Simulation Pinpoints the Most Likely Spots For Life In the Milky Way (sciencemag.org)

sciencehabit writes: Our home galaxy isn't as hospitable to life as you might think. Cosmic radiation, supernova explosions, and collisions with small galaxies make much of the Milky Way too hellish for biology. But a detailed new simulation locates quiet and fertile cosmic neighborhoods, including a surprising locale: wispy streams of stars flung far beyond the main body of the Milky Way.

Comments

And when we finally discover life elsewhere.

[Z00L00K]

And when we finally discover life elsewhere it's not where we expected it to be.

Re:And when we finally discover life elsewhere.

[Velox_SwiftFox]

Outside the Slow Zone

Re:And when we finally discover life elsewhere.

[malditaenvidia]

And when we finally discover life elsewhere it's not where we expected it to be.

In our hearts?

Re:And when we finally discover life elsewhere.

[war4peace]

Thumbs up for reference, Vernor Vinge FTW.

Re:And when we finally discover life elsewhere.

[Anonymous Coward]

In our hearts?

On our skin. Microorganisms.

Multinational project to build a star ship

[Anonymous Coward]

We need to get over our fear of nuclear energy, and all nations must come together to build a star ship and explore the universe. Everyone who is willing should contribute - from top-level physicists to school children. All nations must be allowed to contribute, from agrarian cultures to space-faring nations.

We need to set apart our differences and come together under a unified project of a grand scale. No one nation can build something like the Enterprise. It will take the collective will of every nation on Earth to see a project like this through to completion.

As long as we're fighting each other in war and eating meat this can never happen, unfortunately.

Re:Multinational project to build a star ship

[Anonymous Coward]

Well, since I'll never stop eating meat until I die, I estimate it'll take at least another 20-30 years before you guys can start with the work. But perhaps you're lucky and I die earlier.

Re:Multinational project to build a star ship

[Anonymous Coward]

War never changes.

Re:Multinational project to build a star ship

[ElectricHellKnight]

We need to get over our fear of nuclear energy, and all nations must come together to build a star ship and explore the universe. Everyone who is willing should contribute - from top-level physicists to school children. All nations must be allowed to contribute, from agrarian cultures to space-faring nations.

I like your optimism, but it's just a little too idealistic. (Although I very much agree with getting over the fear of nuclear energy.) Hell, just look at the comment section on this one article. You think people will get along long enough to focus on building a starship? While I don't see the technology for a such a thing arriving anytime soon, I don't think the collective effort of all of mankind will be required to continue human advancement into space. After all, it was during the height of international tensions between superpowers (the Cold War) that the serious effort was made to put a man on the moon.

On a slightly similar topic, why do people always assume that a highly intelligent alien race would be unified? Nearly every type of life (no matter how intelligent) on Earth fights with other members of it's species, why would we not expect the same from life elsewhere in the universe?

Drake Equation

[Elgonn]

The drake equation is a thought experiment of literally unknown variables. This entire simulation is a joke.

Re:Drake Equation

[wonkey_monkey]

I don't think it has anything to do with the Drake equation.

Re:Drake Equation

[BitZtream]

But the same statement still applies.

Its not a simulation, that implies some sort of basis in reality.

This 'simulation' is no more realistic than a simulation in a video game. Its based entirely on made up BS with no actual science behind it. HINT: people calling themselves scientists or people say that are practicing science all the time when they don't know what the word means.

This is fantasy, not science. There used to be an entire cable tv channel devoted to this, now it please Wrestling or something all the time

Re:Drake Equation

[buchner.johannes]

Most variables have become known to some degree in the last few years, namely the number of planets per star, the size distribution of planets, fraction of planets in the habitable zone, etc. see http://arxiv.org/abs/1508.0120... (it does not use the Drake equation).

The unknown in the Drake equation is the fraction of habitable planets in which life (or a intelligent civilisation) arises, which probably remains speculation until either >3 civilations have been found or civilations have been ruled out for a few hundred exoplanets.

Re:Drake Equation

[Anonymous Coward]

Most variables have become known to some degree in the last few years, namely the number of planets per star, the size distribution of planets, fraction of planets in the habitable zone, etc. see http://arxiv.org/abs/1508.0120... (it does not use the Drake equation).

The unknown in the Drake equation is the fraction of habitable planets in which life (or a intelligent civilisation) arises, which probably remains speculation until either >3 civilations have been found or civilations have been ruled out for a few hundred exoplanets.

