Stephen Hawking’s Beautiful Mind

Brief history of Stephen Hawking

Stephen Hawking spent his scientific life exploring some of the deepest questions a human caught in the Einsteinian opera of space and time could ask.

Although Einstein himself never really accepted it, his general theory of relativity predicted that if enough mass or energy were concentrated at one point, space would sag like mattress and eventually close itself off, creating a black hole from which nothing, not even light, could ever escape.

It would be Dr. Hawking’s fate to explore these imagined monsters and ask what their presence portends for the universe, and for those of us who live inside it.

The universe had a beginning

​In 1965, when Dr.  Hawking was 23, the British mathematician Roger Penrose proved that if Einstein’s theory of gravity, general relativity, was correct there is a point of infinite density — a singularity — at the center of a black hole.

In 1970, building on work in Dr. Hawking’s doctoral dissertation, he and Dr. Penrose show that there had to be a singularity at the beginning of time — in other words, a big bang.

That is to say, he showed that the universe had a beginning.

How black holes behave (and misbehave)

In 1970 Dr. Hawking shows that the area of a black hole’s event horizon — a spherical surface marking the point of no return — can only increase, never decrease, as stuff falls into a black hole or it collides and merges with other black holes.

1971 He suggests that mini black holes much smaller than stars created in the Big Bang could be peppering the universe.

1974 He shocks his colleagues and the world by showing that black holes will leak and explode when quantum effects — the weird laws that describe subatomic behavior — are taken into account.

1976 Dr. Hawking says exploding black holes add randomness and unpredictability to the universe, forever erasing information about what might have fallen into a black hole.

Quantum physicists object, saying the universe can’t forget, initiating a 40-year argument about the fate of information.

Dr. Hawking concedes in 2004, but does not say how information is preserved in a black hole, and the argument continues to this day.

A Universe With No Boundaries

1982 Using a mathematical conceit called imaginary time, Dr. Hawking and James Hartle, a theoretical physicist at the University of California, Santa Barbara, propose a model of a self-contained universe that has no boundary in space or time, and thus no place or time when the laws of physics break down.

In their picture of cosmic history, space-time is like a globe of the Earth. Time starts at the North Pole and goes south as the universe gets fatter. Asking what came before the Big Bang, in this case, is like asking what is north of the North Pole, they said.

Moreover, just as nothing weird happens at the North Pole of the Earth, nothing strange happens to the laws of physics at time zero. Earth abides and so does physics, obviating the need for a creator.

‘A Brief History of Time’

1988 Dr. Hawking publishes “A Brief History of Time.” It stays on the London Times best-seller list for four years, starting a gold rush of science books by prominent scientists.

1991 Errol Morris directs a documentary of the same name about Dr. Hawking and his life.

2007 Dr. Hawking is briefly free of gravity at last on a “vomit comet” flight in Florida

2012 Dr. Hawking stars in the opening of the Paralympic Games in London

2015 “The Theory of Everything,” a movie based on a book by his ex-wife, Jane Wilde, wins an Oscar for Eddie Redmayne.

He can’t make his mind up about aliens

2010 Dr. Hawking tells the Discovery Channel, “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans. We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.”

2015 He presides over the announcement of Breakthrough Listen, a $100 million search for signals from extraterrestrial civilizations.

“In an infinite universe there must be other occurrences of life,” he said. “Or do our lights wander a lifeless universe? Either way, there is no bigger question.”

But he is sure about time travel. In 1991, he enunciated what he called the chronology protection conjecture, that will, as he put it, “keep the world safe for historians, It says that the laws of physics do not allow time machines.

Forget me not

In 2016, working with Andrew Strominger of Harvard and Malcolm Perry of Cambridge University, Dr. Hawking took a small step toward a solution of the infamous information paradox. He announced that information about what falls into a black hole might be preserved on the surface, or event horizon, of a black hole.

The universe will remember us, which is no small thing, he declared.

