> a stepping stone to being able to live in space long term in very large, permanently spaceborne crafts.
That is not going to happen, without technology that currently only exists in Science Fiction, like artificial gravity, for the simple reason that we require 1g to live, let alone thrive.
> because of immediate access to materials that’d need to be launched into orbit otherwise.
1. How does this "immediate access" benefit the aforementioned "very large, permanently spaceborne crafts", which apparently won't be moored to planetary bodies?
2. There is no "immediate access". Having rocks next to me, and having the sort of highly refined materials that go into building the tech required for spacecraft, are 2 VERY different things. But, I am always happy to be proven wrong: Let's take a very simple task, like ISRU'ing LOX & Methane, and let's do it, at scale, here on Earth, where there is no lack of energy, breathable atmosphere, building materials and labour. Strange, isn't it, that no one seems to be doing that.
> In a universe where there are large human civilizations not just throughout the solar system but also scattered amongst other star systems, there are numerous paths and discoveries that each branch will take that Earth’s branch in its lonesome may never have trodden.
I agree. But given that, what evidence supports the idea that the branch that eventually allows us to leave our solar system requires us to first waste tons of resources on trying to send people to inhospitable, irradiated rocks for no good reason?
Especially since we have a perfectly good alternative to this waste of time: Sending robots.
> It also just seems a bit cruel to be able to see the vastness of the universe and never be able to touch any of it, in person.
Unless we discover a way to do FTL travel, it doesn't matter if that feels cruel or not, it is reality.
And I can pretty much guarantee that the person discovering the means to cheat physics in such a way won't be doing so while constantly worrying about his habitats airlock malfunctioning, or the piss-regeneration system giving out, or the supply ship getting canceled in the next congressional-bickering about the budget.
It will happen here on Earth, likely by someone who never visited even LEO, someone who works and lives in a stable environment with books, people to talk to, air to breathe and delicious non-freeze dried food to eat, who never has to worry whether there will be enough recycled piss to make his next cup of coffee.
> That is not going to happen, without technology that currently only exists in Science Fiction, like artificial gravity, for the simple reason that we require 1g to live, let alone thrive.
Artificial gravity is easily generated via rotation or thrust.
> 1. How does this "immediate access" benefit the aforementioned "very large, permanently spaceborne crafts", which apparently won't be moored to planetary bodies?
It will be far easier to get materials into space from the moon than from the much deeper gravity well of earth.
> I agree. But given that, what evidence supports the idea that the branch that eventually allows us to leave our solar system requires us to first waste tons of resources on trying to send people to inhospitable, irradiated rocks for no good reason?
How do you see us developing the technology for humans to leave the solar system if we never develop the technology to visit the moon?
Technology is generally driven forward by increments, and having smaller goals leading to the larger one is pretty normal. Also, you don't need to "cheat physics" to explore space.
> It will be far easier to get materials into space from the moon than from the much deeper gravity well of earth.
No it won't, for a very, very simple reason:
Every single kilogram of stuff you launch from the moon, has to be launched FIRST from exactly that "deeper gravity well" here on Earth. Including btw. the fuel required to launch it. Because the Moon is shockingly devoid of any steelworks, factories, fuel refineries, Astronaut training facilities, food processing plants or any of the other myriad sources of stuff required in space.
So yeah, launching something from 1/6th of Earths gravity is easier. However, all this does, is add another launch to the equation.
> How do you see us developing the technology for humans to leave the solar system if we never develop the technology to visit the moon?
For the same reason why we developed radio transmission, without first inventing super-sonic carrier pidgeons.
Technology does not only advance incrementially. Ever so often, a radically new technology emerges, that is leaps and bounds better than existing systems, and often wasn't developed from these systems either.
And btw. Rocket Engines are just one such technology as it happens. Before them, the strongest way to propel something through the air, were propellers, a technology which we since improved by alot, but is still incapable (and never will be capable to) put things into space.
So no, doing what we have done before is not a reqirement for finding a much better way to do it.
> Also, you don't need to "cheat physics" to explore space.
Where exactly did I assume that? But you do need to cheat our current understanding of physics for FTL travel.
Just to nitpick the gravity argument:
I think a major reason there currently is no spacecraft with artificial gravity is that microgravity is the whole point of space currently. You could probably build a spacestation with two sides and a long tether, but you don’t want that because you couldn’t do the interesting research anymore.
The top post of the link is talking about building a ship with a diameter of 200m. In reality you would just need a tether and counterweight. So yes, as far as new space technology goes, "easily."
> No it won't, for a very, very simple reason:
> Every single kilogram of stuff you launch from the moon, has to be launched FIRST... etc
That is the entire point of building out the moon. Sure the investment is difficult, but the longterm return makes it worthwhile. Your argument seems similar to saying "why would we build a steel foundry, when we will need steel to build it in the first place."
> How do you see us developing the technology for humans to leave the solar system if we never develop the technology to visit the moon? etc..
