Brief Answers To The Big Questions
By: Stephen Hawking
Big questions about our universe and the future of humanity.
From the cover:
Stephen Hawking was the most renowned scientist since Einstein, known both for his groundbreaking work in physics and cosmology and for his mischievous sense of humor. He educated millions of readers about the origins of the universe and the nature of black holes, and inspired millions more by defying a terrifying early prognosis of ALS, which originally gave him only two years to live. In later life he could communicate only by using a few facial muscles, but he continued to advance his field and serve as a revered voice on social and humanitarian issues.
Hawking not only unraveled some of the universe's greatest mysteries but also believed science plays a critical role in fixing problems here on Earth. Now, as we face immense challenges on our planet-including climate change, the threat of nuclear war, and the development of artificial intelligence—he turns his attention to the most urgent issues facing us.
Will humanity survive? Should we colonize space? Does God exist? These are just a few of the questions Hawking addresses in this wide-ranging, passionately argued final book from one of the greatest minds in history.
Why should you read this book?
Brief Answers to the Big Questions was Stephen Hawking’s final book, published posthumously. Hawking was considered one of the greatest physicists of our time. He was known for explaining complex topics and ideas in a clear and engaging way so anyone could understand. In this book, Hawking shares his thoughts on some of the most profound questions we have, about where we come from and where we’re going.
Hawking has a message for us. Think big. Be curious. Ask tough questions. This is the very heart and soul of science.
These are the questions Hawking explores: Is there a God? How did it all begin? Is time travel possible? What is inside a black hole? Is there other intelligent life in the universe? Will artificial intelligence outsmart us? How do we shape the future? Should we colonize space? Can we predict the future? Will we survive on Earth?
If you’re curious about these topics, we believe this book is thought-provoking and worth the read.
Excerpts:
“People have always wanted answers to the big questions. Where did we come from? How didn’t universe begin? What is the meaning and design behind it all? If there anyone out there?”
“One of the great revelations of the space age has been the perspective it has given humanity on ourselves. When we see earth from space, we see ourselves as a whole. We see unity, and not the divisions. It is such a simple image with a compelling message; one planet, one human race.”
The first question: Is there a God?
(a brief summary)
Religion was an early attempt to answer the questions we all ask: why are we here, where did we come from?
Around 300 BCE, a philosopher named Aristarchus was fascinated by the moon and the eclipses. He was brave enough to question whether they were caused by gods. He studied the heavens carefully and reached a bold conclusion: the eclipse was really the shadow of the Earth passing over the Moon.
From this discovery he was able to draw diagrams showing the relationship of the Sun, Earth, and the Moon. From there he deduced the Earth was not the center of the universe, but that it orbited the Sun. Aristarchus took it further. Stars were not cracks in the floor of heaven. They were other suns, but very far away.
The universe is a machine governed by principles of laws—laws that can be understood by the human mind.
The laws of nature explain how things work in the past, present, and future. And these laws are universal. They don’t just apply to us, but the entire universe. Unlike manmade laws, the laws of a nature can’t be broken. That’s why they’re so powerful and why, from a religious standpoint, they’re controversial.
So how did we get here?
To make a universe, you only need 3 ingredients: matter, energy, and space.
Albert Einstein realized that mass (matter) and energy were basically the same thing. They are two sides of the same coin. His famous equation E=MC^2 meant that mass can be thought of as a kind of energy, and vice versa.
So really the universe only needs two ingredients: energy and space.
The Big Bang Theory states everything came from a single moment. But where did all this matter and energy come from? How did it come from nothing?
The laws of physics demand everything has to balance out. The sum has to equal zero. This means for every positive form of energy, there has to be the existence of something called “negative energy.”
Imagine a man wants to build a hill on a flat piece of land. He digs a hole in the ground and uses the soil to form the hill. He’s not making the hill from nothing. He’s taking the matter (the soil) from somewhere else. The soil from the hole is now the hill. The hill is the positive energy and the empty hole is the negative energy. The sum is still zero.
The universe works the same way. All the planets and stars and matter are the soil that was removed from the ground, now forming the hill. Everything we see and feel didn’t come from nothing. It’s all positive energy formed by the Big Bang.
If the positive energy is the billions and billions of galaxies, trillions of planets, stars, and endless amounts of cosmic radiation, than the negative energy is the emptiness. It’s the empty space that fills our universe. The vastness of nothing is the hole left in the ground. And the sum still equals zero.
We have to remember all living matter is 99.9999% empty space. Everything is made of atoms and every atom is 99.9999% emptiness. So if we were to condense all the emptiness of every atom, the universe would shrink into a single point of incredible density. It would appear as nothing.
Black holes give us more insight into how this may work.
A black hole is a star so big that it collapses in on itself. The gravitational pull is so powerful, light can’t even escape. It even warps and distorts time itself. So where is all this matter and energy going? How do stars 100x larger than our sun, seemingly disapear into a black hole?
Inside a black hole is a singularity. A singularity is a singular point of infinite density. All the matter that made up the massive star, and all the energy of light and space itself is pulled into a single point. A point so dense there’s no empty space left.
Imagine all the emptiness of every atom is removed. The 99.999999% of empty space is shrunk down so that there is no more empty space. What’s left? The actual matter. The positive energy. The soil is being tossed back into the hole until eventually the hole is filled. Then the sum returns to zero.
As we travel back in time towards the moment of the Big Bang, the universe gets smaller and smaller, until it comes to a point. The whole universe becomes so small that it is essentially a single infinitesimally dense black hole. And just like with black holes, time ceases to exist. So when we ask what was before the Big Bang and how much time went by, there is no answer. Because time didn’t exist.
This is hard for us to comprehend. As big as the universe is, if we were to remove all the empty space of every single atom, the universe would be so small it would appear as nothing. Yet this still begs the question: how did the Big Bang happen?
Everything is made of particles. At the atomic and subatomic level, it’s possible to conjure something out of nothing. At least for a short while.
In quantum mechanics, particles like protons can appear at random, stick around for a while, then vanish, then reappear somewhere else.
If the universe was once very small, smaller than a proton—this means the universe itself could have simply popped up into existence without violating the laws of nature. When it did, vasts amounts of energy was released as space expanded. And again, space stores the negative energy. So it’s possible nothing actually caused the Big Bang. As incomprehensible as it may seem, the universe could have come from nothing.
We don’t have definitive answers but Science is bringing us further and further to truth. What we didn’t know thousands of years ago, we know today. And what we don’t know today, we will know in the future.
This is why we have to ask questions. This is the value of being curious and looking for answers to the unknown.
So what does this have to do with God? For thousands of years we didn’t understand how the universe worked. And so the role of gods filled the void. But the more we understand the laws of nature, the less we need supernatural explanations. Even so, as human beings we struggle with the magnitude of our existence. We struggle to comprehend a universe that came from nothing. We can’t wrap our brains around what existed before the universe or what happens when we die? And when it comes to our own mortality, the uncertainty is too unsettling. This is where religion continues to fill the void.
About the Author
STEPHEN HAWKING was the Lucasian Professor of Mathematics at the University of Cambridge for thirty years and the recipient of numerous awards and honors including the Presidential Medal of Freedom. His books for the general reader include My Brief History, the classic A Brief History of Time, the essay collection Black Holes and Baby Universes, The Universe in a Nutshell, and, with Leonard Mlodinow, A Briefer History of Time and The Grand Design. He also co-authored a series of children's books with his daughter, beginning with George's Secret Key to the Universe. Stephen Hawking died in 2018.