Telescope to map swath of universe
A new radio-telescope capable of reaching back into the history of the universe by 11 billion years is built largely from cellphone components, gamers’ graphics processors and “five truckloads of computers.”
The Canadian Hydrogen Intensity Mapping Experiment near Penticton is a simple set of skateboard-style halfpipe reflectors and signal amplifiers with no moving parts, built for $16 million.
A collaboration between the University of British Columbia, Montreal’s McGill University, the University of Toronto and the National Research Council, the fixed array known as CHIME scans the entire sky, using the rotation of the Earth.
On Thursday, the experiment began collecting a data stream of radio signals equivalent to all the data being streamed in North America, said Mark Halpern, a UBC astrophysicist.
“We are mapping the biggest volume of the universe that anyone has ever measured,” he said.
Several teams of scientists will be looking at fast radio bursts, local pulsars and indicators of dark energy in the deepest recesses of the universe.
“As soon as that equipment is up and running, we expect to start seeing fast radio bursts, possibly several per day,” Halpern said.
Radio bursts are seemingly random flashes coming from outside our galaxy.
Neutron stars in our galactic neighbourhood called pulsars emit bursts of energy like a lighthouse.
Once the regularity of the local pulsars is well understood, the experiment will be able to detect gravitational waves from the effect they exert on the pulsar signals.
Gravitational waves are ripples in space-time predicted a century ago by Albert Einstein, but observed for the first time last year.
“We should be able to see very slow gravitational waves, with a one-month or two-month time frame,” Halpern said. “These things have been very difficult to measure.”
Among the longer-term goals for the facility is to study the emergence of dark energy in the deep past of the universe using measurements of light that left its source between six billion and 11 billion years ago.
“The Earth formed four and a half billion years ago, cooled a bit, life emerged and we got this thing built just in time to catch it,” said Halpern.
Dark energy makes up a large proportion of the substance of the universe and appears to play a role in its accelerating expansion.
“It’s most of what’s in the universe. We know it’s there because we can see what it does,” he said.
Less than five per cent of the substance of the universe is observable matter that makes up the stars, planets and ourselves. The rest is mysterious.
“Far from empty, the universe is full of something that is very far removed from our everyday lives,” Halpern said.