- 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.

Pi Day

Pi Day is an unofficial holiday commemorating the mathematical constant ? (pi). Pi Day is observed on March 14 (or 3/14 in month/day date format), since 3, 1 and 4 are the three most significant digits of ? in the decimal form. In 2009, the United States House of Representatives supported the...

World Space Party - Yuri's Night

Yuri's Night is an international celebration held on April 12 every year to commemorate space exploration milestones. The event is named for the first human to launch into space, Yuri Gagarin, who flew the Vostok 1 spaceship on April 12, 1961. The launch of STS-1, the first Space Shuttle mission,...

Russian Cosmonaut Day

Cosmonautics Day (Russian:Den Kosmonavtiki) is a holiday celebrated in Russia and some other former USSR countries on April 12. Later on, since April 7, 2011 the April 12 was declared as the International Day of Human Space Flight in dedication of the first manned space flight made on April 12,...

World Creativity and Innovation Day

Today is the day to celebrate your creativity and new ideas! World Creativity and Innovation Day has been celebrated in over 46 countries since 2002. People in businesses, organizations, schools, and communities take part in this day to generate new ideas for a brighter future. Marci Segal,...

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