"Thus, life on Titan could involve huge (by Earth standards) and very slowly metabolizing cells, in which case biomass densities would be higher than calculated above."
which the author interprets as
"a life form in our solar system that's not a puny, dumb little thing, but a huge dumb thing. Like dog-sized. Or maybe Volkswagen-sized."
I'm sorry.. but a "huge by (earth standards) cell" doesn't mean dog sized. It means a few times an earth sized cell. Otherwise, why compare it to a cell at all?
Well, the smallest dog breeds have a mass on the same order as the largest cells on earth, so, yeah, "dog sized" is a pretty good standard for a "huge (by earth standards)" cell.
Indeed, specifically a huge one. Making it huge, by earth standards.
See how that works?
Sitting in front of our flat monitors with access to nearly all information which is stored all around planet Earth.
Phones that connect us to billions of people.
Brains large enough to hypothesize the creation of the universe.
We can create rockets that send probes to other planets and even the edge of our solar system.
We regularly travel around in amazing personal vehicles that allow us to travel at over 100 mph in about 10 seconds.
The fact that each one of us had about one quadrillionth percent chance of even being born, yet here we are.
The fact that we can even talk and communicate effectively is amazing.
We can imagine future technologies and have goals to work towards such as immortality, brain-computer interfaces, teleportation, and mining asteroids.
We have so much to be thankful for. Everything is amazing.
I have a dog that can't do anything but eat, pee, poop, and play fetch. What kind of activities do other organisms do that humans can't do? Other than telepathy, and flight, and breathing without oxygen, and energy creation through sunlight.
Yet we still make fellow humans and animals suffer daily. We eat shit food and get depressed and some people even try to kill themselves. We have concepts like good and evil and actually hate other humans just because they are not exactly like our culture or have more stuff than we do. We have enough nuclear missiles in the ocean to eradicate life on earth.
Terraforming mars will be fun. I hope that I live to see the start of that adventure. The next 100 years in general will be very fun. I'm extremely glad that I get to be a part of this awesome world at this extraordinary time in human history. Please, nobody fuck it up too bad.
My point is, regarding the article, ANYTHING is possible. God is possible, ghosts are possible, flying spaghetti monsters are possible but until I see a video with convincing explanation or accredited scientists agree that something is very likely, is there really any point of just making up stuff?
Mars having a thriving self-sustaining human-like civilization underground is possible. Aliens living among us for several years is possible. No scientist will say that either of those hypothesis are absolutely impossible, but there is no point in proposing it unless you're writing a science fiction novel/movie/comic book.
Also, I'd be willing to bet that our sex drive had a decent role in evolution. Basically be strong, smart, and acquire stuff so we can put our dicks into pretty females.
I also think it's putting the horse before the cart. To some degree we don't even shape the world to have kids, we also have kids to shape the world. That is, for them to live, because we like to live. Life likes to live; it also likes to see other life thrive. That with similar genes preferably, sure, but also simply life in general.
Plus, from the perspective of genes, it makes zero difference if "my" genes or similar ones that "belong" to someone else are replicated, completely contrary to how we feel about that.... which to me is another indication that this view of life being this endless and futile struggle (harshly put, like a malignant cancer trapped in a finite universe), is more to do with cultural pathology or delusion than life itself.
Start with "The Selfish Gene", his best IMO.
Did you forget a footnote? :)
(Only click if you're SURE you have 6 minutes to kill)
Unless they are not.
For example, we might get a total surveillance society, ruled by a tyranny that cannot be overthrown, because it controls everyone's use of information. We seem to be heading that way now.
Or a bad singularity that turns the solar system into paperclips.
Or one of those old favourites, nuclear war and ecological catastrophe.
It is not obvious to me that humans will still be around in 100 years. Which would be sad considering we may be the only sapient life in the universe.
Of course, the fact that these things are possible is still incredibly cool. While this article lacks much technical substance, this is the kind of thinking that gave us Cosmos and Pale Blue Dot. I hope enough people retain this author's sense of scientific curiosity and excitement for discovery. While cold logic, expected-value calculations, and cynicism are important in a research setting, outside of the lab it's important for people to be able to get excited about little (or big!) things like this.
We can have scientific progress and childish glee coexist. Thank you for posting this.
I don't see why there has to be any real limitation on conditions or otherwise. As the article mentions, we have been surprised to find extremophiles near thermal vents right here on Earth (which reach temperatures roughly equivalent to the Venusian surface). There we find, for instance, bacteria that rely upon hydrogen sulfide vs sunlight for energy. This is what we consider a "harsh" environment of chemicals, heat, pressure, etc. However, when we attempt to remove organisms from that environment to study them, they usually die pretty quickly. In other words, ours is the harsh environment as far as they are concerned.
Elsewhere, we have found organisms whose DNA was thought to be composed of arsenic vs phosphorous. While this was ultimately refuted, for a period we once again thought we'd discovered something that, in an instant, completely changed our understanding of life.
So, I guess my point is that we assume life must conform to certain requirements and/or conditions until we find life forms that violate our assumptions. Given a Universe as vast and diverse as our own, I sincerely believe that anything is possible and perhaps even likely.
