Widely considered one of the greatest minds in history, Stephen Hawking left our planet on March 14, 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.” Also described as a book every thinking person worried about humanity’s future should read. But who was Stephen Hawking, and why are his achievements and predictions so revered among academics and people in general?
Hawking was, among other things, an English theoretical physicist and cosmologist, first diagnosed with amyotrophic lateral sclerosis (ALS) back in 1963 at the age of 21. 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.
Before we jump into the big mysteries like the existence of God, the Big bang, black holes, Fermi’s paradox, future predictions, time travel, space colonization, and technology, that Hawking spent his life trying to unravel, let’s see what made him so special.
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.
“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, Stephen maintained an enormous personal archive of his responses, which took the form of speeches, interviews and essays” – we are told in the publisher’s note.
“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. It is structured in a way that helps the reader comprehend the complex questions about this existence, and how we can better understand the world around us.
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, God has absolutely no explanatory value: the universe would have been exactly the same as it is even if such a deity had never existed. There are natural laws that 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 or it is also subject to this universal, permanent laws of nature.
Hawking writes that “if you like, you can call the laws of science ‘God,’ but it wouldn’t be a personal God that you would meet and put questions to.” And adds – “although, if there were such a God, 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.
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 of 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”: spacetime included.
Of course, the fact that time and space are nonexistent entities in a primeval atom (think of it as singularity: everything and every time), 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.
Have you ever heard of a little something called the Fermi paradox? If not, here’s (more or less) how it goes:
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. Their stars 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.”
“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 calculate 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 Los Angeles on a March morning, but it may cause a thunderstorm on a June evening in New York.
Simply put: 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 we can't 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.
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 in 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 little time, until, in a flash, time stops existing for you.
According to our present understanding of the universe, “rapid space travel and travel back in time can’t be ruled out.” 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”, which we know nothing about as of yet. Even so, he would be delighted if someone proved him wrong. 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.”
The Stoics believed that there are events that are outside and events which are within our control; unfortunately, our life here on Earth is threatened by both.
The biggest threat is one that 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.”
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 won’t survive the next catastrophe, be it environmental or nuclear! So, the question is not – “should we colonize space?” But “how” and “when should we start taking 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-Treklike future.
Who knows? We may even be alive when the first human colony on Mars is established.
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 Artificial Intelligence (Al) 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 developed warily, it can have a very adverse effect on the human race.
When 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.”
To quote reviewer Zayan Guedim, “Brief Answers to the Big Questions” is not a culmination of all of the great scientists’ work, 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” (The 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.
Why not build your own spaceship, head over to Mars, and try to set up a colony there? Perhaps, that is too much to ask! Let’s go with something simpler, like unleashing your creativity in whatever you do.
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