Trivia

Hard

What Determined The Direction Of Clock Hand Movement?

Sundials
Right-Handed Clock Makers
A Royal Decree
Religious Tradition
A sundial on the campus of the U.S. Naval Hospital in San Diego.
Edward Gohlich/Library of Congress

Answer: Sundials

The hands of clocks and watches rotate from the upper right quadrant of the clock face down to the lower right, around to the lower left, and then back up around through the upper left until they arrive in the upper right quadrant—a familiar movement we simply refer to as clockwise.

But why this right-to-left rotation? Clocks could have just as easily been constructed to rotate in the opposite direction, after all. To understand the rotational direction of clock hands, we need to turn to the clock’s predecessor and where the first clock faces and clock hands were constructed. Prior to clocks, people used the sun to tell time, often in the form of a sundial.

The first clocks with hands were constructed in the Northern Hemisphere and a horizontal sundial in the Northern Hemisphere has a shadow that rotates from the upper right around to the lower left and back up again; early clock makers simply mimicked this familiar motion. Modern clock hands are simply following the same path as the shadows cast by the sundials that preceded them.

Curiously, there are some early exceptions. South-facing vertical sundials have a shadow that moves counter-clockwise and a few early clocks were constructed to follow the shadow path produced by them. Few examples of these older counter-clockwise clocks exist, but a remarkably well-preserved one can be seen in the Münster Cathedral located in Münster, Germany. The Münster astronomical clock not only tells the time with an hour hand that traces the actual path of the sun, but also has minor hands that track the positions of the planets and even has a moon-phase indicator.

Trivia

Hard

The Loudest Sirens Ever Built Were Powered By?

Trivia

Easy

Which Of Our Solar System Neighbors Would Fit Into Russia?

Trivia

Hard

Which Sci-Film Was The First Nominated For A Best Picture Oscar?

Trivia

Easy

What Does the Acronym “LCD” Stand For?

Trivia

Hard

The First Consumer Sewing Machine To Feature Computerized Design Inputs Was Powered By A?

Trivia

Very Hard

Braille, The Tactile Writing System For The Blind, Is Derived From What?

Trivia

Hard

The Largest Known Freshwater Flood In All Of History Is Known As The?

Trivia

Hard

Moon Dust Smells Like?

Trivia

Easy

What Was The First YouTube Video To Reach One Billion Views?

Trivia

Hard

Which Of These Bands Derives Its Name From Military Slang?