Do you believe we are alone in the universe?

The universe is far, far, far too big and ancient a place to reasonably rule out life elsewhere. Even if the galaxy is currently lacking intelligent life other than our own (and I'm not convinced it is - our expectations of what intelligent life should be doing with itself is, obviously, prejudiced toward our own ideals), I don't think it was nor will be. I'm also much more optimistic about FTL.

 

[Umbran]

See, that's the problem. You flat out cannot explore the Milky Way in centuries. Not without faster than light travel anyway. We're not talking centuries, or even millennia. We're talking truly deep time - megayears.

No, on this he is correct - you need a probe to last hundreds of years, maybe a couple thousand. The entire exploration project takes a million or two years, all told.

I will say... again... you don't need a single probe to last forever. One probe makes one trip to one star, then reproduces itself a dozen times over, and the *children* do the further exploring, and the parent can then fail. You don't need individuals to survive megayears - only the species. And that's hard enough.

And no, this is not about colonization. This is sending machines out to explore the galaxy for us, but we aren't along for the trip.

Even something like colonizing Mars, in the long run, isn't feasible. It took billions of years to make Earth as habitable as it is. Domed cities? Great. But, over the long term - as in hundreds of thousands or millions of years - that won't work because eventually you won't be able to replace lost resources in your dome from Earth. Even if you do manage to turn Mars into a "living" planet with a functioning ecosystem, gravity will eventually get you. Mars can't support life indefinitely. The lack of gravity means that the atmosphere will eventually bleed off. Lose the Earth and Mars dies.

Well, if you reset the biome of Mars, and then ignore it, yes, you'll lose the atmosphere in the end.

But, we are in the middle of proving that *accidentally* we can impact an atmosphere enough in just a century to impact the climate of a planet, are we not? Presumably, then, *intentionally* doing so is not out of reach. It would forever be a thing of active management - you can't just set it up and let it go.

 

[Maxperson]

If a culture is able to develop Nano-tech then they would be able to create materials on the atomic level. So a nano-tech probe could land on an ice asteroid and essentially transform it into Unobtainium or Handwavium or what ever else was needed.

Good old Replicators, they will never let us down or turn on us.

If we can already do things like this, a race thousands or millions of years more advanced...


https://qz.com/872050/thinnest-wire-ever-diamond-coating/

 

[Hussar]

Mars has metals, water, minerals, etc. The resources are already there to replace resources for the dome.

Really? Mars has bees? And worms? And arable land? Remember, you aren't just creating structures, but, a complete biosphere.

No, on this he is correct - you need a probe to last hundreds of years, maybe a couple thousand. The entire exploration project takes a million or two years, all told.

I will say... again... you don't need a single probe to last forever. One probe makes one trip to one star, then reproduces itself a dozen times over, and the *children* do the further exploring, and the parent can then fail. You don't need individuals to survive megayears - only the species. And that's hard enough.

And no, this is not about colonization. This is sending machines out to explore the galaxy for us, but we aren't along for the trip.

Fair enough. But, now you're talking about thousands and thousands of generations. All replicating flawlessly, without a single error, down through the generations. Every replication multiplies the number of flaws that can enter the system.

Well, if you reset the biome of Mars, and then ignore it, yes, you'll lose the atmosphere in the end.

But, we are in the middle of proving that *accidentally* we can impact an atmosphere enough in just a century to impact the climate of a planet, are we not? Presumably, then, *intentionally* doing so is not out of reach. It would forever be a thing of active management - you can't just set it up and let it go.

Again, as you say, it's forever a thing of active management. Without constant support from Earth, which we're positing since the Earth has become unlivable, Mars has a half life of a few million years, at best. You cannot actively manage when you don't have the raw materials you need. What happens when your imported, genetically modified bees die? A terraformed planet will always be impoverished when it comes to biodiversity. It can't not be. There's just no practical way to get that much biodiversity out of the Earth's gravity well.

 

[Nom]

It is indeed like taking a spoon full of water from the ocean, finding life, and then concluding that there for the rest of the ocean must not have any life in it.

