A few years back, a
remarkable new hypothesis made its way into the scientific zeitgeist – namely,
that life is an inevitable consequence of physics. The author of this concept,
an associate professor of biophysics at MIT named Jeremy England, has now
published the first major papers testing out this idea, and it’s looking like he
might be right on the money.
England’s hypothesis is a
key bridge between physics and biology. Although it’s not yet conclusively
proven, it potentially holds the key to answering one of the greatest questions
of all: Where did we come from?
Here’s what his work is
arguing. Thanks to the second law of thermodynamics, the universe is heading
towards a state of complete structural disorder. It’s tumbling towards a state
where everything is essentially the same no matter how the constituent parts
are arranged.
This is known as “maximum
entropy”, where everything on an energy level is balanced, everywhere.
Right now, though, there are
pockets of order, of low entropy – objects and things that cannot be atomically
rearranged and still be the same thing (planets and life, for example). They
are the exceptions to an increasingly disordered universe, something first
highlighted by Schrodinger’s seminal 1944 essay What Is Life?
Think of a pool of water
with three color dyes dropped in it. Initially, they remain as separate dots
far apart, but over time, the colors spread out, mix, and in the end, there’s
just one single color. That’s the universe; the dots, in this case, can be pockets
of biological life.
England is suggesting that
biology arises because, in certain environments – like on planets – where the
energy balance is so out of whack, physics guarantees that atoms rearrange
themselves to be able to deal with the chaotic flow of energy. These atomic
structures just happen to resemble what we refer to as “life”.
As England famously
said back
in 2014: “You start with a random clump of atoms, and if you shine light on
it for long enough, it should not be so surprising that you get a plant.”
Using cutting-edge computer
simulations, England and his colleagues dumped basic chemical compounds into an
early-Earth like environment and watched what happened.
The first paper, in
the Proceedings
of the National Academy of Sciences, shows that life-like structural
arrangements of atoms spontaneously arise. Importantly, biological inputs and
variables – the behavior of cells, the formation of DNA, and so on – weren’t
preprogrammed into the simulations.
The second, published in Physics
Review Letters, shows that when driven by an external energy source – the
Sun, in this case – these atoms rearrange themselves in order to absorb and
emit the energy more efficiently. Perhaps most remarkably, these life-like
structures started to copy themselves in order to better handle this energy
flow.
Just using the laws of
physics, life appears and replicates without needing anything other than a few
basic chemicals and the Sun. So – has the greatest question of all been
answered? Perhaps, but this is still a nascent hypothesis, one of several.
England has also received as
much praise for his inventiveness as he has attracted criticism for his
lackadaisical definition of “life”. Admittedly, life is defined pretty poorly,
but some are suggesting that the life-like arrangements seen in England’s work
are too abstract to be properly referred to as being “alive”.
It’s a compelling hypothesis
nevertheless, one that clearly shows order arising from a system trending
inexorably towards total disorder. If it’s correct, then it would be the most
significant addition to evolutionary theory since Darwin’s magnum opus was
first released.
Via Iflscience
Via Iflscience