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Comment Re:Mankind and aliens will prefer orbital colonies (Score 1) 105

Well, you prefaced your comment with "A civilization sufficiently advanced enough to move their whole star system would probably not be...", so I responded to that. I should also make clear that I'm a huge fan of the concept of orbital colonies, both as a stepping-stone for human expansion to the stars, and the romantic appeal of the fierce independence and cooperation such a society will likely breed. But I think it's important not to lose site of the limitations, and the fact that planets offer their own advantages.

As for less advanced civilizations, say our own within a few centuries, orbital colonies still have considerable downsides. Impacts being one of the big ones - a meteor even a few meters across, the sort that barely makes a tiny flash in the sky here, would likely be devastating to any colony with only a paltry few dozen meters of rock shielding - the velocities involved in a collision with eccentric-orbit debris debris tends to be phenomenal. Easily enough to vaporize all but the largest debris just from friction with our upper atmosphere, and there are several vast clouds of such debris that regularly intersect the Earth's orbit.

The second big problem that springs to mind is the actual mass distribution - if I recall correctly the combined mass of the entire asteroid belt is estimated at only about 5% that of the Moon, while the Moon's geologic stability and low gravity would offer ample tunneling potential, even if you restrained yourself to the thin outer shell corresponding to an equivalent mass. Also there's some potential for Mercury (much cooler than Venus), and several of the gas-giant moons. You do have the trans-Neptunian objects and hypothetical Oort cloud, but at that point you're pretty much living in interstellar space for most intents and purposes, and lose out on the many benefits of having a nigh-inexhaustible fusion reactor right next door.

As for gravity - we don't really have any idea what effect low gravity may have on life yet - we know *microgravity* is a big problem, but that also entails a much more radical reduction in many forms of routine exertion, as well as a near-total elimination of all gravitational orientation cues, plus the micro-impact shockwaves from walking, which have been shown to be a major factor in skeletal self-maintenance. Orbital colonies also don't necessarily solve the problem - you can get "centrifugal pseudogravity" easily enough in theory, but we have no idea what the long-term side effects of that might be (unless it's *huge* you introduce not-insignificant tidal forces within the body, just for starters), and it requires material engineering for tensile strengths capable of supporting the entire mass of at least your colony's living areas against 1g (or whatever) acceleration. And tensile strength involves much more sophisticated engineering and much lower fault tolerances than the comparable compression strength necessary for tunnels.

But no, living underground isn't "living in space" as most people think of it, But then what exactly is the appeal you of doing so? Besides, even on Earth you're only sixty-some odd miles from space, it's only the radical inefficiency of our current transportation infrastructure that put it out of reach.

Comment Re:Mankind and aliens will prefer orbital colonies (Score 1) 105

Oh, and to address your "millions of times the surface area" remark - are you so sure you would want it? After all the surface is vulnerable to radiation, impact, radiant heat losses, etc. You could just as easily turn the whole planet into a honeycomb of underground colonies with ample resources available. A molten cores would be an issue, though a passive heating system might be worth the resource loss, but smaller planetoids such as the moon wouldn't offer than problem.

The primary benefits of an orbital colony are that it's more mobile than a planet, and you're not at the bottom of a substantial gravity well. I rather doubt either concern would be terribly significant to a race capable of flinging stars around.

Comment Re:Mankind and aliens will prefer orbital colonies (Score 1) 105

Sure, planets are optional - stars however are kind of appealing - massive nuclear reactors bound together by the mass of their own fuel - sufficient fuel to continue generating energy unflaggingly for hundreds of billions of years, with nothing to break down and no maintenance required.

Of course, if you're orbiting one of those long-burning dwarf stars you need to worry about the fact that they're prone to not-infrequent superflares. Might be nice to have a big chunk of mass for radiation shielding, preferably something nice and stable that would have a fair chance to survive even if your civilization collapses several times sending everyone back to nearly the stone age - I would imagine such considerations would be relevant to journeys lasting tens or hundreds of times longer than our species has existed. Planets are handy for such things, even if you live deep underground the gravity will help keep atmosphere and resources from escaping.

Comment Re:It can't. (Score 1) 105

(Some) RNA self-replicates from amino acids all the time, and is one of our current best guesses for the earliest forms of proto-life - it's can forma an amazingly versatile range of nanomachines. The question is whether it's more likely that a self-replicating strand forms spontaneously on a hospitable world or gets seeded from elsewhere. After that it's just a matter of evolution.

Comment Re:It can't. (Score 1) 105

Hitchhikers *in* asteroids, not on. I agree any on the outer surface would be unlikely to last on an interstellar journey, but an asteroid hundreds of feet across is pretty tiny really,, and offers *far* more radiation shielding than we have on the surface of the Earth - the atmosphere offers only about 10-15 feet of rock equivalent, and the magnetosphere only protects us from charged particles that wouldn't make it far through solid rock anyway.

Comment Re:Where's the Appeal? (Score 1) 105

I think it's basically that, given some fairly plausible assumptions, panspermia would make it almost inevitable that the galaxy is full of at least simple life, and probably at least some complex life as well. And a galaxy full of ife is far more exciting proposition than a field of hundreds of millions of dead rocks.

