Spooks in space

POP. What are the chances that an everyday object – a rock, a chair, you name it – could suddenly appear out of thin air? Not zero, surprisingly. In fact, given enough space and time, it is conceivable that a conscious being could arise, even if only for a microsecond.

OK, such an event would be incredibly unlikely, but not impossible – at least in theory. Physicists have dubbed such hypothetical beings “Boltzmann brains”, after the 19th-century Austrian physicist Ludwig Boltzmann, a pioneer in thermodynamics and statistical mechanics. Boltzmann posed the question of whether the universe could have arisen from a thermal fluctuation; his work presaged the idea that a fluctuation could also give rise to a conscious entity that sees the universe. In this regard Boltzmann brains are not necessarily actual brains, but rather are a metaphor for observers of the universe that might appear spontaneously.

The idea sounds absurd, but ...