Dark Energy Measured More Precisely than Ever

Dark energy is the term scientists use to describe the cause of the accelerated expansion of the universe. Find out how a new analysis provides its most precise measurement yet.

Attending the University of Toronto doesn’t make you an academic superstar. I’m living proof of that.

Even so, as Canada’s top-ranked university, spending time at U of T does give you the privilege of hanging out with a few of them. I had several eminent professors there.

One of them was Professor Emeritus John Percy. He always made a point of teaching an introductory astronomy course aimed at non-science majors as part of his lifelong commitment to science education.

Didn’t Realize Universe’s Expansion Was Accelerating

When I took Professor Percy’s course in the 1980s, several things that preoccupy cosmologists today hadn’t been discovered yet. For example, although the Big Bang theory was fairly well established, scientists didn’t realize that the expansion of the universe was accelerating.

That realization led to one of cosmology’s two greatest mysteries — dark energy. The other, earlier mystery is called dark…