Debate over sending messages to ETs heats up

[Puppycow]

There are hypothetical creatures that COULD develop and live in the atmosphere of a gas giant like Jupiter. But a Brown Dwarf is probably even more massive, turbulent, and violent than a gas giant planet.

But, theoretically speaking, if a brown dwarf, after trillions upon trillions of years, wouldn't it be possible for life to form on the surface? I mean, after all of that time, even a brown dwarf would burn away a lot of it's mass. So maybe the surface of a black dwarf wouldn't have as strong a gravity as it did when it was even a brown dwarf.

No, because these are two very different things. A white dwarf never becomes a brown dwarf, but eventually it should become a black dwarf (there should not be any black dwarfs yet according to theory because the universe isn't old enough).


White dwarf (which becomes a black dwarf eventually)

A white dwarf, also called a degenerate dwarf, is a stellar remnant composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun, and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored thermal energy.[1]
. . .
White dwarfs are thought to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star (including our Sun)—over 97% of the stars in the Milky Way.[5], §1. After the hydrogen–fusing lifetime of a main-sequence star of low or medium mass ends, it will expand to a red giant which fuses helium to carbon and oxygen in its core by the triple-alpha process. If a red giant has insufficient mass to generate the core temperatures required to fuse carbon, around 1 billion K, an inert mass of carbon and oxygen will build up at its center. After shedding its outer layers to form a planetary nebula, it will leave behind this core, which forms the remnant white dwarf.[6]
. . .
The material in a white dwarf no longer undergoes fusion reactions, so the star has no source of energy, nor is it supported by the heat generated by fusion against gravitational collapse. It is supported only by electron degeneracy pressure, causing it to be extremely dense.
. . .
A white dwarf is very hot when it is formed, but since it has no source of energy, it will gradually radiate away its energy and cool. This means that its radiation, which initially has a high color temperature, will lessen and redden with time. Over a very long time, a white dwarf will cool to temperatures at which it will no longer emit significant heat or light, and it will become a cold black dwarf.[6] However, the length of time it takes for a white dwarf to reach this state is calculated to be longer than the current age of the universe (approximately 13.8 billion years),[10] and since no white dwarf can be older than the age of the universe, it is thought that no black dwarfs yet exist.[1][5] The oldest white dwarfs still radiate at temperatures of a few thousand kelvins.

Brown dwarf

Brown dwarfs are substellar objects not massive enough to sustain hydrogen-1 fusion reactions in their cores, unlike main-sequence stars. They occupy the mass range between the heaviest gas giants and the lightest stars, with an upper limit around 75[1] to 80 Jupiter masses (MJ). Brown dwarfs heavier than about 13 MJ are thought to fuse deuterium and those above ~65 MJ, fuse lithium as well.[2] Brown dwarfs may be fully convective, with no layers or chemical differentiation by depth.[3]

The defining differences between a very-low-mass brown dwarf and a giant planet (~13 MJ) are currently being debated.[4] One school of thought is based on formation; the other, on the physics of the interior.[4]

Part of the debate concerns whether "brown dwarfs" must, by definition, have experienced fusion at some point in their history.

Stars are categorized by spectral class, with brown dwarfs being designated as types M, L, T, and Y.[4][5] Despite their name, brown dwarfs are of different colours.[4] Many brown dwarfs would likely appear magenta to the human eye,[4][6] or possibly orange/red.[7] Brown dwarfs are not very luminous at visible wavelengths.

In the picture above^^ a white dwarf would be about the same size as the earth. Much smaller than the brown dwarf in volume, but much heavier in mass. The mass is about the mass of the sun in that picture, crammed into the size of the earth. So it is extremely dense and has extremely strong gravity at the surface.

 

[webfusion]

I probably shouldn't even post this within a thread that's been primarily going in serious and scientific directions -- but I had to anyway.

PIXELS
http://en.wikipedia.org/wiki/Pixels_(2015_film)

 

[Nihilianth]

No, because these are two very different things. A white dwarf never becomes a brown dwarf, but eventually it should become a black dwarf (there should not be any black dwarfs yet according to theory because the universe isn't old enough).