If the rules break down in black holes, they may be lost in other places as well, he warned. If information disappears into a gaping maw, the notion of a “past” itself may be in jeopardy — we couldn’t even be sure of our own histories. Our memories could be illusions.

“It’s the past that tells us who we are. Without it we lose our identity,” he said.

The Earliest Humans in England Didn't Look the Way You'd Imagine

Picture what a person nicknamed "Clark" might look like. Now do it again, knowing that Clark man is the oldest-known Homo sapiens ever discovered in England. Whether the person you pictured was wearing a cheesehead hat or a sort of Stone Age bowler hat, well, we can't verify the man's accessory choices. But we can verify his skin color.

Here's what English people looked like 10,000 years ago.\

Aged to Perfection

A man named Cheddar was originally discovered in 1903 by a construction team making improvements to Gough's Cave in Cheddar Gorge (no, he really has nothing to do with cheese). We've learned a lot about him in the past century. For one thing, we've pinpointed his age to 10,000 years, and we've been able to guess at his hunter-gatherer lifestyle. But a new genetic analysis has gone further than any previous investigation. Finally, we know exactly what he looked like. Behold:




Surprised? So were scientists. But the evidence was clear: the earliest residents of England did not have today's stereotypically pale skin. Cheddar man's genetic markers suggested that his skin pigmentation was closer to that of sub-Saharan Africa, pointing to the possibility that pale skin didn't arise until much later.

Also, he almost certainly had blue eyes, putting an interesting wrinkle in our modern conceptions of which genetic traits go together. He's a great example of how easy it is to trip yourself up by projecting the present onto the past.

Foul Weather, Fair Skin

Anthropologists have long assumed that people in England had paler skin before the rest of the continent, but this new discovery has rendered that assumption false. Instead, Cheddar man and all of his relatives likely stayed dark-skinned about as long as the rest of Europe — until about 4,800 years ago.



Picture what a person nicknamed "Cheddar man" might look like. Now do it again, knowing that Cheddar man is the oldest-known Homo sapiens ever discovered in England. Whether the person you pictured was wearing a cheesehead hat or a sort of Stone Age bowler hat, well, we can't verify the man's accessory choices. But we can verify his skin color. Here's what English people looked like 10,000 years ago.
Aged to Perfection

Cheddar man was originally discovered in 1903 by a construction team making improvements to Gough's Cave in Cheddar Gorge (no, he really has nothing to do with cheese). We've learned a lot about him in the past century. For one thing, we've pinpointed his age to 10,000 years, and we've been able to guess at his hunter-gatherer lifestyle. But a new genetic analysis has gone further than any previous investigation. Finally, we know exactly what he looked like. Behold:


Surprised? So were scientists. But the evidence was clear: the earliest residents of England did not have today's stereotypically pale skin. Cheddar man's genetic markers suggested that his skin pigmentation was closer to that of sub-Saharan Africa, pointing to the possibility that pale skin didn't arise until much later. Also, he almost certainly had blue eyes, putting an interesting wrinkle in our modern conceptions of which genetic traits go together. He's a great example of how easy it is to trip yourself up by projecting the present onto the past.
Foul Weather, Fair Skin

Anthropologists have long assumed that people in England had paler skin before the rest of the continent, but this new discovery has rendered that assumption false. Instead, Cheddar man and all of his relatives likely stayed dark-skinned about as long as the rest of Europe — until about 4,800 years ago. That might seem surprisingly recent (it means that for the majority of humanity's existence, there was literally no such thing as white people). But what caused that evolutionary change?

In the warm climates where humanity first evolved, dark skin was a handy way to reflect a substantial amount of sunlight and stave off cancer caused by UV radiation. But up north, where sunlight isn't as plentiful, reflecting that much light can lead to vitamin D deficiency.

At the end of the day, though, Cheddar man stands as a reminder that the past isn't necessarily much like the present — and that race is a lot more complicated than where you come from.That might seem surprisingly recent (it means that for the majority of humanity's existence, there was literally no such thing as white people).

But what caused that evolutionary change?.