Physicists have created spheres of gas that almost qualify as life. On the scale of weirdness‚ genetically modified organisms and artificial intelligence pale in comparison.
The scientists‚ led by Dr. Mircea Sanduloviciu of Cuza University in Romania‚ created a low temperature plasma of argon gas—a mixture in which some of the argon atoms have split into positively charged ions and negatively charged electrons. They then inserted electrodes into the gas and sparked the chamber with electricity. Spheres of gas formed spontaneously‚ with a layer of positively charged ions on the inside and negatively charged electrons on the outside. The spheres were filled with normal argon gas atoms. The researchers were able to create bubbles as small as only a few micrometers in diameter‚ to as large as a few centimeters in diameter.
These spheres are capable of more than just floating around their chamber‚ however. The scientists say that they can split in two‚ like a bacterium divides into two daughter cells. They apparently are also capable of growing—under the right conditions they can turn normal argon atoms into plasma‚ which is then used to expand the boundary of the sphere. Even more remarkable‚ the spheres are purportedly able to communicate. By emitting electromagnetic energy‚ the spheres could make the atoms inside of other spheres vibrate at a specific frequency. The results of this experiment appear in the 2003 issue of Chaos‚ Solitons‚ and Fractals (volume 18).
For something to be considered alive it has to meet five requirements: it must have a clearly marked boundary separating itself from its environment‚ it has to be able to reproduce‚ grow‚ communicate information‚ and it has to have some kind of inherited genetic information‚ like DNA‚ that it can pass on to offspring.
These spheres meet only the first four criteria‚ so they aren’t alive in the traditional sense. This doesn’t mean however that they don’t constitute some form of life‚ in an expanded sense. Viruses for example aren’t technically alive‚ as they can only reproduce when they have a host cell to use‚ but they meet all the other criteria for life‚ including having their own genetic material.
More importantly however‚ these spheres may help to expand our understanding of the origins of life.
It is thought that life began about 3.7 billion years ago‚ when the Earth’s atmosphere was rife with the gases methane‚ ammonia‚ and carbon dioxide. Electrical storms were frequent at this time‚ and electrical energy may have sparked the formation of the first biological molecules in pools of water (i.e. complex molecules that are created and used by living organisms‚ like sugars‚ or nucleotides‚ the building blocks of DNA). In a now famous experiment conduced in the 1950s‚ Stanley Miller shot an electric current through a mixture of water‚ ammonia and methane. He was able to create several different kinds of complex organic molecules‚ including amino acids‚ which are the building blocks of proteins.
Biomolecules aren’t only found on Earth however. Sugar and alcohol have been found in deep space. An amino acid was also detected in a cloud of gas and dust in deep space last year by scientists at the National Taiwan Normal University. German scientists found earlier last year that amino acids can be generated in deep space simulators‚ by irradiating a mixture of gases and ice with UV light. NASA scientists were also able to create bits of material similar to cell membranes using deep space simulators.
Scientists have been finding amino acids in meteorites for decades. They have found over 70 different amino acids on meteorites. Only about 20 amino acids are used by living organisms on earth.
Europa‚ one of Jupiter’s moons‚ is covered with ice‚ underneath which is believed to lie an ocean of liquid water. The Galileo space probe (which ended it’s 14–year career this Sunday‚ see brief) has detected yellow–brown stains on the surface of Europa‚ possibly implicating the presence of organic substances. Moreover‚ scientists at NASA found that simulating meteor impacts on Europa by shooting aluminum bullets into blocks of ice could generate electrical sparks.
So the potential for life to have evolved elsewhere in the universe as it has on Earth is quite high. Some even surmise that life on Earth was spawned by asteroids carrying biomolecules or even bacteria.
While the synthesis of biomolecules can occur rather quickly‚ the evolution of a living cell is thought to have taken millions of years through an incredibly complex process.
But these new argon spheres take only a few microseconds to form. Dr. Sanduloviciu and his colleagues believe that they have not simply created some new form of pseudo–life—they think they might have found the origin of life on earth. The early atmosphere on Earth was full of ionized gases like the argon gas used in this experiment‚ due to the prevalence of electrical storms. The Romanian scientists postulate that these spheres could have in fact been the starting point for the evolution of life on earth.
Most scientists won’t be swayed to this theory any time soon—the gas bubbles can only be created at temperatures too high for other biomolecules to be synthesized. But these gas bubbles‚ should they stand up to scientific peer review‚ certainly challenge the definition of exactly what constitutes a living thing‚ and raise the number of possibilities for how life could have emerged elsewhere in the universe.