I know people think they're being sophisticated when they insist no limits can be placed on the form of life, but it's not true; it's naive. There are in fact certain very powerful and generic limits that can be placed on life with some powerful mathematics, such as the one I mentioned. It's fun to imagine a life form in science fiction that lives on the surface of the sun, but in reality they are not possible; there's no way they could retain any interesting structure in such a high entropy environment. To argue otherwise is basically to be arguing against thermodynamics. This basically puts this position firmly on the "crank" side, not the scientifically knowledgeable one.
Also, the idea that there are no limits on what life can look like is observationally false. The vast majority of places we look, we do not see life. Even if we manage to find a few simple life forms in a few of the slightly less hostile places in the solar system, it still won't change that fact; life is observationally not abundant everywhere, regardless of conditions. There definitely is a difference between conditions conducive to life and those not. Even what we call "extremophiles" are only surprising in purely local terms; in absolute terms in the Solar System, volcanic vents are still incredibly hospitable places compared to what is out there. In its own way, trying to argue from extremophiles to the general case is its own perversively parochial argument; the idea that extremophiles are actually "extreme" is a very terra-centric viewpoint.
>"If you can't pump out entropy faster than it comes in, you will, by definition, be randomized, which pretty much by definition is not alive
You're essentially just saying "if you can't stay alive, then you're dead". It's a non-statement.
My point was that's a big if. There are environments in which we wouldn't have thought it possible, until it was proven otherwise.
"I know people think they're being sophisticated when they insist no limits can be placed on the form of life, but it's not true; it's naive"
I don't think it particularly sophisticated to hold this view. I think it simply acknowledges the limitations of our knowledge (limitations which have been proven time and again). As a result, "naive" is actually the word I'd use to describe those who believe that their prior observations represent the full set of possibilities. The world was once flat and all of that.
So, ironically, I would say that your entire argument is based on a profound naivete. It is limited to what we currently understand/have observed and it assumes that it is foolish to consider otherwise.
>the idea that there are no limits on what life can look like is observationally false. The vast majority of places we look, we do not see life...
What does that mean? I don't think that anyone's asserting that life must exist in every single place we look; rather simply that some form of life could exist in virtually every single place we look, because we truly do not know what the bounds are. And, at a minimum, it almost certainly exists in places that we don't expect. The more general point is that it's extraordinarily presumptive to conclude that we know definitively what life could be, based simply on our own observations to date.
>the idea that extremophiles are actually "extreme" is a very terra-centric viewpoint.
Well, exactly. That's my point. We've dubbed them "extremophiles" because of our own limited reference point at a particular place in time. Their existence is simply evidence of our limited observational knowledge in the past. Ironically, enough, that's a term that is still generally accepted because even in spite of them showing us that we were wrong about life at some point, we still can't quite wrap our minds around the fact that we were wrong.
Now, you are simply arguing from a slightly evolved set of observational knowledge that happens to accommodate the existence of those "extremophiles". But, you're simply saying "OK, we might have been wrong once. But, we can't be wrong again". It's really an odd argument to make. And you're adding that volcanic vents aren't such a bad place to live after all. Well, yeah. Because we now know that life exists there. You can follow that line of reasoning until we find life at the center of the Sun.
It is why native alien life is unlikely to exist in our own solar system. You see, once life gets started, this process we call evolution takes place. Life takes on a myriad of complex forms. It covers the planet, gradually adapting to survive and thrive on nearly every patch of land. And behold, the planet is transformed.
There is only one planet in our solar system where this has happened. If life had started on some other rock in our solar system, it too would be visibly infested with lifeforms.
The time scale is also important. In very cold environments, such as the ones described, everything happens at a much slower pace. Consider it this way: heat is a proxy for energy (technically it is energy, but it's not all the energy). Energy is required for change. Very cold environments mean less energy, which means less change over the same time period.
Evolution is a pretty tricky thing. If some improvement can't easily be reached through iterative random improvements, then it won't be. And it easily gets stuck in local maximas where little or no improvements are made for ridiculously long periods of time. It's like getting to the top of the hill. There might be a mountain in the distance, but there is no path that leads to it without first going down off the current hill.
I think I'll stick to Arthur C. Clarke's half tree, half animal lifeform in Europa which is better than a single-celled blob.
Do you expect a life form to exist in that environment but ALSO be able to flourish in the human body, a creature of a sort never seen on Titan, 200 degrees warmer and full of entirely different chemicals?
If there's life on Europa, and if it is not based on DNA, that would mean Europan life evolved along a separate path from ours. That would lend support to the idea that life is common in the universe.
If Europa's hypothetical life was based on DNA, it would lend support to the "panspermia" idea, because it's hard to imagine how Earth's life could get to Europa, implying that Earth's life, and Europa's life, both arose somewhere else and traveled to separate destinations.
There are several other possibilities, none of which are discussed in the article.
and if they swim around in very, very cold ethane lakes or oceans,
and if those oceans don't have the pressure or weight of water,
* .5 .5 .5
0.125, under stupidly generous assumptions.
Have you paid your complexity tax today?