Why Stephen Hawking was so important to science

Renowned theoretical physicist Stephen Hawking died Wednesday morning at the age of 76. His contributions to cosmology changed the way we look at the universe. Here's a look at his most revolutionary ideas.

Renowned theoretical scientist's theories on black holes and the universe were revolutionary

Renowned British cosmologist Stephen Hawking brought the study of the universe to the general public with his book A Brief History of Time. (Yonathan Weitzman/Reuters)

On Wednesday morning, renowned theoretical physicist Stephen Hawking died at the age of 76. His contributions to science changed the way we look at the universe.

Born in Oxford, England, Hawking was a mediocre student as a child but went on to revolutionize physics and cosmology — the study of the origin and evolution of the universe.

But he did something perhaps even more challenging: he brought such deep thinking about how the universe began and where it's going to the general public in his bestselling book, A Brief History of Time, which was later turned into a documentary.

Hawking became a fixture in pop culture, with appearances on television shows such as The Big Bang TheoryThe Simpsons and Star Trek: The Next Generation.

While Hawking may be a household name, many people aren't necessarily familiar with his contributions to science.

Here are a few of his most important ideas.

Hawking radiation

Albert Einstein's theory of general relativity, published in 1915, suggested the existence of black holes — an object whose gravitational pull is so intense that once something passes a region known as the event horizon, there's no escape.

Over the years, the theory of black holes gained favour as further research supported their existence.

In 1974, Hawking shocked the physics community by theorizing that some things can escape a black hole before crossing the event horizon. Subatomic particle pairs — such as photons and neutrinos — near that point of no return could result in one particle being ejected. This became known as Hawking radiation.

Hawking did research at the Perimeter Institute in Waterloo, Ont. (Dave Chidley/Canadian Press)

Interestingly, Hawking initially didn't believe it possible. He only came to that conclusion when he tried to prove a young student, Jacob Bekenstein, who had initially made the suggestion, wrong. 

The black hole debate

In 2014, Hawking released a paper titled Information Preservation and Weather Forecasting for Black Holes in which he surprised the astrophysics community by suggesting black holes weren't so black after all. He challenged his initial theory from 1974 that suggested nothing could escape a black hole after crossing the event horizon. His new paper said light may be able to pass through the point of no return area and leak information in the form of matter.

Hawking had a few groundbreaking ideas about black holes. (Wikimedia)

However, he theorized that what comes out of it would not resemble what went in. So, for example, if a Tesla Roadster with a mannequin behind the wheel went into a black hole, the scrambled atoms that might come out would be unrecognizable.

Big bang

These days, the big bang theory is the widely accepted scientific explanation of the origin of our universe, but there was a time when the idea seemed preposterous. Even British astronomer Fred Hoyle, who coined the term in 1949, didn't believe the theory.

Physicists believe the universe grew to astounding proportions in a trillionth of a second after the big bang. (AP Photo/NASA)

In 1970, Hawking, along with fellow physicist Roger Penrose, suggested the universe began with a singularity, a location where space and time are indistinguishable. It's as if a black hole went in reverse. Their research supported the theory that the universe began with a big bang.

Theory of everything

While Hawking's theories revolutionized the way physicists think about the universe, he never won a Nobel Prize because his theories haven't been proven. For example, even if energy is released from a black hole, its temperature would be so low it would be difficult to measure.

At one time, Hawking had hoped to find a theory that could explain all the physical aspects of the universe, one that could unite the theory of general relativity (the study of the very large aspects of our universe) and quantum theory (the study of the very small). 

But in 2010, Hawking admitted that science may never be able to find the "theory of everything."

While the renowned scientist is gone, it's likely that his theories will be discussed for a long time yet.


Nicole Mortillaro

Senior reporter, science

Based in Toronto, Nicole covers all things science for CBC News. As an amateur astronomer, Nicole can be found looking up at the night sky appreciating the marvels of our universe. She is the editor of the Journal of the Royal Astronomical Society of Canada and the author of several books. In 2021, she won the Kavli Science Journalism Award from the American Association for the Advancement of Science for a Quirks and Quarks audio special on the history and future of Black people in science. You can send her story ideas at