'Dark matter' helped kill off the dinosaurs, new book theorizes

What killed off the dinosaurs 66 million years ago?

It’s one of the great mysteries of the universe. The best theory is that a massive, rogue comet slammed into the planet.

See Full Article

But scientists have never been able to explain where this comet came from.

Harvard University particle physicist and cosmologist Lisa Randall has a theory, and it all has to do with another one of the great mysteries of the universe: dark matter.

Dark matter might sound odd or exotic, but as Randall explains in her new book, “Dark Matter and the Dinosaurs,” it’s really just ordinary stuff.

“Dark matter is one of the simpler things to understand,” she told CTV’s Canada AM Friday. “It’s just matter, but it’s not made up of the stuff we’re familiar with: atoms or charged particles.”

Dark matter is completely invisible and doesn’t interact with light; in fact, light passes right through it. But physicists know it exists because it interacts with gravity just like regular matter.

“We know it’s out there. We have seen its gravitational effects in many different ways,” Randall said.

In fact, it’s estimated that only about five per cent of the universe is composed of visible bits of ordinary matter; the rest is made up of dark energy and dark matter.

“In fact, billions of dark matter particles are passing through you this second and you don’t know about it because they just aren’t interacting with you,” Randall said.

Randall’s research team believes that dark matter tends to “clump” into galaxies and has formed a pancake-shaped disk inside the larger disk that is the Milky Way.

Our solar system, meanwhile, is rotating through the Milky Way every 240 million years, bringing with it the sun, the planets and an outer cloud of massive icy objects called the Oort cloud. As the solar system rotates, Randall theorizes that it bobs through this dark matter disk.

“Our idea is that when it crosses that disk, there is an extra gravitational tug on the solar system that could actually dislodge weakly bound objects very far away in… the Oort cloud,” she said.

Randall’s team believes that 66 million years ago, a large comet was dislodged from the Oort cloud, which hurtled through the solar system and collided directly with Earth.

When it did, it caused a massive cloud of debris that blocked out the sun, leading to the extinction of 75 per cent of the planet’s plant and animal species.

Now, Randall is quick to point out that this dark matter disk effect is just a theory -- and one that has been met with “a healthy degree of skepticism” from the astronomy community.

But she is hopeful that a satellite moving through the solar system right now might help to prove her theory.

That satellite is called Gaia and its mission is to measure the position and velocities of a billion stars to help chart a three-dimensional map of the Milky Way and reveal its composition.

Randall hopes the satellite will be able to spot this dark matter disk by noting the gravitational effects it’s having on our solar system and other stars in the Milky Way.

“So we’ll find out whether this disk exists or not.”



Advertisements

Latest Tech & Science News

  • NASA tests nuclear power system for future astronauts on Mars

    Tech & Science CBC News
    Initial tests in Nevada on a compact nuclear power system designed to sustain a long-duration NASA human mission on the inhospitable surface of Mars have been successful and a full-power run is scheduled for March, officials said on Thursday. Source
  • Why some fracking wells are prone to triggering earthquakes

    Tech & Science CBC News
    Why does fracking cause earthquakes in some places and not others? Alberta scientists say they've figured out some factors that make certain wells prone to triggering earthquakes. That could help make it possible to forecast the risk of fracking-induced earthquakes in the future. Source
  • Whales, dolphins will no longer be displayed at Vancouver Aquarium

    Tech & Science CTV News
    VANCOUVER - The Vancouver Aquarium has announced that it will no longer display whales or dolphins. Aquarium president John Nightingale says in a statement that the facility will focus instead on raising awareness of ocean issues impacting other marine animals. Source
  • 2017 was 2nd-warmest across the globe since 1880, NASA says

    Tech & Science CBC News
    Last year was the second-warmest across the globe since 1880, NASA reported Thursday. The global surface temperature average in 2017 was 0.90 C warmer than the 1951–1980 mean, surpassed only by 2016. According to the National Oceanic and Atmospheric Administration (NOAA), however, 2017 was the third-warmest year. Source
  • Fluctuating temperatures claim Montreal's natural Beaver Lake ice rink for good

    Tech & Science CTV News
    MONTREAL - Skating on Beaver Lake, a popular Montreal winter pastime for decades, is now a thing of the past. The city's decision to shutter the natural ice rink has to do with constantly shifting winter temperatures that make it impossible to keep the surface safe. Source
  • Even without El Nino last year, Earth keeps on warming

    Tech & Science CTV News
    WASHINGTON -- Earth last year wasn't quite as hot as 2016's record-shattering mark, but it ranked second or third, depending on who was counting. Either way, scientists say it showed a clear signal of man-made global warming because it was the hottest year they've seen without an El Nino boosting temperatures naturally. Source
  • Pair of Chinese giant pandas get snowy welcome in Finland

    Tech & Science CTV News
    HELSINKI -- A pair of giant pandas has arrived in snowy Finland, China's gift to mark the small Nordic nation's 100 years of independence. Four-year-old male panda Hua Bao and three-year old female Jin Baobao were welcomed Thursday in a ceremony at Helsinki airport attended by the Chinese ambassador to Finland and Finnish officials. Source
  • Dashcam video captures meteor blazing across sky in Alberta

    Tech & Science CTV News
    A mysterious, large fireball seen soaring through the night sky in Alberta on Wednesday was a meteor, an astronomer has confirmed. “We do know that last night at about 5:22 p.m. there was a bright meteor, sometimes called a fireball or bolide, seen off towards the northeast of Edmonton, at least from the local reports,” Frank Florian, as astronomer at TELUS World of Science, told CTV Edmonton on Thursday. Source
  • Political pachyderms: Save the Elephants turns to Trudeau for latest name

    Tech & Science CTV News
    OTTAWA -- Sophie Gregoire Trudeau is hanging out with some heavy hitters these days -- names like Michelle Obama and Martha Washington. She eats fruit and tree bark, and spends her time caring for her nine-month-old son. Source
  • Scientists calculate proteins in a single cell and find 42 million

    Tech & Science CBC News
    Proteins are considered the hardest-working components of cells, influencing everything from structure to function — so cell biologists try to determine their numbers and any changes in the count. The number of protein molecules in a simple cell such as a yeast cell wasn't known with much certainty until now, say researchers from both the University of Toronto and a San Francisco-based biotechnology company that studies aging. Source