The Fabric of the Cosmos: 8 key ideas
The core ideas of The Fabric of the Cosmos, each in under a minute, written in our own words. Want the full depth? Get the book.
- IDEA 1 OF 8
Space and time are puzzling
Greene asks what space and time really are, questions that seem simple but have puzzled physicists for centuries.
He takes readers through the major theories that have changed our understanding of them.
- IDEA 2 OF 8
A spinning bucket raises questions
Greene describes Newton's bucket experiment, in which water in a spinning bucket curves upward.
He uses it to explore whether space is a real thing or just a relation between objects.
- IDEA 3 OF 8
Now differs for different observers
Greene explains that, according to Einstein, observers moving differently disagree about which events happen at the same time.
This suggests that past, present and future may all be equally real.
- IDEA 4 OF 8
Entangled particles stay linked
Greene describes quantum entanglement, in which two particles remain connected so that measuring one instantly affects what we find for the other, however far apart they are.
This challenges ordinary ideas of space.
- IDEA 5 OF 8
Disorder gives time its direction
Greene explains that entropy, a measure of disorder, tends to increase.
He argues that time seems to flow one way because the universe began in a very orderly state. A broken egg does not put itself back together.
- IDEA 6 OF 8
The early universe expanded rapidly
Greene describes inflation, the theory that the universe expanded extremely fast in its first instant.
This would explain why the universe looks so smooth and even on large scales. Tiny early variations could then have grown into galaxies.
- IDEA 7 OF 8
An invisible field gives mass
Greene describes the Higgs field, which fills space and gives many particles their mass.
Empty space, in this view, is not truly empty but filled with fields. Without it, many particles would have no mass.
- IDEA 8 OF 8
Reality may be a hologram
Greene discusses the holographic principle, the idea that everything inside a region might be described by information on its boundary.
He presents it as a strange but serious possibility. The idea hints that our familiar three-dimensional world might be a kind of projection.
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