I'm not sure this is a good analogy. On the evidence we have, the ocean is inherently life-bearing.

Imagine instead that you found a small rock in the ocean, and investigating it you discover that it is actually hollow and there is a colony of some small creature living inside. You can discern no mechanism by which the creatures got there, and the raw ocean environment is highly hostile to them. Surveying the nearby ocean, you discover no further colonies, nor for that matter rocks that might be potential sites for such colonies. Expanding your search to the limits of how far you can go, you find a few candidate rocks, but no evidence of colonies. But there's a lot, lot more ocean out there.

How long would you have to search to find a similar occupied rock? (I avoid the term "colonised" because that implies that the creatures were transported from an external place).

To useful answer that question, you need a workable hypothesis for how the creatures got there. All the evidence suggests that there is no external biological interaction for a very long time, if ever. If you think they came from some sort of proto-lifeform that was transported to the rock, then perhaps its likely that the same happened elsewhere. If you think it was spontaneously generated, then you need a model for how this might have happened and how rare those circumstances are. If you think a superior intelligence was involved, then you need some sort of model of that superior intelligence's actions and purposes.

PS: you're doing all this as one of the creatures in the colony

 

[Vishal Gupta]

A few years ago we didn't even know that our earth spins and not the sun.
So yeah.. we can't be sure that we're alone. Lets wait and see what comes next.

 

[Dannyalcatraz]

Its not increasing points of failure, it is overlapping security features. If your first response fails, you got your second response, then your third response. There is no single thing which can fail and take down the whole system.

It may seem paradoxical, but the more complexity a system has- including overlapping security/redundant subsystems- the more points of failure it has. Compare a 1957 Chevy to a 2018 Caddy: one can be repaired by a shade-tree mechanic, the other requires computers just to figure out what went wrong.

In the case of the probe, failure of the repair tools, the operating software, debugging software, the backup software, etc. could EACH cause a failure requiring outside correction.

If the repair tools fail, it cannot repair itself until THEY are repaired or replaced, which may not happen before systemic failure.

If the operating system fails, the probe becomes a high-tech asteroid.

If the debugging software fails, errors accumulate until it malfunctions catastrophically.

If the backup software is corrupted, there won’t be anything for the systems to reboot from.

If you want a comparison just look at the bodies immune system, multiple overlapping redundancies.

And they still fail...more quickly if we take excessive risks, don’t eat properly, go for annual checkups, take our meds, etc. because our cells are not capable of perfect replication.

Name a system within your body, and odds are, failure of any one will be fatal.

Which is why most manufacturing plants dont rely on a human to jam a microchip into your computer with their thumb.

Even the most sophisticated machine we have today eventually requires a human repair or maintenance visit. But that wasn’t my point.

It doesn’t matter what is contacting what, there is still wear. The metal blades that cut leather for jackets, boots, furniture, etc. become blunted by act of cutting the leather. Casting molds may last months or years, but they all eventually fail, becoming progressively less accurate with each use.

And as errors creep in they get fixed or replaced.

But not by themselves, especially if the debugging or backup software is itself damaged.

It has never been my argument that you can make something that will last forever. Hundreds of years is probably all that you would need to explore the Milky Way completely.

That is fantastically optimistic.

 

[Imaculata]

I'm not sure this is a good analogy. On the evidence we have, the ocean is inherently life-bearing.

Imagine instead that you found a small rock in the ocean, and investigating it you discover that it is actually hollow and there is a colony of some small creature living inside. You can discern no mechanism by which the creatures got there, and the raw ocean environment is highly hostile to them. Surveying the nearby ocean, you discover no further colonies, nor for that matter rocks that might be potential sites for such colonies. Expanding your search to the limits of how far you can go, you find a few candidate rocks, but no evidence of colonies. But there's a lot, lot more ocean out there.

This is not a good analogy either. You have changed it purposefully to make it seem as if our entire universe is hostile to all life, as if to say, isn't it a miracle that life some how developed on our planet? Which is a position I do not agree with. Life developed on this planet, and in doing so, adapted to it's environment, just as a puddle of water assumes the shape of a dip in the road. It is not extraordinary that the puddle is then perfectly attuned to the shape of that dip in the road.

