Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Particle Life

github.com

Post reply on HN
Print view View original

91–97 of 97 posts

Re: Particle Life

#91

Post by squigz »

aydyn wrote: post #90
squigz wrote: post #89

Earlier quoted context omitted.

> From a cellular perspective, human cells are not really more complex than smaller multi-cellular organisms like amoebas. That's a very limited and poor perspective. Yes, individual human cells are no more complex than others, but that doesn't encompass the entire system that has to emerge. A human being is - obviously, I would think - a far more complex system than a simple amoeba.

You missed the point. What's the barrier to stop simple organisms from developing into more complex and eventually intelligent systems? There's no delineation between "intelligent" and "simple" life. It's a smooth fitness landscape that evolution would (arguably) climb over time.

Evolution doesn't always work like that though. There's a fair bit of luck involved. You're right that 'intelligence' would certainly help an organism survive, but that is hardly a guarantee.

Re: Particle Life

#92

Post by aydyn »

squigz wrote: post #91
aydyn wrote: post #90

Earlier quoted context omitted.

You missed the point. What's the barrier to stop simple organisms from developing into more complex and eventually intelligent systems? There's no delineation between "intelligent" and "simple" life. It's a smooth fitness landscape that evolution would (arguably) climb over time.

Evolution doesn't always work like that though. There's a fair bit of luck involved. You're right that 'intelligence' would certainly help an organism survive, but that is hardly a guarantee.

It does "work like that", this is literally my field. Evolution is a random walk where organisms higher up on a fitness landscape are more likely to survive. Over time, the probability of climbing the fitness landscape approaches 1.

To claim that intelligent life would not evolve from simple life, you have to posit fitness barriers, i.e. steep discontinuities in the fitness landscape that prevent organisms from climbing. One of those barriers might be the jump from single-cell to multi-cellular in high heat/high entropy environments.

But you haven't posited any such mechanisms.

Intelligence has evolved multiple times on earth's history (just that the other species are extinct). So there is strong evidence that in earth-like environments there is no such barrier.

Re: Particle Life

#93

Post by RetroTechie »

billytetrud wrote: post #18
UncleOxidant wrote: post #16

Earlier quoted context omitted.

> One would either have to belive that intelligent life is vastly less likely than non-intelligent life That seems like a valid belief. Getting to a technological stage such that a species would be detectable over the vast distances of space could indeed be quite rare. You have to also consider the temporal aspect: intelligent, technologically advanced species may have evolved several times but gone extinct before we…

> That seems like a valid belief. Its not at all clear in general. It might be true. But it also might not. It seems quite reasonable to believe that life inevitably evolves into intelligent life if given enough time. Why some life would and some life wouldn't isn't at all clear. > advanced species may have evolved several times but gone extinct before we could notice them. All the potential answers to the Fermi Para…

> It seems quite reasonable to believe that life inevitably evolves into intelligent life if given enough time.

Intelligence is an arbitrary yardstick. Compared to a yeast cell that just sits on a surface, a tree that grows toward light, strengthens its stem in response to wind forces etc, could be considered intelligent.

More useful is tool use: animals that use sticks, stones etc. to get at food unreachable without those tools.

But even that won't do: a planet full of life like that, but it never gets off that planet. Bits of life getting spread by meteor strikes etc? Possible. But chances of that drop off sharply with distance (within solar system -> interstellar -> between galaxies & up).

The missing bit? Technology itself evolving from simple -> complex much like life evolved before that. In our (1) case: simple tools -> use of mechanical devices to replace muscle power -> industrial revolution -> automation -> entering the AGI age (where biological life may not be a strict requirement for a civilization to advance further).

Quite possible that tool-using intelligent life is relatively common, but some of those extra steps to 'get off the home planet' are rare.

And even if all of that happens: well... the universe is big. And so are timescales. Blips on the radar are easily missed.

Re: Particle Life

#94

Post by utkarsh858 »

brap wrote: post #54

If this doesn’t convince you spontaneous life is possible I don’t know what will

This is not spontaneous, all the parameters have to be carefully tweaked to get some tangible stable complex structures. Also initial set of parameters are 20 which is not simple! Compared to that the complex structure is not much complex.