White dwarf (which becomes a black dwarf eventually)


Brown dwarf


[qimg]http://upload.wikimedia.org/wikipedia/commons/thumb/4/40/BrownDwarfComparison-pia12462.jpg/306px-BrownDwarfComparison-pia12462.jpg[/qimg]

In the picture above^^ a white dwarf would be about the same size as the earth. Much smaller than the brown dwarf in volume, but much heavier in mass. The mass is about the mass of the sun in that picture, crammed into the size of the earth. So it is extremely dense and has extremely strong gravity at the surface.

Well. Ok. White dwarfs would not become brown dwarfs. But would it be possible, do you think, in the great, great future from now, for life to evolve on a black dwarf?

I probably shouldn't even post this within a thread that's been primarily going in serious and scientific directions -- but I had to anyway.

PIXELS
http://en.wikipedia.org/wiki/Pixels_(2015_film)

! Awesome! Totally worth it for you to have posted that here! Thank you.

 

[Puppycow]

Well. Ok. White dwarfs would not become brown dwarfs. But would it be possible, do you think, in the great, great future from now, for life to evolve on a black dwarf?

I have no idea. I'm not a scientist. But fwiw, my opinion would be no, it's probably impossible. There would be no water I believe, for one thing, and the gravity is so strong. Plus most other stars would likely be dead by then too. Just doesn't strike me as a hospitable place for life.

 

[Gawdzilla Sama]

Now I want to watch some "Red Dwarf".

 

[Nihilianth]

I have no idea. I'm not a scientist. But fwiw, my opinion would be no, it's probably impossible. There would be no water I believe, for one thing, and the gravity is so strong. Plus most other stars would likely be dead by then too. Just doesn't strike me as a hospitable place for life.

If it were cool enough, there could be water. And I really think that the evolution of life could overcome gravity. I am not sure how much algae, for instance, would be affected by a large amount of gravity. From there, life could evolve and become more complex, with the ability to deal with a large amount of gravity.

 

[Dinwar]

Life requires a thermal gradient, which black dwarves won't have (dwarfs?). Plus, white dwarves/black dwarves would lack most of the chemicals necessary to form complex molecules, thanks to the processes that form them. They might be able to gether some, but I have serious doubts about their capacity to gather enough--and to maintain it--for abiogenesis.

 

[Nihilianth]

Life requires a thermal gradient, which black dwarves won't have (dwarfs?). Plus, white dwarves/black dwarves would lack most of the chemicals necessary to form complex molecules, thanks to the processes that form them. They might be able to gether some, but I have serious doubts about their capacity to gather enough--and to maintain it--for abiogenesis.

The thermal gradient could be just beneath the surface. In order for a black dwarf to hypothetically support life, I would imagine it would have to have had a loooooong time to cool enough for water to sit on the surface, but yet hasn't had enough time to cool so much that it has completely solidified down through its core. It would also have to have an active and thick atmosphere to hold in the heat on the surface from any thermal vents just below it. As for lack of chemicals, why would that happen?

 

[Dinwar]

My mistake--I was thinking of neutron stars for some reason. White dwarves are made of carbon, oxygen, hydrogen, helium, and a few other trace elements. Not exactly fantastic for life, to be honest; no phosphorus, no sulfur, no iron, etc.

 

[portlandatheist]

Is that your position or one you're ascribing to another poster?

Sorry for the late response. No, its not my position, I'm just trying to make the point that if are alone, then we have to presume there is something very unique about our particular situation. Could be that life is very common, just not life with high technology. Could be lots of things

 

[Puppycow]

Sorry for the late response. No, its not my position, I'm just trying to make the point that if are alone, then we have to presume there is something very unique about our particular situation. Could be that life is very common, just not life with high technology. Could be lots of things

"If we are alone in the Universe, it sure seems like an awful waste of space." -Carl Sagan

We could be effectively alone even if there are others like us in the universe. Maybe even the same galaxy. It's just so big. We may be extinct long before we find them.

Personally, I'm curious. I want to know, even if trying to find out puts us at some risk which is hard to quantify. That's why I would be for trying to send messages. I think it would be a shame if our species came and passed without ever making contact in some manner, even if there's a huge time lag due to the speed of light problem. I think there's a greater likelihood we kill ourselves than we are killed by aliens.

