  urlLink Taming the multiverse Parallel universes are no longer a figment of our imagination. They're so real that we can reach out and touch them, and even use them to change our world, says Marcus Chown. [...] But how is it that atoms can be in many places at once whereas big things made out of atoms-tables, trees and pencils-apparently cannot? Reconciling the difference between the microscopic and the macroscopic is the central problem in quantum theory. The many worlds interpretation is one way to do it. This idea was proposed by Princeton graduate student Hugh Everett III in 1957.
According to many worlds, quantum theory doesn't just apply to atoms, says Deutsch. "The world of tables is exactly the same as the world of atoms. " But surely this means tables can be in many places at once. Right. But nobody has ever seen such a schizophrenic table. So what gives? The idea is that if you observe a table that is in two places at once, there are also two versions of you-one that sees the table in one place and one that sees it in another place.
The consequences are remarkable. A universe must exist for every physical possibility. There are Earths where the Nazis prevailed in the Second World War, where Marilyn Monroe married Einstein, and where the dinosaurs survived and evolved into intelligent beings who read New Scientist. This article came out some time ago - it's really only for my own reference that I'm putting the link here.
Follow the links to the left for a layman's guide to quantum physics. The idea of a multiverse is mind-boggling, but gives rise to all these amazing possibilities. There's an alternate universe, where Cindy is perhaps a suffering slave to Cockroach King of Siberia (or a place known as Siberia to us). Or a Cindy may not exist, for my mother had chosen to marry not my father but that Malay suitor she always proudly talked of. Hmmmm. 