Re: Particle Life

#96

Post by SkyBelow »

billytetrud wrote: post #88
SkyBelow wrote: post #29

Earlier quoted context omitted.

There are a number of possibilities, which depends upon what methods of interaction we are looking at. For example, with direct contact, we can estimate a probability of life along side how possible space travel is. Perhaps space travel isn't easy or fast at all and so there is plenty of life, but it is mostly stuck to its solar systems and maybe a few neighboring stars. Overall, given that we can send and receive si…

> Perhaps space travel isn't easy or fast at all Except we have excellent knowledge about lower bounds on how easy and fast space travel can be. And its plenty fast enough to explore the entire galaxy on geological timescales. Voyager 1 is traveling at 17 km/s which would take it 1 light year every 17,700 years. Given that the galaxy is 100,000 light years across, that means that Voyager 1 could travel across the gal…

>In short, if you think space travel is a barrier, you're plainly very wrong. Even with today's technology we could send machines throughout the galaxy in a pretty short period of time. In the near future, that time will drastically reduce.

We can send a small object anywhere, but we can't send enough of them everywhere. If an intelligent species directed such an object to our galaxy, how close would is need to be for us to detect it? They physical object alone would be near impossible without it being extremely close, and even if it was producing a signal to be detected there is a limit based on size and how much energy it has on board. Even that would be hard to detect at any sort of galactic distances.

>And yet there are vastly larger motivations for sending a spacecraft than sending a signal.

Unless the signal is directed, it covers an exponentially increasing area, which is also why it has limited range. There is a fundamental trade off between range and area, meaning that there is an upper bounds on the volume we can contact. How likely is life found in that volume?

>Whether anyone would consider that "rare" or not is irrelevant.

When it is part of the question, how is it irrelevant? If it was on the other side of the galaxy, how would they know to send someone to our solar system and how far could we view their spacecraft if they weren't in our solar system? And that still assume a neighbor in the galaxy. If they weren't, the space between galaxies greatly changes the equation.

Re: Particle Life

#97

Post by billytetrud »

SkyBelow wrote: post #96
billytetrud wrote: post #88

Earlier quoted context omitted.

> Perhaps space travel isn't easy or fast at all Except we have excellent knowledge about lower bounds on how easy and fast space travel can be. And its plenty fast enough to explore the entire galaxy on geological timescales. Voyager 1 is traveling at 17 km/s which would take it 1 light year every 17,700 years. Given that the galaxy is 100,000 light years across, that means that Voyager 1 could travel across the gal…

>In short, if you think space travel is a barrier, you're plainly very wrong. Even with today's technology we could send machines throughout the galaxy in a pretty short period of time. In the near future, that time will drastically reduce. We can send a small object anywhere, but we can't send enough of them everywhere. If an intelligent species directed such an object to our galaxy, how close would is need to be fo…

> enough of them

How much is enough? A von neumann machine shouldn't need to be that big. You can send a single one to a solar system and let it replicate itself indefinitely. A single seed can sprout an entire civilization.

> If an intelligent species directed such an object to our galaxy, how close would is need to be for us to detect it?

We could probably detect it for many hundreds of lightyears if not orders of magnitude further. Why? Because an intelligent species capable of sending a von neumann machine to another solar system would probably be intelligent enough to make large scale infrastructure projects like dyson swarms. Such structures would basically be visible from any distance we could see the individual star from, which we can do from at least 50 million light years.

And not only that, but we could see evidence of a von neumann machine coming through in the distant past as well, even if for some reason its no longer active, because it would have left an enormous amount of artifacts behind.

> When it is part of the question, how is it irrelevant?

Fair enough. But what I mean is that if life isn't "rare" (for any definition of rare really), one would expect to see a massive amount of evidence of life and civilizations etc. Since we don't see that evidence, we should assume either that life is rare, or we're not the "average" planet that the copernican principle assumes.

> If it was on the other side of the galaxy, how would they know to send someone to our solar system

They wouldn't have to know. They would simply send spaceships everywhere and would happen across us by random chance within a million years.

Post reply on HN