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

The Fermi paradox revisited: Technosignatures and the contact era

arxiv.org

Post reply on HN
Print view View original

111–120 of 353 posts

Re: The Fermi paradox revisited: Technosignatures and the contact era

#111

Post by spookthesunset »

superposeur wrote: post #102

In my opinion, the excitement occasioned by the discovery of so many exoplanets has clouded our collective judgement on the Fermi Paradox, leading the overwhelmingly most probable resolution to be underemphasized. Namely: there is no life out there. Not due to baroque mechanisms such as techno-self-destruction but just due to its sheer unlikeliness. As large as the number of stars in the observable universe is (let’s…

I think the probability of there being other life is much closer to 100%. There just has to be. Our universe offers way to much of the correct “stuff” that can create life that it just has to exist elsewhere.

Why haven’t we seen it? Well that is one of life’s great mysteries.

But the idea we are all alone in this giant thing called the universe… it just doesn’t feel right. The more we learn about things the more we realize humans aren’t really special and neither is our planet. Hell the idea that there are other galaxies is a concept that was only realized around a 100 years ago!

We humans think we know a lot but the truth is there is way, way more stuff we don’t know.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#112

Post by hackernudes »

damontal wrote: post #96
thereddaikon wrote: post #92

Earlier quoted context omitted.

I think the answer is pretty obvious, we are the precursor species. Or it could be any number of things other than nobody out there. For example, advanced life could be out there but it might be rare enough that you only end up with a handful of space capable civilizations at any one time. The milky way is a big place. If we assume that ultimately there isn't a clever way around the speed of light then two civilizati…

or we are in a simulation

That doesn't really solve the problem because the simulation is (apparently) big enough to allow life to evolve. Why couldn't life evolve multiple times in a simulation?

Isn't the argument about simulation more about pondering the question "what is the fundamental nature of reality?", not "why is there life?". If you say that some beings are interfering with our simulation (either designing life, or preventing other life, etc...), that is just another word for god.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#113

Post by spookthesunset »

georgeg23 wrote: post #108
superposeur wrote: post #102

In my opinion, the excitement occasioned by the discovery of so many exoplanets has clouded our collective judgement on the Fermi Paradox, leading the overwhelmingly most probable resolution to be underemphasized. Namely: there is no life out there. Not due to baroque mechanisms such as techno-self-destruction but just due to its sheer unlikeliness. As large as the number of stars in the observable universe is (let’s…

I don't think people realize how quickly EM radiation falls off with distance, and how large the scale of "transmitters" would need be before we could detect. Today we can finally, barely detect massive planets occluding suns, and we can only do this in our neighborhood of this galaxy. Modulated communication from a source not at planetary scale is currently impossible for us to detect. We need something much much bi…

I also suspect that in time we will discover new mediums of communication that have better properties than the electromagnetic spectrum. Maybe when we listen on those mediums there will be a ton of chatter…

Re: The Fermi paradox revisited: Technosignatures and the contact era

#114

Post by btilly »

thereddaikon wrote: post #92
AlanSE wrote: post #50

Earlier quoted context omitted.

That argument seems to violate the basic rules of exponentials. If an advanced species did settle on an stasis, then that will only last until some subset of the population decides to go beyond the stasis. Particularly for a space-faring civilization, the time scales and resources are so fast, that any multiplication factor beyond unity will eventually go bananas. Any individuals with the prerogative to multiply will…

I think the answer is pretty obvious, we are the precursor species. Or it could be any number of things other than nobody out there. For example, advanced life could be out there but it might be rare enough that you only end up with a handful of space capable civilizations at any one time. The milky way is a big place. If we assume that ultimately there isn't a clever way around the speed of light then two civilizati…

Von Neumann pointed out that an advanced civilization, with technology that we can predict should be developable, can colonize the entire galaxy in roughly 10 million years.

Which is a blink of time by geological standards.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#115

Post by sirmike_ »

superposeur wrote: post #102

In my opinion, the excitement occasioned by the discovery of so many exoplanets has clouded our collective judgement on the Fermi Paradox, leading the overwhelmingly most probable resolution to be underemphasized. Namely: there is no life out there. Not due to baroque mechanisms such as techno-self-destruction but just due to its sheer unlikeliness. As large as the number of stars in the observable universe is (let’s…

I do not think so. We know nothing. We really cannot answer if there is life out there or not at our stage. Not until we figure out the loads of problems hampering our very ability to *start to answer the question in earnest. Not to say our efforts thus far do not count as they do.

