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

The search for extraterrestrial life as we don’t know it

scientificamerican.com

Post reply on HN
Print view View original

61–70 of 102 posts

Re: The search for extraterrestrial life as we don’t know it

#61

Post by albert_e »

kposehn wrote: post #11

I've always found the framework we use to search for extraterrestrial life to be too based on our own experience. It could take countless forms, most of which we could never recognize or understand, and might be present everywhere without us knowing. I'm glad that more of the science community is pushing to broaden our horizons.

I am in the same boat as you.

There is also this to consider: limits of our own imagination/ comprehension.

If we are like microbes swimming inside a droplet of water, we won't be able to imagine/ comprehend / detect beings of the scale of say flies.

Our mental abilities may also be limited in similar ways. I think that puts a limit on what we can perceive / detect / understand.

Re: The search for extraterrestrial life as we don’t know it

#62

Post by gumby »

Zigurd wrote: post #47
gumby wrote: post #28

The issue of "if you lose your keys at night, the first place you look is under the lamppost" problem with searching for alien life has bothered me too, since I was about the age of this professor's trip to Hawaii. But unlike her my musing never resulted in anything useful. I'm so glad someone is thinking about this and that that person sounds like a broad thinker!

Alternatives to the biochemistry of Earth life are hard to imagine. Silicon replacing carbon is one possibility but, as yet, despite silicon being vastly more common than carbon, we know there is no silicon life on Earth. It's just at too much of an inherent disadvantage, if it is even possible. I would bet on panspermia over silicon life.

Conceiving an alien intelligence is pretty impossible too.

Re: The search for extraterrestrial life as we don’t know it

#63

Post by antihipocrat »

perihelions wrote: post #13

Question for people up to date with modern biochemistry: if there were extraterrestrial microbes on Earth right now, with totally unique chemical origins unrelated to proteins, nucleic acids, saccharides, etc., how likely would we be to notice them? And which analytic method would find them first? Is there a systemic search for this kind of crazy stuff, and where are the review papers for them? I don't know the keywo…

If found, how could we even be sure that their origin was extra terrestrial?

Re: The search for extraterrestrial life as we don’t know it

#64

Post by Rury »

kposehn wrote: post #11

I've always found the framework we use to search for extraterrestrial life to be too based on our own experience. It could take countless forms, most of which we could never recognize or understand, and might be present everywhere without us knowing. I'm glad that more of the science community is pushing to broaden our horizons.

The thing is, people don't realize this argument fully. If you are to accept that life could take countless forms, most which we could never recognize or begin to understand, then it's quite possible rocks are lifeforms, as we don't recognize them as life now nor understand how they could be living. Since most people seemingly don't like the argument that rocks are living, then this shows that this argument (along with others) is flawed with very definition that they want "life" to have.

Re: The search for extraterrestrial life as we don’t know it

#65

Post by andsoitis »

Does life really have to be based in chemistry?

Is it more effective to search for phenotypical effects of life than life itself?

Do we care about life elsewhere unless it as advanced or more advanced than us?

Even if we could find in “space”, can we find it in “time”?

Re: The search for extraterrestrial life as we don’t know it

#66

Post by andsoitis »

Rury wrote: post #64
kposehn wrote: post #11

I've always found the framework we use to search for extraterrestrial life to be too based on our own experience. It could take countless forms, most of which we could never recognize or understand, and might be present everywhere without us knowing. I'm glad that more of the science community is pushing to broaden our horizons.

The thing is, people don't realize this argument fully. If you are to accept that life could take countless forms, most which we could never recognize or begin to understand, then it's quite possible rocks are lifeforms, as we don't recognize them as life now nor understand how they could be living. Since most people seemingly don't like the argument that rocks are living, then this shows that this argument (along wi…

> quite possible rocks are lifeforms

Humans are closer to fungi than rocks are to life.

Re: The search for extraterrestrial life as we don’t know it

#67

Post by Rury »

andsoitis wrote: post #66
Rury wrote: post #64

Earlier quoted context omitted.

The thing is, people don't realize this argument fully. If you are to accept that life could take countless forms, most which we could never recognize or begin to understand, then it's quite possible rocks are lifeforms, as we don't recognize them as life now nor understand how they could be living. Since most people seemingly don't like the argument that rocks are living, then this shows that this argument (along wi…

> quite possible rocks are lifeforms Humans are closer to fungi than rocks are to life.

This statement has nothing to do with what I am saying.

Re: The search for extraterrestrial life as we don’t know it

#68

Post by gsatic »

justinclift wrote: post #54
akiselev wrote: post #26

Earlier quoted context omitted.

Very, very unlikely like astronomically so. Most microorganisms are so small they're practically transparent so we have to exploit biochemistry to "stain" them - hence why you'll often hear of bacteria classified as either Gram positive or negative, because of the Gram stain. If the biochemistry is unique or even slightly different i.e. right handed chirality, we'd basically have zero of our usual tools at our dispos…

> There's already a whole world of terrestrial microbes that we expect or even know for certain to exist but can't culture, let alone stain, which means we can't really study them. That sounds pretty cool for a hobbyist to potentially spend time on. Anything you could recommend to look at, for following up on this unknown stuff?

[flagged]

Re: The search for extraterrestrial life as we don’t know it

#69

Post by nwallin »

cletus wrote: post #36

I'm not sure what the point of this is. In the last 60+ years we've obviously learned a lot and widened our definition of where life on Earth can live (eg subsea volcanic vents, in rocks in Antarctica). We obviously don't know the limits of biochemistry and thus in what environments life can evolve and where it can continue to live where it exists. We're certainly not going to be detecting a world full of microbes fr…

> We're certainly not going to be detecting a world full of microbes from light years away.

JWST would be able to detect an oxygen rich atmosphere like ours, which is a sure sign of life. Oxygen rich atmospheres are not a stable equilibrium; without all the plants and plankton on Earth, the oxygen in the atmosphere would all recombine, and Earth would be left with an atmosphere with no oxygen but additional CO2.

Atmospheres can either be CO2 rich or methane rich; they can't have significant amounts of both CO2 and methane. They don't exist in equilibrium; either a planet will preferentially convert CO2 to methane or methane to CO2, and there won't be any left of the other.

There are a handful of other atmospheric biosignatures that JWST can detect. Chemical compositions that are a sure sign of life; chemical signatures that are conclusive or strong indicators that life is present, even if we can't classify or describe it. Classifying exoplanets' atmospheres is a primary mission goal of JWST; it's what it's designed to do, and it's doing it right now.

Re: The search for extraterrestrial life as we don’t know it

#70

Post by andsoitis »

Rury wrote: post #67
andsoitis wrote: post #66

Earlier quoted context omitted.

> quite possible rocks are lifeforms Humans are closer to fungi than rocks are to life.

This statement has nothing to do with what I am saying.

To posit that rocks are quite possibly life forms takes the meaning out of what we mean when we say “life”.
Post reply on HN