The technological difficulty with going to the moon is way more than just rocketry. There's life support systems, shielding, navigation, long term space habitation etc... There are literally hundred if not thousands of technologies that will need to be refined over time, and manned moon missions will go a long way to advancing them.
> But you do need to cheat our current understanding of physics for FTL travel.
My point was that you do not need ftl to travel through space.
> In reality you would just need a tether and counterweight.
And a ship that still maintains its course, and can still be steered when bound to such a contraption. Oh, and a tether material that can actually hold against that strain under conditions found in space reliably. The temperature differential between in- and out-of-sun would destroy most materials under such a stress. And a way to deploy the whole thing, start its rotation, and keep it stable over time.
So no, as far as any technology is concerned, this is not done "easily".
And all this effort STILL doesn't get you gravity. It gets radial acceleration over a short distance. Just imagine, for a moment, the difference in "gravity" experienced between the feet and the head of a person in such a contraption, and what that will do to their brains, skeleton, muscles, circulatory system, etc.
Oh, and: While the whole "rotating thingamabob" idea works theoretically in space, there is no practical way to use in on the surface of a low-gravity planetary body. So, what's the plan for keeping people alive against 1/6th gravity on a permanent Moon Base?
> That is the entire point of building out the moon
Building out what exactly, foundries and factories? On the moon? You know, the place where the dust alone is enough to kill almost any machinery exposed to it?
Let me ask you a question: If oil is found in antarctica, where would we build the refinery? I think we both know the answer to this one. And building machinery as comparatively simple as an oil refinery in antarctica is a cakewalk compared to building even a simple ore-smelter on the Moon.
You're getting piled on, but you're absolutely right. We don't even have the capability to permanently inhabit Antarctica, which has 1. an atmosphere of breathable air at the right pressure, 2. survivable temperature range, 3. abundant water, 4. a magnetic field and radiation shielding, 5. safe transit to and from. How does anyone think we can inhabit Mars, which doesn't have any of these?
Build a city of 100K on the northern-most habitable tip of Antarctica and have it (physically, socially, and economically) last 10 years, and I'll be convinced that we are ready to at least attempt Mars.
Not sure if that's a good argument. There are lots of places more hospitable and less remote than Antarctica that aren't inhabited either - the reasons why a large number of people would inhabit an area or not are complex.
We have the technology as a species to be able to inhabit Antarctica; there's just no compelling reason to do so at present, so we don't.
That's my point, it takes more than technology to inhabit a place. We might barely have the technology to live in Antarctica (or the middle of the Sahara desert), but it's still not economically feasible, there are no resources there that we need, and there's no social/societal need to be there. Even if we had the technology to safely get to Mars and viably live there (like aliens arrived and handed the technology to us), there's no point to doing it.
We definitely have the capability to permanently inhabit Antarctica, except there's nobody who's both willing and permitted to do it. This is also the main problem with Moon/Mars colonies; it could be done but who will pay for it? It's not an economically sound proposal.
We don't really know how much we need. I think we'd probably do just fine in 0.9g for instance, and maybe even substantially lower than that. Humans thriving in Lunar gravity isn't out of the question, we don't have data that rules out such a possibility.
That is not going to happen, without technology that currently only exists in Science Fiction, like artificial gravity, for the simple reason that we require 1g to live, let alone thrive.
> because of immediate access to materials that’d need to be launched into orbit otherwise.
1. How does this "immediate access" benefit the aforementioned "very large, permanently spaceborne crafts", which apparently won't be moored to planetary bodies?
2. There is no "immediate access". Having rocks next to me, and having the sort of highly refined materials that go into building the tech required for spacecraft, are 2 VERY different things. But, I am always happy to be proven wrong: Let's take a very simple task, like ISRU'ing LOX & Methane, and let's do it, at scale, here on Earth, where there is no lack of energy, breathable atmosphere, building materials and labour. Strange, isn't it, that no one seems to be doing that.
> In a universe where there are large human civilizations not just throughout the solar system but also scattered amongst other star systems, there are numerous paths and discoveries that each branch will take that Earth’s branch in its lonesome may never have trodden.
I agree. But given that, what evidence supports the idea that the branch that eventually allows us to leave our solar system requires us to first waste tons of resources on trying to send people to inhospitable, irradiated rocks for no good reason?
Especially since we have a perfectly good alternative to this waste of time: Sending robots.
> It also just seems a bit cruel to be able to see the vastness of the universe and never be able to touch any of it, in person.
Unless we discover a way to do FTL travel, it doesn't matter if that feels cruel or not, it is reality.
And I can pretty much guarantee that the person discovering the means to cheat physics in such a way won't be doing so while constantly worrying about his habitats airlock malfunctioning, or the piss-regeneration system giving out, or the supply ship getting canceled in the next congressional-bickering about the budget.
It will happen here on Earth, likely by someone who never visited even LEO, someone who works and lives in a stable environment with books, people to talk to, air to breathe and delicious non-freeze dried food to eat, who never has to worry whether there will be enough recycled piss to make his next cup of coffee.