My point is we do not even know with certainty if life rose on Venus or Mars within the known scope of time we think has passed as an example. That is a question we could for sure answer in the next 100 years with relative certainty. I would hope we could in any case.

And once we get to the point of answering that question.

In my personal opinion -- of course there is life out there in the universe. It is too big and vast and has presumably been around for too long for us to be the only ones.

Sure the universe is crushingly vast compared to our small bits and pieces of knowledge. But so is our imagination. Whether it is a Hollywood set of a sci fi show or a astrophysicist rolling through endless equations; one day we just might find the answer.

This is one of those things we will not know about until we do.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#116

Post by btilly »

AnimalMuppet wrote: post #83
AlanSE wrote: post #50

Earlier quoted context omitted.

That argument seems to violate the basic rules of exponentials. If an advanced species did settle on an stasis, then that will only last until some subset of the population decides to go beyond the stasis. Particularly for a space-faring civilization, the time scales and resources are so fast, that any multiplication factor beyond unity will eventually go bananas. Any individuals with the prerogative to multiply will…

But in real life, it never actually is an exponential. There always is some limiting resource or saturation point or something, that turns it from an exponential into an S curve. An argument based on "the basic rules of exponentials" typically ignores second-order effects (there seem to always be some, even if we may not be able to see them in advance). > that will only last until some subset of the population decide…

It never is truly an exponential in the limit, but exponential growth for surprisingly long times is very common.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#117

Post by api »

AnimalMuppet wrote: post #87
api wrote: post #12

Earlier quoted context omitted.

If something visits us from another star system it's also likely to be an AI. Hibernation for thousands of years to travel between stars would be almost trivial for machine intelligence. Just turn yourself off. It'd be easy to tie this directly to solar power. Have an array of solar panels that powers you near a star and in interstellar space you just naturally go to sleep. When you approach the next star system the…

Even for an AI, you'd need storage media that are stable for thousands of years, and hardware that will still turn on after thousands of years, and solar panels that are still functional after thousands of years. Oh, yeah, and a fair amount of those thousands of years will be exposed to radiation, including relativistic iron nuclei (fun stuff). Your AI may not quite be itself when it arrives.

Things last longer at <100 degrees kelvin, which is what you'd be talking about in interstellar space unless you are running a hot reactor.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#118

Post by georgeg23 »

spookthesunset wrote: post #113
georgeg23 wrote: post #108

Earlier quoted context omitted.

I don't think people realize how quickly EM radiation falls off with distance, and how large the scale of "transmitters" would need be before we could detect. Today we can finally, barely detect massive planets occluding suns, and we can only do this in our neighborhood of this galaxy. Modulated communication from a source not at planetary scale is currently impossible for us to detect. We need something much much bi…

I also suspect that in time we will discover new mediums of communication that have better properties than the electromagnetic spectrum. Maybe when we listen on those mediums there will be a ton of chatter…

Within EM, gamma rays (highest frequencies) may be able to achieve sufficient spatial directivity for interstellar communication, but we'd have to be very lucky to have a beam pointed at us. Also currently our gamma ray receivers suck, and they have to be in space because our atmosphere largely blocks it.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#120

Post by denton-scratch »

wokwokwok wrote: post #40

Good grief, did anyone read the paper, or are you all just sprouting your own personal Fermi paradox theories? > The basic assumption of this work is the hypothesis that alien civilizations do not bother to explore merely biotic planets, so that the radiosphere criterion becomes the main trigger for alien civilizations to send interstellar probes The tldr; in this work is that they assume there’s a finite (short) dur…

Well, I didn't notice the bit about a "noisy period" - I took the sphere to be the surface of a volume, not a shell. I think the idea was that once you start emitting detectable information, you don't stop.

It's all hypothetical. All the stuff about probes: it doesn't matter whether the aliens are interested in talking to us. It doesn't matter whether they are interested in space and stuff. The authors define this sphere as the space wherein a hypothetical alien civilization COULD have detected our existence, and COULD have signalled or sent a probe in response.

Also, they choose to define their sphere in terms of the beginning of the radio era. That's arbitrary. There might be other signals that planets carrying life emit, that we don't know about.

SETI searches for radio signals like a drunk searches for his keys under the street-light.

Note: I only read the abstract.

Post reply on HN