Considering the extreme difficulty in getting organic chemistry processes to work in the laboratory, having random chance work to get any pre-biotic sequences is of such low probability that all the hand waving and blackboard erasures of the current biology experts, etc., means nothing.

We do not know and cannot show any viable means of creating the full sequence of pre-biotic chemicals needed for the first organism to exist. When one of the top organic chemists in the world puts out that challenge and nobody responds, one can then say that all of these experts know full well that they do not have a clue and are just deluding everyone else as to how life even came to be.

Just using probability to say that life came about without at least a semblance of an idea of possible sequences that could work is useless. You need at least some possible viable sequence for the full biotic complement of chemicals to be available. Since the sequence requires processes and solvents that are inimical to previous and follow-on chemicals, this sequence development is a major, major problem that is regularly ignored by those who use probability to say life can arise.

When these things are taken into account, the simple fact that there is life here on this planet can be seen as a unique event throughout all of the universe.

On some estimates of random action giving rise to life anywhere in the universe, the probabilities are so low that the universe would need to exist for many magnitudes of time longer than its apparent age at this time. Your "one in a billion" is oh so many magnitudes of order higher than the probabilities estimated.

Of course, your view can be very different and if you can come up with a viable sequence then simply accept the challenge that has been put out. There will be an awful lot of relief if this could be done.

The simple truth is, we have no idea. Of course we don't. Data points so far: One. Statistics on that kind of basis tend to be rather meaningless.

One thing we do know to be extremely unlikely: That we - exactly we, us, here at this specific point in time - should somehow have arrived at a point where we can confidently secondguess the universe in all its glorious details. We can't, and we don't really even have the foggiest idea what kind of life is possible, or how it comes about in the first place.

All the Drake equations in the world can't hide the fact that we know nothing. Every single galaxy may be bursting with life, or we may the only specimens anywhere in the dark, cold void.

My personal guess - which is no better or no worse than anyone else's - is that life or its functional equivalents is more or less everywhere, but that intelligent critters like ourselves are exceedingly rare.

> We do not know and cannot show any viable means of creating the full sequence of pre-biotic chemicals needed for the first organism to exist. When one of the top organic chemists in the world puts out that challenge and nobody responds, one can then say that all of these experts know full well that they do not have a clue and are just deluding everyone else as to how life even came to be.

There are many more stars than chemsists, and the universe has had much more time to get lucky than our chemists have had. The universe has gone through more chemical permutations than our scientists can dream of.

Your computer ran billions of instructions in the time it takes to read this. Therefore, it probably made a mistake in that time, even if the chance of a mistake in any one instruction is "astronomically low", right? No, many real-life frequencies are way below one in a billion.

That's a good point, but I think it's reasonable to say that the frequency at which planets are similar to Earth is high. Non-tidally locked, geologically active, high-water-content, with enough gravity to trap oxygen/CO2 but not hydrogen/helium, and within a certain distance from a star based on its output planets can't be that uncommon. I'm pretty sure Venus actually fits all those requirements - which isn't to say that there is life on Venus, just that superficially most of what we consider "the requirements" are there. In fact Mars fits all those requirements too, aside from geological activity.

We can't know how probable life is given similar conditions to Earth because our sample size is too small. But there are definitely a lot of Earth-like planets out there.

Yes, there must be a lot of Earth-mass rocky planets out there in habitable zones. Twenty years ago I'd have said we just don't know. There may've been some real progress too on figuring out the origin of life, but our knowledge is still compatible with almost all potentially-habitable planets being lifeless -- it wouldn't badly contradict what we know so far (afaik) and would explain why we haven't seen any advanced aliens taking stars apart, etc.

Well, I think you're assuming intelligent life must be common given that life is common. I'm of the opinion that life in general is pretty common, but that intelligent life is very uncommon, possibly unique. I'm basing this assumption on the fact that life has existed on Earth for ~4b years but intelligent life has only existed for about ~40,000 years, depending on when you consider humanity to have become "intelligent."

Not assuming that -- I'm just uncertain. I was arguing against "life must be common" but not arguing for "life must be uncommon". I think your scenario is plausible, though I wouldn't want to bet that way -- octopuses are very distant relatives of us.

Odds are good that we are the lone source of intelligent life in our galaxy. In the universe? Not so much. The question really comes down to FTL travel. No FTL and we are likely to turn inward and look to artificial environments and virtual realities. If there is FTL then its possible that we could continue to look to the stars for a good long while.

Obligatory xkcd: https://www.xkcd.com/638/

How do we know that there isn't life teeming in our galaxy if we can't even detect neutrino/quantum/ansible/tech-undiscovered signals?