If you’ve got a minute, that is. (Whatever that even means. These facts kind of blew our minds.) 

• According to Einstein’s theory of relativity, time moves slower the closer an object is to the center of the earth. For example, a year at the top of Mt. Everest, one of the tallest peak’s on Earth’s surface, has been measured to be 15 microseconds (about 15 millionth of a second) longer than a year at sea level.

• Similarly, people on a long distance flight age a few more microseconds than those on the ground.

• Time is based on the Earth’s rotations and revolutions. The amount of time it takes the Earth to spin on its access isn’t 24 hours, but 23 hours, 56 minutes, and 4.2 seconds.

• Daylight Saving Time started in the U.K. in 1917, but Benjamin Franklin came up with the idea in the 1700s…as a joke. He said that waking up earlier in the morning during the summer would save on candles because they’d be done with work that much earlier in the day.

• Gravity acts as a drag on the planet, and it’s been doing so for billions of years. Result: Each century a day gets longer by just under 2 milliseconds. During the dinosaur era, there were 370 days in a year.

• You’re living in the past: The brain’s perception of reality trails events as they actually occur by about 80 milliseconds. (Also, the sunlight illuminating the Earth right now is the sunlight from about eight-and-a-half minutes ago.)

• Colloquially, the smallest measurement of time is the blink of an eye. Scientifically, it’s Planck time. In Planck time, a blink of an eye takes about 525,000 trillion trillion trillion Plancks.

• The most accurate clock: the one at the National Institute of Standards and Technology in Colorado. It measures a mercury atom’s vibrations. It’s so accurate that it will only be a second off every 15 billion years.