Why we might be alone in the Universe

[Anomalocaris]

The third is entirely relevant to the thesis.   Even if we exhaustively eliminated any possibility of any technological civilization from every part of the entire universe whence any indication of any technological civilization can even be theoretically be accessible to us,  we would have ruled out the presence of technological civilization from just a few % of the volume of the observable universe, and just for one single conical slice of time.    But we are so far from having exhaustively ruled that out, that to first, second and third degree of approximation we can say we are 0% of the way there. 

In other words, we are not in, and has no prospect of ever being in, any position to observationally contradict the probabilistic assessment that other technological civilization likely exist in some numbers elsewhere in the universe.

Even if the average distance between any technological civilization that ever arise is 1 billion light years when they arise, there can still be >10,000 technological civilizations that arose within the observable volume of universe.

Finding a second data point is crucial to making any determination as to how common life is in the universe. As it stands now, the size of the universe cannot tell us a thing. In order to make any claims about the abundance of life in the universe (or lack thereof) we need:

1) To find another example of life. (We haven't found one yet.)

OR

2) Figure out the probability of abiogenesis. (We have no clue how probable abiogenesis is.)

As for technological civilizations and/or advanced life on other planets, we can assume that IF abiogenesis is fairly common, advanced lifeforms in the universe will also be very common. If advanced life forms are common, then it seems plausible that other technological civilizations exist somewhere out there.

The issue discussed in the video is that (for all we know) the chance of abiogenesis could be so infinitesimally small that even in an area many times the size of our observable patch of the universe, it may be unlikely for it to happen more than once.

If this is true, then it is useless to speculate about other technological civilizations because (without abiogenesis) such civilizations won't even have a chance to emerge.

Second data point as in a second independent abiogenesis as you conceive it is not the only way to constrain deductions based on current understanding of possible chemical process of abiogenesis.   We actually do have a an alternative data point.  That is how long did it take for abiogenesis to occur in the one instance where it is known to have occurred, after conditions can reasonably be said to have allowed it.

The answer is very quickly.  That is a strong data point, as strong as discovering several independent occurrence of abiogenesis on other planets, for the contention that abiogenesis is a easy process to facilitate on a time scale of hundred million years in geological and chemical conditions prevalent on early earth.

[Gawdzilla Sama]

With the discovery of RNA (IIRC) in comet tails we have shortened the time needed to "cook life" on a planet. We know life started here 3.9 billion years or so ago. That wouldn't be that long, geologically, after the moon-forming impact of Thea.

[Anomalocaris]

In parallel to this, a recent article presented experimental result which show DNA can be synthesized naturally and directly in geochemical environment thought to be prevalent on early earth. This eliminates the need for a RNA precursor and lowers the hurdle and path complexity of abiogenesis.

[vulcanlogician]

Second data point as in a second independent abiogenesis as you conceive it is not the only way to constrain deductions based on current understanding of possible chemical process of abiogenesis.   We actually do have a an alternative data point.  That is how long did it take for abiogenesis to occur in the one instance where it is known to have occurred, after conditions can reasonably be said to have allowed it.

The answer is very quickly.  That is a strong data point, as strong as discovering several independent occurrence of abiogenesis on other planets, for the contention that abiogenesis is a easy process to facilitate on a time scale of hundred million years in geological and chemical conditions prevalent on early earth.

The early start of life on earth is addressed at 9:35 in the video.

[madog]

Did intelligent life evolve yet on earth? ... must have missed it 

[Gawdzilla Sama]

Did intelligent life evolve yet on earth? ... must have missed it 

[AFTT47]

It may be that intelligent life is very rare Our big brains have a lot going against them from an evolutionary standpoint. They use a great deal of energy, they make birthing difficult, they leave offspring vulnerable for a long time, etc. The conditions favoring big brain development might not happen often. The dinos dominated the planet for hundreds of millions of years without them.

[madog]

Did intelligent life evolve yet on earth? ... must have missed it 

Oooooh, my distant relatives  .... don't tell Ken Ham or kent Hovind 

[Gawdzilla Sama]

It may be that intelligent life is very rare Our big brains have a lot going against them from an evolutionary standpoint. They use a great deal of energy, they make birthing difficult, they leave offspring vulnerable for a long time, etc. The conditions favoring big brain development might not happen often. The dinos dominated the planet for hundreds of millions of years without them.

And by "dominated" you mean "they stodged along brainlessly." They had no more awareness than a cow.

[ignoramus]

Why would a free to roam horse in the wild be any less happy than us?

We are debt slaves and technology slaves ... What's to love?