“Most promising signs yet” of alien life on a planet beyond our Solar System • Hacker News Board

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#31

Post by volemo » Thu, Apr 17, 2025, 9:30 AM UTC

ta8645 wrote: post #18

seanhunter wrote: post #6

Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

If life is quite common, that still leaves an option that we are among the oldest of civilisations.

Besides, lack of comical presence doesn’t necessarily mean demise: maybe all face the problematic consequences of uncontrolled industrialisation and go solar punk?

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#32

Post by nottorp » Thu, Apr 17, 2025, 9:31 AM UTC

sph wrote: post #7

throwaway290 wrote: post #2

TL;DR - K2-18b - detected dimethyl sulfide and dimethyl disulfide, false positive possibility is now very low - "produced by marine-dwelling organisms on Earth", possibility they were produced by other processes (unrelated to life as we know it) not high but maybe unknown unknowns - other factors like distance from the star are in favor of life & water - previous studies detected methane and carbon dioxide

> false positive possibility is very low No, it means we will soon discover how these compounds form naturally. Would love to be wrong, of course.

If plankton farts them, it's natural too, right?

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#33

Post by allan_s » Thu, Apr 17, 2025, 9:31 AM UTC

metalman wrote: post #19

weberer wrote: post #5

Here's the primary source https://iopscience.iop.org/article/10.3847/2041-8213/adc1c8 They possibly detected dimethyl sulfide, which is only known to be produced by living organisms.

only know to be produced.....is a whoa bessy phrase,?¿ as in 70 years ago an undergraduate figured out that dimethyl sulfide was produced by living organisms and he asked his professor what else made it, and got shrug and "nothing else I know of" and everybody has been cutting and pasting since, OR, an international team spent years and millions working on the chemistry behind dimethyl sufide in an epic known to all…

actually we know how to produce it without involving living organism

https://en.wikipedia.org/wiki/Dimethyl_sulfide#Industrial_pr...

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#34

Post by Philip-J-Fry » Thu, Apr 17, 2025, 9:31 AM UTC

ta8645 wrote: post #18

seanhunter wrote: post #6

Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

Say another human-like civilisation existed and was more technologically advanced, what sort of tell-tale signs do you expect to see?

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#35

Post by okamiueru » Thu, Apr 17, 2025, 9:31 AM UTC

ta8645 wrote: post #18

seanhunter wrote: post #6

Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

Not sure how bad it could be given the hypothetical "millions of years more technologically advanced". They'd need to have a pretty good reason to care about us. Otherwise, we'd be so insignificant that it seems much more likely that whatever natural resources they'd want, would also be likely nearer and easier to obtain.

War-mongering, and otherwise zero-sum mentality shouldn't make all sense if they have the technology to actually reach us. [3-body spoiler warning] Kinda like in the Three Body Problem. It was kinda silly how advanced the Trisolarian were, while still bothering traveling to earth, rather than approach the problem in any number of more obvious ways

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#36

Post by otabdeveloper4 » Thu, Apr 17, 2025, 9:32 AM UTC

seanhunter wrote: post #6

Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…

> It just seems so unlikely that we are somehow that special.

That prior is formed by sci-fi media, not science.

> I always felt it overwhelmingly likely that it developed elsewhere too

"Life" is an information complexity characteristic. We know that information complexity is not uniformly distributed in the universe, and in fact the vast majority of the universe is extremely information-poor. Logically from the scientific data you'd assume that "life" in the universe also has a very lopsided distribution.

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#37

Post by falcor84 » Thu, Apr 17, 2025, 9:33 AM UTC

aardvark179 wrote: post #27

ta8645 wrote: post #18

Earlier quoted context omitted.

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

You seem to be conflating life, multicellular life, and intelligent life. Life appears to have developed on Earth pretty quickly, multicellular life took a long time to appear, and we are only aware of one species that developed civilisation building capabilities. Life might be very common, but intelligent life still be incrediblY rare.

Indeed. We might finally start getting some real estimates for those factors in the Drake Equation.

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#38

Post by oulipo » Thu, Apr 17, 2025, 9:34 AM UTC

ta8645 wrote: post #18

seanhunter wrote: post #6

Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

Possibly a more advanced civilization than us has long understood that it should not try to contact and bother other ones, but rather focus on their happiness where they are

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#39

Post by exe34 » Thu, Apr 17, 2025, 9:36 AM UTC

okamiueru wrote: post #35

ta8645 wrote: post #18

Earlier quoted context omitted.

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

Not sure how bad it could be given the hypothetical "millions of years more technologically advanced". They'd need to have a pretty good reason to care about us. Otherwise, we'd be so insignificant that it seems much more likely that whatever natural resources they'd want, would also be likely nearer and easier to obtain. War-mongering, and otherwise zero-sum mentality shouldn't make all sense if they have the techno…

Did you read the parent in haste or did they edit their post? They said:

> [1] It means that civilizations should exist that are millions of years more technologically advanced than us;

> [2] and should be leaving telltale signatures across the sky that we'd likely have detected by now.

> [3] And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived.

> [4]Suggesting that our demise too, will come before too long.

So they were talking about the great filter, not alien invasions, which is what you appear to be replying to.

Re: “Most promising signs yet” of alien life on a planet beyond our Solar System

#40

Post by Andrew_nenakhov » Thu, Apr 17, 2025, 9:36 AM UTC

ta8645 wrote: post #18

seanhunter wrote: post #6

Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…

If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…

It is quite plausible that life is abundant, but sentience is not. If we take Earth, it formed 4.5 billions years ago, conditions became suitable to support life like 4B years ago and first known signs of life are dated 3.7B years ago.

Now, in just .5B years Earth would likely become uninhabitable due to Sun becoming a red giant. In other words, on Earth life spent 90% of its total available time before sentience emerged. So on one side life is constrained simply by time, and on the other, sentience might not be necessary for organisms to thrive: crocodiles are doing just fine without one for hundreds of millions of years. To think of it, it is only needed for those who can't adapt to the environment without it, so humans really might be very special, indeed.