Lord Kelvin
In 1900 the great physicist Lord Kelvin (William
Thomson) announced that everything that could be known was known in the field
of physics. There were only two “small
clouds” on the horizon which he believed would soon be cleared away: the failure of the detection of the “ether,”
(the Michelson and Morley experiment), and the explanation of the spectrum of
the so-called black body radiation, the radiation given off by heated
materials. He couldn’t have been more
wrong. The absence of the ether gave
rise to Einstein’s theory of relativity,
and the second problem spurred the development of quantum theory, both theories
that are viewed as the core of the revolution in physics at the beginning of the 20th
century.
Now scientists, including the French physicists Gilles Cohen-Tannoudji and Sylvain Hudlet argue that we are
on the verge of a new revolution in physics.
Today, physicists and astrophysicists are faced with much bigger
‘clouds’ than those perceived by Kelvin.
The first one is that both relativity and quantum theory are valid in
their own domain, but are not represented by a single theory. The second unresolved problem is the nature
of dark matter and dark energy. Another
conundrum is what exactly caused the “inflation” of the universe right after
the Big Bang, an idea needed to explain the structure of the universe.
For many years now scientists have tried to develop a
Grand Unification Theory (GUT), also known as a theory of everything, that would reconcile gravitation and
relativity with the quantum world, more specifically, the Standard Model of
particles and their interactions. One of
the current attempts is string theory, which tries to build up a model of the
universe on mathematical principles.
However, a growing number of
physicists have started viewing the idea of unifying quantum theory with
gravitation as doomed to fail. They
argue that both space and gravitation are not fundamental but emergent phenomena, reflections of a yet
hidden reality. Emergence, the idea that
a physical system can have properties that aren’t just the combination of the
properties of its components, but are new. The existence of “emergent” properties is now increasingly,
albeit reluctantly, accepted by the scientific community.
In this blog I will explore the telltale signs that a
revolution in physics is imminent. I will talk to physicists and
astrophysicists whose research on open
questions in physics might contain the
seeds of the next scientific revolution. Stay tuned to this blog...
