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Widely considered one of the greatest minds in history, Stephen Hawking left our planet on 14 March 2018, precisely 139 years after the birth of Albert Einstein.

Brief Answers to the Big Questions is the last book he ever authored, his “parting gift to humanity.”

And if not for anything else – it’s worth all your time and energy just because of that.

Who Should Read “Brief Answers to the Big Questions”? And Why?

According to an NPR review, Brief Answers to the Big Questions is “a book every thinking person worried about humanity’s future should read.”

We share the opinion.

However, in case you expected a different answer to the question from the title, we are willing to be a bit more precise.

So, if you want to know what Hawking thought about the existence of God, the Big Bang, black holes, Fermi’s paradox, future predictions, time travel, space colonization, AI, and/or our responsibilities in relation to the future of our planet – then this book is definitely for you.

Now, go back to the quote from the NPR review at the beginning of this section; that one sentence was enough, wasn’t it?

About Stephen Hawking

Stephen Hawking was an English theoretical physicist and cosmologist, Lucasian Professor of Mathematics at the University of Cambridge for the three decades between 1979 and 2009, director of research at Cambridge’s Centre for Theoretical Cosmology, and one of the most recognizable popularizers of science of the past century.

Born 300 years – to the day – after Galileo Galilei’s death, Hawking was a brilliant student, but he fell into a deep depression after he was diagnosed with the terminal Lou Gehrig’s disease (aka ALS or MND) when he was barely 21 years old.

Even though doctors predicted that he’d live no more than two years after the initial diagnosis, Hawking beat their forecasts by half a century, a period during which he developed a reputation as both an heir to Einstein and a leading public intellectual.

As a matter of fact, Hawking’s most well-known book, A Brief History of Time – first published in 1988 – is one of the bestselling science books in history, having sold more than 15 million copies.

Ranked number 25 in BBC’s poll of the 100 Greatest Britons in history, Stephen Hawking is widely considered the most important theoretical physicist of the past half a century, and one of the most remarkable human beings who ever lived.

“Brief Answers to the Big Questions PDF Summary”

According to none other than Freeman Dyson, the Holy Trinity of 20^th-century physics consists of Albert Einstein, Richard Feynman, and Stephen Hawking.

Few – if anyone – would argue with him.

Not only because neither of these three needs any introduction; not even due to the fact that the last one of the three authored one of the best nonfiction books of all time, A Brief History of Time.

Published on October 16, 2018, Brief Answers to the Big Questions – unfortunately – was the last one he ever got to write before leaving our planet.

“Regularly asked for his thoughts on the ‘big questions’ of the day by scientists, tech entrepreneurs, senior business figures, political leaders and the general public” – we are told in the publisher’s note – “Stephen maintained an enormous personal archive of his responses, which took the form of speeches, interviews and essays.”

Brief Answers to the Big Questions is based on this personal archive; in development at the time of his death, the book was subsequently completed in collaboration with Hawking’s academic colleagues, his family and the Stephen Hawking Estate.

Kip Thorne – a longtime friend of Hawking and Sagan, and the winner of the 2017 Nobel Prize in Physics – introduces the book thus:

Stephen’s answers to six of the questions are deeply rooted in his science. (Is there a God? How did it all begin? Can we predict the future? What is inside a black hole? Is time travel possible? How do we shape the future?)… His answers to the other four big questions cannot possibly be rooted solidly in his science. (Will we survive on Earth? Is there other intelligent life in the universe? Should we colonize space? Will artificial intelligence outsmart us?) Nevertheless, his answers display deep wisdom and creativity, as we should expect.

Ready to go?

Key Lessons from “Brief Answers to the Big Questions”

1.      Is There a God?
2.      How Did It All Begin?
3.      Is There Other Intelligent Life in the Universe?
4.      Can We Predict the Future?
5.      What Is Inside a Black Hole?
6.      Is Time Travel Possible?
7.      Will We Survive on Earth?
8.      Should We Colonize Space?
9.      Will Artificial Intelligence Outsmart Us?
10.      How Do We Shape the Future?

Is There a God?

It depends on what your definition of God is.

If you think of God as a humanlike sentient Being who’s omnipotent and omniscient – then, no, there’s certainly no God.

Or, better yet, even if there is, he has absolutely no explanatory value: the universe would have been exactly the same as it is even if he had never existed.

There are natural laws which govern everything and scientists throughout history have uncovered most of them, one by one, slowly but surely.

Now we know for sure that the same laws govern both the movement of a tennis ball and the movement of a planet.

