Agriculture
Keeping Bugs Away from Food
Flush-Free Fertilizer
Hungry bug seeks hot meal
Amphibians
Newts
Toads
Tree Frogs
Animals
Lucky Survival for Black Cats
Walktopus
Ultrasonic Frogs Raise the Pitch
Behavior
Babies Prove Sound Learners
Swedish Rhapsody
Brain cells take a break
Birds
Songbirds
Lovebirds
Rheas
Chemistry and Materials
The Taste of Bubbles
Lighting goes digital
Bandages that could bite back
Computers
Nonstop Robot
A Light Delay
The Book of Life
Dinosaurs and Fossils
Dino-Dining Dinosaurs
Supersight for a Dino King
The bug that may have killed a dinosaur
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
Deep History
Slower Growth, Greater Warmth
Petrified Lightning
Environment
A 'Book' on Every Living Thing
Seabirds Deliver Arctic Pollutants
Plant Gas
Finding the Past
Sahara Cemetery
Chicken of the Sea
Big Woman of the Distant Past
Fish
Skates
Manta Rays
Saltwater Fish
Food and Nutrition
Turning to Sweets, Fats to Calm the Brain
Allergies: From Bee Stings to Peanuts
Strong Bones for Life
GSAT English Rules
Finding Subjects and Verbs
Problems with Prepositions
Capitalization Rules
GSAT Exam Preparation Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Scotiabank Jamaica Foundation Grade Six Achievement Test (GSAT) Scholarships
Tarrant High overcoming the odds
GSAT Exams Jamaica Scholarships
GSAT Practice Papers | GSAT Mathematics | Maths
2014 GSAT Results for Jamaican Kids
Access denied - Disabled boy aces GSAT
GSAT Mathematics
Setting a Prime Number Record
Math of the World
Prime Time for Cicadas
Human Body
Taking the sting out of scorpion venom
From Stem Cell to Any Cell
Gut Microbes and Weight
Invertebrates
Invertebrates
Crawfish
Giant Squid
Mammals
Bats
Opposum
African Mammals
Parents
Choosing a Preschool: What to Consider
The Surprising Meaning and Benefits of Nursery Rhymes
What Not to Say to Emerging Readers
Physics
One ring around them all
Invisibility Ring
Spin, Splat, and Scramble
Plants
When Fungi and Algae Marry
Tracking the Sun Improves Plant Pollen
Bright Blooms That Glow
Reptiles
Anacondas
Boa Constrictors
Snapping Turtles
Space and Astronomy
A Whole Lot of Nothing
Sounds of Titan
Pluto's New Moons
Technology and Engineering
Dancing with Robots
Space Umbrellas to Shield Earth
Machine Copy
The Parts of Speech
Countable and Uncountable Nouns
What is a Noun
What is a Preposition?
Transportation
Robots on a Rocky Road
Middle school science adventures
Charged cars that would charge
Weather
Weekend Weather Really Is Different
A Change in Climate
Either Martians or Mars has gas
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™