General Discussion
Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region Forums‘Shadow Biosphere’ theory gaining scientific support
http://www.rawstory.com/rs/2013/04/13/shadow-biosphere-theory-gaining-scientific-support/Never mind aliens in outer space. Some scientists believe we may be sharing the planet with weird lifeforms that are so different from our own theyre invisible to us.
Across the worlds great deserts, a mysterious sheen has been found on boulders and rock faces. These layers of manganese, arsenic and silica are known as desert varnish and they are found in the Atacama desert in Chile, the Mojave desert in California, and in many other arid places. They can make the desert glitter with surprising colour and, by scraping off pieces of varnish, native people have created intriguing symbols and images on rock walls and surfaces.
How desert varnish forms has yet to be resolved, despite intense research by geologists. Most theories suggest it is produced by chemical reactions that act over thousands of years or by ecological processes yet to be determined.
Professor Carol Cleland, of Colorado University, has a very different suggestion. She believes desert varnish could be the manifestation of an alternative, invisible biological world. Cleland, a philosopher based at the universitys astrobiology centre, calls this ethereal dimension the shadow biosphere. The idea is straightforward, she says. On Earth we may be co-inhabiting with microbial lifeforms that have a completely different biochemistry from the one shared by life as we currently know it.
It is a striking idea: We share our planet with another domain of life that exists like the realm of fairies and elves just beyond the hedgerow, as David Toomey puts it in his newly published Weird Life: The Search for Life that is Very, Very Different from Our Own. But an alternative biosphere to our own would be more than a mere scientific curiosity: it is of crucial importance, for its existence would greatly boost expectations of finding life elsewhere in the cosmos. As Paul Davies, of Arizona State University, has put it: If life started more than once on Earth, we could be virtually certain that the universe is teeming with it.
Xipe Totec
(43,872 posts)Ways need to be found to determine whether or not the shadow biosphere exists, says Dimitar Sasselov, professor of astronomy at Harvard University and director of the Harvard Origins of Life Initiative. If you want a clue you can count up the amount of carbon that is emitted by living things cows, sheep, grass, plants, forests and all the planets bacteria. When you do, you find there is a discrepancy of around 5% when you compare the amount given off from Earths standard biosphere and the amount you find in the atmosphere.
In other words, there is slightly too much carbon dioxide in the atmosphere than can be explained by the emissions of standard lifeforms on Earth. There could be an error in these calculations, of course. Alternatively, the shadow biosphere could be responsible for this excess, says Sasselov.
Really?
Perhaps the emissions are coming from self-propelled metallic macro organisms that consume large chained hydrocarbons. We could call these creatures auto-mobiles.
randome
(34,845 posts)But I have no idea how they can possibly separate carbon from living things and gasoline-powered machines.
HereSince1628
(36,063 posts)snip
Another, quite independent way that we know that fossil fuel burning and land clearing specifically are responsible for the increase in CO2 in the last 150 years is through the measurement of carbon isotopes. Isotopes are simply different atoms with the same chemical behavior (isotope means same type) but with different masses. Carbon is composed of three different isotopes, 14C, 13C and 12C. 12C is the most common. 13C is about 1% of the total. 14C accounts for only about 1 in 1 trillion carbon atoms.
CO2 produced from burning fossil fuels or burning forests has quite a different isotopic composition from CO2 in the atmosphere. This is because plants have a preference for the lighter isotopes (12C vs. 13C); thus they have lower 13C/12C ratios. Since fossil fuels are ultimately derived from ancient plants, plants and fossil fuels all have roughly the same 13C/12C ratio about 2% lower than that of the atmosphere. As CO2 from these materials is released into, and mixes with, the atmosphere, the average 13C/12C ratio of the atmosphere decreases.
<more>
zeemike
(18,998 posts)It helps a lot....for us chemistry challenged.
randome
(34,845 posts)DCBob
(24,689 posts)1) invisible alien lifeforms
2) some yet to be identified ecological/chemical process
Most likely its number 2.
