Does the existence of a multiverse hold the key for why nature’s laws
seem so simple?
It’s May 1964 and, on a low hillside in New Jersey, the physicists
Robert Woodrow Wilson and Arno Allan Penzias are listening in on the
Universe. They are standing beneath what looks like a gargantuan ear
trumpet attached to a garden shed: the Holmdel Horn Antenna, built by
Bell Laboratories to investigate microwaves as an alternative to radio
waves for telecommunication. When interest in microwave communication
waned, Bell lent out the Holmdel horn to interested scientists.
Penzias and Wilson were interested. Both aged around 30, they planned to
map the sky with microwaves. But they were baffled: when they pointed
the horn at a dark region beyond the galaxy and only sparsely populated
with stars, instead of the silence they expected, they detected a kind
of background hiss – a hiss that filled the entire sky.
Meanwhile, the physicist Robert H Dicke was working on a related puzzle.
Two decades earlier, Dicke had invented the microwave detector. Now he
and his lab were trying to develop sensitive instruments to test the
cosmological predictions that emerged from Albert Einstein’s general
theory of relativity, particularly how it related to Edwin Hubble’s
astonishing discovery that the Universe is expanding. The reigning,
steady-state theory claimed that the Universe had always been expanding,
balanced by a continuous creation of new matter. The rival theorists,
including Dicke, took expansion at its face value, running it backwards
in time to propose that, about 14 billion years ago, the Universe burst
into existence in a cataclysmic explosion from a very tiny point.
An exploding universe should have left a uniform faint cloud of
microwave radiation, which Dicke’s team was determined to find. News of
the group’s efforts reached Penzias and Wilson, prompting Penzias to
give Dicke a call. Over a brownbag lunch, Dicke’s colleagues recall him
picking up the receiver, repeating phrases such as ‘horn antenna’ and
nodding. After hanging up, he turned to his group and said: ‘Well boys,
we’ve been scooped.’ Dicke realised that Penzias and Wilson had
discovered the Big Bang....