There are a lot more unknowns than that.

Even you missed the fact that the definition of the "habitable zone" is based on a sample size of one.

And that the "number of planets per star" is actually "the number of planets per star that we can see in this tiny corner of the universe".

Re:Drake Equation

[thinkwaitfast]

The DE is the Fermi Problem.

Re:Drake Equation

[Anonymous Coward]

Even you missed the fact that the definition of the "habitable zone" is based on a sample size of one.

True, but then that helps our argument, not yours.

Because while the habitable zone might be larger than we anticipate (and thus make it more likely for life to exist), it absolutely cannot be smaller than we anticipate (since we are the lower bound on that, any lower and we would not exist).

Re:Drake Equation

[Gavagai80]

We also need to define civilization. We've not even ruled out the possibility of other civilizations in our own solar system, below the ice of Europa or Enceladus. We can surmise that they're probably not space-faring, but we haven't mapped those worlds in enough detail to rule out even that.

Re:Drake Equation

[malditaenvidia]

This 'simulation' is no more realistic than a simulation in a video game.

I don't know about that: racing and flight simulators do take things like physics and weather into account. Farming sims have a firm basis on reality, by means of being boring, hard work.

Re:Drake Equation

[wonkey_monkey]

But the same statement still applies.

Does it? Where does it state that they made up all their numbers?

Its based entirely on made up BS with no actual science behind it.

No actual science? How did you come to that conclusion? You checked, did you, that they used no science at all? Or did you count all the science and find out that they didn't use enough?

Did they, perhaps, accidentally simulate gravity using an inverse-cube law?

Re:Drake Equation

[Anonymous Coward]

The article does state that they "estimated" a number of their most important variables. To come to the daft conclusion that it is not based on science at all is, well, pretty daft. My problem with the article is that they assume that an Earth-like planet will be the only place we'd find life like what we know from here. To my knowledge all we'd need is a wobbling sphere, temperatures high enough to sustain liquid water, at least partially, and enough carbon to go around. None of these requirements naturally lead to the conclusion that only rocky worlds revolving around sun-like stars are eligible. It's a good place to start, but the premise is still off.

Re:Drake Equation

[sycodon]

400 billion stars in our Galaxy, 100 billion galaxies in the Universe (that we can guess at). So even with ONE Planet for each star the odds of intelligent life out there is overwhelming.

Re: Drake Equation

[Anonymous Coward]

The thing us, while generic planets like you mention could well be everywhere, looking only for Earth-likes means we'd be guranteed to find more life since we'd only be looking for a known minimum initially.

For all we know there could be life using other liquids capable of replicating waters uses in biology.(namely galvanic and minimally reactive with whatever chemistry develops around it)
We already found those extremophiles capable of replacing phosphors with arsenic and still be healthy.
  We've developed metallic DNAs and such. A metal-rich and enery-rich planet could lead to life using slightly more energetic chemistry to sustain themselves.
We already know they can work, but whether they can come about so easily in nature is the important question.

Everyone always assumes we are the height of biology, the best it can get, but we aren't. Not even slightly. There is SO MUCH room for improvement over our biology and chemistry.
We are, quite simply, the 'most efficient', AKA the least amount of effort to continue existing, the very driving force of evolution. It has no goals, it just is.
Given more energy, naturally or artificially, we could be so much more. But due to our planets lack of readily available energy, our genome has made loads of compromises over the time we evolved.
How it will react to our industrialized society is still up for time to decide. We haven't been in the era long enough for anything major to change.
We also have another major climate shift happening, which will, without a shadow of doubt, lead to another ice age in the next thousand years, just like it has every other time the climate has gotten chaotic ine ice and sefiment cores.
People like to think Earth is perfect for life, 'it was made for us'. Was it fuck. Earth is unstable as hell and I'm surprised we made it out the last ice age!
Half the human race will almost certainly die in the next one. Along with half of the rest of Earths species.
So much for stable. That's if an asteroid doesn't wreck us or some land dispute causes a nuclear war.
So, remember kids, we are very lucky to even be alive right now. You never know when that might end.

Re:Drake Equation

[rgbatduke]

Except that the consideration of uniformity at and up to the boundaries of sight around 13 billion LY away implies that the visible cosmos is only a small fraction of the whole thing, which is at least 100-200 times larger (length scale) that the visible portion. Which means that you are underestimating everything by at LEAST a millionfold. To quote Adams:

Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.