 

[Gawdzilla Sama]

We could be effectively alone even if there are others like us in the universe. Maybe even the same galaxy. It's just so big. We may be extinct long before we find them.

This is why I find Fermi's Paradox to be non-paradoxical.

 

[Elind]

Another reason I have doubts that ETs might pose a danger to us is the Fermi paradox: if there are ETs out there who want to conquer planets like Earth, and they have the technology to come here, then why aren't they already here? I think it's likely that interstellar travel poses such a huge problem, that no species native to one star system is likely to pose a threat to one from a different star system. IOW, no species ever makes it to Star Trek. If there happened to be two species on different planets in the same solar system, say Mars and Earth, one could conceivably pose a threat to the other as warp drive isn't necessary.

I think that any species that can travel between stars must be able to live between stars, where material is so much easier to obtain (at least in solar systems). So why would they want to "conquer" a deep planetary gravity well? The only reason would be for the view of a sunrise or sunset, and that can be easily simulated anywhere.

 

[Elind]

"If we are alone in the Universe, it sure seems like an awful waste of space." -Carl Sagan

We could be effectively alone even if there are others like us in the universe. Maybe even the same galaxy. It's just so big. We may be extinct long before we find them.

Personally, I'm curious. I want to know, even if trying to find out puts us at some risk which is hard to quantify. That's why I would be for trying to send messages. I think it would be a shame if our species came and passed without ever making contact in some manner, even if there's a huge time lag due to the speed of light problem. I think there's a greater likelihood we kill ourselves than we are killed by aliens.

We don't need to find "sentient" life, let alone technologically advanced life, to know that we are not alone. A bacteria somewhere would be good enough. Just think of the tiny fraction of life on earth that has included humans.

 

[Dinwar]

So why would they want to "conquer" a deep planetary gravity well? The only reason would be for the view of a sunrise or sunset, and that can be easily simulated anywhere.

I think that any culture that can travel between continents must be able to live between continents, where material is so much easier to obtain (at least on islands). So why would they want to "conquer" an inhabited continent? The only reason would be for the view of a sunrise or sunset, and that can be easily simulated anywhere.

 

[Elind]

I think that any culture that can travel between continents must be able to live between continents, where material is so much easier to obtain (at least on islands). So why would they want to "conquer" an inhabited continent? The only reason would be for the view of a sunrise or sunset, and that can be easily simulated anywhere.

That's a pretty silly attempt at humor, or logic. Would you like to try something more rational, or have you no idea at all what I was saying?

 

[MG1962]

I think that any culture that can travel between continents must be able to live between continents, where material is so much easier to obtain (at least on islands). So why would they want to "conquer" an inhabited continent? The only reason would be for the view of a sunrise or sunset, and that can be easily simulated anywhere.

Where can you get a good supply of timber between continents?

 

[Gawdzilla Sama]

Where can you get a good supply of timber between continents?

Lowe's, Home Depot, Robinson Crusoe Lumber.

 

[Dinwar]

That's a pretty silly attempt at humor, or logic. Would you like to try something more rational, or have you no idea at all what I was saying?

I find what you said to be wholy devoid of rataional consideration of the issues involved, and I find your belittling dismissal of disagreement to be unconscionable. There are parallels between space exploration and ocean exploration--not perfect ones, but to dismiss comparisons because they are not perfect is completely irrational.

By your logic, Europe should have never come to the New World. Or come here in the first place. Your statement contradicts reality, and is therefore wrong.

Where can you get a good supply of timber between continents?

Re-read the quoted text, including the paranthetical this time.

 

[Elind]

I find what you said to be wholy devoid of rataional consideration of the issues involved, and I find your belittling dismissal of disagreement to be unconscionable. There are parallels between space exploration and ocean exploration--not perfect ones, but to dismiss comparisons because they are not perfect is completely irrational.

By your logic, Europe should have never come to the New World. Or come here in the first place. Your statement contradicts reality, and is therefore wrong.

Re-read the quoted text, including the paranthetical this time.

I see that you don't understand the difference between oceans and space.

 

[Dinwar]

I see that you don't understand the difference between oceans and space.

