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

skyatnightmagazine.com

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

#101

Post by trhway »

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.

>we are only aware of one species that developed civilization building capabilities.

well, the first one just doesn't leave any chance for any other one.

>Life might be very common, but intelligent life still be incrediblY rare.

the time period between big ape and nuclear bomb is extremely short - few millions years. In a hundred or a thousand - doesn't really matter - years we'll be an interstellar species or may be we destroy ourselves by Covid-2319. The point is that complexity develops exponentially and tremendous changes are happening in an extremely a short period of time - i.e. if life has 4B years to develop when it most probably has 4.01B years to develop civilization.

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

#102

Post by ivan_gammel »

vladimirralev wrote: post #69
ivan_gammel wrote: post #49

Earlier quoted context omitted.

> And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. If dark forest theory is right, alien civilizations may stay undetectable by hiding biological signatures of their worlds.

Dark forest theory is wrong. Staying undetectable is always inferior to both staying undetectable and safely deploying varyingly detectable decoy targets at safe distance to probe the situation and gather intelligence.

Deploying decoy target requires more advanced technology (space travel) than hiding the signature (we may be able to do it long before we reach another star). I don’t think this is a good argument. Let’s say, some civilization decides to invest in decoy. It needs to shine brightly, the energy footprint is huge, a lot of work has to be done to transform the entire system. Then what? If there’s a hostile player, capable of destruction, they research and destroy the target, and start surveying the neighborhood. You cannot just build a decoy on another end of the galaxy, right? The further you have it, the more complicated is the task. And then you can only hope that the time left will be enough to collect enough energy (even if you have the tech) for defense.

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

#103

Post by bufferoverflow »

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…

> millions of kilometres away

Yes, millions, but that's a major understatement.

It's 124 light years away. Which is around a million billion km away. (a.k.a quadrillion)

It's just so damn far.

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

#104

Post by hidroto »

xrisk wrote: post #76
poulpy123 wrote: post #53

Earlier quoted context omitted.

actually a living organism is needed to produce it this way

Wikipedia says "In industry dimethyl sulfide is produced by treating hydrogen sulfide with excess methanol over an aluminium oxide catalyst”. Which part requires a living organism?

I think they are being a little glib by saying a human is need to make the industrial processes.

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

#105

Post by nurettin »

whatever1 wrote: post #50
nurettin wrote: post #30

Earlier quoted context omitted.

Not to take away from you personally, but civilization as we understand it is our own cliche. Organisms developed on different planets could absolutely have a different view on life and society in general. Even on earth we have highly intelligent and physically capable organisms that care naught for your conceptions of how groups should function together. There are even organisms that seem to have no intersection wit…

I mean game theory and equilibria are universal. I don’t see why the basic rules of civilization would not apply to any level of organism sophistication.

Yes, but what we live in is well beyond a decision with four outcomes and all this assumes "we are doing it right".

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

#106

Post by hidroto »

mr_mitm wrote: post #75
londons_explore wrote: post #21

This is happening 124 light years away from earth. That means if we develop a way to make a space ship accelerate at 1g for a long period of time, you could go there in just 10 relativistic years. Unfortunately, whilst science allows such a rocket, our engineering skills are far from being able to build one.

Calling it simply an engineering issue is not properly conveying the ridiculousness of such a journey. For a small space ship of 1000 tons, this would take ten thousand times the current yearly energy consumption of mankind. So we'd need to figure out how to generate the energy and then store it on a space ship before even thinking about the engineering. And that's ignoring the mass of the fuel. The classical rocket…

It does not have to be a chemical rocket. https://en.wikipedia.org/wiki/Breakthrough_Starshot

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

#107

Post by Someone »

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…

> an exoplanet millions of kilometres away

Not millions, not even billions. 124 light years is about 10¹⁵ kilometers, or a million billion kilometers.

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

#108

Post by plomme »

goognighz wrote: post #82
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…

Interestingly we can’t actually know that we are correct in our calculations of what a planet lightyears away has as its atmosphere because we will never be able to go there and make sure we are correct. It’s a calculation and nothing more. For all we know that planet may not even exist. That’s what’s mind blowing about astronomy. We really don’t have any way of proving anything about what we are observing. All we ca…

Spectroscopy is well established.

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

#110

Post by cess11 »

goognighz wrote: post #89
IsTom wrote: post #54

Earlier quoted context omitted.

While it has more time to become a red giant, it'll become more luminous over time and life on Earth will be impossible much earlier. I've seen estimates of 0.5B to 1.5B years.

lol 0.5B to 1.5B is a pretty big difference. Sounds like we really don’t know what we are talking about.

Maybe it'll help if you think of it as 5-6.5 billion years instead.
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