So let's shoot for order of 100 quadrillion galaxies in the material Universe, each with order of 100 billion stars, with order of 10 to the twenty-seventh planets. Yes, most of that is out beyond the surface horizon of the Big Bang and nearly all of it is as fundamentally disconnected from us by time and space as if it didn't exist at all (and to a logical positivist, perhaps it does not, showing the idiocy of the position that meaning derives from empirical testability) but the point is that your estimate of 4 times 10 to the twenty second is very conservative, and the actual number is likely many orders of magnitude larger. And even the estimate of 100 times larger in all directions is a lower bound -- there is no defensible upper bound AFAIK so far, and there may not be an upper bound if space is actually infinite.

rgb

Re:Drake Equation

[sycodon]

Well, I try not to get ahead of myself.

Re: Drake Equation

[Grishnakh]

Another factor is: why do you want to seek out life? If you just want to find other living alien species, that's fine if you're a xenobotanist or whatever, but that's an entirely different goal from finding intelligent alien life, where presumably the goal is to make contact and communicate. You're not going to do that with alien plants and their equivalent of small insects. Just look at Earth: there's countless species, but plants are completely unintelligent, and there's only a handful of animal species that have any real ability to communicate beyond simple stuff like "I'm hungry and my food dish is empty". And out of those species, there's only one species which has created written communication and technology. If we find life teeming on other planets, it's very likely we'll find a bunch of planets with very interesting lifeforms, but nothing that's built a civilization or technology or advanced communication. Heck, if you make a time machine and go back in time 1 million years, you'll find humans, but they won't be all that interesting to talk to unless you want to talk about how to make a sharpened stick or something; we've only been really interesting for the past 10k years or so. So the point is: the incidence of intelligent, civilized life may be very, very low, and I think far more rare than life in general.

Re:Drake Equation

[sudon't]

I agree. The Drake Equation makes predictions based on a sample of one, and with no knowledge of how life even begins. But this simulation really says nothing except that, these areas of the galaxy are safer for life, therefore we ought to look here when looking for life. They're simply attempting to map out those regions.

Re:Drake Equation

[sudon't]

Most variables have been figured out? We have no idea how life began! It's possible that it might take more than a planet simply orbiting in a Goldilocks zone for life to arise. It may be that an axial wobble is needed to create seasons, and that a moon might be necessary to create tides. If that's the case, a lot of relatively unlikely events have to first take place. How many planets have all that going on? Even if we knew how many planets did have all that going on, it would still tell us nothing, because we simply don't know what exactly caused life to arise. As far as we can tell, it's only happened once, even on this planet. If we could figure that out, we might be able to make some predictions.

Re:Drake Equation

[buchner.johannes]

That's what I said.

An optimist could also argue that we have some rough idea how life began, at least on Earth. We do have some pieces of evidence of how it went from A to B.

Way too many assumptions

[Anonymous Coward]

Many of the events like supernova and collisions occur on timescales of millions of years, which can be a very long time with respect to chemical, biological, and evolutionary processes. Despite some areas of the galaxy being very busy, there's still mostly open space, such that collisions aren't especially likely for a given entity. Perhaps some of the regions where such events are more frequent are statistically less favorable to long periods of calm on the order of tens and hundreds of millions of years, but life can't really be ruled out. Given that there are more stars in those regions, there may be a much larger number of opportunities where life could develop. Also, interactions between stars can also help life form. They might nudge frozen comets and send them on collision courses with planets where they can provide ingredients that help make them habitable. They can also alter the orbits of planets, which can have the effect of moving planets into habitable zones that otherwise weren't habitable. With respect to cosmic rays and radiation, our magnetic field protects us from many of those things and that may be beneficial for the formation of life. However, as we've learned on Earth, life can develop and thrive in some extremely hostile places. We shouldn't assume that life couldn't develop mechanisms to withstand the effects of things like cosmic rays.

Perhaps those parts of the galaxy wouldn't be favorable for the lengthy evolutionary processes that took place on Earth and might be hostile to humans, but it's incredibly arrogant to assume they are hostile to all life. We have a sample of one, so how the hell can we know how life might evolve elsewhere in the galaxy? And remember, being that those are busier areas of the galaxy, there are more stars and more planets, and sheer numbers have to count for something. As Q once said of Jean-Luc Picard, "oh, the arrogance!"

