Sep 21: An astronaut takes a bird's eye view of migration and more...
Earthquakes and gold, stone-age puberty, grey sharks retreat from reefs and a black hole merger
On this week's episode of Quirks & Quarks with Bob McDonald
Earthquakes create a spark in quartz that can form massive gold nuggets
Scientists have figured out why up to 75 per cent of all the gold ever mined forms with quartz crystals in areas with a long history of earthquakes. Chris Voisey, a Canadian geologist at Monash University in Australia, said he was trying to solve how gold arose inside quartz. In his study in the journal Nature Geoscience, he found that earthquake stress on quartz crystals generates an electrical voltage that causes dissolved gold to precipitate into a solid, allowing the growth of the largest nuggets ever found.
Ice Age Teens went through puberty just like today's kids
A new analysis of the bones of teenagers from 25,000 years ago shows they experienced puberty in much the same way as teens today. An international team of researchers including Paleolithic archaeologist April Nowell analyzed the bones of 13 teens found across Europe, and by looking at particular markers in the bones, they were able to see which stage of puberty the teens were in when they died. The researchers could not only infer things like whether their voices were breaking, but by doing muscle analysis, they found that the teens were healthy and active, and likely involved in hunting and fishing. The research was published in the Journal of Human Evolution.
Grey sharks are abandoning warming coral reefs in the Indian Ocean
The grey shark in the Indian Ocean uses beautiful coral reefs as a home base, returning each day after a night of fishing. But lately the sharks have been staying away for longer periods of time, up to 16 months. Dr. Michael Willamson, a research scientist at the Zoological Society of London, found that climate change is stressing the reefs. The sharks seek out cooler but potentially more dangerous waters. Venturing away from the protected reef area leaves them more vulnerable to illegal shark fishing. The paper was published in the journal Communications Biology
A cosmic collision 9 billion years ago could be the origin of the supermassive black hole at the centre of our galaxy
Using data from The Event Horizon Telescope, Dr. Yihan Wang worked with Dr. Bing Zhang at the Nevada Institute of Astrophysics to study the origins of the supermassive black hole at the centre of our galaxy. From the EHT image of the Sagittarius A* Dr. Wang and his team made an accretion model and saw that it spins very fast and that the spinning is misaligned. They believe it may have been made by merging with another supermassive black hole about 9 billion years ago. Their paper was published in Nature Astronomy.
Astronaut Roberta Bondar gives a bird's eye view of migration
32 years after she flew on the space shuttle, Roberta Bondar is still showing us what the Earth looks like from space — and from closer to the ground. Dr. Bondar trained as a wildlife photographer after her astronaut career. For a new project collected photos from space, from airplanes and helicopters, and from the ground, to bring a new perspective on the migration of two important bird species, the threatened lesser Flamingo and the endangered Whooping Crane. The book is called Space for Birds: Patterns and Parallels of Beauty and Flight.
