A Brief History of Time

by Stephen Hawking

  • Will There Be An End to The Universe?

    There are three models obeying Alexander Friedmann’s assumptions that predict the future of our universe. The first of these models is that the expansion of the universe is slow enough that the gravitation attraction of various galaxies will slow down the expansion and eventually stop it. Eventual

  • Why is all this important?

    Although it may seem that much of physics is theoretical, impractical in real life, or perhaps cannot even be proven conclusively. But it is this same understanding of the universe that has led us to where we are today. We have come very far from where we began. And this is all thanks to our own

  • What is the unified theory of physics?

    Unfortunately, in physics, there are two main partial theories that describe the universe. These are, as mentioned, the general theory of relativity and quantum mechanics. As such, the main goal of theoretical physics is to unify these two theories. Unfortunately, so far, all attempts have failed a

  • Is time travel possible?

    One method of time travel is to attain a speed faster than the speed of light. According to the laws of the universe, that’s impossible. You would require an infinite amount of energy or have very little to no mass. Another method of time travel would be to jump into a wormhole. A wormhole is a th

  • What is time?

    From our experience, time only moves forwards. You can’t unbreak an egg. By the same logic that tells us the universe is expanding and so must have a beginning, then time itself must have a beginning too, right? We know that the general theory of relativity, or more specifically, gravity rules the

  • What are black holes?

    Black holes are something of a misnomer, considering that they are neither black nor holes at all. Rather, black holes are stars that are massive and compact enough to have so strong a gravitational field that light cannot escape it. This idea goes all the way back to 1783 as described by John Miche

  • What is the universe made of?

    In school, we’re taught that atoms are the smallest unit of matter. They cannot be divided any further and everything in the world is made of​ atoms. That’s not 100% accurate, because atoms themselves are made up of three components, which are protons, electrons, and neutrons. Unfortunately, it does

  • Quantum Mechanics

    Quantum mechanics is one of the partial theories that are being used by scientists to describe the universe. Rather than detail what happens on large scales like the theory of relativity, it handles small-scale phenomena. The emergence of quantum mechanics depends largely on the uncertainty princi

  • What is the general theory of relativity?

    Everyone presumably knows about Einstein’s most famous formula, E=mc2, but what does it mean? To start things off, E stands for energy, while m is mass and c is the speed of light. This is the theory of relativity. Although it seems simple, it can explain a great many things in the universe. For o

  • Was there a beginning of the universe?

    We now know that the universe began during what’s known as the Big Bang. This wasn’t so in the twentieth century when most people took it for granted that the universe was unchanging, having existed in that way forever and will remain as such. There were many proponents of this theory at the time.

  • What is a theory?

    There are a lot of things about the universe that we know to be true. For instance, that the Earth is round, that the speed of light is a constant, and that gravity is an attractive force that applies to everything. The thing is, not all of these can be proven directly by observation. Though simpl

  • What do we understand of the world?

    This book, written by one of the greatest thinkers of our time, seeks to simplify and explain to the general public some big ideas and concepts in the field of physics. According to Stephen Hawking, we as a species have come a long way in our journey to understand the world and the universe, that w

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