Menu
World Science
New clues for finding alien life
Climate change sparked rise of the lizards
Technology delivers net through TV aerial
Indigenous burn control a myth: study
Galapagos whales hold pollutant mystery
Bicycle scheme reveals rider behaviour
Frog bladder holds a surprise
Relocating species to ensure survival
Plant growth could slow warming: NASA
Astronomers find planet with a diamond heart
Free radicals not such a bad thing
Ants lay trail to complex problem-solving
Imagine more, eat less: study
'Stealth fungus' seeks, destroys crops
Saturn rings born from Titanic collision
New thinking on asteroid belt
Hungry Maoris burned forests to grow food
Ocean may contain nuclear powered microbes
Voyager reaches edge of solar system
Medical science examines urban myths
Clusterwinks bask in the afterglow
Cyclone batters Saturn for five years
Arctic icecap 'safe' from runaway melting
Fearless woman helps unlock anxiety puzzle
Lensing putting universe out of focus
A new study has found the optical effect called gravitational lensing is causing some distant galaxies to appear brighter than they really are.

The report in the journal Nature may have implications for our understanding of how the early cosmos developed into the universe we see today.

Lead author, Professor Stuart Wyithe from the University of Melbourne's School of Physics, says the most distant galaxies were being viewed through a kind of cosmic hall of mirrors.

"When light from these galaxies passes other galaxies or supermassive black holes on its way to the Earth, the mass of the nearer objects causes the light to bend," says Wyithe.

This process is called gravitational lensing. First theorised by Albert Einstein, it happens because mass distorts space time.
Impacting the numbers

Wyithe says it's not a problem on small scales.

"But on cosmic scales it magnifies and distorts the light, changing both the shape of and numbers of images that appear to be coming from the more distant galaxies. It also makes them appear brighter than they really are," he says.

Because gravitational lensing is one of the best ways of detecting these ancient galaxies in the very early universe, it means a higher number of distant bright galaxy targets are being counted.

Acording to Wyithe that changes the number of bright early galaxies that are actually there.

Future surveys will need to be designed to account for this gravitational lensing bias, especially in these very young early galaxies when the universe was less than 500 million years old.

"We want to understand the history of the universe, how the first galaxies grew and how they interacted with their environment. So one of the most basic things to do is to count how many galaxies there are," says Wyithe.

"And one of the best ways to do this is through the observations of the Hubble [Space Telescope]. So the information needs to be accurate to reach the right conclusions."

Wyithe says the James Webb Space Telescope, scheduled for launch in 2014, may help make sense out of this gravitationally biased view of the distant universe.

"It will have exquisite resolution and sensitivity at longer wavelengths to disentangle these very distant objects from the foreground lensing galaxies," he says.

Print
Reefs reeling from Queensland floods
Public asked to define a galaxy
Polygamy produces more virile offspring
Sleep best time to reinforce memory
Some Himalayan glaciers advancing: study
Massive coal fires caused Great Dying
Kid's self-control predicts health, wealth
Fish in groups decide quicker, better
One-clawed dino found in China
Conservationist and marine photographer recognised
Awards for medical research pioneers
Tough conditions favour giants
Bat uses carnivorous plant as a toilet
Telescope spots 'oldest galaxy' yet seen
Scientists unravel probiotics gut defence
Humans came out of Africa via Arabia: study
Bovine bellies yield biofuel clues
Saturnian moon's ocean full of gas
Sun rises on next solar generation
New test targets 'mad cow' disease
Dogs sniff out cancer in stool
Great drying reveals clues to big wet
Ant genome may reveal survival secrets
Dud mates stress out female finches
Kepler dramatically boosts exoplanet count
Scientists grow blood vessels
CO2 gets Martian sand dunes moving
Team makes nanosheet breakthrough
Menu
Music thrills trigger reward chemical
Lunar water may have come from comets
Birds falling from the sky 'not unusual'
NASA spots hot, Earth-like planet
Lifespan of early humans, Neanderthals same
Echidnas' unusual mating habits revealed
Funky frogs sniff out danger
La Nina lives up to predictions
Cuckoos ramp up effort in 'arms war'
Lensing putting universe out of focus
Penguins to shrug off flipper band
Device may silence ringing in the ears
Scientists find tiny 'dawn runner' dinosaur
'Goldilocks' planet lost in translation
Smoking causes gene damage in minutes
Climate matched Europe's ups and downs
Accuracy gave bows the early upper hand
Chemistry comes from the genes
Researchers aim to resurrect mammoth
Smaller corals take the heat
Blood drug could save crash victims
Gaps in flood knowledge: experts
Malaria parasite caught in the act
White blood cell protein aids melanoma