The Nine Greatest Enigmas in Physics


Jim Al-Khalili is about to untangle the world's greatest science conundrums...

How does the fact that it gets dark at night prove the Universe must have started with a big bang?

Where are all the aliens?

Why does the length of a piece of string vary depending on how fast it is moving?

Our subject is 'perceived paradoxes' - questions or thought-experiments that on first encounter seem impossible to answer, but which science has been able to solve.

Our tour of these mind-expanding puzzles will take us through some of the greatest hits of science - from Einstein's theories about space and time, to the latest ideas of how the quantum world works. Some of our paradoxes may be familiar, such as Schrödinger's famous cat, which is seemingly alive and dead at the same time; or the Grandfather Paradox - if you travelled back in time and killed your grandfather you would not have been born and would not therefore have killed your grandfather. Other paradoxes will be new to you, but no less bizarre and fascinating.

In resolving our paradoxes we will have to travel to the furthest reaches of the Universe and explore the very essence of space and time. Hold on tight.


  • The wizardry of Jim Al-Khalili is irresistible. Marvel at the mind-bending Zeno’s paradox! The amazing ambiguity of Schrödinger’s Cat! The preposterous postulations of perpetual motion! The extraterrestrial extrapolations of Fermi’s paradox! and other wonders of physics, philosophy, even poetry. “I have had tremendous fun writing this book,” says Professor Jim. Reading it is the best fun you can have beyond a pop-science comic book and a home particle accelerator
    The Times

About the author

Jim Al-Khalili

Professor Jim Al-Khalili, OBE FRS, is a physicist, author and broadcaster based at the University of Surrey. He received his PhD in theoretical nuclear physics in 1989 and has published over a hundred research papers on quantum physics.
His many popular science books have been translated into twenty-six languages. He is a recipient of the Royal Michael Faraday medal and the Institute of Physics Kelvin Medal.
In 2016 he received the inaugural Stephen Hawking Medal for Science Communication. He lives in Southsea, Hampshire, with his wife Julie.
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