My recurring dream for the JWST is that we switch it on and get immediately overwhelmed with indirect spectroscopic evidence of biology within multiple exoplanets, ushering in a whole new era of science. Watching that launch will be the most heartstopping moment of my life.
My recurring dream for the JWST is that it actually ever launches. :(
>Watching that launch will be the most heartstopping moment of my life.
You got that right. When Elon launched the car I was like "eh this will be just like any other launch" then as the launch started I was perched on the edge of my chair shouting "CLIMB CLIMB CLIMB BABY CLIMB" at my phone. JWST will be one of the most nerve-racking moments of my life if I watch the launch due to it's many delays.
I can see why people would focus on the risk of a flashy explosion, but I think the real risk will be with the deployment process and having gotten everything right with JWST. ESA launches are very reliably, JWST is a one time design.
I think as long as we are using rockets to lift things from our world, there will be some level of fear of failure. After all, rockets are essentially an explosion attempting to be controlled.
The problem is that the technology that JWST is built with is no longer available. The development cycle moved so fast that the industrial bits needed to manufacture JWST are no longer there, even if we have complete and detailed plans.
Very similar with how building a Saturn V today is logistically impossible, even if we can build more modern, efficient and cheaper rockets.
There is not a single crewed vehicle in operation or even planned that supports spacewalks. If it's not next to the ISS, people aren't going to be able to fix it.
At best we could send a robot, which would probably be more easily operated from the ground.
There've been several proposals for an Orion-mated orbital module with an airlock, as well as an ESA one based around their ATV. After all, the eventual goal of Orion is to allow deep-space missions to asteroids etc.
Even coming up with something from scratch is unlikely to cost the $10B we'd lose from a failed JWST.
>Could you enlighten me on how JWST could find the evidence of life?
Near Infrared Spectroscopy [0]. JWST will be the first instrument in space capable of performing NIR spectroscopy, which will be used to analyze the starlight shining through exoplanets' atmospheres for evidence of biological molecules.
If the odds of life spontaneously starting and then surviving are really low, then there really may be no other life in our galaxy (<1 trillion stars) or even the observable universe (<1 trillion trillion stars).
We have a sample size of just one (our solar system). But we already know that life on Earth began very soon after it cooled enough to have liquid water - that gives us some confidence that it can't be that hard for life to start.
We know life's been around on Earth for ~4 billion years, surviving multiple insane climate swings from subtropical vegetation and species living in the Arctic to the entire planet freezing over, multiple massive impacts from space, insane volcanism that people today just would not even recognize as volcanism. Hopefully that means life's somewhat durable.
If what you mean by 'life' is bacterium, sure. That's all that was here for 3 billion years. I don't think we'd find that very exciting.
Eukaryotes are basically a fluke. The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth.
It's arrogant to assume that life as we know it is both inevitable and inevitably complex in a manner similar to our complexity.
A practically infinite universe means potentially infinite diversity, including phenomenon that may not recognize as life at all to us, but should be equally interesting.
> The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth.
That story is very much in flux still. We're not very certain on how that occurred, let alone how many times over those billions of years.It's linked to the Great Oxygenation Event, likely, but we're still in the very early stages of understanding that era.
> A practically infinite universe means potentially infinite diversity, including phenomenon that may not recognize as life at all to us, but should be equally interesting.
As is usual in science, it depends. If you are dealing with matter like us, then there are only a few universal solvents (5? I can't find the citation). In those solvents, there are a countable amount of ways that the chemistry will allow for 'life' to 'evolve'. The ways that the life can then evolve are really complicated and diverse, but there does seem to be a evolution/development trade-off, where you have to go through developmental 'keyholes' to get to a new level of complexity. Is that infinite? I've no idea, but it feels like a different ordinal of infinity.
"Eukaryotes are basically a fluke. The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth."
Isn't it possible that once it happened, it filled a niche that prevented something similar from happening again? Thus, the fact it only happened once doesn't tell you how probable it was to happen at all.