What about that other galaxy,

[Black Parrot]

far, far away?

Re:What about that other galaxy,

[pipedwho]

That's old news from a long time ago.

Re:What about that other galaxy,

[Anonymous Coward]

That's old news from a long time ago.

And who wants to meet Jar Jar anyway?

Although if we're lucky, Han will shoot him first.

Re:What about that other galaxy,

[Foobar of Borg]

That's old news from a long time ago.

And who wants to meet Jar Jar anyway?

Probably Yo-Yo Ma or Boutros-Boutros Ghali. They'll all have some Mahi-Mahi.

Lots of assumptions

[surfdaddy]

Well, we are carbon life forms and we are looking at the situation from our perspective. I would say the chances of these simulations being accurate are vanishingly small. Do we REALLY understand how and where life forms? Being carbon-based, is it really realistic to assume any and all life is like us, formed like us (even if our other assumptions about our own formation are correct)? At one time we thought we were the center of the universe, right here on earth. We also thought that Mars has always been dry, and we thought that Pluto would be a featureless cold world. And THAT's only assumptions within our solar system!

You can be pretty confident that this "detailed new simulation" isn't very accurate at all.

Re:Lots of assumptions

[h33t l4x0r]

So we should assume that most life will be non-carbon-based? How does that make more sense?

Re:Lots of assumptions

[stevelinton]

The simulation is probably accurate, the summary article not so much. The simulation answers a rather more nuanced question -- something like "where in the galaxy could Earth;s history possibly have been replayed?" Some places there aren't enough heavy elements, others there are too many supernovae, or near-misses with other stars. Yes, life could evolve in other places, maybe -- on a neutron star, or in the complex magnetic structures in gas clouds near the central black hole or ..... but, although the article suggests it, that is not really the question being answered by the simulation here. Also note that elements much heavier than iron are pretty rare everywhere. Even if you could identify a feasible biochemistry based on iridium or something, there is very unlikely to be enough iridium anywhere for it to evolve.

Re:Lots of assumptions

[buchner.johannes]

Stars predominately form He (which is chemically inert), C, N, O (see CNO-cycle), a bit of Fe as well as a little bit of heavier elements from supernovae. Therefore life anywhere will most likely be formed of a combination these elements just because of their abundance.

Re:Lots of assumptions

[delt0r]

Well really bad scifi aside (Dr Who, star trek). A proper look at elemental abundance and chemical properties, something that we do know with a lot of accuracy, non carbon based life forms are a pipe dream. The only proposed element is silicon, and it is shit. Total shit. It simply does not form the range of compounds you need. Does not have any kind of useful solvent. doesn't naturally form anything interesting even in the slightest. And where you have silcon you have carbon. In fact silicon is far more prevalent on earth than carbon, yet life only uses it for shells of some diatoms.

Compare to carbon, where we have giant clouds of interesting organic molecules just floating around in space, that can bond to itself and other elements in an infinite range of ways with and equally diverse range of properties. Water is a *very* good and strong solvent and highly polar. But in a pinch i guess say methane may work as a solvent. But it wouldn't be as good as water.

In short there are very good reasons to believe all life in this universe will be carbon based. But lets not forget, that gives a huge scope for varation from what we see here on earth. With equal certainty all alien life will not be biocompatible with us. If we found anything with DNA, RNA etc, it would be very strong grounds to suspect common origin.

Some people i work with here, are astrobiologist. Honestly carbon is as impressive as a bable fish.

Re:Lots of assumptions

[avandesande]

I am not sure how life forms, but I can tell you that the ratio of elements on the planets are governed by a common set of physics that should be consistent throughout the universe. It seems probable that carbon based life forms predominate.

Re:Lots of assumptions

[Anonymous Coward]

My computer isn't carbon-based.

Re:Lots of assumptions

[delt0r]

And it is also not life. Could replicators be made? perhaps (that is a big perhaps, try starting with raw SiO2 and create semiconductor grade silicon). But this is *not* life as people are talking about. Also it doesn't work as well as you would think, a von neumann replicator perhaps (ie provide a lot of pre built parts).

Re:Lots of assumptions

[gstoddart]

Well, we are carbon life forms and we are looking at the situation from our perspective. I would say the chances of these simulations being accurate are vanishingly small. Do we REALLY understand how and where life forms? Being carbon-based, is it really realistic to assume any and all life is like us, formed like us (even if our other assumptions about our own formation are correct)?

