Brief Answers to Big Questions By Stephen Hawking (Summary)

This book is the last book authored by Stephen Hawking. In this book, he tries to answer some of the big question that have been wandering in this world. Is there a god? Is time travel possible? What is inside a black hole? These are the questions that everyone wants the answer to. Hawking tries to give his viewpoint on all the questions by giving scientific logic. So lets start.

1. Is there a god? God created everything. The universe and the human beings. But time and space are intertwined according to Einstein’s general theory of relativity. So before universe was created, there should have been no time. Then how can God exists without time? It’s like asking what is to the south of the south pole. The Big Bang started everything. There exist negative energy for everything that exists in this universe. The universe was the result of the big bang. So he believe there is no god.

2. Can we predict the future?

For predicting the future we have to take into account different theories like multiple history theory of Richard Feynman and calculate the position of a body in the future time. To calculate the future of any body, yo have to know the position and speed of that body in the present time according to Laplace. But according to the Heisenberg’s uncertainty principle, you cannot measure the position and speed both quantities accurately at the same time. The more accurately you measure position, the less accurate will be its speed and vice versa. So predicting the future is not possible.

1. What is inside a black hole?

Black hole is a body that has infinite gravity. Even a ray of light that enters into the black hole cannot escape from it. So we cannot see the black hole. But energy cannot be destroyed so the objects that goes inside black hole has energy since they have mass. So where does that energy go? By research it has been proved that black hole emits heat waves. What’s inside a black hole we can never know. It is because while entering the black hole when we reach into the event horizon, if the black hole is small then we get squeezed in width and stretched in length to become a ramen. But if the black hole is small, the force is equal at every point in the event horizon, so you will get dragged into it easily and will come back in the form of heat wave.

1. Is time travel possible?

Time travel and space travel like wormhole have been an interesting topic in the field of theoretical physics. According to Einstein’s general theory of relativity, if you want to travel in time then you have to move faster than the speed of light. To move an object in the speed more than light, you need infinite amount of energy. So do not talk about time travel in front of Einstein. However, Hawking tell us that although it is not verified, it cannot be ruled out. There are different theories that suggest we can travel in time and also move back in time. There may be some phenomena in which time and space can be bend or warped. By riding these warps we may be able to travel in time and space.

1. Will AI outsmart us?

This is one of the question that has been in the community since the concept of AI was created. According to Moore’s law, the speed and processing capacity of computers double every 18 months. But this has been depleted since computers are not growing in the same rate. However, AI has been developing in a fast rate. If learning capacity of computers increase in the same way, then at some point they may become able to create AI which are more intelligent than them and this process will continue until AI become intelligent than humans. Human’s evolution is slow but computers evolve fast. There may come a time when human have to hit the kill switch of the intelligent computers. But may the time not be as late when the computers can fuse out their kill switch.

1. Earth and Space

Are there other intelligent life in the universe? Will we survive on earth? Should we colonize space? These are the question no one knows answers to. We may not know what will happen to earth in few 100 years. We may go extinct as the dinosaurs. The nuclear war may end all the lives on the earth. Diseases may end our race. So we have to think about the alternatives other than the earth. We should explore the universe, try to understand what is in vault for us. Without these things we will be like castaways in an island never trying to return home. They may be some planet habitual like earth on far away galaxies. They have have their own race, culture and innovations. We have to thing for long term. Traveling to other galaxies may take 1000 years but we should do the starting. We have traveled to moon. Mars is the next destination. We should keep looking for what we don’t know.

This was a short summary of the book. The book has a lot more than that is listed here. You can get a lot of knowledge about physics and the nature of physics. I will highly recommend this book if you are into physics and into astronomy too.

I will rate this book 3.5/5.

Thanks 🙂