No ET! Ever?

[ErGingerbreadMandude]

USA voted Trump into presidency. Please don't lump the rest of the world with them

[Rhondazvous]

Our ability to detext e.t. Life is limited by the paradigm w use. We look for stars with planets in a comfort zone suitable for carbon-based life forms. Life forms based on other elements such as sulfur are outside our circle of awaremess, so we haven't developed a paradigm that would allow us to detest such life.

[Anomalocaris]

Our ability to detext e.t. Life is limited by the paradigm w use. We look for stars with planets in a comfort zone suitable for carbon-based life forms. Life forms based on other elements such as sulfur are outside our circle of awaremess, so we haven't developed a paradigm that would allow us to detest such life.

Except through sheer baseless fantasy, we have not yet been able to dream up, even at high level, how life can be possible without some chemical basis that would allow the formation of a very large variety of very complex, interacting molecules, and some medium that dissolve constituents of these molecules to transport them to a central location, without also instantly destroying these molecules once they form.

We may not yet know much of all there is to know about physics, but we think we have a good working knowledge of chemistry.  Chemistry say there is strong reason to suppose the rather unique chemicals and physical properties of water and carbon make these two by far the best candidates to fulfill the above stated conditions.

So it's not just because earth life is water and carbon based. It's no other chemical can come close to providing a similarly board basis for metabolism and genetic inheritance.

[Rhondazvous]

Our ability to detext e.t. Life is limited by the paradigm w use. We look for stars with planets in a comfort zone suitable for carbon-based life forms. Life forms based on other elements such as sulfur are outside our circle of awaremess, so we haven't developed a paradigm that would allow us to detest such life.

Except through sheer baseless fantasy, we have not yet been able to dream up, even at high level, how life can be possible without some chemical basis that would allow the formation of a very large variety of very complex, interacting molecules, and some medium that dissolve constituents of these molecules to transport them to a central location, without also instantly destroying these molecules once they form.

We may not yet know much of all there is to know about physics, but we think we have a good working knowledge of chemistry.  Chemistry say there is strong reason to suppose the rather unique chemicals and physical properties of water and carbon make these two by far the best candidates to fulfill the above stated conditions.

So it's not just because earth life is water and carbon based. It's no other chemical can come close to providing a similarly board basis for metabolism and genetic inheritance.

I'm not sure how to make your conditions for life independent from Earth conditions. Can we say no other model is possible under any conditions when we haven't seen any other model?

The difference between science and religion is the religionist thinks he knows everything and dismisses anything that falls outside his accept truth. But the scientist is open to whatever presents itself as valid fact, even if he hitherto though it impossible.

[vorlon13]

There are more different kinds of molecules that contain the element carbon than all the other different kinds of molecules containing all the other elements besides carbon.

So there is a good reason to presuppose all life forms we encounter are going to be carbon based. (naturally evolved life forms, I'm not commenting on anything we might manufacture)

[Rhondazvous]

Evolution recognizes that certain traits develop under certain conditions and other traits develop under other conditions. Suppose there were only one condition on Earth. Say the entire Earth was like it is in Alaska or the North pole. We could presuppose that life cannot exist without some way to protect itself against cold. If we never encounter any other conditions, our presupposition remains safe.

[Anomalocaris]

Evolution recognizes that certain traits develop under certain conditions and other traits develop under other conditions. Suppose there were only one condition on Earth. Say the entire Earth was like it is in Alaska or the North pole. We could presuppose that life cannot exist without some way to protect itself against cold. If we never encounter any other conditions, our presupposition remains safe.

Actually, what we are doing is using deductions based on existing empirical knowledge to allocate limited research resource to maximize the chance of success, not assuming everything out there must conform to deductions based on existing empirical knowledge.

If we live on a plant where the whole environment is like the North Pole, then we have empirical knowledge that life is possible under North Pole like conditions.   Let's suppose we have no great confidence in our chemistry, so we can't say whether life is possible if it were 70 degrees warmer.   We have limited research resource, and we are just starting to look for alien life, how do we proceed?   Do we dissipate our limited resources on the infinite varieties of environment not known to be able to support life, or do we focus most of them on environment similar to ours, which we already know can support life?

