“I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.” – Stephen Hawking
Stephen Hawking was a distinguished theoretical physicist who shined light on some of the most mind-blowing physical phenomena.
It was break-free imagination and undying curiosity that brought his discoveries to life, while he merely sat immobile in a wheelchair for 56 long years.
He contributed greatly towards the understanding of Black Holes and how our universe came into existence. His research brought together widely distinct domains such as Quantum Theory and General Relativity, to give ground to his research. He was also among the first people to pursue research for the “Theory of Everything” that couldn’t reach a significant result while he was alive.
Tributes flew in from all parts of the world when Stephen Hawking passed away on the 14th of March this year, leaving behind a mourning scientific community and a legacy of path-breaking discoveries.
We remember him for his contribution to Modern Physics, his witty humor, his efforts to arouse public interest in science and his life-long perseverance with Amyotrophic Lateral Sclerosis (ALS) that paralyzed most of his body.
His story is an inspirational one – the reason why he is not only recognized as the Physicist Stephen Hawking but also the international celebrity who preached hope and courage against disability of any kind.
His international bestseller novel, “A Brief History of Time” is famously regarded as the book that was hardly ever read till the end. Mainly because of the tough-nut cosmological topics the book touches. So, here is a brief description of these complex discoveries by the genius of Stephen Hawking, to wrap around your head.
The Existence of Space-Time Singularity
In 1970, Hawking alongside Roger Penrose, proposed the concept of space-time singularities. The infinitely dense regions in space where mass contracts into such a small volume that the resulting gravitational force becomes infinite. Singularities exist at the center of a Black Hole from where even light can’t escape from falling into it.
This happens when an object (like a star) collapses at the end of its life and gravity smushes it into a tiny super-dense accumulation of mass or a singularity.
The research has been compiled in a research paper submitted to The Royal Society.
Hawking also theorized that the reverse process of a singularity may explain the beginning of the universe. The initial point from where the Big Bang took place, might have been a singularity.
The Origin of the Universe
Leading the idea of the Big Bang singularity, another idea was proposed to explain the origin of the universe – the Hawking-Hartle State, developed by Stephen Hawking and Jim Hartle.
It is a state of the universe before the Big Bang. It proposes that time had no meaning in the Hawking-Hartle state but there were matter and space. Because there was no time, the concept of “beginning” is meaningless and hence, the universe had no beginning as we call it.
It just existed like that. The theory is also called No Boundary Proposal because initially, the universe didn’t have any boundaries. The magical theory was proposed in 1983 and received wide acceptance in the physicist community.
Black Hole Thermodynamics
As he is known for bringing together diverse fields of physics to explain complex phenomena, this one is no different.
The four laws of Black Hole Thermodynamics were discovered by Stephen Hawking, James Bardeen, and Brandon Carter.
These laws form an analogy between the laws that govern thermodynamics and the behavior of black holes. These laws take into account, concepts like entropy, angular momentum and electric charges. It is hard to demonstrate these laws without the use of mathematical equations, hence to learn more about these laws, you can follow the Wikipedia page.
It is mentionable; the second law of Black Hole Thermodynamics says that just like entropy which increases with time, the surface area of a black hole will also keep on increasing with time.
This was later demolished by the concept of Hawking radiation which showed that black holes can shrink with time.
Hawking Radiation is the most famous work by Stephen Hawking.
It says that the black holes are not eternal entities and they evaporate or even explode with time. This happens when a pair of quantum particles (a positive one and a negative one) comes into existence near the event horizon of a black hole, for a very short period of time. The pair is destined to annihilate each other.
But, due to the strong pull of the black hole, this quantum pair breaks, and the negative particle falls into the black hole. The negative particle reduces the mass of the black hole and the positive one is pushed away. The escaped positive particle looks like a radiation and is known as Hawking Radiation. It is still to be observed in actual but has been widely accepted to exist in theory.
The Top Down Cosmology is an approach that tries to describe the formation of the universe by tracing back (hence top down) the history of the universe from the present state. This is contrary to the notion of studying the universe from a point of origination, rather it goes back towards the point of origination.
The quantum theory says that there is no single way in which the universe could have evolved, rather it has evolved in all the possible ways.
The Top Down Cosmology chooses to consider the specific way of evolution in which life comes into existence and the universe is like we observe it today.
The approach was proposed by Hawking and Thomas Hertog of CERN in 2006.
More from Hawking
Hawking has authored a number of books for the general public as well as for children that are not as famous but are equally interesting. Here is a list of these books.
Interviews with Stephen Hawking
Hawking on what existed before the big bang (with Neil De Grasse Tyson)
Stephen Hawking: Last Week Tonight with John Oliver
Stephen Hawking: The Last Speech
Stephen Hawking on Donald Trump’s US: “I Fear I May Not Be Welcome” | Good Morning Britain