I have the impression other similar things may have happened as well. Recent articles about a viral-like protein that may be crucial to how long term memory works suggest that chance combinations of life that melded may be a theme.
>Isn't it possible that once it happened, it filled a niche that prevented something similar from happening again?
Except it did happen again. Chloroplasts and mitochondria organelles are so different they are considered to have been generated from separate events.
Assuming that there are niches though is dangerous, because it assumes the evolution is guided, which it isn't. It's entirely possible that this has happened many times throughout history, but the resulting new organisms couldn't compete and died off without a leaving a trace.
That's why assuming it only happened twice is survivor bias.
"Assuming that there are niches though is dangerous, because it assumes the evolution is guided, which it isn't"
No, I wasn't suggesting that evolution is guided. If something evolves, and it ends up in the way of anything evolving similarly, it's not purposeful. It just is, as long as some catastrophe doesn't clear the way.
Edit: your comment "It's entirely possible that this has happened many times throughout history, but the resulting new organisms couldn't compete and died off without a leaving a trace." is a distinction without a difference to me. That's what I meant by it not happening, and the existing organisms occupying a niche.
I think finding life on any other world would be very exciting even if uni-cellular. While we know which organic compounds are common in the nearby universe, we have no idea what other "architectures" are feasible, even granted an environment (temperature, pressure, solar spectrum) roughly like ours (including extremophiles). Life optimizes, but it's also path-dependent. Surely Earth's genetic code is accidental and path-dependent, but how constrained is the protein design space? For example, given a star like ours, do we have optimum chlorophyll? Or if you make your living as a sulfate reducing prokaryote, how many different ways can you do that?
No telescope will tell us what the ribosomes of Barnard b look like, of course.
But if only macroscopic life excites you, is it clear that you need eukaryotes for complex (multi-cellular) life? And how can you know it happened only once? It could also be that it happened multiple times, but one strain outcompeted (or just ate) every other. There could be undiscovered alternate "eukaryotes" if they remained single-cellular, too.
Actually, cell-level endosymbiosis seems to have happened a bunch of times. Chloroplasts in plants are basically the same deal. The amoeboid paulinella chromatophora seems to have an independent lineage of chloroplasts. The Wikipedia page on endosymbiosis has more examples. It's starting to look pretty common.
Also, complex multicellularity (IIRC defined as differentiated cells) has evolved (according to the latest theory) six times. So that looks pretty likely to happen eventually, as well.
Human-level technological civilization, yeah, that looks like a one-time thing so far.
Edit: check out this article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3910982/ They just casually mention "diatom-derived plastids", which are basically organelles that used to be diatoms, eukaryotic organisms in themselves!
Uh, that would be absolutely, positively very exciting to find microbes that originated someplace other than Earth. If you expect we'll find little green humanoid-looking things, you're going to be highly disappointed for likely centuries.
> bacterium, sure... I don't think we'd find that very exciting.
I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever. For the religious, discovery of extra-terrestrial bacteria will upend most of the interpretations of their holy books. Those books are the foundation of modern Western society (Do not kill, do not steal, do not take another man's wife, etc). By upending the basis of society we have no idea how humanity will end up. Will we throw everything based on the bible away? Reinterpret them? Will the Jews and Muslims reconcile? Will the Christians set out on another crusade? Will that crusade be to the extra-terrestrial bacteria to sterilize them?
> event that created Eukaryotes ... happened only once.
The insemination event which led to your birth also happened only once. However, it is does happen often enough in systems that have the right conditions. And there are trillions of available planets, right here in the Milky Way.
> I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever.
Scientists yes, the rest won't care that much. It'll make the news sure but it'll be out of the headlines within a week. Maybe I'm a cynic but I'd put money on that being the case.
Additionally speaking as a religious person, it wouldn't change any of my beliefs. And I'm struggling to see how it would for others of my faith really.
