Renowned bongo-playing, Nobel-prize-winning theoretical physicist Richard Feynman would have been 100 this year. But what he described in a famous series of lectures to undergraduates at the California Institute of Technology as the central mystery 鈥� indeed the 鈥渙nly mystery鈥� 鈥� of quantum theory remains unsolved even now, 30 years after his death.
Now Feynman鈥檚 successor at Caltech, physicist , is flying in to this year鈥檚 festival to help us get to grips with the mystery 鈥� and its startling implication that everything, including us, might exist in multiple copies in countless parallel universes.
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Sound more sci-fi than sci-fact? Well, the problem starts with a basic experimental fact: that the building blocks of reality such as fundamental particles, and the atoms built with them, don鈥檛 behave like objects in the world around us.
Sometimes they do, existing in a specific time and place. But sometimes their existence seems altogether fuzzier鈥� they appear, somehow, to be in several places at once, as if they were waves rippling through reality.
Most strangely of all, which guise they show themselves in seems to depend entirely on how we choose to look at them. Demand through a measurement that they should appear at a certain point in a certain way and they will 鈥� even though they were clearly not there before.
Dead and alive?
That idea that we as conscious beings somehow have some role to play in making reality sends cold shivers down many physicists鈥� spines. It was famously mocked by the quantum pioneer Erwin Schr枚dinger with his thought experiment about a cat that is both dead and alive before we open a box to check how it鈥檚 doing.
The quantum many worlds hypothesis is just one of many potential solutions physicists have devised to spare their blushes. It鈥檚 equivalent to saying that Schr枚dinger鈥檚 cat is always both dead and alive at the same time. When we make a definitive measurement of it, or any quantum object, we split the universe into two copies of itself, one in which the cat is alive, and one in which it is dead.
And of course, we make two copies of ourselves in the process. Still not convinced? No problem 鈥� perhaps in a parallel universe there鈥檚 a copy of you that is.
麻豆传媒 Live is our award-winning festival of ideas and discoveries. It will run from 20 to 23 September at ExCeL London, and feature more than 120 speakers giving thought-provoking talks on everything from to .