To be fair, that does seem to describe the existence of life on our own planet.

I don't think so - in every direction we look things appear largely to be the same. It seems entirely reasonable that extends to life. The only limiting factor is we cannot see other planets to find out.

Is that a reasonable assumption to make? I don't think we have any evidence of other places we look being "largely the same" with respect to life conduciveness. It took billions of years for our own planet to achieve multicellular life, which is a significant fraction of our best estimate of the lifetime of the entire universe up to this point.

We can't really see at that scale yet. But at the scale we can see, our star system seems to be rather mundane.

But the universe is big and there are billions of billions of other planets which could very well have similar conditions, that also exist for billions of years

I suppose it's easier to believe you're a special snowflake than it is to believe you're just average.

Even though you are unique snowflake there are and will be millions like you.

Maybe we are not special. But we can accidentally be one of the first.

The question isn't about what's easier to believe, it's about what the evidence supports. The probability for life (or multicellular life or intelligent life or technological life) to evolve on any given planet is strictly between 0 and 1. You can believe what you want, but the facts don't support any stronger statement than that.

Our planet is only 4 billion years old; for the first billion years or so, it was sizzling-hot and under constant bombardment.

Given the Copernican principle, yes. I thought we gave up claiming our position as the centre of the universe long ago?

Probably the Universe is full of things even more amazing than life as we know it.

I think they might be referring to the fact the human species seems to think it's exceptional and has a unique place in the universe.

Every star system and planet is rare -- unique, even -- if we're specific enough about the details. The hard part is knowing what details are important when we only have a sample size of 1.

Before any of that is possible, a "Cambrian Explosion" is required.

It may be that prokaryotic life is common, but the mitochondria and plastids of eukaryotes took a very long time to emerge (absent for more than half of the total habitable life of the earth).

> but the mitochondria and plastids of eukaryotes took a very long time to emerge.

Not an expert, but mitochondria didn't "emerge." Mitochondria co-evolved as bacteria, merged and became organelles through complex protein-import machinery and insertion into inner membranes of protein carriers for extracting energy for the host cell.

There were no eukaryotes... and then there were.

This was the ignition of complex, multicellular biology. What else could explain it?

I will admit that I thought they were closer to the Cambrian Explosion. This is much farther away than I thought.

"Eukaryotes emerged approximately 2.2 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs."

https://en.m.wikipedia.org/wiki/Eukaryote

fungi, farming before they were even fungi.

What about mitochondria? I did not address your mention of eukaryotes, only mitochondria, which existed as bacteria long before eukaryotes. You're intentionally ignoring the error in your OP and my pun: mitochondria did not emerge with eukaryotes, they "merged." Your lack of addressing mitochondria in your response makes it a straw man.

You are talking about different semantics. You're talking about a merge in the context of a mechanical process, and they are talking about emergence in the context of speciation. There's no reason to expect the verb to be the same if the subject is different.

There are not "different semantics." There is semantics. It's a mass noun and singular. If you're attempting to hand wave by calling my comment a semantic argument, and therefore insignificant, then you are simply incorrect. Semantics are of vital importance to language and communication. Without semantics, no one would have any idea what anyone else was saying. And my use of "merge" was a pun. Woosh!

I'll try to be helpful and not combative.

I think it is a matter of semantics because it seemed like you have a different understanding of the meaning of the word emerge then the person you are responding to. Within the context of the original post, the word emerge has nothing to do with the physical location of mitochondria and the eukaryotic cell. Instead, the meaning of emergence was to come into existence from non-existence. That is to say, your objection relies on a different semantic understanding of the word used. It is unclear to me if you don't understand this meaning or if you understand it but disagree with others using it.

Similarly, I would argue that a "mitochondria" not living in a parent so is not a mitochondria at all. Again, this is a matter of semantics. It relies on the meaning of the word mitochondria and how it is defined.

Bay way of comparison, is a person who buys a house homeless or a homeowner? Are humans prototocells because our evolutionary history can be traced back to them?

> Similarly, I would argue that a "mitochondria" not living in a parent so is not a mitochondria at all.

I'm not sure why you're continuing to try to make it clear to me that you're not wrong when we simply disagree, but your statement here employs nominal fallacy, or naming fallacy. Mitochondria is that same bacteria that it used to be prior to entering into a symbiotic relationship within the cell. It's a relatively new scientific revelation that mitochondrion organelles lived as bacteria discrete from its current function inside a cell. We may call this that and that this, to keep track of function, but it doesn't mean that a spade isn't a shovel.

1) A thing can have a different name depending on where it is - for example, "power converter mounting bolt" and "control panel cover fastening bolt" might both be M8 bolts, and interchangeable. This isn't any sort of fallacy.

2) In any case, mitochondria have evolved, and are now distinct species from their ancestors that cannot survive outside the cell.

