Living things on the earth share so many traits it is hard to imagine how life could be differently assembled using molecules unlike DNA, proteins, and lipid membranes. In fact, the known elements particularly those that are used in biochemistry limit the reactivity and functionality of molecular structures to the elements we know are used by living things. Carbon, oxygen, nitrogen, sulfur, hydrogen, and many salts and ions like calcium, sodium, magnesium and iron have very specific roles in the molecular structures that function in cellular life. Carbon is the backbone of all organic compounds, reactions occur between nitrogen, hydrogen, oxygen, carbon, phosphorous, and sulfur. Many associations with calcium, iron and magnesium cause biomolecules to restructure themselves, either activating or deactivating their biochemistry.
With this astounding knowledge about living things, why would anyone care to speculate on chemistries that are known not to occur in the real world? That is, what is the motivation behind imagining a living system composed of elements that simply can not undergo reactions needed for life to occur? Doesn’t this sound like imaginative daydreaming? Imagine elephants with wings. Could such a beast fly? Obviously not so why would any scientists imagine that they could? There are known laws of physics that make flight possible. The Wright brothers determined the principles of aerodynamics and the mechanics of flight. They found that there are a limited number of ways to assemble a flying machine. All are based on their discoveries of how birds maneuver in the air. The Wright brothers patented their discovery of these laws of physics and became quite wealthy. No one has yet discovered laws that contradict their discoveries. This is why all airplanes and jets fly off of those same principles of aerodynamics.
But recently, with all the speculation about life on other planets, moons, and even comets, serious scientists have begun to imagine how biology might exist on worlds that are so unlike the Earth that we are certain that carbon-based life would not survive for more than seconds.
Science Daily said this:
“Taking a simultaneously imaginative and rigidly scientific view, chemical engineers and astronomers offer a template for life that could thrive in a harsh, cold world — specifically Titan, the giant moon of Saturn. A planetary body awash with seas not of water, but of liquid methane, Titan could harbor methane-based, oxygen-free cells.”
From the Huffington post: NASA really wants to explore Saturn’s Moon Titan – and for good reason. For one thing, it is the only other world in our solar system which has liquid lakes on the surface. Yes, those lakes are made up of liquid ethane, or methane, which isn’t ideal for swimming to put it mildly. It’s also far colder than Earth, has a thick and poisonous hydrogen cyanide atmosphere and possibly even deep below-surface oceans of water and ammonia.
But it’s possible that the moon contains life (its atmosphere is full of organic compounds) and so it’s a prime target for further study by other means.
Titan is believed to have oceans of liquid methane, not water. the temperature of liquid methane is -292 Celsius. This is 292 degrees below the freezing point of water. Paulette Clancy and first author James Stevenson, a chemical engineer, conceived of a membrane composed of carbon, nitrogen and hydrogen molecules that are abundant on Titan, a moon of Jupiter. The microscopic sphere they conceived of would have a membrane not of lipids but of molecules based on carbon as a backbone. This means it is organic chemistry, which is often used as a misnomer for biochemistry. The sphere, if it could form in real life, would be smaller than our known virus’ and it would be hollow. Their idea is that the hollow sphere could act as a “cell” and contain the organic chemistries needed for life much like our own cells made of lipid molecules are packed with the biochemistry of life. Virus’ are so small that they cannot pack the needed chemistries for metabolism to occur independently of infecting a host cell a hundred thousand times larger than itself.
Model of the acrylonitrile sphere.
These young scientists at Cornell University have stretched their imaginations to the limits of practical thought and conceived of a way they believe cellular life might arise on such a world devoid of oxygen and water. Though everything we know about life requires oxygen and water, here is one stretch of the imagination that conceived of nonbiological structures that might exist on other worlds. There are so many biochemical and cellular facts ignored in this attempt at conceiving of how life might exist “not as we know it” that it really comes down to being a useless excuse to get published. Amazingly, this simulation of a synthetic membrane did get published.
Another hoaky science. I can’t wait for global warming to be real.
Who cares and why am I making noise about this work? Because this is not science. Yet it stirs the imaginations of evolutionary biologists and astrobiologists to step over the borders of science and into fairy tales. Science is neglected for vain imaginations all to create the illusion that life could have evolved elsewhere without the benefit of what we know to be true. Does this sound strange? In time, such research will become the references for grants or for budgets to send spaceships to Titan and other targets in our solar system for the purpose of searching for life. I too want to explore the solar system and if possible, turn science fiction into fact but not at the expense of sanity. Decisions should not be based on false premises or phony biology. Curiosity should be enough to entice our exploration; finding out first hand what the universe is made of and what is real should be our driving force not phony science.
Right on the money as always! The scary part about bad science (maybe not entirely, but pretty close) is not that its incorrect, but that people will follow, make decisions, and/or create policies based on these “findings.” Then we all have to live with their bad science! Great read.