There is no reason to presume that life (like the puddle) could not adapt to a different environment. It is not even a given that life can't develop in the void of space itself. We simply do not know. Right on our planet, life exists in some of the most hostile places; sometimes right on the edge of underwater volcanoes. Which shows that life (as we know it) seems extremely resilient to hostile environments.

Also, we didn't even remotely "Survey the nearby ocean". We hardly looked at anything nearby at all. We looked at one grain of sand in a sandbox so huge, that we can't even assert that we searched nearby... we hardly searched at all, because we lack the means to do so, given the huge distances. We didn't examine a single other planet with life on it. In our own solar system we are not done with examining all of the objects in it either.

So, instead of comparing our planet to a rock in an ocean, it would be more accurate to compare our entire solar system to a rock, which we've only examined a small area of. And of the area of this rock that we examined, we found life.

 

[Maxperson]

Really? Mars has bees? And worms? And arable land? Remember, you aren't just creating structures, but, a complete biosphere.

Once the initial transplant of those creatures is done, the rest is just maintaining the equipment to sustain them. That can all be done locally.

Fair enough. But, now you're talking about thousands and thousands of generations. All replicating flawlessly, without a single error, down through the generations. Every replication multiplies the number of flaws that can enter the system.

That's simply not true. Your body replicates cell constantly and errors happen all the time without any ill effect. It's only when a cell replication botches itself into a disease like cancer or leukemia that things go to hell in a hand basket. The same would apply to the probes. Lots of errors would simply have no effect, depending on what the error was. There also wouldn't always be an error on a replication, and if the materials last a very, very long time(and they would with a species that advanced), you'd only need a handful(if any, depending on material quality) replications.

 

[Umbran]

Fair enough. But, now you're talking about thousands and thousands of generations. All replicating flawlessly, without a single error, down through the generations. Every replication multiplies the number of flaws that can enter the system.

Yep. I made that point several pages back.

Without constant support from Earth, which we're positing since the Earth has become unlivable, Mars has a half life of a few million years, at best.

So, a few hundreds of times longer than we have had civilization? This is supposed to be a criticism?

You cannot actively manage when you don't have the raw materials you need. What happens when your imported, genetically modified bees die?

Why do they die?

Up to the point that you know their wild population is stable, you're keeping breeding populations in captivity on the side, to repopulate the species. You've been working out their needs in enclosed spaces (which you need to support the people until terraforming is done anyway) gradually moving them over to Mars surface conditions over the generations.

A terraformed planet will always be impoverished when it comes to biodiversity. It can't not be. There's just no practical way to get that much biodiversity out of the Earth's gravity well.

Dude, bugs and seeds are lightweight - way lighter than humans! We can transport enough seeds to comprise a viable breeding population of pretty much any plant you can name in a sack that weighs less than a single human. Bees are hardly big compared to, say, you. Add whatever technology comes along after CRISPR, and biodiversity won't really be the issue.

There are big questions around terraforming, but getting the plants and bugs isn't the hard part. The hard part is understanding medium and long term atmosphere and climate dynamics.

 

[Dannyalcatraz]

Dude, bugs and seeds are lightweight - way lighter than humans! We can transport enough seeds to comprise a viable breeding population of pretty much any plant you can name in a sack that weighs less than a single human. Bees are hardly big compared to, say, you. Add whatever technology comes along after CRISPR, and biodiversity won't really be the issue.

There are big questions around terraforming, but getting the plants and bugs isn't the hard part. The hard part is understanding medium and long term atmosphere and climate dynamics.

Tangentially, sci-fi writer James Blish was aware of things along those lines many decades ago when he penned the sci-fantasy short story,“Surface Tension”.

In it, a human colonization ship crash-lands on a distant planet which is Earth-like but whose only landmass is completely covered in shallow puddles of water and mostly microscopic life forms. Normal humans could not survive on this planet, so the crew must genetically engineer their descendants into something that can survive. (Blish coined the term pantropy to refer to this concept.) They create a race of microscopic aquatic humanoids to complete their mission and colonize the planet.