3) Fittingly, a spade is pointed, while a shovel is square tipped.

also, how long does it stay emerged

Was it this billion years or that billion years

probability of our experience matching another planet’s experience in the same time frame is low

There haven't been that many billion-year periods. The big bang was 13.7 billion years ago.

Emergence of eukaryotes specifically entailed aerobic respiration of the mitochondria, which was a massive increase of chemical energy (when glucose and oxygen are present).

Chloroplasts enabled direct harvest of photons from our parent star.

We are actually older than the plants.

These are going to leave a signature in the gas of an exoplanet, if they happen.

Oxygen on our planet was a wasteproduct of life before life learned how to use it.

If some planet had oxygen rich atmosphere from the get go it might have sped up the evolution of life by a billion years or few.

“Why aren’t we in a galaxy?!?”

"Because we occupy a unique and privileged place in the universe."

That would mess with the scientists.

That is basically what the anthropic principle says:

  the range of possible observations that we could make about the universe is limited by the fact that observations could only happen in a universe capable of developing intelligent life in the first place

https://en.wikipedia.org/wiki/Anthropic_principle

You can imagine the pivotal moment here, where someone (according to Wikipedia, it was Immanuel Kant, which is a neat fact all by itself) said "hey, that band of faint stars could be a gravitationally rotating disk seen from the inside, and what if those other oblong smudges we see are entire other disks really really far away?"

For residents of our hypothetical planet, that moment, which seems very important to me, would be hard to have!

This is an analogy to the Three Body Problem from Liu Cixin!

I’ve heard that book(series?) pop up quite a lot recently. Is it worth a read?

It's a three book series. It has a prequel, which adds little to the trilogy. It's highly awarded. It's interesting in that it was originally written in Chinese and it's uncommon for a translated book to make this big of an impact in sci-fi circles.

You see it a lot in space conversations because it covers planetary gravity in an interesting way.

I had a hard time getting through book 1, the other two in the trilogy are easier to read, but they're certainly entertaining and original.

It is, somehow, very bleak and pessimistic compared to your average (western?) sci-fi.

I've had good success with the audiobook + ebook combo in general. I'll listen to an audiobook while cooking, showering, etc and read it physically on a tablet or my phone when I want.

I started reading the first book before I started using this method, and abandoned the series a couple times but saw it coming up so often in sci-fi recommendations I kept wanting to get through it

I found the first half of book one elicited no interest in reading in my down time, but was just barely interesting enough to not quit listening.

By the second half of book one and the entire rest of the series (plus the author approved fan fiction fourth book) I completely gave up on the audiobook because the story was so good that I wanted to read it as quickly as possible. I actually switched to reading on my phone in the shower over listening.

It starts off slow but gets good and stays extremely good. One of my favorite series.

Yep. Some good sci-fi. Each one is a bit different, but terrific. Funny enough I was thinking earlier this week that I should re-read them since it’s been a number of years.

If you are have already read a bunch o sci-fi books, yes.

Otherwise it'll be like drinking from a firehose.

I really liked the first book, towards the second and third it got a little bit slow and repetitive. Not anywhere on par with e.g. Hyperion Cantos, but otherwise very good read.

There’s very little which holds ground versus Hyperion though… so GP if you haven’t already, go read that

No. It's a tedious slog, devoid of interest on any axis: characters, plot, worldbuilding and science are all paper-thin. Its popularity baffles me.

It's popularity is pretty easy to understand. It was the first proper scifi novel written in the native tongue of over a billion people.

What is “proper” vs eg the others on this list? Honest question.

https://en.m.wikipedia.org/wiki/Chinese_science_fiction

Did you read the wiki link? There's very little, and much of it is more kafka-esque political commentary rather than hard scifi.

I don't know, I lived in China for 9 years, and scifi and fantasy media were highly discouraged by the party (as mentioned in the wiki link), and no one I knew had anything to recommend that was originally written in Chinese. When Three Body Problem came out, people went nuts. Every nerd and engineer in the country read it.

Thank you. It’s amazing that +1bn people with theoretical access to the world’s resources didn’t spontaneously create 10000 sci-fi books. Similar isolation the other way around. Societies are still so isolated (language, culture, political leanings) despite so much integration.

>theoretical access to the world’s resources

There's the rub. Access to the world's cultural resources is highly limited in China. They've outright firewalled the internet.

I don't think that's true either. I think it was just the first such to get translated to English. I think it's popular because the premise is interesting. The Dark Forest is just part of the vocabulary now, and that's not an accident, it's genuinely worth thinking about and, if not technically new, at least newly popularized.

On a "technicality" front, I'm sure you could find something if you dug through the archives, but really there was no hard modern scifi in China that was heavily published and got any traction until TBP. The party even discouraged fantasy media. I lived there and hung out with nerds, and they were ecstatic when the book came out.

