'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

  • Echo device sent private conversation to family's contact: Amazon

    Tech & Science CTV News
    SEATTLE -- An "unlikely" string of events prompted Amazon's Echo personal assistant device to record a Portland, Oregon, family's private conversation and then send the recording to an acquaintance in Seattle, the company said Thursday. Source
  • U of T astronomers observe 'black widow' star with incredible precision

    Tech & Science CBC News
    Imagine walking out to your backyard, setting up a telescope, pointing it at Pluto and being able to see something the size of a flea on its surface. That's the equivalent of what astronomers from the University of Toronto have done. Source
  • 'Black widow' star sighting one of the highest-resolution observations in astronomy history

    Tech & Science CBC News
    Imagine walking out to your backyard, setting up a telescope, pointing it at Pluto and being able to see something the size of a flea on its surface. That's the equivalent of what astronomers from the University of Toronto have done. Source
  • Have a stomach ache? Swallow a sensor

    Tech & Science CBC News
    Diagnosing the cause of stomach pain could soon be as simple as swallowing two small pills that work together to report back about what is happening in your body. This technology uses biosensors, an analytical device that converts a biological response into an electrical signal. Source
  • Forecasters expecting near-normal hurricane season for Atlantic in 2018

    Tech & Science CTV News
    HALIFAX -- The Canadian Hurricane Centre is expecting a "near-normal to above-normal" number of storms in the Atlantic Ocean this year. The United States' National Oceanic and Atmospheric Administration released its seasonal outlook Thursday, predicting 10 to 16 named storms, with five to nine of them being hurricanes and one to four being major hurricanes. Source
  • Astronaut David Saint-Jacques part of backup crew in advance of his own liftoff

    Tech & Science CBC News
    Canada's next man in space doesn't have his official liftoff date until the end of this year, but David Saint-Jacques says he's ready if called into action in the coming weeks. Saint-Jacques is serving as a backup to European Space Agency astronaut Alexander Gerst, who is part of a three-person team scheduled to launch from Kazhakstan on June 6. Source
  • Self-driving Uber was aware of pedestrian but didn't stop, probe on fatal Arizona crash finds

    Tech & Science CBC News
    The self-driving technology deployed in an Uber which struck and killed a woman crossing the street in Arizona recently, noted a pedestrian was on the road, but didn't stop, a preliminary report from the National Transportation Safety Board says. Source
  • Canadians confused about GM foods, support mandatory labelling: study

    Tech & Science CTV News
    HALIFAX -- The vast majority of Canadians believe genetically modified foods should have to be labelled at the grocery store, according to a new study, which a researcher says shows most consumers are confused about the science behind their dinner plates. Source
  • B.C. and N.B. floods a warning of what's to come, climate change researchers say

    Tech & Science CBC News
    Dawn Harp and Lars Androsoff were fully confident flooding didn't threaten their home near southern British Columbia's Kettle River. Then the couple awoke at 1:30 a.m. PT on May 11 to the sound of floodwaters flowing beneath their Grand Forks home's floorboards. Source
  • U.S. forecasters release hurricane and tropical storm predictions

    Tech & Science CBC News
    U.S. government forecasters are releasing their prediction for how many hurricanes and tropical storms they expect to form over Atlantic and Caribbean waters in the next six months. The six-month Atlantic hurricane season officially starts June 1. Source