The distance that light travels in about a three hundred millionth of a second. Wait, that’s just the actual definition.

“The length of the path travelled by light in vacuum during a time interval of ⁠1/299792458⁠ of a second, where the second is defined by a hyperfine transition frequency of caesium.”

This is the actual definition, but it’s also pretty weird.

About the length of a golden retriever

Enough thread for 10 to 15 stitches.

Half the width of a car.