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Except through sheer baseless fantasy, we have not yet been able to dream up, even at high level, how life can be possible without some chemical basis that would allow the formation of a very large variety of very complex, interacting molecules, and some medium that dissolve constituents of these molecules to transport them to a central location, without also instantly destroying these molecules once they form.

We may not yet know much of all there is to know about physics, but we think we have a good working knowledge of chemistry.  Chemistry say there is strong reason to suppose the rather unique chemicals and physical properties of water and carbon make these two by far the best candidates to fulfill the above stated conditions.

So it's not just because earth life is water and carbon based. It's no other chemical can come close to providing a similarly board basis for metabolism and genetic inheritance.

I'm not sure how to make your conditions for life independent from Earth conditions. Can we say no other model is possible under any conditions when we haven't seen any other model?

The difference between science and religion is the religionist thinks he knows everything and dismisses anything that falls outside his accept truth. But the scientist is open to whatever presents itself as valid fact, even if he hitherto though it impossible.

Chemistry is independent of earth conditions.  We make our deduction based on chemistry, not earth conditions.

[Rhondazvous]

Evolution recognizes that certain traits develop under certain conditions and other traits develop under other conditions. Suppose there were only one condition on Earth. Say the entire Earth was like it is in Alaska or the North pole. We could presuppose that life cannot exist without some way to protect itself against cold. If we never encounter any other conditions, our presupposition remains safe.

Actually, what we are doing is using deductions based on existing empirical knowledge to allocate limited research resource to maximize the chance of success, not assuming everything out there must conform to deductions based on existing empirical knowledge.

If we live on a plant where the whole environment is like the North Pole, then we have empirical knowledge that life is possible under North Pole like conditions.   Let's suppose we have no great confidence in our chemistry, so we can't say whether life is possible if it were 70 degrees warmer.   We have limited research resource, and we are just starting to look for alien life, how do we proceed?   Do we dissipate our limited resources on the infinite varieties of environment not known to be able to support life, or do we focus most of them on environment similar to ours, which we already know can support life?

---

I'm not sure how to make your conditions for life independent from Earth conditions. Can we say no other model is possible under any conditions when we haven't seen any other model?

The difference between science and religion is the religionist thinks he knows everything and dismisses anything that falls outside his accept truth. But the scientist is open to whatever presents itself as valid fact, even if he hitherto though it impossible.

I agree with the first part of what you said. With limited resources, it's best that we work with what we know. Not on speculations such as I presented. I was just giving us food for thought, not for spending money.

Having said that, I still have one little caveat. The idea that chemistry is independent of environment. Would you not say that a chemical will react differently when environmental conditions such as temperature or the presence of certain other chemicals is different? So being, a chemical that doesn't evolve into life on Earth might do so in other conditions. Again, this is speculation for the future. I'm not suggesting that we spend resources on it at this time.


Chemistry is independent of earth conditions.  We make our deduction based on chemistry, not earth conditions.

[Aoi Magi]

Chemicals might behave differently under different different conditions but they do so by following the rules of nature and this are predictable. And since the rest of the universe seemingly follows the same natural laws, so predictable assumptions can be made safely about it.

Having said that, many scientists agree that we probably won't recognize an Alien lifeform at first glance given the wide variety of life on Earth itself. But on the other hand, since we know there are many planets similar to ours and that the base constituents oh the organic molecule thought to have caused life on Earth is freely available in the universe, it is safe to assume lifeform similar to ours can be found on places with similar conditions.

[Godscreated]

Even if it were possible for other planets to have intelligent beings that had developed as far along as we have and even to the point of intergalactic travel, how would they know which civilization have been destroyed and the ones that haven't. If radio waves can travel as far as light wouldn't some of these be chasing the "dog's tail" and never finding a planet with advanced life due to it being destroyed by others.

GC