Sep 26, 2021 03:44 AM
What does the Copernican principle say about life in the universe?
https://bigthink.com/13-8/copernican-principle/
EXCERPT: . . . A principle will hold until it doesn’t. In astronomy, an essential principle is the Copernican principle, inspired by the mid 16th-century ideas of Nicolaus Copernicus. Copernicus famously proposed that Earth was not the center of the universe; the sun was. The Earth, he suggested, was just another planet orbiting the sun like Mars or Jupiter. Apart from the now obvious step in the right direction concerning the nature of our planet, the principle has a more profound, even if less justified, consequence: by equating Earth with other planets, it removed its exceptional place in the cosmic order and, with it, that of us humans as well. The principle, as understood today, is usually stated as, “Earth is an ordinary planet, and we, human observers, are ordinary too.” There is nothing special about either Earth or our species.
However, such statements are scientifically unjustified, and the meaning of the principle is often confused. We currently do not know enough about exoplanets to make a statement about how special Earth is. And we know far less about the possible existence of life in other worlds and about what kind of life that would be. So, to blindly extend the Copernican principle to guide our thoughts about Earth in comparison to other worlds when it comes to habitability is not just a false extrapolation but also imprudent. We simply do not know enough to make such pronouncements.
As an aside, it is also incorrect to equate the Copernican principle with a cry against human exceptionalism. The principle says nothing about the nature of life or about any implicit hierarchy that would erroneously place humans at the apex of Creation. Instead, it relates first to Earth as being a planet — which is indisputable — and, at a second level (more related to a post-Copernican theology than astronomy), to dethrone humanity as a sort of God-chosen species. Humans do not appear to be at the apex of Creation, being instead part of the complex web of life. Human hubris has led us into some very dark existential risks, and those are indeed consequences of the notion of human exceptionalism. But they have little to do with the Copernican principle.
The danger of the Copernican principle is to take it as some sort of final statement about our planet and life on it. As remarked above, we currently do not know enough about the distribution of exoplanets and how Earth-like they are — in the sense of having the correct biochemistry and geophysics to support life — or about how life could manifest itself in other worlds. A principle is a lamppost for further search and not a statement of final truth... (MORE - missing details)
How would humans decompose on Mars?
https://astronomy.com/news/2021/09/how-w...se-on-mars
EXCERPT: . . . All this is why Connor and Passalacqua agree: A body on Mars, if left outside or even buried in the loose martian soil, would probably dry out and mummify.
The first few stages — algor mortis, livor mortis, and rigor mortis — would still take place, Connor says. But there might be almost no other overt signs of decomposition, she adds. Autolysis and putrefaction would continue until the body froze, with one significant caveat: Most of the bacteria in our body are aerobic, meaning they need oxygen to function. On Mars, only the anaerobic bacteria that don’t require oxygen could proliferate until freezing, which means putrefaction would be severely limited.
After freezing, the body would dry out as its moisture sublimated away, leaving a well-preserved, natural mummy behind, the likes of which might have made the ancient Egyptians jealous. “The desiccated tissues would likely be very stable for an indefinite period,” Connor says.
“If you think about those peat bog bodies from the Medieval period, I would assume it would be kind of like that,” Passalacqua says. Those bodies — also remarkably well preserved — are mummified in part because peat bogs are oxygen-poor environments, which again limit the body’s own breakdown and prevent most organisms from coming in and finishing the job.
“If you think about a body going from something that looks like a person to something that looks like a skeleton, I don’t think you’re really going to get that in [the martian] environment. [Bodies] might dry out and mummify, but I don’t think much else would change,” Passalacqua says.
Exceptionally preserved martian mummies might sound like a cool idea. And the easiest and most straightforward option is, indeed, to bury the deceased. However, if human settlements on Mars really take off, cemeteries may require a bit of zoning planning and forethought, as the bodies in them would not decompose, preventing the reuse of plots.
Cremation, while a popular — and space-efficient — body disposal option on Earth, is probably not the best method on Mars. That’s because cremation requires keeping a chamber in excess of some 1,000 F (538 C) for several hours, which in turn requires immense energy input. In an environment where such fuel could be limited, that’s a costly solution. “That’s a huge amount of energy that’s just wasted to burn a body and not use for anything else,” Passalacqua speculates. After all, “you’re in this weird Mars environment, you probably want to be as economical as possible in all things.”
But both burial and cremation have a significant downside: the loss of potentially precious biomass. Remember that on Earth, decomposition is the ultimate recycling program, returning that biomass to the environment. “The environment that we’re in [on Earth] always wants to exploit [biomass] as much as possible. But the Mars environment’s not going to be able to exploit those resources at all, it’s just going to be lost resources for everybody,” Passalacqua notes.
