3 ms·

Again, we’ve found exactly one instance of life so no amount of probabilities or sweeping claims like this can be taken seriously regardless of if it’s passed o

Again, we’ve found exactly one instance of life so no amount of probabilities or sweeping claims like this can be taken seriously regardless of if it’s passed off as scientific or not. We can not claim other elements can’t give rise to life.

adrian_b 3y ago
The claim that any form of life that has appeared naturally must use organic molecules based on carbon-carbon bonds is less strong than the claim that the speed of light cannot be exceeded, but nonetheless both claims refer to things that are impossible based on the current knowledge. Either claim (and many other impossibility claims like them, e.g. that an apple cannot fall upwards) could be invalidated by a single counter-example, but in none of these cases we know of any circumstance that would make the counter-example possible. In science everything can be changed by a new discovery, but any such new discovery cannot contradict the known facts, whatever was known to be true within certain limits must remain true within those limits and can become false only outside them. If any other chemical elements could be used to make structures complex enough to grow and multiply, that would have to happen in some conditions so different of everything that we have seen in the Solar System that we cannot imagine them. For features of life on Earth like the use of nucleic acids it is valid to say that this is something specific to the only instance of life that we know an other forms of life could store information is some others from the millions of possible organic macro-molecules. On the other hand, other features of life, like the use of the HCNOS elements, cannot be said to be an accidental feature of the only instance of life that we know, because their usage appears to be an unavoidable consequence of the composition of the Universe and of the chemical properties of the elements. Some ideas that existed in various early SciFi works, like silicon-based life or other such variants are in complete contradiction with the chemistry known for now. One could suppose that somewhere, perhaps in the depth of a giant planet, there may be ambient conditions, like very low temperatures, very high pressures and a chemical composition that could make some molecules to be stable even if they cannot be stable in the experimental conditions that can be reproduced on Earth and where some chemical reactions that cannot happen on Earth could happen there. This is not completely impossible, because for now the simulations of chemical reactions are not precise enough to predict what happens in conditions very different from those that can be verified through experiments. Nevertheless, for now there are not much more grounds to believe in things outside the known chemistry than to believe in teleportation or warp drive. Supposing that there would be somewhere such living beings based on an unknown chemistry, it is certain that they could not be extracted from their environment and brought to the surface of a planet like those currently known without being destroyed in the process.

adrian_b 3y ago

The claim that any form of life that has appeared naturally must use organic molecules based on carbon-carbon bonds is less strong than the claim that the speed of light cannot be exceeded, but nonetheless both claims refer to things that are impossible based on the current knowledge. Either claim (and many other impossibility claims like them, e.g. that an apple cannot fall upwards) could be invalidated by a single counter-example, but in none of these cases we know of any circumstance that would make the counter-example possible. In science everything can be changed by a new discovery, but any such new discovery cannot contradict the known facts, whatever was known to be true within certain limits must remain true within those limits and can become false only outside them. If any other chemical elements could be used to make structures complex enough to grow and multiply, that would have to happen in some conditions so different of everything that we have seen in the Solar System that we cannot imagine them. For features of life on Earth like the use of nucleic acids it is valid to say that this is something specific to the only instance of life that we know an other forms of life could store information is some others from the millions of possible organic macro-molecules. On the other hand, other features of life, like the use of the HCNOS elements, cannot be said to be an accidental feature of the only instance of life that we know, because their usage appears to be an unavoidable consequence of the composition of the Universe and of the chemical properties of the elements. Some ideas that existed in various early SciFi works, like silicon-based life or other such variants are in complete contradiction with the chemistry known for now. One could suppose that somewhere, perhaps in the depth of a giant planet, there may be ambient conditions, like very low temperatures, very high pressures and a chemical composition that could make some molecules to be stable even if they cannot be stable in the experimental conditions that can be reproduced on Earth and where some chemical reactions that cannot happen on Earth could happen there. This is not completely impossible, because for now the simulations of chemical reactions are not precise enough to predict what happens in conditions very different from those that can be verified through experiments. Nevertheless, for now there are not much more grounds to believe in things outside the known chemistry than to believe in teleportation or warp drive. Supposing that there would be somewhere such living beings based on an unknown chemistry, it is certain that they could not be extracted from their environment and brought to the surface of a planet like those currently known without being destroyed in the process.