- January 8 -

Earth's Rotation Day

On January 8, 1851, French Physicist Leon Foucault invented a pendulum device to prove the Earth’s rotation. It had long been believed that the Earth rotated, but Focault discovered that he could demonstrate this with a simple experiment using a tall pendulum with a heavy weight. 
 He...

Earth's Rotation Day

On January 8, 1851, French Physicist Leon Foucault invented a pendulum device to prove the Earth’s rotation. It had long been believed that the Earth rotated, but Focault discovered that he could demonstrate this with a simple experiment using a tall pendulum with a heavy weight.

He constructed an early form of this device in his house’s cellar, made up of a 5-kilogram weight attached to a 2-meter cable. Underneath the pendulum, he placed sand to mark the path of the swinging. He observed a slight clockwise movement of the plane—which meant that even if the pendulum was swinging straight back and forth, the Earth underneath it moved slowly. Excited with his discovery, Focault sent invitations to Parisian scientists for a demonstration of his refined pendulum apparatus on February 3, 1861 at the Paris Observatory.

The best known version of the device, called Focault pendulum after its inventor, was comprised of a 67 m long wire and a 28 kg brass-coated lead bob as the weight. During Focault’s first public demonstration of the device in March 1861, it was suspended from the dome of the Pantheon in Paris and made to swing freely. The idea was to show that the plane (ground) in which the pendulum sways rotates with time. The pin placed at the bottom of the weight marked the track of the pendulum’s swinging against the plane, proving the Earth’s rotation. The experiment showed that the pendulum’s swing rotated clockwise at 11 degrees per hour and created a full circle in 32.7 hours.

Today, Focault pendulums can still be found in many museums and science centers around the world, swinging continuously to show and remind curious visitors around the world of the simple experiment that proved the Earth’s rotation.

Source:
http://www.lomography.com/magazine/lifestyle/2012/01/08/today-in-history-earths-rotation-proven

Categories:

More holidays on this day:

Bubble Bath Day

You may also like...

Interesting events from Science category.

Pistol Patent Day

A Colt Paterson is a revolver. It was the first commercial repeating firearm employing a revolving cylinder with multiple chambers aligned with a single, stationary barrel. Its design was patented by Samuel Colt on February 25, 1836, in the United States, France, and England, and it derived its...

World Contact Day

World Contact Day was first declared on March 1953 by an organization called the International Flying Saucer Bureau, as a day on which all IFSB members would attempt to send a telepathic message into space. The IFSB voted to hold such a day in 1953, theorising that if both telepathy and alien...

International Astrology Day

International Astrology Day (most often observed on either March 20 or March 21) is an annual observance/holiday celebrated by astrologers and astrology enthusiasts. It is seen by astrologers as the beginning (first day) of the astrological year. It is the first full day of the astrological sign of...

Paranormal Day

This is a day to honor all those who believe in paranormal experiences as well as those who engage in paranormal activities. Even if you are a diehard skeptic, you can still enjoy this day as an opportunity to hang out and watch scary movies. The term of paranormal has been in the English...

Global Accessibility Awareness Day

Global Accessibility Awareness Day (GAAD) is dedicated to increasing understanding and stimulating discussion about digital accessibility and inclusion. The purpose of the day is to get people talking, thinking and learning about digital (web, software, mobile, etc.) accessibility and users with...

Microsoft Released Windows

On November 10, 1983, at the Plaza Hotel in New York City, Microsoft Corporation formally announced Microsoft Windows, a next-generation operating system that would provide a graphical user interface (GUI) and a multitasking environment for IBM computers. The history of Windows dates back to...

Download KeepIn Calendar

Enjoy the interesting stories even on your phone or tablet