It's true the universe is very large and feels infinite, but we know that it's about 25 billion galaxies (the size of the Milky Way) and that it has finite mass.
Sure, these numbers are incredibly large, but like you said, we're dealing with probabilities that are also incredibly small. There should be a cutoff somewhere for the observable universe as to what it is probable or improbable of producing.
The universe and the observable universe are different things. As far as we can measure, the universe appears to be flat (by measuring the observable universe). With finite mass, but expanding space, how is it not infinite?
If it were the case that is incredibly unlikely for life to get started in general, we would still be making those observations, give that we are here. This is the problem with only having one poorly understood data point that we ourselves are part of.
I'm optimistic that there is life out there. And if so, we should be able to get hard evidence by studying exoplanet atmospheres in the next few decades. Until then, it is very difficult to assess.
We have a selection bias happening here. We observe life because if life didn't appear as soon as the Earth was cool enough, the odds of us being here and able to reason about that would be small. We shouldn't consider it particularly abundant until we find a separate biosphere where life developed independently.
I personally think it's really easy to get molecules making copies of themselves, but we don't have enough data to claim that.
No, we can actually gain some statistical confidence here that life can't be that hard to start. That doesn't mean it's true to reality, just that with the information we have at sample size = 1, we do actually know something.
The fact that we're not on some planet around a red-dwarf a trillion years from now discussing this, but on a relatively young world does in fact tell us something.
Further, the speed at which it happened here is very compelling.
This planet is 4.6B years old
Life is at least 3.5B years old. Maybe older. And for the first few hundred million, Earth was a fireball. So it happened almost as soon as it was possible to.
Other thing to keep in mind though is that, an ocean is a big places so there are lots of events where life has a chance to start. So even if the individual chance for an event to spawn life is low, you have a lot of chances. Way, way bigger than 1 trillion chances per planet I'd bet.
And after life reaches a certain point, wiping it out is incredibly hard. I don't know what it would take to wipe out all life, as in every last bacteria too, on Earth...
So while I might accede intelligent (especially technological) life might be rare, I sincerely doubt life itself is.
Not meaning to be condescending, that's not how probability works or is expressed.
Also, the fact that the ocean "is a large place" says nothing about how probable or not the events to create and sustain life are.
I understand most people have this gut feeling that because the universe is vast and ancient there must be something out there (and I have it too), but we just don't know.
We just have no idea exactly how hard life is to develop and be sustained. We just started having theories (a handful at that) about how we transcended from chemistry to biology. The prevalent theory for example is that the moon's unusually big size and proximity was the catalyst for that to happen. How many planets have extremely big moons in such close proximity? How many million other factors played a role assuming the tide theory is even close to accurate?
It's just an infinitely complex problem and we just don't know.
Not quite, it's the opposite. We're having a hard enough time theoreticizing how self-replicating nucelotides with adequate lipid-bilayer maintaining molecular machinery occurred naturally on our volcanic, reducing-atmosphere of a planet.
Abiogenesis isn't the same as evolution, and given what limited knowledge we have of prebiotic Earth, life shouldn't have naturally occurred here. Ocean size doesn't matter in this case when the ocean isn't able to form a single self-replicating cell. The dice being rolled don't even have the number you need.
This same argument can be applied to argue that aliens speak English.
The reason we know that aliens don’t speak English is that, as vast as the universe is, the set of possible languages is much larger and so rich with possibility that it need never repeat.
So why do we think the set of languages spoken by chemistry is any different?
Remember, it's not that you're rolling 1 billion dice expecting to get all sixes. It's that you're constantly re-rolling the dice that aren't sixes to get sixes.
I don't get this point. The probability argued would take this into account. It could be that the probability is _that_ small that even if you keep rolling you don't reach it.
How do you figure? The distances are tremendous, and it seems like we ate guessing at what the climate is like on the nearest exoplanets. How would we spot life? Wed need probes to travel near the speed of light to have any chance. That's a long way off.
