How Do the Tides Work, and Why Two a Day?
Twice a day the sea climbs up the beach and slides back down, on a schedule set by an object 384,000 kilometers away. Here is how the Moon, and a bit of the Sun, moves the whole ocean.
How Do Satellites Stay in Orbit Without Falling?
Thousands of satellites circle overhead right now, and gravity is pulling on every one of them. So why don’t they fall? The answer is stranger and simpler than it sounds.
What Is AI Safety, and Why Does It Matter?
As AI gets more capable, a whole field has grown up around one worry: making sure these systems do what we actually want. Here is what AI safety means and why it matters.
What Is Dark Matter, and Why Can’t We See It?
Most of the matter in the universe is invisible. We cannot see it, touch it, or make it in a lab, yet without it galaxies would fly apart. Here is what dark matter is.
How Do Rockets Actually Reach Orbit?
Getting a rocket up to space is the easy part. The real trick, and the reason rockets are almost all fuel, is going sideways fast enough to fall around the planet forever.
Do You Really Own Your Digital Games?
You may have spent hundreds building a digital game library. Legally, you don’t own any of it the way you think. Here is what ‘buying’ a digital game really means.
How Long Does It Take to Get to Mars?
Getting to Mars is not a quick hop. It takes about seven to nine months, follows a long curve, and you can only leave every couple of years. Here is why.