Agriculture
Keeping Bugs Away from Food
Cleaning Up Fish Farms
Flush-Free Fertilizer
Amphibians
Bullfrogs
Toads
Salamanders and Newts
Animals
Roach Love Songs
Who's Knocking?
Blotchy Face, Big-Time Wasp
Behavior
Baby Number Whizzes
A brain-boosting video game
Night of the living ants
Birds
Cardinals
Albatrosses
Rheas
Chemistry and Materials
Toxic Dirt + Avian Flu = Science Fair Success
The science of disappearing
Bandages that could bite back
Computers
A Light Delay
Nonstop Robot
Getting in Touch with Touch
Dinosaurs and Fossils
Dinosaur Eggs-citement
Dino Flesh from Fossil Bone
Meet the new dinos
E Learning Jamaica
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
Hints of Life in Ancient Lava
Getting the dirt on carbon
Coral Islands Survive a Tsunami
Environment
Out in the Cold
A Stormy History
Eating Up Foul Sewage Smells
Finding the Past
Chicken of the Sea
Fakes in the museum
Stone Age Sole Survivors
Fish
Parrotfish
Nurse Sharks
Seahorses
Food and Nutrition
Chocolate Rules
Strong Bones for Life
Symbols from the Stone Age
GSAT English Rules
Finding Subjects and Verbs
Who vs. Whom
Capitalization Rules
GSAT Exam Preparation Jamaica
Ministry of Education Announces 82 GSAT Scholarships for 2010
GSAT stars reap scholarship glory
Mastering The GSAT Exam
GSAT Exams Jamaica Scholarships
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Exam Preparation
2014 GSAT Results for Jamaican Kids
GSAT Mathematics
10 Common Mistakes When Preparing for the GSAT Math Test
GSAT Mathematics Quiz, Teaching Math, teaching anxiety
Math and our number sense: PassGSAT.com
Human Body
A Sour Taste in Your Mouth
A Fix for Injured Knees
Cell Phones and Possible Health Hazards
Invertebrates
Crustaceans
Spiders
Lice
Mammals
Aardvarks
Marmots
Cocker Spaniels
Parents
Children and Media
What Not to Say to Emerging Readers
Choosing a Preschool: What to Consider
Physics
Road Bumps
IceCube Science
Project Music
Plants
City Trees Beat Country Trees
Hungry bug seeks hot meal
Bright Blooms That Glow
Reptiles
Sea Turtles
Chameleons
Tortoises
Space and Astronomy
Holes in Martian moon mystery
Melting Snow on Mars
Cool as a Jupiter
Technology and Engineering
Supersuits for Superheroes
Beyond Bar Codes
Algae Motors
The Parts of Speech
Countable and Uncountable Nouns
Pronouns
What is a Preposition?
Transportation
Robots on a Rocky Road
Middle school science adventures
Revving Up Green Machines
Weather
Weekend Weather Really Is Different
Antarctica warms, which threatens penguins
A Dire Shortage of Water
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™