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A Universe from Nothing
Why There is Something Rather than Nothing
- Read in 15 minutes
- Audio & text available
- Contains 10 key ideas
Synopsis
Krauss describes the new scientific theories and observations that demonstrate how the universe could have spontaneously arisen from nothing. He makes the case that this is not only plausible, but inevitable. Krauss presents evidence to show how the universe began and evolved, and theorizes about its ultimate end.
Key idea 1 of 10
Einstein’s theory of relativity linked space and time into spacetime, and showed that massive objects could distort it.
For centuries, Newton’s theory of gravity was thought adequate to explain the motion of all matter in our universe. But in the early 20th century, in order to explain the previously mysterious gravitational behavior of very large and very distant objects, Einstein published his theory of relativity. The theory (made up of the theories special and general relativity), revolutionized physics and allowed cosmologists to examine and understand our universe in completely new ways.
Special relativity is Einstein’s theory about the structure of spacetime. It established that space and time are not discrete entities but are interlinked so that the speed at which time passes is relative to the speed at which an object moves. The theory also postulates that nothing can travel faster than the speed of light.
Special relativity also demonstrated that matter and energy are interchangeable. Matter can turn into energy and vice versa, as described by the famous equation E=mc2.
General relativity is Einstein’s theory of gravitation, which showed that massive objects distort spacetime. In the same way that a marble laid upon a very thin sheet of rubber causes the rubber to bend, heavy objects cause spacetime to bend. The larger the object, the more the rubber (or spacetime) around it bends and the more it pulls in surrounding objects.
This warping of spacetime is confirmed by a phenomenon called gravitational lensing: when light travels close to a massive object, such as a black hole, the spacetime “valley” created by the object can bend the light around the object. Astronomers use this method to study stars and galaxies behind massive objects.
Einstein’s theory of relativity linked space and time into spacetime, and showed that massive objects could distort it.
Key ideas in this title
- Einstein’s theory of relativity linked space and time into spacetime, and showed that massive objects could distort it.
- Scientific evidence confirms that the universe is expanding, and that this expansion is accelerating.
- Scientific evidence confirms that the universe originated in the Big Bang 14 billion years ago.
- Scientific observation confirms the universe is flat: its expansion will slow down gradually.
- Empty space is not empty: it is dominated by invisible dark energy and dark matter.
- Even supposedly empty space is full of spontaneously generated virtual particles annihilating each other.
- The universe likely began as a tiny region of empty space that inflated rapidly.
- One day the universe will have expanded so much that we will perceive nothing but our own galaxy.
- Science tailors its theories to observation, while theology tries to make the universe conform to preconceived beliefs.
- Final summary
