I know what schrodinger's cat is. You can still make an educated prediction using science.
Aliens are not unknowable, because they exist within the observable universe, meaning that they CAN be observed. We just have to find some to observe. Until then, we can make an educated prediction about the existence of alien life using what we already know about our own planet. I can use this as an example to explain how we can "know" without knowing.
We have been able to reproduce the conditions of early Earth, and we have been able to make artificial organic compounds in these early conditions. The next step is to get them to form a proto-cell, which is a little more difficult, but it only needs to happen once, in such a way that it would copy itself. We also know that this is possible, using the theory that lipids formed around bubbles which contained some solute and RNA (the precursor to DNA). After that happens, then evolution can take over, allowing for speciation. Evolution was slower at first because ****** reproduction had not yet evolved, but it started to speed up when oxygen bagan to appear in the atmosphere. The oxygen killed off many of the photosynthesizing, unicellular life, and allowed for natural selection to begin. The ones who could use oxygen thrived in this enviro...
I know what schrodinger's cat is. You can still make an educated prediction using science.
Aliens are not unknowable, because they exist within the observable universe, meaning that they CAN be observed. We just have to find some to observe. Until then, we can make an educated prediction about the existence of alien life using what we already know about our own planet. I can use this as an example to explain how we can "know" without knowing.
We have been able to reproduce the conditions of early Earth, and we have been able to make artificial organic compounds in these early conditions. The next step is to get them to form a proto-cell, which is a little more difficult, but it only needs to happen once, in such a way that it would copy itself. We also know that this is possible, using the theory that lipids formed around bubbles which contained some solute and RNA (the precursor to DNA). After that happens, then evolution can take over, allowing for speciation. Evolution was slower at first because ****** reproduction had not yet evolved, but it started to speed up when oxygen bagan to appear in the atmosphere. The oxygen killed off many of the photosynthesizing, unicellular life, and allowed for natural selection to begin. The ones who could use oxygen thrived in this environment.
Knowing these things, we can look for the right chemicals on planets to create life as we know it. We do this using spectroscopy. The elements in the atmosphere reflect certain wavelengths of light, and we can gather information from the colors we get. We look for things like methane a lot, and oxygen is good too. Water is obvious, as it is one of the only compounds we know of that has the right chemical conditions for life. There are others, but water is most likely for life, seeing as how hydrogen and oxygen are 2 out of 3 of the top three most common elements in the universe.
Anyway, the probability that life exists elsewhere is huge. We have even found the materials needed to form life on freaking comets. This, by the way, is interesting, because it backs up the theory of panspermia, which is the explanation that life actually originated somewhere else, but came to Earth on a comet. I find that idea interesting, but it would still require that abiogenesis occur elsewhere to be brought here.
As you can see, we are pretty certain that aliens exist. We don't know about intelligent life, because that brings into question the Fermi Paradox, but life in general is highly probable.
***, on the other hand, is not within the observable universe. However, its existence can be reasoned about. We can come to a logical conclusion, even when we cannot know for sure.
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