I do, in fact, understand the difference. I also have a passing familiarity with what it took to get folks across oceans in past eras; they're not so different as you imagine (at least, they weren't previously), in terms of resource management and the like (though admitedly on a smaller scale). Besides, your statement is a flat-out and inexcusable lie. I stated that the comparison is not perfect. My point was merely that there are factors that you are not considering--including factors that drove Europeans to make some extraordinarily dangerous journies in the past. Before we dismiss the posibility of another species on another planet making a journy to other stars, it would be useful to understand what drove Europeans to explore the oceans.

More importantly, though: you do not differentiate between a lack of understanding and disagreement. Please don't waste our time denying it; your posts prove the point. If you wish to convince anyone of anything, that's something you need to work on. I understand your point just fine--I simply do not find it convincing, and have given one reason for that (I have more, but this one was so obvious that I thought it the best to bring up).

 

[Elind]

I do, in fact, understand the difference. I also have a passing familiarity with what it took to get folks across oceans in past eras; they're not so different as you imagine (at least, they weren't previously), in terms of resource management and the like (though admitedly on a smaller scale). Besides, your statement is a flat-out and inexcusable lie. I stated that the comparison is not perfect. My point was merely that there are factors that you are not considering--including factors that drove Europeans to make some extraordinarily dangerous journies in the past. Before we dismiss the posibility of another species on another planet making a journy to other stars, it would be useful to understand what drove Europeans to explore the oceans.

More importantly, though: you do not differentiate between a lack of understanding and disagreement. Please don't waste our time denying it; your posts prove the point. If you wish to convince anyone of anything, that's something you need to work on. I understand your point just fine--I simply do not find it convincing, and have given one reason for that (I have more, but this one was so obvious that I thought it the best to bring up).

We are not discussing the motivations for exploration. The issue is the practicalities of living in space versus on a likely hostile planet to aliens. Simple.

 

[Roboramma]

I think that any species that can travel between stars must be able to live between stars, where material is so much easier to obtain (at least in solar systems).

I'm having trouble parsing this sentence: between stars is necessarily outside of solar systems, as it's clearly contrasted not with within stars, but within star stystems. And material isn't easier to obtain between stars than within solar systems: the opposite is true.

I think you meant to say that species that can travel between planets must be able to live between planets, where material is so much easier to obtain.

If that's what you meant, I tend to agree. On the other hand there is only so much "easy to obtain" material in any solar system, and while they might go for that first, that doesn't mean that they wouldn't want to harvest that materials buried down a gravity well as well.

 

[Gawdzilla Sama]

I read that as "Living outside a star's gravity well saves large amounts of energy needed to leave a solar system." The recent idea that there are many "solo" planets in space means that you can land on a body and mine it without going in the deeper gravity zone of a star.

And, of course, if you're just looking for matter to convert to other matter, the Pillars of Creation would seem to be enough of that for a while, I think.

 

[Elind]

I'm having trouble parsing this sentence: between stars is necessarily outside of solar systems, as it's clearly contrasted not with within stars, but within star stystems. And material isn't easier to obtain between stars than within solar systems: the opposite is true.

I think you meant to say that species that can travel between planets must be able to live between planets, where material is so much easier to obtain.

If that's what you meant, I tend to agree. On the other hand there is only so much "easy to obtain" material in any solar system, and while they might go for that first, that doesn't mean that they wouldn't want to harvest that materials buried down a gravity well as well.

Yes, I took liberties with the phrasing.

 

[Mike!]

Lowe's, Home Depot, Robinson Crusoe Lumber.

They're only open on Friday.

 

[Dinwar]

We are not discussing the motivations for exploration. The issue is the practicalities of living in space versus on a likely hostile planet to aliens. Simple.

Discussing practical considerations without discussing motivation is akin to building complex plumbing systems without asking what you're building them for. If it's for a kangaroo rat, it's rather pointless from the get-go. It puts the cart before the critter that may one day evolve into a horse. The motivations DRIVE the practical considerations. A ship of the line wasn't equiped anything like a Disney Cruise Ship.

