What is the true nature of reality? To find out, Nobel Laureate Anton Zeilinger takes us (along with his fictional students Alice and Bob) on a voyage through a quantum wonderland, explaining entanglement, teleportation, time-travel paradoxes and why our view of the world must change.

Originally published in America in 2012, a new Afterword in the light of the author's 2022 Nobel Prize means the book brings readers up-to-date with the most recent developments in quantum teleportation. This describes the author's collaboration to perform the first intercontinental video call encrypted using quantum cryptography, and how Chinese scientists teleported entangled quantum states to an orbiting satellite. Readers also learn how both volunteer humans and astronomical objects billions of light years away have been part of experiments to conclusively prove that quantum states cannot provide a full description of reality at a local level.

Einstein had always refused to accept aspects of quantum theory, deriding the notion of instantaneous communication between faraway 'entangled' particles as 'spooky action at a distance'. However, this playful yet deep book takes readers through a series of ingenious experiments conducted in various locations that demonstrate entanglement is indeed real, and speculates that information is an essential part of reality.

From a dank sewage tunnel under the River Danube to the balmy air between a pair of mountain peaks in the Canary Islands, with various time-travel paradoxes explained along the way, the author and his fictional physics students Alice and Bob demonstrate the true nature of quantum entanglement and teleportation using photons, or light quanta, created by laser beams. The ideas described have laid the foundations for a new era of quantum technology, including the development of quantum computers and much more.