Obviously I meant the elements as part of minerals, not in raw elemental form.
Like in a tide pool?
Eppur si muove la Tartaruga.
uracil, cytosine, and thymine synthesis has been demonstrated at –440 degrees Fahrenheit, it doesn’t require liquid water.
Note that while the RNA world theory has not been proven, the fact that both sugars and pre-cursers to RNA can synthesize in outer-space is part of the reason I am now more confident that we should expect or maybe, more correctly ‘not be surprised’ to find at least simple life where conditions allow.
The Drake equation is not supposed to be anything but a thought experiment meant to help organize our thinking about what we need to know to have an estimate of how many civilizations there are. It is very high level, and each of the terms in it may break down into many, many other conditions as we discover more about the universe. For example, we may eventually need a term for proximity to gamma ray bursts or supernova. It may turn out that galactic phenomena we don’t understand make life much harder afross large portions of a galaxy. It might turn out that we need a term for thr number of stars that did not have ‘hot Jupiters’ that might have migrated outwards and destroyed any nascent life on other planets. Or it may turn out that there are many as-yet unknown phenomena that are critical to the development of life, and we don’t even know what we don’t know.
The best use of the Drake equation is to help us know what we need to study to at least narrow down the ranges in the known parameters. In my opinion, if you are using it to generate actual numbers or percentages and expect them to be useful, you’re using it wrong.
Years ago, when I thought about the Drake Equation, I thought that maybe one solar system in ten might hold a planet that was roughly like Earth. Then when I found out about tidal locking around red dwarfs, I revised that down to one in a hundred.
Now that we have got some good data from the Kepler survey, and from half-a-dozen other sources, the number of Earth-like planets seems much smaller. I’d be surprised if there were more than one Earth-like planet per thousand stars; it’s probably more like one in ten thousand. And that’s without trying to estimate how many of these Earth-clones have developed life.
Every time we get more data, the chances of finding a biosphere that resembles our own in any way gets smaller and smaller. Not only is it going to be difficult to find anything resembling Earth-life out there, it’s going to be damn tricky to find somewhere to stand outdoors in comfort.
In my opinion, if you read my post without realizing it was a tongue-in-cheek way to make points similar to yours, you’re reading it wrong.
No, likely too high-energy for the process - especially given the tidal range on the early Earth. Remember, the moon was a lot closer then. Coastal areas were not where you wanted to be.
perhaps, but even if that is the case it suggest at least 25 million earth-like planets in the milky-way alone, and perhaps 2.5 billion billion in the universe in total.
We are dealing with very silly numbers indeed.
No, I got that. It just twigged me to make a general point about the equation. Sorry if I implied that I was criticizing your post. That was not intended.
Are you accounting for the bias in our current measurements? Kepler lost its primary mission before it could really categorize many Earth-like planets around Sol-like stars. The doppler shift detection method is biased towards very large planets very close to their stars.
TESS should help us get better data, but right now I think there are some large error bars around our estimates of Earth-Like planets.
Also, there is no reason why life needs a biosphere ‘like our own’. It may turn out that the most common place to find life is on moons around giant planets, or on some other type of planet for which we don’t have an analogue in our solar system.
With regards to life, we have exactly one data point. That makes it very hard to make any sort of assumptions as to what makes life likely.
I don’t believe there is any other intelligent life (at our level or higher) in our galaxy. Possibly primitive life though.
I believe there is a high chance of intelligent life in other galaxies, but we’ll never know and they’ll never know.
We really have no data from which to draw that conclusion. If another civilization was broadcasting into space at the level we do, we would have to be extraordinarily lucky to hear it, and then only if it was coming from our immediate galactic neighborhood.
We can say that there appear to be no Kardashev level III or greater civilizations in our galaxy (able to harness the power of their entire galaxy), and no Kardashev level II societies (capable of harnessing the entire output of their star) within say, a few hundred light years. Tabby’s star was a candidate for what that type of star might look like at first blush, but it turns out to be just a lot of dust around the star.
We are not quite Kardashev level I - able to harness all the energy available on our planet. Civilizations in that range would likely not be detectable by us past a few dozen light years unless they were intentionally beaming high power signals right at us.
The fact that we haven’t detected another civilization is just not that meaningful at ths point, other than to tell us that civilizations capable of works we could detect are not ubiquitous. But the galaxy is a very big place, and so far we’ve only had measurement equipment that could detect earth-like signals from just the tiniest part of it nearest us.
Hence the phasing, I don’t believe. And that has nothing to do with our lack of detection. We can’t even create life from scratch in a lab. If we could do that, then we might have an idea of how easy it can happen spontaneously in nature. I think it is incredibly rare. Rare enough that if even if there are 25 million habitable planets in our galaxy it still wouldn’t be enough.
What is your definition of “in a lab”?
A fully man-made version of PhiX174 was produced in 2003 and the newer syn3.0 has the smallest genome needed for free living so far.
I can’t speak for Ashtura but I would take that to mean we have not been able to recreate conditions in a lab to see abiogenesis spontaneously occur. The example you gave is bioengineering.
They have successfully created ribonucleotides from simple precursors, the question is how they mix the ingredients together. Ribonucleotides a simple result of the fundamental principles of organic chemistry and experiments show that self-assemble happens but the auto-replicating part is not solved. The above post seem to assume that those precursors aren’t common in the universe or that Ribonucleotide self-assembly is somehow supernatural or extremely rare.
https://www.nature.com/news/2009/090513/full/news.2009.471.html
It seems that heating precursors in water, evaporating away the water and them to UV is all that is needed. While we don’t know if this is what caused life to happen on Earth, the fact that they can reproduce it in a lab shows that it could happen on other worlds.
Once again, we have no evidence of extra-terrestrial life yet with what we know now we wouldn’t be surprised if we do find it.
Of course it could happen in other worlds. After all, it happened here. I’m just saying i think the odds of it happening are small enough that if it didn’t happen anywhere else in this galaxy I would not be surprised. 25 million habitable worlds is really not that many. That’s lottery ticket odds.
I think you may be combining the number of known exoplanets with their rates.
We already know that we excluded systems like binaries that reduced the number of exoplanets we even detected.
I would be fairly surprised if only 1 in 40,000,000,000,000 suns has a planet in the correct zone. Although that number may closer to the number that actually result in a combo of factors. The estimate was about 40 billion Earth-sized planets orbiting in the habitable zones based on data that was known to exclude dozens and dozens of possibilities because of the limitations of the methods and to be honest to remove the number of false positives.
That is an ultra conservative upper limit, not a hard upper limit. As an example, we now think that up to 50–60% of binary stars are capable of supporting habitable terrestrial planets and the above WAGS completely excluded them.
40 billion in the universe, or in this galaxy? There’s only around 100 billion total planets in this galaxy. You’re saying 40% of those are hospitable to life?