How does the anthropic principle mean that we should have been contacted or found alien life? And are you speaking of the weak, strong, participatory, or final anthropic principle? All are controversial to some degree, and not all are completely science based; the SAP, in particular, is described as being more teleological and speculative than WAP. None of the versions of the anthropic principle seems to in any way indicate that humanity should have come into contact with alien life if it exists.
Here's a couple of links I went to in looking for information about the anthropic principle:
The Anthropic Principle
How The Anthropic Principle Became The Most Abused Idea In Science
You and your fellow atheists claim life exists elsewhere. Then, somewhere in space, there would have to be what causes life. One of the big criticisms of believers of aliens is that they have no other information to support their beliefs. Instead, they present arguments such as amino acids exist all over in space and they form proteins. Creation science discovered chilarity to disprove this. Protein can only be created within the cell. Why didn't the atheist scientists study what causes life on planet Earth on go from there?
The Anthropic Principle is based on the universe was prepared for the emergence of life and especially of human life. It is used to develop scientific explanations in cosmology. One of the arguments for it are the fine tuning facts discovered by atheist scientists when looking to explain their Big Bang Theory as follows:
- the production of a mixture of Hydrogen and Helium after the Big Bang
- long living hydrogen burning stars
- the production of the elements C, O, N, S in a star
- the distance of a planet (earth) to the star (sun): not too far, not too close
- the minimum size of the planet (to hold an atmosphere)
- atomic and molecular stability
- the unique properties of such a simple molecule as water
It's presented by Barrow and Tipler in The Anthropic Cosmological Principle.
The Anthropic Cosmological Principle by John D. Barrow
My question to
Montrovant is why not start with the above and then find a planet to meet the qualities of Earth? I think NASA is trying to do this with Mars, but not really succeeding. Instead, we get more hypothesis based on evolutionary thinking such as ice/water on Mars and that somehow that means life, a microble. Actually, NASA made a video of a small fish which I saw darting across the screen as the type of life they thought could exist, but it was quickly pulled. One atheist scientist I spoke with said he thought that the evidence on Mars shows that life could have existed there in the past. I posed the same question to him and he said he's working on looking for further evidence such as fossils and such.
ETA: I think he's conceding that there is no life on Mars even though he didn't say that. I mean they've probed Mars, but haven't found a microbe. That said, they continue to probe for life, but it seems they have changed their focus to previous life.