Someone asks this question every time this topic comes up.

Of course we don't understand how life forms. Yes, it's possible life exists in some form we can't even guess at.

Now, here's the rub: we have no idea how we would look for life which is fundamentally different from is. None, nada, zip. We can look for conditions we could exist in, because we know what to look for. What we can't do is imagine how in hell we'd look for a "silicon-based Dactarian shit worm".

You simply can't design any meaningful scientific experiment which says "and now we will try to identify possible places where a silicon-based Dactarian shit work could exist". Because we have no idea under what conditions it would thrive in, or how it could possibly exist.

Looking for conditions which would be favorable to forms of life we have no idea how would work or exist isn't science, it's science fiction -- because anything you tried to look for is just pulling random ideas out of your ass.

So what actual scientists have done is say "well, let's not concern ourselves with making stuff up and looking for it, let's look for what we do know."

Because it's the only thing we can do.

Do you really expect a "very accurate simulation" based on things which are at best speculative fiction? Because that's what looking for any form of life which isn't carbon based is. But it sure aint science.

Re:Lots of assumptions

[Anonymous Coward]

Not assume, just understand that life out there may not be that familiar to us. We may not even recognize it if we see it.

Re:Lots of assumptions

[TeknoHog]

silicon ... Does not have any kind of useful solvent.

Compare to carbon, where we have giant clouds of interesting organic molecules just floating around in space, that can bond to itself and other elements in an infinite range of ways with and equally diverse range of properties. Water is a *very* good and strong solvent and highly polar. But in a pinch i guess say methane may work as a solvent. But it wouldn't be as good as water.

I don't see what water (as a solvent or otherwise) has to do with the carbon vs. silicon issue. The interactions between water and carbon-based life are mainly due to other elements such as hydrogen, oxygen and nitrogen in organic compounds, not the carbon backbone itself.

If water were such a great solvent for organic compounds, then I'd be very afraid to drink any...

Re:Lots of assumptions

[Anonymous Coward]

carbon based life are the von neumann replicators.

Re:Lots of assumptions

[delt0r]

And your computer isn't, and not all von neumann replicators are life. Even proposed nanobots used carbon based chemistry. ie Drexler's engines of creation.

Re:Lots of assumptions

[delt0r]

So a solvent is important for moving things around. Mobility of compounds in other words. It turns out that some form of general mobility is always required, otherwise it would just sit there doing nothing. Without mobility nothing can spontaneously from. Water is again much like carbon, especially unique. However it is true that other solvents are possible. The most likely being liquid methane, because it can plausibly exist.

It should also be noted that *no one* has came even close to the most basic set of metabolism for anything other than carbon based life, in a water based solvent.

Re:Lots of assumptions

[Anonymous Coward]

We also thought that Mars has always been dry

We thought it had intelligent life before that (the face on Mars.)

Re:Lots of assumptions

[amorsen]

If water were such a great solvent for organic compounds, then I'd be very afraid to drink any...

Selection bias. Water is an almost universal solvent. Everything we see is stuff that is left behind after water dissolves the rest, so to us, water does not seem very potent.

Re:Lots of assumptions

[Foobar of Borg]

And it is also not life.

Says you, ugly bag of mostly water!

Re:Lots of assumptions

[david_thornley]

Stellar composition isn't uniform. Some stars formed with few heavy elements (lithium and up) because there weren't as many supernovas around before they were forming.

Re:Lots of assumptions

[Ranbot]

Well, we are carbon life forms and we are looking at the situation from our perspective. I would say the chances of these simulations being accurate are vanishingly small. Do we REALLY understand how and where life forms? Being carbon-based, is it really realistic to assume any and all life is like us, formed like us (even if our other assumptions about our own formation are correct)? At one time we thought we were the center of the universe, right here on earth. We also thought that Mars has always been dry, and we thought that Pluto would be a featureless cold world. And THAT's only assumptions within our solar system!

You can be pretty confident that this "detailed new simulation" isn't very accurate at all.

It's funny you bring up Pluto, because I was thinking about how the surprising processes at work there, far from the warmth of a star show we have very little basis for predicting things in the universe. Any large body that can internally retain heat in it's core has the potential for a stable environment to support life.

Re:Lots of assumptions

[Anonymous Coward]

"With equal certainty all alien life will not be biocompatible with us."

