Agriculture
Hungry bug seeks hot meal
Got Milk? How?
Earth-Friendly Fabrics
Amphibians
Poison Dart Frogs
Frogs and Toads
Salamanders and Newts
Animals
Polly Shouldn't Get a Cracker
Clone Wars
Missing Moose
Behavior
Pain Expectations
Ear pain, weight gain
A Light Delay
Birds
Eagles
Songbirds
Nightingales
Chemistry and Materials
Atom Hauler
Gooey Secrets of Mussel Power
Earth from the inside out
Computers
Games with a Purpose
A Light Delay
Galaxies on the go
Dinosaurs and Fossils
The man who rocked biology to its core
Early Birds Ready to Rumble
Dino Flesh from Fossil Bone
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
Undersea Vent System Active for Ages
Life trapped under a glacier
Hot Summers, Wild Fires
Environment
Ready, unplug, drive
A Stormy History
Pollution Detective
Finding the Past
Unearthing Ancient Astronomy
Stone Tablet May Solve Maya Mystery
If Only Bones Could Speak
Fish
Dogfish
Tuna
Catfish
Food and Nutrition
Allergies: From Bee Stings to Peanuts
Eat Out, Eat Smart
Yummy bugs
GSAT English Rules
Capitalization Rules
Problems with Prepositions
Pronouns
GSAT Exam Preparation Jamaica
Tarrant High overcoming the odds
The Annual GSAT Scholarships
How are students placed after passing the GSAT exam
GSAT Exams Jamaica Scholarships
GSAT Practice Papers | GSAT Mathematics | Maths
Results of GSAT are in schools this week
GSAT Exam Preparation
GSAT Mathematics
How to Slice a Cake Fairly
Math is a real brain bender
42,000 students will sit for the GSAT Exam in two weeks
Human Body
Sun Screen
A New Touch
Kids now getting 'adult' disease
Invertebrates
Sponges
Ticks
Bedbugs
Mammals
Persian Cats
Wombats
Deers
Parents
Raise a Lifelong Reader by Reading Aloud
Choosing a Preschool: What to Consider
What Not to Say to Emerging Readers
Physics
Gaining a Swift Lift
Extra Strings for New Sounds
Invisibility Ring
Plants
Fast-flying fungal spores
Underwater Jungles
Making the most of a meal
Reptiles
Box Turtles
Tortoises
Iguanas
Space and Astronomy
Ready, Set, Supernova
Saturn's New Moons
An Icy Blob of Fluff
Technology and Engineering
Roll-Up Computer Monitors to Go
A Light Delay
Beyond Bar Codes
The Parts of Speech
Adjectives and Adverbs
Problems with Prepositions
Countable and Uncountable Nouns
Transportation
Ready, unplug, drive
Charged cars that would charge
Tinkering With the Basic Bike
Weather
Science loses out when ice caps melt
Where rivers run uphill
The Best Defense Is a Good Snow Fence
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™