"Greg Egan - Mitochondrial Eve" - читать интересную книгу автора (Egan Greg)

A few weeks later, I found myself showing Lena around the basement of the UNSW
physics department, where my own research equipment was crammed into one
corner. It was late at night (again), and we were alone in the building;
variously coloured fluorescent display screens hovered in the darkness, like
distant icons for the other post-doctoral projects in some chilly academic
cyberspace.

I couldn’t find the chair I’d bought for myself (despite security measures
escalating from a simple name tag to increasingly sophisticated computerised
alarms, it was always being borrowed), so we stood on the cold bare concrete
beside the apparatus, lit by a single fading ceiling panel, and I conjured up
sequences of zeros and ones which echoed the strangeness of the quantum world.

The infamous Einstein-Podolsky-Rosen correlation – the entanglement of two
microscopic particles into a single quantum system – had been investigated
experimentally for over twenty years, but it had only recently become possible
to explore the effect with anything more complicated than pairs of photons or
electrons. I was working with hydrogen atoms, produced when a single hydrogen
molecule was dissociated with a pulse from an ultraviolet laser. Certain
measurements carried out on the separated atoms showed statistical
correlations which only made sense if a single wave function encompassing the
two responded to the measurement process instantaneously – regardless of how
far apart the individual atoms had travelled since their tangible molecular
bonds were broken: metres, kilometres, light-years.

The phenomenon seemed to mock the whole concept of distance – but my own work
had recently helped to dispel any notion that EPR might lead to a
faster-than-light signalling device. The theory had always been clear on that
point, though some people had hoped that a flaw in the equations would provide
a loophole.

I explained to Lena, “Take two machines stocked with EPR-correlated atoms, one
on Earth and one on Mars, both capable of, say, measuring orbital angular
momentum either vertically or horizontally. The results of the measurements
would always be random… but the machine on Mars could be made to emit data
which either did, or didn’t, mimic precisely the random data coming out of the
machine on Earth at the very same time. And that mimicry could be switched on
and off – instantaneously – by altering the type of measurements being made on
Earth.”

“Like having two coins which are guaranteed to fall the same way as each
other,” she suggested, “so long as they’re both being thrown right-handed.
But if you start throwing the coin on Earth with your left hand, the
correlation vanishes.”

“Yeah – that’s a perfect analogy.” I realised belatedly that she’d probably
heard this all before – quantum mechanics and information theory were the
foundations of her own field, after all – but she was listening politely, so I
continued. “But even when the coins are magically agreeing on every single