There’s absolutely no evidence whatsoever that these laws are: a) local; b) breakable.

In other words, if God exists, he (or she) is also subject to this universal, permanent laws of nature.

“If you like,” writes Hawking, “you can call the laws of science ‘God,’ but it wouldn’t be a personal God that you would meet and put questions to. Although, if there were such a God,” he adds, “I would like to ask however did he think of anything as complicated as M-theory in eleven dimensions.”

We would too, Stephen, we would like too.

How Did It All Begin?

Well, you know the simple answer: with the Big Bang.

After Edwin Hubble discovered a century ago that the universe is expanding – the stuff of Woody Allen’s nightmares – we realized that at one point in time (think 15 billion years ago) the universe was nothing more than a single dot, the primeval atom, the Cosmic Egg.

This primeval atom was extremely dense and hot; everything came from it.

And when we say everything, we do mean “everything”: time-space included.

Of course, the fact that time and space are non-existent entities in a primeval atom (think of it as singularity: everything and everytime), it’s meaningless to ask what came before the Big Bang.

It’s the same as asking what is south of the South Pole.

The Big Bang is the beginning – since before it time (which exists only within our universe) didn’t exist.

Is There Other Intelligent Life in the Universe?

Have you ever heard of a little something called the Fermi paradox?

If not, here’s (more or less) how it goes:

• There are 200 billion stars in our galaxy only, the Milky Way;
• By all estimations, about 20 percent of them should have an Earth-like planet orbiting them in the Goldilocks zone, “where the distance from the star is in the right range for liquid water to exist on their surface;”
• In other words, there should be at least 40 billion potential Earths just in our cosmic neighborhood;
• Life appeared on Earth just half a billion years after the Earth became habitable – which happened 4 billion years ago, almost 10 billion years after the Universe was formed;
• If life needs so little time to appear on an Earth-like planet and if there are so many Earth-like planets around us – then where are the aliens?

Difficult to answer, but there are a few things to take into consideration here:

• First of all, there’s a difference between life and intelligent life;
• Multi-celled organisms appeared on Earth 2.5 billion years after the first single-celled organisms were formed;
• Asteroids and comets constantly slam planets; it is one of these (and a small one, mind you) that completely wiped out the dinosaurs (the dominant species at the time) about 70 million years ago.

So, in other words, we might have been lucky.

Life has probably appeared on many, many planets in our cosmic neighborhood; however, it’s difficult to say if on any of them it managed to evolve to an intelligent phase.

Its star might have become a red giant too early; asteroids might have destroyed its life forms.

Either way, even “if there is intelligent life elsewhere, it must be a very long way away otherwise it would have visited Earth by now.”

Can We Predict the Future?

“If at one time we knew the positions and speeds of all the particles in the universe,” noted once Pierre-Simon Laplace, “then we would be able to calculate their behavior at any other time in the past or future.”

In other words, if you know the precise speed of your car and the direction it is moving, you’d be able to correctly guess where it would be 30 minutes from now.

Interestingly enough, this is the scientific view of things: there’s nothing supernatural in the world, so in a way, everything should be predictable.

However, there are a few problems with this.

The two most critical: the chaos factor, and the quanta.

First of all, it is highly improbable that anyone would ever know the precise position and speed of all the articles in the universe; a butterfly flapping its wings in China can cause winds in LA on a March morning, but it may cause a thunderstorm on a June evening in NY.

Put simply: there are just too many variables and too many factors to be taken into consideration; calculations of this type, though theoretically conceivable, are impractical.

Did we say theoretically conceivable?

Well, after Heisenberg and the quantum theory, even that part is debatable; it seems that it is impossible for us to know both the correct speed and the correct position of any small particle.

Too bad, because we were really hoping to find something akin to Marty McFly’s sports almanac one day in the future.

Or the past.

It’s too complicated.

What Is Inside a Black Hole?

If you ever get there, please – be sure to tell us.

Unfortunately, you won’t be able to, because you’ll be either turned into spaghetti before reaching the horizon (if it is a stellar mass black hole) or be crushed out of existence at the singularity (if it is a supermassive black hole).

Just be sure to never reach the event horizon, aka the moment past which nothing – not even light – can escape the gravity of a black hole.

Think of it as going over the Niagara Falls in a canoe; until a certain point, if you paddle fast enough, you should be able to get away; however, once you are past the edge, there’s no way back for you.