Cirque du So-What
(25,808 posts)toward the end of the article, it's mentioned that samples of desert varnish have barely been examined for evidence of cryptic organisms. I haven't yet ingested enough caffeine this morning in order to consider all the possibilities, but this seems to be a wide-open field for research. Hell, researchers still haven't gotten a firm grip on the nature of prions, for that matter. In any event, looking for 'alternative' lifeforms is just one example of why publicly-funded research is necessary. Corporations only get involved in basic research when they get a whiff of money to be made off of it.
exboyfil
(17,857 posts)From http://www.virology.ws/2004/06/09/are-viruses-living/
"Lets first define life. According to the online Merriam-Webster Dictionary, life is an organismic state characterized by capacity for metabolism, growth, reaction to stimuli, and reproduction.
Viruses are not living things. Viruses are complicated assemblies of molecules, including proteins, nucleic acids, lipids, and carbohydrates, but on their own they can do nothing until they enter a living cell. Without cells, viruses would not be able to multiply. Therefore, viruses are not living things."
I remember studying this when I Homeschooled my daughter in Biology. Prions can be characterized the same way.
http://scitechstory.com/2009/12/31/prions-not-alive-but-they-can-evolve/
"Prions are mostly protein. Although protein is a fundamental component of living cell material, prions are not alive. The behave something like viruses, without DNA or RNA yet able to reproduce by forcing living cells to do the reproduction for them."
Both of these replicate and are subject to evolution but are not "alive". You can wiggle out somewhat since they need the machinery of living organisms to reproduce and mutate.
Some examples of replication phenomenon in chemistry include crystals.
http://www.wired.co.uk/news/archive/2013-02/01/living-crystals
I think we are close to proving a plausible pathway for abiogenesis. We don't have to show the actual pathway because that has probably been destroyed by time, but any single pathway shows it is possible.
I would say examine the "varnish" with all tools we currently have available (direct observation being the most important as well as experiments changing the environment). Be prepared to argue whether it is just chemistry or truly life (which I would characterize as replicating and evolving without existence of current biosphere).
byeya
(2,842 posts)had been studied and nothing but chemistry was the answer at that time. When Indians, and later, early Euros, came into the area they scraped off some of the varnish to make designs and words, etc. Centuries passed(in the case of American Indians) and there
remained the bare sandstone indicating that the formation of desert varnish is an extremely slow process.
I'd go with chemistry until some real evidence is uncovered. What we have here is an hypothesis, an interesting one, but no more than an educated guess.
Robb
(39,665 posts)Or "something similar." Never knew it was a mystery, because people I knew who loved a good mystery didn't talk it up.
hunter
(38,263 posts)Maybe with today's improved tools researchers will be able to see something.
Science often takes time. Even into the mid-1950s theories of continental drift were still controversial. It wasn't until oceanographers documented seafloor spreading and the resulting magnetic striping, along with strong evidence of subduction, that theories of plate tectonics were accepted.
It's not a bad bet that there are many sorts of life we don't see because it lives very slowly.
Another observation: If we can't see that sort of life here on Earth, how would we see it on a place like Mars?
leftyohiolib
(5,917 posts)Heidi
(58,237 posts)Mornin', sunshine!
:kick:
xchrom
(108,903 posts)You do look divine! Spring suits you! :air kisses:
Thanks for the laughs!
Maybe someone drank prions in their coffee that day.
SansACause
(520 posts)This would be a good time to pull out Occam's razor.
caseymoz
(5,763 posts)They find this phenomenon in one place and they make a huge guess based upon it? Not good science. It's still pretty good science fiction, though.
Yo_Mama
(8,303 posts)I realize that the US isn't the best at scientific education, but this is an important distinction. Absent some bleeping evidence, this is just a hypothesis:
http://teacher.nsrl.rochester.edu/phy_labs/appendixe/appendixe.html
...
A scientific theory or law represents an hypothesis, or a group of related hypotheses, which has been confirmed through repeated experimental tests.[b/]
It's an interesting hypothesis, but it's just a guess. What separates science from other methods of understanding our world is the reliance on evidence!
MattBaggins
(7,894 posts)cthulu2016
(10,960 posts)Seriously, this belongs in creative speculation
MineralMan
(146,189 posts)light are almost certainly the cause of desert varnish. UV light is transformative in many ways.