As for living between.....well, unless your recycling program is 100% efficient, we can dismiss the idea of perpetually living outside of any gravity well out of hand. At some point, you need to resupply. This could be as simple as sending small landing parties down to grab whatever you need for the big ship (to further belabor my analogy, this is akin to taking a jollyboat or longboat out to refill casks of fresh water), or as complex as establishing mining/resupply collonies (think Midway, or any island that's inhabited only by a military base). Regardless, at some point either your fuel, your water, your air, your components, or SOMETHING will give, and you'll need to fix it. And that means going to where the materials to fix it are located. And that, the overwhelming majority of the time, will mean going to something with a gravity well (even nebula have SOME gravity, otherwise they wouldn't be nebula for long).

As for hostile planets, anything capable of traveling between the stars will be able to detect life on other planets; it's basic navigation ("What's the atmosphere like? Where's a good landing point? Dear gods that's a city; DO NOT land there!!!!"). Maybe they can overwhelm the local life, maybe not; maybe they want to, maybe not; either way, there's always the option of finding uninhabited bits to land on.

 

[Elind]

Discussing practical considerations without discussing motivation is akin to building complex plumbing systems without asking what you're building them for. If it's for a kangaroo rat, it's rather pointless from the get-go. It puts the cart before the critter that may one day evolve into a horse. The motivations DRIVE the practical considerations. A ship of the line wasn't equiped anything like a Disney Cruise Ship.

As for living between.....well, unless your recycling program is 100% efficient, we can dismiss the idea of perpetually living outside of any gravity well out of hand. At some point, you need to resupply. This could be as simple as sending small landing parties down to grab whatever you need for the big ship (to further belabor my analogy, this is akin to taking a jollyboat or longboat out to refill casks of fresh water), or as complex as establishing mining/resupply collonies (think Midway, or any island that's inhabited only by a military base). Regardless, at some point either your fuel, your water, your air, your components, or SOMETHING will give, and you'll need to fix it. And that means going to where the materials to fix it are located. And that, the overwhelming majority of the time, will mean going to something with a gravity well (even nebula have SOME gravity, otherwise they wouldn't be nebula for long).

As for hostile planets, anything capable of traveling between the stars will be able to detect life on other planets; it's basic navigation ("What's the atmosphere like? Where's a good landing point? Dear gods that's a city; DO NOT land there!!!!"). Maybe they can overwhelm the local life, maybe not; maybe they want to, maybe not; either way, there's always the option of finding uninhabited bits to land on.

I really don't know what your point is in regard to what I said, which is simply that beings capable of travelling between stars most probably have little interest in planets as a place to live because their needs are much easier served in space and the chances are that any given planetary environment will be hostile to their biology.

 

[Dinwar]

I really don't know what your point is in regard to what I said,

Then I can only conclude you are being willfully obtuse, have no understanding of how travel works, and a fundamentally mystical view of space travel as a whole.

My point is that you are wrong, in pretty much everything you say. This is demonstrable via historical evidence and via even a preliminary understanding of the concepts involved.

Ever hear of atrophy? Attrition? SOS? Emergency landings? Scientific exploration? Refueling? Revictalling? Rewatering? Have you, in fact, studied ANY long-term voyages into areas without many resources? Because space is such an area--the whole reason we call it a vacuum is because there isn't much there. Matter is fundamentally clumpy in our universe.

...because their needs are much easier served in space...

Assuming a 100% perfect recycling program (never achieved and in opposition to the laws of physics as we understand them, so it's fundamentally magical thinking), or that all necessary materials can be found in space (a pure assumption based off of nothing but your desire for space-exploring civilizations to never land on anything). And ignoring--completely, willfully, and unconscionably--any psychological, social, political, military, economic, or other need.

...and the chances are that any given planetary environment will be hostile to their biology.

Just to be clear: You are arguing--apparently seriously--that a species capable of traveling through SPACE long-term is going to have trouble handling a hostile environment. Some sure; a species from a low-gravity world isn't going to do well on Jupiter. But for most your argument boils down to the assumption--again, no evidence supports ANY of your conclusions--that these beings are fully capable of building an interstellar vehicle that has no attrition that can't be fixed by grabbing random bits of matter floating about, but not capable of building the equivalent of a scuba suit or habitat. The concept is comical. Space IS a hostile environment, to any life-form that evolved on a planet, pretty much by definition--so anything capable of handling long-term habitation in space has already proven the viability of technology that can protect them from hostile environments.

