exploded. They were also able to estimate the speed of expansion at different times in the history of the universe. Their analyses suggest that dark energy is spread equally throughout space and time, the scientists say. The findings also help validate what Albert Einstein called a "cosmological constant." The famous scientist came up with the idea when he proposed a theory of gravitation in 1917, but he quickly retracted the part about the cosmological constant. It just seemed too weird at the time. Weird, but true. Astronomers plan to continue studying supernovas that exploded at various times. The more they do, the closer they'll get to understanding what dark energy is all about.E. Sohn

Supernovas Shed Light on Dark Energy
Supernovas Shed Light on Dark Energy








Designed and Powered by HBJamaica.com™