A beginner’s guide to black holes
Black holes have intrigued physicists and science fiction buffs. Here’s a beginner’s guideHT48HRS_Special Updated: Jul 02, 2016 10:29 IST
What happens when you get sucked inside a black hole? The 2014 film Interstellar depicted NASA pilot Joseph Cooper (Matthew McConaughey) plunging into the black hole called Gargantura. While it destroys his ship, Cooper ends up in a four-dimensional cube called Tesseract.
“The simulation of the black hole in the movie was accurate,” says Professor Shiraz Minwalla, who teaches string theory at Tata Institute of Fundamental Research (TIFR). Minwalla is a recipient of the Bhatnagar award and the New Horizons in Physics prize.
While a lot of research has been done on black holes, there are new developments every now and then. In fact, on June 28, astronomers announced the discovery of a black hole close to earth (it is still 7,200 light years; one light year is equivalent to 5.8 trillion miles).
Ahead of Minwalla’s session at Chai and Why (informal science sessions) on black holes, he offers some pointers:
What are black holes?
A black hole is a lump of space time (where time and three-dimensional space are clubbed together) that is so warped that nothing that enters this region can escape it, including light.
How do black holes occur?
When a star runs out of nuclear fuel, the force of gravity tries to make it collapse onto itself. However, the fermionic constituents (or particles like protons and neutrons) of matter resist being pushed too close together. When the star is several times the mass of the sun or heavier, the gravitational attraction of the star forces the star to collapse onto itself forming a black hole. If the star is lighter, then it settles down into a white dwarf or a neutron star.
Black holes are the simplest objects in the universe, because they are composed of space time itself. While black holes are conceptually simple, they are complicated in terms of quantum mechanics because they carry a huge entropy (degree of randomness). The simplicity of black holes makes them not too complicated to study; the quantum complexity makes it clear that they are not properly understood.
A proper understanding of black holes will help our understanding of gravity, quantum mechanics and their inter-relationship.
How can black holes shed light on the origin of the universe?
According to the general theory of relativity, at the centre of the black hole is a singularity — a location where space time is infinitely curved. If we use current observations on the state of the universe, and Einstein’s equations to ‘run the movie of the universe backwards’, we once again run into a singularity at early times.
It is possible that the singularity at the centre of a black hole is not dissimilar from the singularity at the ‘beginning’ of our universe. If that’s true, a complete understanding of the black hole singularity would help us understand the beginning of the universe.
DON’T MISS: Chai and Why? session on black holes will be held on July 3, 11am
At: Prithvi Theatre, Juhu, Vile Parle
Call: 97571 57795
First Published: Jun 29, 2016 00:00 IST