 

[RecoveringYuppy]

Just to be clear: You are arguing--apparently seriously--that a species capable of traveling through SPACE long-term is going to have trouble handling a hostile environment.

I think the point is that they will prefer the habitats they built to their own desires. Terraforming is largely impossible for the objects in our solar system and is likely to be possible only for a very small minority of planets. Things like gravity, day/night are virtually impossible to fix without basically dismantling and rebuilding the planet. But concepts like O'Neill cylinders (or their successors) get those things right easily and with a hell of a lot less material than a planet needs.

 

[Elind]

Then I can only conclude you are being willfully obtuse, have no understanding of how travel works, and a fundamentally mystical view of space travel as a whole.

My point is that you are wrong, in pretty much everything you say. This is demonstrable via historical evidence and via even a preliminary understanding of the concepts involved.

Ever hear of atrophy? Attrition? SOS? Emergency landings? Scientific exploration? Refueling? Revictalling? Rewatering? Have you, in fact, studied ANY long-term voyages into areas without many resources? Because space is such an area--the whole reason we call it a vacuum is because there isn't much there. Matter is fundamentally clumpy in our universe.

Assuming a 100% perfect recycling program (never achieved and in opposition to the laws of physics as we understand them, so it's fundamentally magical thinking), or that all necessary materials can be found in space (a pure assumption based off of nothing but your desire for space-exploring civilizations to never land on anything). And ignoring--completely, willfully, and unconscionably--any psychological, social, political, military, economic, or other need.

Just to be clear: You are arguing--apparently seriously--that a species capable of traveling through SPACE long-term is going to have trouble handling a hostile environment. Some sure; a species from a low-gravity world isn't going to do well on Jupiter. But for most your argument boils down to the assumption--again, no evidence supports ANY of your conclusions--that these beings are fully capable of building an interstellar vehicle that has no attrition that can't be fixed by grabbing random bits of matter floating about, but not capable of building the equivalent of a scuba suit or habitat. The concept is comical. Space IS a hostile environment, to any life-form that evolved on a planet, pretty much by definition--so anything capable of handling long-term habitation in space has already proven the viability of technology that can protect them from hostile environments.

My my, you do like to waffle and can't address a simple supposition without doing so with indignation that your waffle isn't appreciated.

 

[The Atheist]

This is demonstrable via historical evidence and via even a preliminary understanding of the concepts involved.

Sorry mate, you lost me here.

What historical evidence are you using regarding space travel?

What happened on Earth, a planet, is going to bear no relationship to travel in space, so I'm sure you couldn't have been referring to ancient explorers because that would be plain silly.

Do tell.

 

[Dinwar]

Sorry mate, you lost me here.

What historical evidence are you using regarding space travel?

Every major voyage had to plan for the loss of vital materials. Even facilities equipped to recycle some can't recycle all--which means eventually, you run out. On sailing ships they had to resupply pretty constantly. Submersable habitats can recycle many more materials, but eventually run out. The ISS isn't exactly self-sustaining. Literally EVERY craft designed for long-term habitation has experienced attrition of vital materials.

Space travel? For the most part no, though we have some experience with it that's worth considering. But when it's as universal as this, it's worth considering. Merely dismissing it as "they have advanced tech" is magical thinking. It's not an explanation.

What happened on Earth, a planet, is going to bear no relationship to travel in space, so I'm sure you couldn't have been referring to ancient explorers because that would be plain silly.

Okay, hot shot: You're in a space ship. You're going.....somewhere. Doesn't really matter. How are you going to deal with the abrasion by micrometeors? They don't exactly manufacture solar sails or ship viewports in space. You can carry some with you, but eventually you'll run out--at which point you're either dead, or you find somewhere with the appropriate materials and make some (assuming you're intelligent enough to make a space ship, you will be intelligent enough to foresee this eventuality and provide for the manufacturing of at least some materials, given the correct raw materials).

This is space--not the magical land of unicorn farts and rainbows where wishes become reality. Entropy holds true. So does the fact that machines have finite lifespans. Space travel will be subject to some of the same issues that literally every other form of travel suffers from: those issues related to the wear and tear on the equipment itself, and replacing things lost during travel.