We have spectroscopy. Complex biological molecules can be identified through spectrographic analysis of starlight passing through the exoplanet’s atmosphere. JWST is equipped with a near infrared spectrograph to do exactly this.
Traveling near the speed of light or at it will never happen. Infinite energy / mass problem. Plus everyone back at earth will have aged equivalent to the number of light years away, while it may feel only like a couple weeks on the ship. Unless we develop some type of wormhole technology, we're pretty much confined to our immediate system for any realistic exploration and communications.
I think the comment was made in relation to star's age, as it is one of the oldest in our galaxy. If life requires time to develop, this planet gave it a good shot at that. Also, the planet's climate may have been more favorable to life in the star's heyday, which means that even if nothing living will be around when we'll get there, that still makes it a very promising archeological place.
Finding living organisms would in general be bad news, but it depends on the type of life. It would tell us about why we don't see a universe filled with intelligent life. It would increase the probability though that the great filter is ahead of us, especially if the life is multi-cellular.
Long story, short: It would have to be sentient life in order to get any long-lasting attention. In the recent past, plenty of scientists were sure that simple life (e.g., lichens) existed even on Mars. The general public didn't go nuts over that. So finding simple life—for sure, this time—wouldn't change anything this time around, either.
If the Great Filter is ahead of us, becoming a space-faring civilization sooner increases the odds of surviving it.
(And that's the main argument for the Great Filter being behind us, it is hard to imagine that we are fighting against astronomical odds to become space-faring.)
The argument the great filter is ahead of us though is based on the observation that even with slower then light spacetravel, over the timeframes of the existing universe a species could still colonize the entire Milky Way in something like a 100,000 years with von Neumann probes (of which organic life would be a good basis for building one).
There should be life everywhere it's possible by technological panspermia - but we don't seem to observe that. What stops elder civilizations from doing this, is the big mystery.
Unless of course, as a poster above notes, if we fire up the JWST and discover chlorophyll-fringes in the spectra of just about every rocky planet we can see. That'd imply a lot.
I posted this above, but it's a good answer to you as well.
I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever by the discovery of extra-terrestrial life. For the religious, discovery of even extra-terrestrial bacteria will upend most of the interpretations of their holy books. Those books are the foundation of modern Western society (Do not kill, do not steal, do not take another man's wife, etc). By upending the basis of society we have no idea how humanity will end up. Will we throw everything based on the bible away? Reinterpret them? Will the Jews and Muslims reconcile? Will the Christians set out on another crusade? Will that crusade be to the extra-terrestrial bacteria to wipe them out as well?
Doesn't surprise me at all. There are a multitude of opinions. But the question was "what will change", discussing those that accept the new findings and have no need to change is orthogonal to answering the question.
Some will outright deny the existence of the new information about extra-terrestrial life.
But, for most believers, I bet there will be a re-articulation of the tenets of the faith, a transformation of their existing doctrine into something that seems compatible with the new information.
Maybe this is not quite the right way to look at it, but it seems to me that, taken together, these religious faiths have already survived many, many highly traumatic historical and informational challenges and persecutions (e.g. invasion of the "sea peoples" in the Eastern Mediterranean, rise and fall of the Greek Empire, rise of the Roman Empire, destruction of the temple in Jerusalem, Constantine's conversion, religious councils which redefined Jesus, fall of the Roman Empire, Galileo, Copernicus, Reformation, Magellan, Enlightenment, British Empire, Darwin/Evolution, Napoleon, Hubble–Lemaître and modern cosmology, the Holocaust, etc ...)
For example, it seems to me like modern astronomy has drastically challenged and damaged the very notion of a saintly or holy figure "ascending into heaven," but believers whose holy books explicitly describe such an event have not abandoned their faiths in large numbers because of it.
Another example is modern biology and theories about the origin of humanity. That didn't stop religions based on the book of Genesis.
IMHO, hard evidence of extra terrestrial life will be just one more speed bump in the history of these faiths.