I do not think you have presented any evidence to support this.

"If we found anything with DNA, RNA etc, it would be very strong grounds to suspect common origin."

Or this. What you are implying is that abiogenesis and evolution can happen more than one way. I think it is highly unlikely. I think we will eventually come to find that "life" as it is defined originates from the mathematics embedded in the laws of physics themselves, and that there is only one way it could have happened up to a cellular level, and even beyond that I think we will find remarkable similarities between intelligent life on Earth and intelligent life elsewhere in the universe. There is a thought experiment you can do, which is to ask, could it have happened any other way? Incredibly, for many this such as having five fingers or having a head on top of a body, etc... you will find it can only happen one way if it evolved. So, I suspect, if we do find life, it will look a lot like us. That said, even if it does not, at the cellular level, I would bet good money you will find very similar things going on (DNA, RNA, etc...). I do not think it means "common origins" but rather that we both live in the same universe governed by the same laws of physics.

Re:Lots of assumptions

[delt0r]

You would think wrong. The math the chemistry the everything. There are literally 1000 ways to skin this cat. No one believes in the field that this set of amino acids/DNA and RNA is somehow the "fundamental" optimal or even particularly special. In fact the real question is why just 20? why not 10 or 50 amino acids. There are more than possibilities for DNA, or you go as low as 2? It is like assuming everyone is going to be humanoid. It works in shit sci fi but doesn't hold up to proper science.

This is good research.

[Anonymous Coward]

We need to know where to send the civilization-killing bombs. Better them than us.

Simulation is wrong.

[UnknownSoldier]

Life tends to favor binary stars. Our single sol is the anomaly.

Re:Simulation is wrong.

[Anonymous Coward]

It would be the other way around, if anything.

That said, you're a kook.

Re:Simulation is wrong.

[KGIII]

[citation needed] for the first sentence. No, I'll need actual proof, not speculation.

Re:Simulation is wrong.

[Anonymous Coward]

All our evidence indicates the opposite.

Re:Simulation is wrong.

[UnknownSoldier]

There are many things modern Science / scientists are ignorant about. Whiteholes, the 6 fundamental forces (strong intergalactic and weak intergalactic), Life all over the universe, hell, let alone life in our (own) solar system.

Your fallacy is assuming Science is the only way of knowing truth. Science, the CCW system, only removes falsehood. The polar opposite CW system adds truth and is not based on proof.

You're like a blind man asking for proof of color -- the only valid proof is experience. You'll get your answer in ~2022.

Until then, the question you should be asking is not "Prove how you know these things?", but one of yourself: "Why don't I (yet) know what others know?"

Re:Simulation is wrong.

[KGIII]

Thanks. I chuckled.

We can rule out....

[meglon]

....the entire local area that's received radio broadcasts of Slim Whitman, obviously. https://www.youtube.com/watch?...

Supernovae as risk

[Framboise]

The research focuses on risks for life linked to cosmic radiation produced by supernovae (and massive stars in general).

This is only one of the risks. In dense regions of galaxies stars perturb the planetary orbits sufficiently frequently to destroy any climate stability. The solar system has been lucky not to have a star nearing the whole solar system in the last 4 billions years, such that even the outer planet orbits are near from circular.

On the other hand it is not difficult for life to screen strong cosmic radiation, such as
in the ocean and deep in the earth crust where most of the biomass exists. So the argument of cosmic radiation killing all life is probably wrong.

Re:Supernovae as risk

[wonkey_monkey]

On the other hand it is not difficult for life to screen strong cosmic radiation, such as in the ocean and deep in the earth crust where most of the biomass exists.

And that's why I'm staying in the basement.

Re:Supernovae as risk

[Anonymous Coward]

IMO, the basement is the best place to build a mini stargate, if you've got 100 pounds of pure titanium, 200 feet of fiber optic cable, seven 100,000 watt industrial-strength capacitors, and a toaster.

Re:Supernovae as risk

[rgbatduke]

Building stargates aside, the problem with radiation is tied to the problem with magnetic moments. The radiation from the local sun alone is enough to make life anywhere from pretty unlikely at all to pretty unlikely to evolve into a rich ecology if the planet in question hasn't got enough of a magnetic field to provide a radiation shield from both cosmic rays and the solar wind. Without it, atmosphere is just blown away by the solar wind and cosmic rays reach the surface in abundance. The solar magnetic field may also be important, or rather the coupled geosolar field may be key. Oceans won't last without a stable atmosphere for the billions of years (apparently) necessary to get "interesting" life forms.