And the reality is, most of those materials will not be replaceable without dipping into some gravity well in some way. You don't find a lot of rocket fuel--or solar sail material, or windows, or solar panels, or the components to make any of those--in the matter-deprived interstellar regions. Even if you say "But rogue planets!!!!" you're still going into a gravity well, only with less chance of success because rogue planets won't allow for most analyses. You'd be flying blind.

The idea that we have to ignore even the most basic lessons from the past merely because THIS travel is in space, and THAT travel was in the ocean is insane. As long as the trip requires a vessel of some sort, that vessel WILL need repairs, WILL need replenishment, and WILL have to find somewhere to do all that.

Again, that's ignoring all the OTHER reasons to land on planets, and the fact that the only semi-rational argument against my stance thus far presented was the equivalent of arguing that we can build nuclear submarines but not snorkels.

 

[Roboramma]

Dinwar, I think Elind wasn't very clear about what he/she was saying. It certainly wasn't explicit, but I think the idea is not so much not needing some new materials or manufacturing, but not getting those materials from objects of a size on par with the earth, where the gravity means the cost to bring whatever you're harvesting back into space will be quite high. Instead, you still need raw materials, but those can be accessed from objects with lower gravity, like asteroids or comets.

Of course in this way you're not likely to find everything you need on a single body, but that need not be big deal as you can travel to more than one such object, mine whatever you need, and then take those raw materials to some sort of space-based manufacturing plant. Avoid going down a gravity well, but still get your raw materials and manufacturing.

Of course it's also possible that I'm misunderstanding, but the above is my own viewpoint. On the other hand, as I said, at some point you've used up all the asteroids in your neighbourhood, but there are still plenty of resources left on a planet, and at that point you go down and harvest those resources too.

 

[Dinwar]

Dinwar, I think Elind wasn't very clear about what he/she was saying. It certainly wasn't explicit, but I think the idea is not so much not needing some new materials or manufacturing, but not getting those materials from objects of a size on par with the earth, where the gravity means the cost to bring whatever you're harvesting back into space will be quite high. Instead, you still need raw materials, but those can be accessed from objects with lower gravity, like asteroids or comets.

IF--and this is the fundamentally unproven assumption--you can 1) find the materials and 2) convert them into some useable form. Neither are immediately obviously the case for small celestial bodies, and a space-traveling species cannot assume that they will always be available. Unless they are suicidal or suicidally stupid they will need to have contingency plans for harvesting materials from objects with deep gravity wells.

Plus, like I said, you don't need to bring the whole ship down there. Smaller shuttles of some sort would be an option--keep the big ship outside the gravity well, grab what you need (or want) with the shuttles, then fly up to the main ship. If we're assuming that they can manufacture what they need fuel is not an issue; they'll manufacture it on the planet. Shuttles would by definition and necessity be smaller (otherwise the ship couldn't carry them), so they'd require less resources. Again, this is how this problem has ALWAYS been solved: we don't beach tall ships or land the ISS every time we need to restock the drinking water.

Then there's the psychological aspect--which cannot be ignored. Some people do not fit with society. They want to go somewhere else. Take, for example, the settlement of the West. A lot of black people moved West (I believe into Oklahoma) and made towns for themselves because, let's face it, white people back then sucked for the most part. They built their own towns, universities, etc., to avoid the social issues they were running into. That sort of thing is pretty much inevitable in any herd, pack, communal, or other group-oriented species: some folks don't fit. For them, asteroids probably won't be an option--but planets are, even if they are hostile. And if not, having a prison that's literally impossible to escape from has a certain amount of appeal. Siberia and Australia were good; Venus would be better.

 

[Elind]

Dinwar, I think Elind wasn't very clear about what he/she was saying. It certainly wasn't explicit, but I think the idea is not so much not needing some new materials or manufacturing, but not getting those materials from objects of a size on par with the earth, where the gravity means the cost to bring whatever you're harvesting back into space will be quite high. Instead, you still need raw materials, but those can be accessed from objects with lower gravity, like asteroids or comets.

Of course in this way you're not likely to find everything you need on a single body, but that need not be big deal as you can travel to more than one such object, mine whatever you need, and then take those raw materials to some sort of space-based manufacturing plant. Avoid going down a gravity well, but still get your raw materials and manufacturing.

