Doctors estimated that Stephen Hawking would only have a few years to live.

He was diagnosed in 1963 with amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease. Only ten percent of those affected live for more than 10 years. But Hawking lived for 55 years!

ALS affects nerve cells in the brain and spinal cord – those affected lose their ability to move their muscles, speak and even breathe. Hawking, a mathematical physicist, cosmologist, and an author is regarded as one of the most brilliant scientists of all time. With his death on March 14 at age 76, we have lost a man who dared answer perhaps the most profound question of all – where did the universe come from?

**A Brief History of Hawking**

Stephen Hawking was born in England, on Jan. 8 1942. During his years at Oxford University, he found his work relating to physics extremely easy. It was the field of cosmology and the question it brought – where our universe came from, that began to excite the young scientist.

His ALS diagnosis initially left him in a deep depression. But Hawking combated this – as he could not speak due to his condition, he used a computer device that would, through the vibration of his cheek, translate his thoughts aloud. As he could not write, Hawking thought through complex equations in his head, employing geometry.

A recipient of numerous awards and author of the bestselling book *A Brief History of Time*, Hawking also showed a playful side, guest starring on popular TV shows such as the Big Bang Theory.

**Black Hole Theory**

Hawking is noted for his work about black holes. Black holes swallow up everything and anything unable to fights its gravitational force. It was thought that not even light could escape the wrath of the black hole – but Hawking disproved this.

By devising an equation (dubbed “Hawking radiation”) that proved black holes have a temperature, it was proved that radiation could escape the black hole. To prove this theory, Hawking managed to combine two essential theories, the theory of relativity and quantum mechanics.

Quantum mechanics describe how the smallest objects in the universe, such as particles, work. The theory of relativity explores something on a grander scale – that larger objects, such as planets, are able to manipulate space and time. Hawking analyzed the “event horizon” located at the edge of a black hole. The event horizon is a point of no return – once stuck in there, there is little chance of escape. Hawking looked at how particles in this zone reacted with one another.

Usually, particles -- positive and negatives – cancel each other out. This is a property that can apply to many different areas in life. However, particles on the event horizon have different properties. The positive particle has a luckier fate as it is “flung away” from the hole, due to the sacrifice of the negative particle, which is sucked up by the black hole. The lucky positive particle is what we know as “Hawking radiation”, its escape is powered by heat. As Hawking radiation escapes from the black hole, Hawking’s work proved that someday, though not anytime soon, the black hole could disappear.

*Sources: NYTimes, CNN, TheVerge, Guardian, NBC, BBC*