Agriculture
Earth-Friendly Fabrics
Flush-Free Fertilizer
Got Milk? How?
Amphibians
Bullfrogs
Poison Dart Frogs
Frogs and Toads
Animals
Poor Devils
A Grim Future for Some Killer Whales
New Monkey Business
Behavior
GSAT Mathematics Quiz, Teaching Math, teaching anxiety
A Grim Future for Some Killer Whales
Wired for Math
Birds
Vultures
Pheasants
Lovebirds
Chemistry and Materials
Salt secrets
Butterfly Wings and Waterproof Coats
Watching out for vultures
Computers
Supersonic Splash
Middle school science adventures
It's a Small E-mail World After All
Dinosaurs and Fossils
Three strikes wiped out woolly mammoths
A Big, Weird Dino
Dino Bite Leaves a Tooth
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
Earth
Coral Gardens
Quick Quake Alerts
Petrified Lightning
Environment
Shrimpy Invaders
A Stormy History
The Birds are Falling
Finding the Past
A Plankhouse Past
Digging Up Stone Age Art
Big Woman of the Distant Past
Fish
Freshwater Fish
Tilapia
Puffer Fish
Food and Nutrition
Packing Fat
Allergies: From Bee Stings to Peanuts
Recipe for Health
GSAT English Rules
Adjectives and Adverbs
Capitalization Rules
Who vs. That vs. Which
GSAT Exam Preparation Jamaica
Preparing for the GSAT Exam
2014 GSAT Results for Jamaican Kids
GSAT stars reap scholarship glory
GSAT Exams Jamaica Scholarships
Results of GSAT are in schools this week
GSAT stars reap scholarship glory
Access denied - Disabled boy aces GSAT
GSAT Mathematics
How a Venus Flytrap Snaps Shut
Setting a Prime Number Record
A Sweet Advance in Candy Packing
Human Body
A Sour Taste in Your Mouth
Teen Brains, Under Construction
Fighting Off Micro-Invader Epidemics
Invertebrates
Dragonflies
Scallops
Clams
Mammals
Pitbulls
Chinchillas
African Hippopotamus
Parents
The Surprising Meaning and Benefits of Nursery Rhymes
What Not to Say to Emerging Readers
Children and Media
Physics
Hold on to your stars, ladies and gentlemen
Dreams of Floating in Space
The Mirror Universe of Antimatter
Plants
Cactus Goo for Clean Water
Assembling the Tree of Life
Pumping Up Poison Ivy
Reptiles
Snapping Turtles
Iguanas
Komodo Dragons
Space and Astronomy
A Smashing Display
Saturn's Spongy Moon
Slip-sliding away
Technology and Engineering
Crime Lab
Roll-Up Computer Monitors to Go
Are Propellers Fin-ished?
The Parts of Speech
Pronouns
What is a Verb?
What is a Noun
Transportation
Tinkering With the Basic Bike
Charged cars that would charge
Robots on the Road, Again
Weather
Recipe for a Hurricane
Where rivers run uphill
Polar Ice Feels the Heat
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™