One of the fascinating questions about life on Earth is how did it get here in the first place? There are a vast number of theories ranging from the mundane to the outright fanciful, but most scientists gravitate to what they see as elegant ideas. That is, scenarios which don’t require anything “special” to have happened.
But can things simply create themselves out of nothing? Professor Nail Akhmediev from the ANU Research School of Physics and Engineering believes they can and indeed did in the case of life on Earth. Professor Akhmediev’s background is solitons; a special class of wave which can persist for long periods.
“You might not think that solitons would have anything to do with life on Earth,” Professor Akhmediev says, “But think about a single celled organism such as an algae for a moment. It takes in energy in the form of sunlight, it takes in materials in the form of food and so long as the flow of these two things persist, it’s alive. The dissipative solitons have very similar properties, they consume energy and materials and whilst the supply of these two things continues, the localized soliton wave remains ‘alive’.”
But one thing that does distinguish dissipative solitons from cells, is that solitons can be completely described by mathematics. “Something as complicated as a cell has so many parts and processes describing it in an exact mathematical way would be almost impossible.” Professor Akhmediev explains, “But with solitons we can do just that.”
The importance of an exact mathematical treatment is that the results you get are certain. With numerical models like those used in climate research, the answers you get out are statistical and as we see every week in the media, open to debate. With an exact model, the result is an answer, not a probability. If 3X=6 then X=2 and not 2.2, not 1.8 just 2.
“We have seven parameters in our equations that we can vary and what we find is that over a surprisingly broad range of values, dissipative solitons will simply spontaneously create themselves. There’s no need for any special external input, you just provide the energy and matter then self sustaining solitons will just happen.”
The similarities between solitons and living things don’t end there. Solitons can bifurcate, essentially reproducing themselves. Amazingly enough, they can also get sick. “If the flow of energy or matter is reduced what we see is the soliton begin to oscillate and if it is interrupted, just like cells, they die.” The nature of the solitons also changes in response to changes in their environment in a process very like evolution.
But how like-life can a wave really be? “Obviously cells are far more complex, but what we’ve proved mathematically is that when the conditions are right, localized self sustaining entities can be spontaneously created.” Professor Akhmediev says.
What this all tells us is that in a situation where you have energy and matter localized entities that consume, excrete and multiply are essentially an inevitability. So on any planet like the Earth with benign conditions, if you wait long enough, you’ll get life.
What makes this work especially interesting at the moment is that with advances in spaceflight and massive new generation telescopes we may soon be able to test the idea directly. If Professor Akhmediev and his solitons are right, the universe should be teeming with microbial life!