Another issue that I think is very much up in the air is how important the moon is to evolution. We have a very limited sample in our own solar system, but there are three planets that "should" be in a generically habitable zone. Earth and Venus are almost the same size, but Venus has no moon. As a consequence (?) it has an incredibly dense atmosphere (where I'm speculating that the collision that resulted in the moon blew off a substantial fraction of the Earth's early atmosphere and altered the composition of that which remains). Mars is perhaps too small to bind an atmosphere of the right composition, but in any event it lacks enough of a magnetic field to keep the solar wind from stripping off the atmosphere it has/had. It may have life. It may have HAD life. But it is very unlikely to be a place where life can develop into a complex ecology, let along intelligence.

It could well be that intelligent life requires several more "ands" of additional conditions: a planet with the "right" magnetic field in the habitable zone for the star in question, that has to have the "right" magnetic field as well, with at least one largish moon close enough to churn up its atmosphere (or worse, a moon that "has" to be formed by a collision between two proto-planets that strips the crust/atmosphere of the larger survivor), with the "right" mix of leftover heavy elements from the previous supernovae that created the stardust from which the whole system condensed to keep the core molten and magnetized, with the "right" mix of lighter crustal material to provide the needed carbon, oxygen, nitrogen, and hydrogen, especially oceans of water and at least eventually an atmosphere with a substantial proportion of oxygen.

But there are almost certainly more than Avogadro's number of planets out there, which is a lot of times to roll the dice for what is likely a fairly finite set of conditions. There are almost certainly billions of planets in just the visible part of the Universe alone, tens or hundreds or thousands per galaxy, that have all or most of the conditions needed for basic "life", and some fraction of them the conditions needed for the eventual evolution of intelligent life. However, we have no reliable way of computing the probability of life given those conditions, or intelligence given life. If either one requires the moon-forming collision, life could be quite rare as that probably doesn't happen (given all the other conditions) very often.

rgb

Re:Supernovae as risk

[delt0r]

You don't' really need a magnetic field. Earth for example has 10 metric tons per sq meter of atmosphere to protect you. And it does. Also even without a magnetic field an atmosphere can easily last billions of years, see venus. It is easy to imagine a set of parameters that would result in stable liquid water for billions of years, that requires no such magnetic field. As for moons... There is a big difference between alien life and multicellular alien life. It took a long time for that to get of the ground here, and many ways to get some form of cyclic thing going. Also there is nothing suggesting you need that either. It has been proposed with little evidence that it is required.

Re:Supernovae as risk

[Anonymous Coward]

When the Martians realised that their atmosphere was dissipating and their water evaporating, they came to Earth.

Re:Supernovae as risk

[rgbatduke]

I agree that this is controversial, but it is by no means a slam dunk that it isn't necessary. And if it isn't, it makes it more likely that a moon-forming atmosphere stripping collision is needed (or else bombardment by comets or whatever you think is needed for an ocean). And then there are the issues associated with radiation. The point is that there may be some subtleties associated with the requirements for life that mean that high radiation zones (sustained) are indeed inimical to life. Or (sure) not. It will likely be a decade or three before we even have a good enough theory (backed by at least SOME observations) to resolve these questions.

Green stars

[Anonymous Coward]

The research focuses on risks for life linked to cosmic radiation produced by supernovae (and massive stars in general).

This is only one of the risks.

Exactly. The largest risk of all being green stars. Stay away from green stars!

Observer bias

[argStyopa]

If the premise of the study is to highlight the risks of near stellar neighbors and cluttered neighborhoods, of COURSE the conclusion will be that remote systems are 'safer'.

This is like asking a cancer doctor where it's safest to live, and getting the answer "in a sealed lead-lined vault"....yes, disregarding the need for air, water, and food, and only focusing on the cancer risk, that's probably great.

