The Tall T
An upside-down T. Which of its two lines is longer?
How to play
Look first, then answer
An upside-down T. Which of its two lines is longer?
- Under a minute · one question · then the explanation
How it works — best read after you have tried it
Up is longer
The two lines are the same length. Vertical lengths are overestimated compared with horizontal ones, and cutting the base in half with the upright adds to it: the base is read as two halves, the upright as one whole.
The effect has been studied since at least the 1850s, by Adolf Fick and later Wilhelm Wundt, and it is one reason a tall building looks taller than it is wide even when the two are equal.