January 30, 2019

What is dark energy?

Until recently, astronomers assumed that gravity was slowing the expansion of the universe that began with the big bang. At the end of the last century, […]
January 30, 2019

What is dark matter?

The other 27 percent of the universe is made of this stuff, which is easier to detect than dark energy because astronomers can measure its gravitational […]
January 30, 2019

Is time travel possible?

It’s not only possible – humans are doing it all the time! Of course, we’re all moving forward in the time right now (at a rate […]
January 30, 2019

What is an asteroid?

Asteroids are chunks of rock that orbit the sun and wander around the solar system. They’re the rubble left over from the solar system’s formation roughly […]