TNPSC Current Affairs October 07, 2020

Topic: Awards and Honours, Persons in News

Nobel Prize for Physics 2020

The Nobel Prize in Physics for the year 2020 was awarded to three astrophysicists Roger Penrose from the UK, Reinhard Genzel from Germany, and Andrea Ghez from the USA.

Key facts:

Roger Penrose:

Roger Penrose received half of this year’s prize for the discovery that a black hole formation is a robust prediction of the general theory of relativity. Black holes were one of the first and most extreme predictions of Einstein’s General Theory of Relativity which came in 1915.

The theory explains gravity, as objects try to follow a straight line through a universe whose geometry is warped by matter and energy. As a result, planets, as well as light beams, follow curving paths.

Dr Penrose proved that if too much mass accumulated in too small a place, collapse into a black hole was inevitable. At the boundary of a black hole, called the event horizon, one would have to go faster than the speed of light to escape it, which is impossible. At the centre of a black hole, where the density became infinite, the laws of physics, would no longer apply.

Genzel and Ghez:

Genzel and Ghez received the second half of the prize for the discovery of a supermassive black hole at the centre of the Milkyway galaxy, now known to be the Sagittarius A*. It has a mass four million times that of the Sun and is confined to an area roughly the size of our Solar System.

In 2019, scientists got the first optical image of a black hole which is at the centre of the Messier 87 galaxy. Sagittarius A* is the second black hole whose photographs have been captured by the Event Horizon Telescope project. It is yet to be released.

Dr. Ghez is only the fourth woman to win the Nobel Prize in Physics, following Marie Curie in 1903, Maria Goeppert Mayer in 1963 and Donna Strickland in 2018.

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Topic: Economic Policies in India

What is Purchasing Manager’s Index (PMI)?

PMI is an indicator of business activity- in the manufacturing and services sectors. It is a survey-based measure that asks the respondents about changes in their perception about key business variables as compared with the previous month.

The PMI is a number from 0 to 100:

PMI above 50 represents an expansion when compared to the previous month;

PMI under 50 represents a contraction, and

A reading at 50 indicates no change.

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Topic: Places in News

Temporary Shelters for Migratory Birds: Sambhar Lake

Recently, the Rajasthan government has decided to build temporary shelters for migratory birds near the Sambhar Lake (near Jaipur) before 2020’s winter season.

Key facts:

Every year, a large number of birds from the cold northern regions of Central Asia come to Sambhar Lake. In 2019, more than 20,000 migratory birds died due to avian botulism in the lake. Rajasthan High Court took suo motu cognisance of the mass death and asked the expert committee to carry out an investigation and make recommendations.

The Court has constituted a seven-member expert committee to study the impact of salt-forming and identify any illegal salt mining in the lake. It has suggested the state government seek the centre’s support for more funds for creating an infrastructure for the safety and security of birds.

Sambhar Lake:

It is India’s largest inland saline water body located near Jaipur in Rajasthan. It is surrounded on all sides by the Aravali hills. It is the source of most of Rajasthan’s salt production.

Sambhar has been designated as a Ramsar site (recognised wetland of international importance) because the wetland is a key wintering area for tens of thousands of flamingos and other migratory birds.