Here is a fact: light is essential to life on Earth. Plants, and the cycle of oxygen itself, are based on photosynthesis, even though we’ve discovered organisms in the dark depth of oceans relying instead on chemicals to survive. Light, however, is so essential that one of the anticipated technological revolutions is artificial photosynthesis. Yes, a man-made process to do what plants do in nature: producing energy by light.
Energy production from sunlight is not a novelty – after all, solar energy is one of the most popular forms of renewable energy sources. But scientific research seems now in the process of going deeper into the photosynthesis mechanics itself. For a few years now, UK projects have shown that it’s possible to improve natural photosynthesis and make it more efficient in order to produce new fuels and enhance crop production. One of the teams even tried a synthetic biology approach, with the aim of creating an artificial “leaf” that would convert the sun’s energy into liquid fuel.
“The sun gives its energy away for free but making use of it is tricky. We can use solar panels to make electricity but it’s intermittent and difficult to store. What we are trying to do is take the energy from the sun and trap it so that it can be used when it is needed most.” (Richard Cogdell, University of Glasgow)
And it’s news of this week that researchers at Caltech University have developed an electrically conductive nickel oxide film that, using a chemical process similar to natural photosynthesis, could help create devices for harnessing sunlight and create fuel. That is, a photocatode capable of splitting water into a usable (hydrogen) fuel. While commercial products based on this technology might still be far away in time, this prototype is a fundamental stepping stone.
“What we have to do is combine both of these elements together and show that the entire system works. That will not be easy, but we now have one of the missing key pieces that has eluded the field for the past half-century.” (Nate Lewis, Caltech)
But there’s even more. A couple of recent experiments have shown that it’s also possible to “synthesize” matter from light itself. The theory is, again, known since at least 80 years in quantum physics; Gregory Breit and John Wheeler, the two scientists that first wrote about it, believe that – very rarely – two particles of light, i.e. photons, do combine and generate an electron (together with its antimatter twin, a positron). But they also thought that, in practice, the conversion of light into matter would prove impossible to perform in the controlled environment of a laboratory. This was proved wrong just last year, in an amazing experiment. From energy to matter to life itself, light seems truly at the core of all wonders.
“We have shown in principle how you can make matter from light. If you do this experiment, you will be taking light and turning it into matter.” Steven Rose, Imperial College of London
Photo Credit: How Stuff Works; Lance Hayashida/Caltech Marcomm; Hemera/Thinkstock