What is the Foucault’s Pendulum in new Parliament? How does it work?

The new Parliament which was inaugurated on Sunday by Prime Minister Narendra Modi is home to many interesting architectural features – perhaps none more than a Foucault’s Pendulum.The pendulum, which hangs from a large skylight from the triangular roof of the Constitution Hall, is meant to symbolise the "integration of the idea of India with that of the universe".But what is it? How does it work?Let’s take a closer look:What is it? How does it work?The Foucault’s Pendulum was named after French physicist Léon Foucault who invented it in the mid-19^th Century.Foucault in 1851 built the first-of-its-kind pendulum comprising a 28-kilo iron ball and a 67-metre steel wire.[caption id="attachment_12662932" align="alignnone" width="640"]

French phycisist Léon Foucault. Image courtesy: Wikimedia Commons/Zátonyi Sándor[/caption]Foucault hung the pendulum inside France’s Panthéon and then pushed it to one side and released it – after which it began swinging back and forth.

This was the first laboratory demonstration that the Earth spins on its axis, as per Britannica.

According to Britannica,  though the pendulum swings back and forth the Earth rotates beneath it. This means relative motion is at play.“At the North Pole, latitude 90° N, the relative motion as viewed from above in the plane of the pendulum’s suspension is a counterclockwise rotation of the Earth once approximately every 24 hours (more precisely, once every 23 hours 56 minutes 4 seconds, the length of a sidereal day). Correspondingly, the plane of the pendulum as viewed from above appears to rotate in a clockwise direction once a day. A Foucault pendulum always rotates clockwise in the Northern Hemisphere with a rate that becomes slower as the pendulum’s location approaches the Equator. Foucault’s original pendulums at Paris rotated clockwise at a rate of more than 11° per hour, or with a period of about 32 hours per complete rotation. The rate of rotation depends on the latitude. At the Equator, 0° latitude, a Foucault pendulum does not rotate. In the Southern Hemisphere, rotation is counter-clockwise,” the piece states.In short, as the Earth rotates on its axis the pendulum changes the direction it swings in.What about the pendulum inside the new Parliament?As per The Hindu,  the pendulum in the new Parliament was crafted by Kolkata’s National Council of Science Museum (NCSM).With a height of 22 metres and a massive weight of 36 kilos, the pendulum is said to be India’s largest such object, as per Indian Express.It takes the pendulum 49 hours, 59 minutes, and 18 seconds to complete one rotation.Tapas Moharana, who was in charge of the project, told Indian Express all the parts of the pendulum were made in India.It took Moharana’s around 10 to 12 months to create the pendulum after they got a call last year from the Central Public Works Department (CPWD) asking how this could be achieved.The piece has been crafted with gunmetal and affixed with an electromagnetic coil to ensure hassle-free movement, Moharana added.According to The Hindu, setting up such a pendulum is no mean feat as as one must ensure that its motion is influenced – to whatever extent possible – by gravity alone.The newspaper reported that Pune’s Inter-University Centre for Astronomy and Astrophysics in 1991 commissioned the first such public installation of the pendulum.

The NCSM, which was tasked to do so, only managed to set it up by 1993 after much trial and error.

NCSM later installed another such fixture in Brisbane’s Queensland Science Museum.The newspaper quoted E Islam, who worked on these set ups, and who later headed up Kolkata’s Birla Industrial and Technological Museum, as writing:“As was expected from theory, the pendulum at Pune apparently turned 4.86º per hour clockwise, while in Brisbane it turned 6.92º per hour anti-clockwise. The success of our new design was thus unmistakably established by experimental results from both the hemispheres.”With inputs from agenciesRead all the Latest News, Trending News, Cricket News, Bollywood News,India News and Entertainment News here. Follow us on Facebook, Twitter and Instagram.