Of course it's also possible that I'm misunderstanding, but the above is my own viewpoint. On the other hand, as I said, at some point you've used up all the asteroids in your neighbourhood, but there are still plenty of resources left on a planet, and at that point you go down and harvest those resources too.

That's He.

I thought I was perfectly clear. Short of warp speed, any beings travelling, and living, between stars or even within their own solar system will be in a technological position to choose where they live and where they visit.

I simply propose that while they will certainly be able to visit planet surfaces, it seems likely that there will be no need to settle, or conquer, planets that are not ideally suited to them. Speculation on the fundamental need for "lebensraum" are fantasy. Even most humans live out their lives within one relatively small geographic area; and who said they would be limited to one habitat in space?

 

[Dinwar]

I thought I was perfectly clear. Short of warp speed, any beings travelling, and living, between stars or even within their own solar system will be in a technological position to choose where they live and where they visit.

This is simply not true. Or, rather, is a serious oversimplification. Emergencies happen, and the longer you are away from your base of operations (whatever that may be) the more likely you are to encounter some sort of emergency. A micrometeor punching through a vital component of the ship at several times the speed of sound in air would necessitate an emergency stop at the nearest source of stuff to repair the ship (you cannot carry enough spare parts to preclude this posibility).

I simply propose that while they will certainly be able to visit planet surfaces, it seems likely that there will be no need to settle, or conquer, planets that are not ideally suited to them.

I see no reasons supporting this conclusion. YOU wouldn't go somewhere not ideally suited for YOU, but that in no way precludes more adventerous or despirate folks existing. You are projecting your attitudes onto this hypothetical species, which is inherently wrong.

Even most humans live out their lives within one relatively small geographic area; and who said they would be limited to one habitat in space?

Most=/=all. And modern humans don't have a whole lot of areas to colonize, so we cannot take modern humans as an analogy for a species that can colonize other planets. A better analogy is countries with uninhabited frontiers. In those situations, you're right that most stay home--but an appreciable number of folks do move into those frontier regions, even when they are not ideally suited.

 

[Elind]

This is simply not true. Or, rather, is a serious oversimplification.

You are the one oversimplifying. You seem to think that future space habitation will be similar to something like the ISS.

 

[RecoveringYuppy]

You are the one oversimplifying. You seem to think that future space habitation will be similar to something like the ISS.

Indeed. The presumption is that they will at least be big enough to address the "recycling" problem by having a functioning bio-cycle, possibly also emulating other Earthly cycles (carbon cycle, etc).

 

[Dinwar]

You are the one oversimplifying. You seem to think that future space habitation will be similar to something like the ISS.

Nope. I am assuming that it's going to be isolated and in a hostile environment. The first is given, considering the fact that we're talking about some sort of vessel--for the purposes of replenishing supplies, ALL vessels are isolated. Even cars need to stop at gas stations. The second is given, considering the fac that space is dangerous. Look at what happens when a grain of sand traveling at a significant percentage of c hits something; NO ship can just laugh off a hit like that. xkcd did a neat "What If" on this topic using baseballs; the result was equivalent to a nuclear bomb. And that's just one hazard; any one of a billion different things can go wrong, necessitating repairs on a timescale from "when you get around to it" to "we're all dead if you don't fix it now".

ANYTHING that has those issues to contend with will NECESSARILY have to find some celestial body to harvest for resources to repair itself. If you wish to disagree with me, those are the points you need to disprove. Dismissing them, as has been your MO in thread, doesn't make them go away.

The presumption is that they will at least be big enough to address the "recycling" problem by having a functioning bio-cycle, possibly also emulating other Earthly cycles (carbon cycle, etc).

This will still require energy. Earthly cycles are driven by nuclear energy in the planet's interior and solar energy from the exterior. Without those, we'd have no cycles at all--there wouldn't be sufficient energy. What this means is that SOMETHING is being used up, and will eventually run out. Furthermore, even the largest ship cannot carry an infinite number of replacement parts; I've yet to hear of anything that can carry even sufficient replacement parts to duplicate itself. Which means that unless you are postulating as-yet unknown technology (ie, magical thinking), you've got to account for damage and repairs.