Scientists are building a new telescope in the Okanagan that could be a stepping stone to understanding some of the biggest questions in the universe.
“We’ve gone from mapping the local neighborhood to mapping the universe,” said Tom Landecker, principal research officer at the Dominion Radio Astrophysical Observatory (DRAO).
Construction is underway for the new major telescope at the DRAO on White Lake Road, part of a project dubbed CHIME (Canadian Hydrogen Intensity Mapping Experiment).
The project, collaboration between UBC, McGill, the University of Toronto and the DRAO, aims to map data on a never-before-seen scale.
“This will be the biggest volume survey ever been done in astronomy with one instrument,” said Mark Halpern, a physics and astronomy professor at UBC and collaborator on CHIME. “We’re mapping on a scale of the universe essentially, cosmic scales. The scales we’re talking about here are enormous.”
The observations that can be made could possibly lead to some amazing discoveries in relatively new scientific territory, the study of dark energy.
Dark energy is a difficult concept to explain, and not just to the layman.
“If it seems mysterious to you, we’re all in the same boat. We have a name for it, that’s it,” Halpern said.
Looking out on the night sky, most of the stars seen by the naked eye are in our own Milky Way galaxy, save for one or two relatively close by neighbours. What CHIME aims to measure goes exponentially beyond our tiny corner of the universe.
The half-pipe shaped radio telescope contains 500 antennas focusing light from a stripe of sky onto the focal line where the data is measured. Thankfully CHIME scientists were able to find a well-situated rotational sphere which allows it to gather data from all directions.
“As the Earth turns, that sweeps out half the sky. With no moving parts we are taking a huge area survey,” Halpern said. “The Earth is the moving part.”
What the telescope is looking for is one of the most common atoms in the universe, neutral hydrogen, or more commonly known as hydrogen gas.
Scientists are very familiar with the structure of hydrogen, and this familiarity allows the CHIME telescope to locate the atom throughout the universe due its unique signature which also allows researchers to calculate how fast it is moving away from the Earth, and essentially the acceleration speed of the universe.
The mapping of the hydrogen atoms could be a key to unveiling some of the mystery surrounding what exactly dark energy is, and why it’s causing the universe to accelerate.
“We would like a second fact on the thing which is the dominant ingredient in the universe,” Halpern said.
The signal the telescope is looking for is extraordinarily small, which makes it a very sensitive operation.
“We calculated this out once,” Halpern said. “When we’re done collecting the signal for a year, we’ve gathered enough energy to pick a paper clip up off the floor by one millimetre. That’s how bright the neutral hydrogen is. So you can imagine a cell phone, a camera even, emit much, much more power that what we’re looking for.”
The sensitivity of the signal can be an issue here on Earth. The first line of defence from the now everyday wireless devices we carry are the signs posted a few kilometres out from the observatory asking those passing through to turn off their cell phones and wireless devices.
“There’s a never-ending battle here. Cars now have keyless entry, those have radio transmitters in them,” Halpern said.
The hills surrounding the observatory are the second line of defence. The area was selected for experiments in the 1950s after a group scouted locations across North America. The site on White Lake Road was considered the perfect spot.
“This place had the flat land you could build the telescope on, the hills to protect from interference and close to a pleasant place to live,” Landecker said, adding that the last reason can be a big factor for the human side of the experiment.
“We’ve done other experiments at the peak of the Chilean Indies, I’ve built three different cameras that are operating at the South Pole. You go where you have to, but it’s very hard to work in a place that is very far from your home and far from a nice place to be,” Halpern said.
The experiment is expected to take five years and Halpern said there is no way of knowing whether the results will confirm existing knowledge or change the way we think about the universe.
“There is a very boring answer available, which is the acceleration has been constant forever. That’s the sort of least informative answer, but it’s certainly possible,” he said. “Until we get our data we have no idea. This is a really groundbreaking experiment. We’re measuring a thing no one has measured. So we don’t know if this cements our understanding of acceleration, or opens a whole new line of inquiry.”