Did you read all three? The first one isn't great but as a trilogy I found it quite good. There are several places where the story building contradicts itself but if you are willing to look past those then it's solid science fiction. It's not on the level of Arthur C. Clarke or Asimov but they were obviosly big influences.

I found the first the best, second unbearable, and third absolutely not worth it given the slog of dark forest.

Liu's writing is incredible, but he reminds me of George RR Martin or.....bare with me..Vince McMahon. Unable to get beyond the "fleshing out" phase.

Same, it was nearly impossible to finish due to it being so dull.

I had the exact opposite thought - the first book was interesting and thought-provoking, while the other two just piled on more and more scifi concepts that (imo) have been better explored by other authors.

No. I was ready to give up on the first one about a third of the way through but people told me "it gets good later"; it didn't. So when I hear people saying that about the trilogy it's a bit of a "fool me once, shame on you" situation.

It brings me sanity to hear others say this. I thought the story was convoluted and characters uninteresting.

It was tedious, but so was Herodotus. Tedious does not mean uninteresting ...TBP was very interesting; especially the takedown of group-think revolutionary marxists. For example, and purposely vague to avoid spoilage, the young female guard's behavior echoes much of what we're seeing in today's colleges.

Read Born Red for a first hand account of such follies. We in the West love to pretend inconvenient history doesn’t exist.

Well, you know, that's just your opinion, man.

I read maybe half of the first book, and it was so bad I had to put it down. Maybe the translation is dry, or maybe the thin, stereotypical characters wore on me.

From the perspective of someone who has read 100's of SF books: not really. But if you haven't or if you want to have a taste of what looking at SF through a Chinese lens would look like then it's probably worth it.

The best sci-fi trilogy I’ve ever read. I don’t know why there is a lot of hate on hn towards it.

It's written with a different focus than traditional western sci-fi. Pacing is different, characters are unexpected in certain ways, etc. I can see how people don't like the style, I personally enjoyed the 'something different'.

Some recommendations based on that: The Forever War trilogy is IMO the best "future war" mil sci fi series.

The standalone book Old Man's War is also incredible.

And of course....Hyperion is the king of the entire genre. If you haven't read those I'd highly recommend it, will change your life.

Yes. It's the best science fiction I've read in years.

If you go in expecting adventure fiction, then it's not enjoyable. It's more like reading something like Olaf Stapledon.

It's a manic roller-coaster that will make you feel like the ground beneath your feat suddenly vanished. Absolutely crazy flights of fantasy.

Books 2 and 3 were some of the best books I've _ever_ read.

Makes me think of Krikkit in HHGTTG (from whence the view of the rest of the universe was cut off by a dust cloud. When its inhabitants finally did get to see it their immediate reaction was "It'll have to go")

For a VERY different take on this concept, do yourself a huge favour and read “Nightfall” by Isaac Asimov. Just thinking about it sends shivers up my spine.

If you like such ideas I have a couple good books for you. Not exactly related to this phenomenon but about space...logistics? With regard ET threats especially.

[1] The Three-Body Problem (trilogy)

[2] The Forever War

If you like such ideas I have a couple good books for you. Not exactly related to this phenomenon but about space...logistics? With regard ET threats especially.

[1] The Three-Body Problem (trilogy)

[2] A Fire Upon the Deep

If you don't want to read the books at least check out the idea of the "Zones of Thought" that is the interesting concept in the second book.

Strong second for A Fire Upon the Deep and its prequel, A Deepness in the Sky, both Hugo winners.

”The Three-Body Problem” is also a Hugo winner (2015)

Asimov's Nightfall tells the story of the beings living on a planet surrounded by 6 suns. The sky is always bright with at least a sun over head. They've only known the universe consisted of bright sky and the 6 suns for centuries. On a rare eclipse event where all the suns are hidden, they are suddenly in darkness and looking into billions of stars at the night sky.

surely such a system would be extremely unstable right?

Isaac Asimov is a science fiction author (a good one, too), but the work he created was not a real description of our universe -- it was fiction, and playing with ideas.

There actually is a sextuple star system in the night sky. Castor looks like a single star but actually consists of three binary stars: two of them in a binary system that is itself in a binary system with the other binary star. I don't know if there could be a stable position for a planet that would never experience nights, but there is at least some reason behind the idea.

For stable, always day position, maybe the planet could be in L1 point between two suns?

Is Krikkit in HHGTTG a playful take on this?

Since they're pulled together from the intergalactic medium, I'm pretty sure those stars and everything around them are pure hydrogen/helium. You'd need a few generations of star formation/nucleosynthesis before you could have rocky planets and carbon-based life.

It would be a somewhat safer place for life than within a galaxy proper - far less chance of a close approach by another star kicking your planet out of its solar system, less chance of taking a sterilising hit by a close by gamma ray burst.

Those living on such a planet might even reasonably conclude that advanced life on a planet within a galaxy, like our own, was very unlikely.