On 06-25-21 08:21, Argos wrote to Toadster <=-
Do you think there is life on other planets? It is my feeling that there is, but it's highly unlikely that it would look anything like humans, because humans evolved on Earth.
There's a large number of possibilities of what life on other planets could be like, and yes, highly likely to be unlike us. We've inherited some traits from successful species hundreds of millions of years ago, like being tetrapods (4 footed, though we evolved again to only need to walk on 2 feet), bilateral symmetry and vertebrate. But I don't see why those traits are necessary for an intelligent, sentient species. They just happen to be dominant traits in our lineage.
We live on a very young 3rd rock in a very vast solar system and
beyond. If one thinks it is not even remotely plausible there exists
some form of what we call life, their just nuts. In short, absolutely !
I believe that primitive life is almost everywhere that liquid water (and possible other suitable media, though water has some unique physical properties) exists. I also believe that we are close to finding primitive microbial life elsewhere in our solar system - Mars, Europa, Enceladus, to name a few of the more likely candidates. But Titan offers the possibility of life based on exotic chemistry, and you can't rule out the clouds of Venus, where conditions might be suitable for acid loving microbes.
As for complex life, especially sentient life, that's another matter. The Earth's history suggests more complex life requires a largely stable environment, punctuated by infrequent catastrophies, which allow niche species the opportunity to evolve and become dominant. Earth also has some other key characteristics - a large moon that acts as an "anchor" to keep the planet's tile within a relatively narrow range. The Moon also provides tidal activity, and the collision which created it also provided a relatively fast period of rotation for a terrestrial planet. In addition, the Sun is a relatively quiet star for its type and age. It's also towards the heavier end of what it could be to allow sufficient time for live to evolve to where are. It is predicted that Earth will become uninhabitable within around a billion years, as the Sun heats up (The Sun is around 30% hotter than it was when it was formed).
While there's plenty of lighter (and longer lived!) stars around, these require their life bearing planets to orbit closer, which means (1) there's a higher chance the planets could be tidally locked to their star (no idea how this would affect evolution, and could possibly mean no magnetosphere - another vital component on Earth), and (2) such planets will be a closer target for any stellar flares - many smaller stars can be very active.
So the best answer I can offer for the probability of intelligent life is "We don't know", as there's too many unknowns. However, the sheer size of the Universe suggests there must be intelligent species _somewhere_, even if they're too far away for us to be able to ever know about each other.
... How does Moses make his tea? Hebrews it!
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