While we simply don't KNOW the primary drivers of life generation (or the Drake equation would be a lot less hand-waving), and while yes, there's a danger of nearby stellar events, one might also consider:
- our solar system didn't just appear ex nihilo: the heavier elements present suggest that our system formed from nova or supernova remnants. A more cluttered stellar neighborhood is going to have more of such events. While these events would be indeed dangerous (likely exterminatory) for nearby life, life might regrow with such staggering frequency that the stellar scales are outmatched
- radiation: dangerous, sure, but we exist because of mutations. LIFE is based on mutation. (And hell, there's persuasive evidence here on earth that living with higher level of background radioactivity actually increases life span; then again, that could also be a raised average due to selective weeding by same.) A higher-radiation environment is not necessarily inherently bad for life, and may actually accelerate the mutative processes.

These are just a couple of reasons that inner regions might be better. A lot of it is simply guesswork at this point.

Re:Observer bias

[avandesande]

Some people are surprisingly resistant to radiation- this guy lived to 64- they dug him up 15 years after he died and there was enough radioactivity in his bones they could expose photographic negatives. https://en.wikipedia.org/wiki/...

Contradiction in terms

[tomxor]

Forget the summary or the article, the title makes no sense... "pinpoint" and "likely" are pretty close to antonyms of each other... that's like saying a weather simulation has pinpointed where it's going to rain next week.

Oh Boy!!!

[Anonymous Coward]

Yippee!!! Anther simulation! Go Science! Said no one ever.

earth life evolved lots of defenses

[peter303]

It is thought life evolved in deep ocean near vents. In a hiP hiT environment you dont need many enzymes (protein catalysts) to drive metabolic and protein synthesis reactions. Life then migrated to more hostile environments after evolving enzymes. These hostile environment include hot and cold temperatures, low pressure, solar radiation, free oxygen and parasitic viruses.

I could see in life evolving in the interior ocean of an ice moon in a more hostile solar system. Then evolve mechanisms to survive the more hostile environment.

Re:earth life evolved lots of defenses

[Oligonicella]

It is also thought life evolved in fresh water. It is also thought that life evolved amidst the clays. It is also thought.....

All thoughts about this are conjecture.

Abuse of Mods

[DumbSwede]

If I had mods today I would put this back up to 0 or 1.
Not that I agree, or that this is insightful, but why the down rating? This person is entitled to their opinion.
You don't agree? Well that is not what mod points are for. Craft a well worded reply and perhaps get some positive mods.

Down mods should be for Trolls and Hate speech or occasionally when something over a 1 is overrated.

Re:Abuse of Mods

[Anonymous Coward]

Glad you don't have mod points. The people that DO have mod points correctly surmised the parent post is off topic space nutter crap. Now piss off.

Re:Abuse of Mods

[Grishnakh]

He was probably modded down because it's just dumb. Schoolchildren building a starship? Are you kidding me? Agrarian nations? What are they going to contribute, aside from food for the people doing the hard work? We already buy food from agrarian nations, so it's not like anything's going to change there. Finally, we simply don't have the technology for a starship. Warp drive doesn't exist except in theory (and that theory requires some kind of exotic matter or negative energy or something like that which doesn't exist), and we're so primitive that we can't even build anything in space except some simple modules in LEO (whoopee). So at best you're talking about a big-ass rotating generation ship given our current understanding of physics, fueled by nuclear reactors. We don't know how to do nuclear fusion yet (at least not in a way that nets energy), so we need to develop that. And we need to develop the ability to mine the Moon and asteroids and do construction in space, which of course is well beyond our current capabilities.

Basically, we need to do a bunch of things before we're ready to even think about building a starship. And we're not really doing them, we're just sitting on our asses bombing underdeveloped countries which have fossil fuel reserves. And fossil fuels aren't going to help any in space.

As for what mod points are for, there is a rating called "-1 overrated". That's perfectly suited to posts which are just plain dumb, and is exactly why that rating exists.

Re:Abuse of Mods

[david_thornley]

The old Project Orion (lobbing nukes out the rear) was considered a possibility for interstellar travel, but I'm going to suggest that we don't know how to set up a crew environment that will keep them healthy and reasonably happy in eighty years going through interstellar space.

Unfashionable is the new fashionable

[BoogieChile]

So small, unregarded yellow suns in uncharted backwaters of the unfashionable end of the spiral arms of the Galaxy is actually where it's really at. Who knew?

Outreach

[tmjva]

Remember this old SPI game? Journey to the center of the map and collect "Wisdom Chits" pick up the "X" wisdom chit and you go hostile!

Corrected

[JohnStock]

"Cosmic radiation, supernova explosions, and collisions with small galaxies make much of the Milky Way too hellish for _our type_ of biology"