Of course at present we have no particular reason to believe such a setting is real, but it makes for a much more compelling story - and humanity is built upon it's ability to tell stories of what might be, and then try to discover, or even create, the truth. From the day one of our pre-verbal ancestors first dreamt of a rock or bone of a certain shape that would make a more effective tool and set out to find or eventually create it, to todays scientific journals describing the experiments and conclusions of our most curious minds, storytelling has been our species defining advantage

Comment Re:Mankind and aliens will prefer orbital colonies (Score 3) 105

A sufficiently advanced and adventurous colony might even redirect their host star through a series of gravitational slingshots sufficient to set in on a course to another galaxy. Sure, hurling stars around is a bit of a herculean task by our current standards, but a dwarf star isn't *that* big, and if you've got the long-term vision to consider intergalactic travel, the acceleration phase shouldn't deter you.

By the same argument though, I would advocate for terraforming other worlds in our own system, once we've determined that they don't host life of their own of course. No sense destroying such a potentially vast scientific resource for a project that will take thousands of years.

The beauty of terraforming though is that, done carefully, it may not need much human intervention at all. Just release the right mix of engineered microbes with an optimized mutation rate, and let the planet develop into a primordial "slime world" on it's own. Then, once it has a robust and thriving microbial biosphere, introduce the thin veneer of complex life that we are more familiar with. Maybe it takes thousands of years, so what? As long as it's a self-guided project we just need to get it started, and maybe give it an occasional nudge if it starts destabilizing.

Comment Re:It can't. (Score 1) 105

And even the "firing" doesn't necessarily need sapient life - the impact that flung the material that formed the moon free from the Earth probably flung some pretty large chunks of material completely free from Earth, and possibly even from the Sun. There may even now be primitive cryogenically preserved microbes in the heart of some of those planetary fragments slowly coasting across the cosmos, just waiting to impact a promising new world. If the fragments are big enough the microbes could survive reentry - a few miles of shielding should be more than sufficient, and would still represent only a relatively small fragment.

If such an impact were to happen today, there's lots of Earth life that might survive the voyage. Even relatively complex animals such as the tardigrade, which has been shown to be able to survive naked exposure to space for months on end with no apparent long-term damage, and would no doubt have a far easier time of it in the middle of a big chunk of ice and rock.

Comment Re:It can't. (Score 2) 105

Indeed, especially if kept near absolute zero within a chunk of rock and ice potentially miles across . And you don't even necessarily need spores - a single strand of RNA capable of replicating itself from naturally occurring organic molecules might be all you need to jump-start a biosphere on a new planet.

Comment Re: Obey traffic laws; offer emergency override (Score 1) 236

No, we're talking specifically about the person passing out while, or immediately after, calling 911, but before telling the car to take them to the ER. So that there's reason to believe there's a problem that can be helped by pulling the car over. You can't have cops pulling over every guy taking a nap in his car, that would get ridiculous, and be an invitation to abuse.

Comment Re:commentsubjectsaredumb (Score 1) 587

I won't make the argument that pharmacy behavior indicates a valid scientific endorsement of a drug, that would be stupid. I'm only stating that when a common "cure all" of days past has since been scientifically shown to have dramatic medicinal properties on a large number of fronts, maybe it was included on the shelves for good reason.

Comment Re:Obey traffic laws; offer emergency override (Score 1) 236

Okay, I may have been a bit confrontational there. I'm all for having the default behavior be "obey the cops" - provided there's a manual override available. Because even today there's places where the police's official advice is that if you're at all uncomfortable being pulled over - don't. Drive to the nearest police station instead.

As for a person with a medical emergency - one would hope that if they're capable of dialing 911 they can just as easily tell the car to take them to the emergency room - and that will almost certainly be faster than waiting for an ambulance to reach them, then go to the hospital. And that's a pretty contrived example, in any other case an officer is extremely unlikely to be able to tell the difference between "guy who just had a heart attack/stroke/etc" and "guy taking a nap"

Comment Re:Cops shouldn't be allowed to take control (Score 1) 236

Really? Even if it was a scruffy-looking "cop" in a bad neighborhood? I doubt it. The problem is that, at least at present, the AIs fall far short of being able to exercise the sort of situational judgment necessary for such things. And any technological signaling solution is going to be hacked.

Comment Re:Obey traffic laws; offer emergency override (Score 2) 236

So, all Jack the Ripper needs is to put a flashing light on his car and he can force his victims to a stop? No thanks.

Hell, it's not unheard of for actual police officers to engage in kidnapping, rape, and murder - if you suspect such a situation, they should NOT be able to trivially disable your vehicle.

Sure, it should automatically respond to police signals just as a conscientious driver would. But you should also be able to override that behavior, just as a driver with a sense of self-preservation sometimes must.

Meanwhile, an unconscious occupant would seem to me to be one of the points of an automated vehicle. Any automated vehicle which needs me to continue to pay attention to the road in case of emergency is a horrible danger to everyone else, because passengers won't do so reliably. And if I don't have to pay attention to the road, then I may as well play video games, take a nap, etc. Just like if I had a chauffeur. You wouldn't pull over a limo because the passengers were unconscious would you?

"More software projects have gone awry for lack of calendar time than for all other causes combined." -- Fred Brooks, Jr., _The Mythical Man Month_

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