To sum up:

If you want to explore the inside of a black hole, then be sure to choose a big one; however, you’ll be the only one to know what’s inside it – for a very small part of time, until, in a flash, time stops existing for you.

Is Time Travel Possible?

According to our present understanding of the universe, “rapid space travel and travel back in time can’t be ruled out.”

In fact, the M-theory (“our best hope of uniting general relativity and quantum theory”) may allow for something as extraordinary and exciting as time travel.

However, if possible, time travel would cause serious logical problems, so Hawking really hopes that there’s some Chronology Protection Law we know nothing about as of yet.

Even so, he would be delighted if someone proves him wrong.

In fact, in 2009 he even held a party for time travelers in his college, Gonville and Caius in Cambridge.

To ensure that only genuine time travelers came, he didn’t send out the invitations until after the party.

Of course, no one came on the day of the party.

“I was disappointed,” writes Hawking, “but not surprised, because I had shown that if general relativity is correct and energy density is positive, time travel is not possible. I would have been delighted if one of my assumptions had turned out to be wrong.”

Will We Survive on Earth?

The Stoics believed that there are events which are outside and events which are within our control; unfortunately, our life here on Earth is threatened by both.

The biggest threat is one we can do nothing about: an asteroid collision. “We have no defense against it,” says Hawking. “The last big such collision with us was about sixty-six million years ago, and that is thought to have killed the dinosaurs, and it will happen again. This is not science fiction; it is guaranteed by the laws of physics and probability.”

However, there are also two threats we are able to – and should – do something about: climate change and nuclear weapons.

Hawking, however, is only partially optimistic:

One way or another, I regard it as almost inevitable that either a nuclear confrontation or environmental catastrophe will cripple the Earth at some point in the next 1,000 years which, as geological time goes, is the mere blink of an eye. By then I hope and believe that our ingenious race will have found a way to slip the surly bonds of Earth and will, therefore, survive the disaster. The same of course may not be possible for the millions of other species that inhabit the Earth, and that will be on our conscience as a race.

Should We Colonize Space?

If you read carefully Hawking’s quote above, then you already know the answer: of course, we should.

Otherwise, there’s a big chance that we don’t survive the next catastrophe, be it environmental or nuclear (god forbid that it is an asteroid!)

So, the question is not “should we colonize space?” but “how” and “when should we start taking the matters seriously?”

Hawking’s answers are “now” and “with concrete deadlines.”

In his opinion, our current goals of having a moon base by 2050 and a manned Mars landing by 2070 are possible and should be the introductory chapter to a Star-Trek-like future.

Who knows?

We may even be alive when the first human colony on Mars is established.

Will Artificial Intelligence Outsmart Us?

As far as Hawking is concerned, even less fabulous than the Star Trek scenario for our future is the one depicted in Terminator.

Namely, if humans became intelligent creatures by continually adapting to change, and if AI means allowing computers to do the same, shouldn’t this lead to an advanced AI network reaching self-awareness sometime in the future?

Well, chances are: it should.

However, this doesn’t mean that people should stop developing AI, because, on the other hand, it may also lead to an almost utopian future for humanity.

So, the conclusion: AI is capable of outsmarting us, so we must develop it with caution.

That was the essence of an open letter signed by Hawking, Elon Musk, and a host of AI experts in 2015, in which the leaders of today warned that unless AI is deployed warily, it can have a very adverse effect on the human race.

How Do We Shape the Future?

Asked “what world-changing idea, small or big, would you like to see implemented by humanity?” Hawking answers quite straightforwardly:

“This is easy. I would like to see the development of fusion power to give an unlimited supply of clean energy, and a switch to electric cars. Nuclear fusion would become a practical power source and would provide us with an inexhaustible supply of energy, without pollution or global warming.”

Reminding us that “we never really know where the next great scientific discovery will come from, nor who will make it,” Hawking ends his book with a cheerful and buoyant cry addressed to just about everybody:

So, remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes the universe exist. Be curious. And however difficult life may seem, there is always something you can do and succeed at. It matters that you don’t just give up. Unleash your imagination. Shape the future.

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“Brief Answers to the Big Questions Quotes”

Our Critical Review

To quote reviewer Zayan Guedim, Brief Answers to the Big Questions “is not a culmination of all of the great scientist’s works, and it doesn’t provide any particularly new discoveries.”

Even so, it is still “effortlessly instructive, absorbing, up to the minute and – where it matters – witty” (Guardian).

The best part?

There’s a lot of hope in Hawking’s final message.

And he more than deserved for us to pay attention.