In a place where bringing your own resources comes with high monetary and physical costs, is that really ideal? Perhaps the best choice could be to recycle that biomass, as would occur on Earth... (MORE - missing details)
https://bigthink.com/13-8/copernican-principle/
EXCERPT: . . . A principle will hold until it doesn’t. In astronomy, an essential principle is the Copernican principle, inspired by the mid 16th-century ideas of Nicolaus Copernicus. Copernicus famously proposed that Earth was not the center of the universe; the sun was. The Earth, he suggested, was just another planet orbiting the sun like Mars or Jupiter. Apart from the now obvious step in the right direction concerning the nature of our planet, the principle has a more profound, even if less justified, consequence: by equating Earth with other planets, it removed its exceptional place in the cosmic order and, with it, that of us humans as well. The principle, as understood today, is usually stated as, “Earth is an ordinary planet, and we, human observers, are ordinary too.” There is nothing special about either Earth or our species.
However, such statements are scientifically unjustified, and the meaning of the principle is often confused. We currently do not know enough about exoplanets to make a statement about how special Earth is. And we know far less about the possible existence of life in other worlds and about what kind of life that would be. So, to blindly extend the Copernican principle to guide our thoughts about Earth in comparison to other worlds when it comes to habitability is not just a false extrapolation but also imprudent. We simply do not know enough to make such pronouncements.
As an aside, it is also incorrect to equate the Copernican principle with a cry against human exceptionalism. The principle says nothing about the nature of life or about any implicit hierarchy that would erroneously place humans at the apex of Creation. Instead, it relates first to Earth as being a planet — which is indisputable — and, at a second level (more related to a post-Copernican theology than astronomy), to dethrone humanity as a sort of God-chosen species. Humans do not appear to be at the apex of Creation, being instead part of the complex web of life. Human hubris has led us into some very dark existential risks, and those are indeed consequences of the notion of human exceptionalism. But they have little to do with the Copernican principle.
The danger of the Copernican principle is to take it as some sort of final statement about our planet and life on it. As remarked above, we currently do not know enough about the distribution of exoplanets and how Earth-like they are — in the sense of having the correct biochemistry and geophysics to support life — or about how life could manifest itself in other worlds. A principle is a lamppost for further search and not a statement of final truth... (MORE - missing details)
How would humans decompose on Mars?
https://astronomy.com/news/2021/09/how-w...se-on-mars
EXCERPT: . . . All this is why Connor and Passalacqua agree: A body on Mars, if left outside or even buried in the loose martian soil, would probably dry out and mummify.
The first few stages — algor mortis, livor mortis, and rigor mortis — would still take place, Connor says. But there might be almost no other overt signs of decomposition, she adds. Autolysis and putrefaction would continue until the body froze, with one significant caveat: Most of the bacteria in our body are aerobic, meaning they need oxygen to function. On Mars, only the anaerobic bacteria that don’t require oxygen could proliferate until freezing, which means putrefaction would be severely limited.
After freezing, the body would dry out as its moisture sublimated away, leaving a well-preserved, natural mummy behind, the likes of which might have made the ancient Egyptians jealous. “The desiccated tissues would likely be very stable for an indefinite period,” Connor says.
“If you think about those peat bog bodies from the Medieval period, I would assume it would be kind of like that,” Passalacqua says. Those bodies — also remarkably well preserved — are mummified in part because peat bogs are oxygen-poor environments, which again limit the body’s own breakdown and prevent most organisms from coming in and finishing the job.
“If you think about a body going from something that looks like a person to something that looks like a skeleton, I don’t think you’re really going to get that in [the martian] environment. [Bodies] might dry out and mummify, but I don’t think much else would change,” Passalacqua says.
Exceptionally preserved martian mummies might sound like a cool idea. And the easiest and most straightforward option is, indeed, to bury the deceased. However, if human settlements on Mars really take off, cemeteries may require a bit of zoning planning and forethought, as the bodies in them would not decompose, preventing the reuse of plots.
Cremation, while a popular — and space-efficient — body disposal option on Earth, is probably not the best method on Mars. That’s because cremation requires keeping a chamber in excess of some 1,000 F (538 C) for several hours, which in turn requires immense energy input. In an environment where such fuel could be limited, that’s a costly solution. “That’s a huge amount of energy that’s just wasted to burn a body and not use for anything else,” Passalacqua speculates. After all, “you’re in this weird Mars environment, you probably want to be as economical as possible in all things.”
But both burial and cremation have a significant downside: the loss of potentially precious biomass. Remember that on Earth, decomposition is the ultimate recycling program, returning that biomass to the environment. “The environment that we’re in [on Earth] always wants to exploit [biomass] as much as possible. But the Mars environment’s not going to be able to exploit those resources at all, it’s just going to be lost resources for everybody,” Passalacqua notes.
In a place where bringing your own resources comes with high monetary and physical costs, is that really ideal? Perhaps the best choice could be to recycle that biomass, as would occur on Earth... (MORE - missing details)