Because Physics! The origin of life on Earth

Space.com reports on a new theory about how “abiogenesis” (the transition of ordinary stuff like water and dirt containing molecules into “life”) might have started on Earth. Previous theories suggest that the first self-replicating life form probably came to be randomly in some kind of primordial soup. But some interesting new theories have emerged that suggest that this process wasn’t random at all and was actually bound to happen because of two special thermodynamics concepts known as “entropy” and “equilibrium”.

Entropy is defined as “lack of order or  predictability; [a] gradual decline into disorder”. A system in a high state of entropy is in an “energetic” state, with atoms that are vibrating, excited, and interacting a lot. The opposite of Entropy is Equilibrium; at absolute zero (minus 273.15 degrees Celsius), atoms stop moving altogether, and are in a state known as a “cold death”. As time goes on, unless gravity takes over, all physical systems are eventually doomed to reach a state of equilibrium and the Universe will become cold and lifeless.

“Stop ranting you fat nerd!” I hear you cry. Here’s the tie-in: the new theory suggests that life might be the eventual outcome of the laws of thermodynamics because self-replication (or reproduction) – a key feature of all known life – “is also a very efficient way of … increasing entropy in [a] system.” Bio-molecular systems are designed to keep entropy going, just like your own body is always trying to maintain a constant temperature of 37 degrees Celsius. So the theory is suggesting that physics likes entropy so its rules are designed to keep it going. So here you is!

The Space.com article proposes “a cooling cup of coffee left on a desk”, which instead of going cold, uses chemical reactions to “self-organise” itself to keep a center pocket of liquid within the cup warm. It is this physical self-organisation that could lead to reproduction for the sake of maintaining entropy. “Some physical systems may be sufficiently out of equilibrium that they “self-organize” to make best use of an external energy source, triggering interesting self-sustaining chemical reactions that prevent the system from reaching thermodynamic equilibrium and thus maintaining an out-of-equilibrium state.” And a system replicating itself leads to lots of individual warm spots.

If this theory were to be somehow proven, it would not only solve the mystery of how life got started on our planet, but it would have huge implications for search for extraterrestrial life. Since the laws of physics are thought to be the same everywhere in the Universe, life would have popped up where there are any “physical systems may be sufficiently out of equilibrium” to “self-organize” and reproduce. Now, that’s a lot of aliens!

 

 

 

 

We Might Have Just Come a Step Closer to Solving the Mystery of Life

A popular theory in science is that life got started when a bunch of molecules randomly bumped together in a bubbling pool of water heated by a volcanic vent roughly 3.8 billion years ago. Now Some chemists at Cambridge have come close to explaining how that might have been possible:

Sciencemag.org reports:

“DNA is better known, but many researchers today believe that life on Earth got started with its cousin RNA, because that nucleic acid can act as both a repository of genetic information and a catalyst to speed up biochemical reactions. But those favoring this “RNA world” hypothesis have struggled for decades to explain how the molecule’s four building blocks could have arisen from the simpler compounds present during our planet’s early days. Now, chemists have identified simple reactions that, using the raw materials on early Earth, can synthesize close cousins of all four building blocks. The resemblance isn’t perfect, but it suggests scientists may be closing in on a plausible scenario for how life on Earth began. “