Instead, he believed that the universe was dynamic and could be either expanding or contracting. However, this assessment didn’t jive with Einstein’s calculations. At the time, scientists believed that the universe as we observed it was static - not growing or shrinking. Specifically, suspicion began in the early 1900s with Albert Einstein. We can trace the history of dark energy itself back to the first moments of the Big Bang, but human scientists didn’t begin to suspect its existence until billions of years later.

More than half the “stuff” in the universe is made up of a mysterious energy that we can’t observe. This invisibility seems to come from the fact that photons - or light particles - don’t interact with dark energy. Likewise, instead of imagining this energy as something the color of coal, “dark” more so signifies that it’s invisible to both the human eye and human instruments. In this case, the link that scientists believe explains why our universe’s expansion is speeding up instead of slowing down.

If point A and point B are both observable events, then dark energy is the unknown link that connects them. Instead of describing an observed phenomenon - like inky, black energy tendrils radiating through space - the name “dark energy” instead refers to a gap in physicists' knowledge. Here’s what you need to know about dark energy - including how it’s different than dark matter and what it might be made of. These mysterious entities make up over 90 percent of “stuff” in the universe and may be the only thing keeping life as we know it from snuffing out in a cosmic “snap” or “crunch” of the universe itself. Physics is good at explaining many of our universe’s strange phenomena - from the way invisible beams of the light fan into rainbows to how rocket fuel can propel us into space.Įven so, there are still many bizarre events in our cosmos that evade even physics’ understanding and perhaps none so baffling as the existence of dark energy and dark matter.

What is dark matter made of