Because 2020 was not eventful enough... UFOs

[Vertigo 7]

They wouldn't want us as slaves, because by the time they could reach us they'd be advanced to build robots to fill those workforce gaps.

Unless it was impractical to transport that much equipment for some reason.

[brucewarren]

It would all depend on whether the alien civilisation was merely technically advanced or whether it was morally advanced as well.

The Federation (Star Trek) is. The Empire (Star Wars) is not. Both are high tech but I know which I would prefer to live in.

There's no reason whatsoever to just assume that high tech requires civilised moral codes. Human history has demonstrated in blood
that it all too possible for an advanced tech society to be governed by utter savages.

Robots are high tech. High tech is expensive. Slaves are low tech. Low tech is cheap. if the aliens have no moral compass they
might well consider expendable slaves to be far more cost effective than expensive to operate and maintain high tech machinery.

[Mightysword]

It would all depend on whether the alien civilisation was merely technically advanced or whether it was morally advanced as well.

The Federation (Star Trek) is. The Empire (Star Wars) is not. Both are high tech but I know which I would prefer to live in.

There's no reason whatsoever to just assume that high tech requires civilised moral codes. Human history has demonstrated in blood
that it all too possible for an advanced tech society to be governed by utter savages.

I disagree.

What you think would had happened if humanity were similar to the Klingon? Personally I don't think we would had made it through the cold war and would head straight down the Fallout road if we were that aggressive. The Sith Empire makes even less sense logically. It's not even a matter of evil, it's just barbaric, and any society like that would self-destruct or regress itself over and over before reaching any relevant point. The Krogan from mass effect is an example of I think what would logically happens if a civilization achieve technology without the enlightenment to handle it.

In a way I think Nuke is the first milestone in term of advance technology for humanity. For the first time we invented something that's very powerful that opened up a lot of new possibilities, but we can also for the first time have something to wipe ourselves off the map with. And between nuke to whatever point a civilization achieve FTL travel, I imagine there will be many more milestones, and each will probably be even more potent than the last. For example one milestone I think is probably accessibility to space, not just for research but also to live and produce. At that point space militarization will happen, and will pose even a greater threat to the species survival than nuke does now. And if a civilization makes it pass that, it would also be more morally progressed.


So no, while it's not a guarantee of course, I believe there is actually strong reasons to believe technically advanced and morally advanced go hand in hand in any civilization. Otherwise it would be more than likely to destroy itself with it.

[BrasatoAlBarolo]

What about a Vulcan first contact scenario?
Let's suppose the trigger isn't warp drive, but a manned Mars landing (which is likely going to happen during the present century). The fact humanity starts to "colonize" another planet is going to wake up some kind of interest in an advanced race observing us, convincing them to make contact and help us progress, provided we respect certain conditions or we reach certain social milestones without help (e.g.: no more wars between us or no more people dying of hunger).

To be honest, though, as somebody already pointed out, we're suggesting that aliens have a human-like way of thinking, which is probably unlikely. What if they grew and evolved on a planet with a sulfuric atmosphere? What if they lived and evolved in a gas giant and they eat palladium? What if the concept of "good" or "evil" is something like "you're evil if you eat vegetables, you're good if you eat your mom when you reach maturity"? Their ethics could be very different, so different from ours we hardly can comprehend it.
From what we know, they could be shaped like rockets, travelling on a giant Lady-Gaga-shaped spaceship. Coming there just to ask "why do you worship a spaceship?".

On top of that, I'm not really sure "morals" grow with tech growth in mankind. Cold war didn't trigger a global nuclear war not because "a lot of people would die", but because "the fallout would make impossible for me taking all those juicy resources I'm interested in". The scientific community is willing to "share and cooperate" worldwide, but they're not the ones to choose. I mean, just look at how different have covid responses been around the world! Scientific community agreed on what to do, but they're not the ones picking the choice.
Same is going to happen to space exploration, or a new form of energy which incidentally can be used for huge booms. Technological progress doesn't mean moral growth for us, why would do for an alien race?

[Olterin]

I have to agree, tech progress doesn't strictly speaking mean morality progress. Nor can we count on any possible aliens having any ethical guidelines remotely similar to our own. The only truly sensible and fairly universal means of measuring their level of advancement is the amount of energy available to them (Kardashev Scale). As I said before, it's a lot closer of an analogy to look what we humans do about ant colonies or bee colonies than what happened with Columbus. Until we get to fusion power and frequent use of space resources, we're not even a Type 1 civilization, essentially ants for anyone with the means of interstellar travel. Should they exist, we better hope we're not an inconvenience that just gets cleared away to make room for a Hyperspace Bypass

The Earth does not have anything on it that would warrant an interstellar civilization to conquer us (*). Resources? Pfah, there's plenty more, more readily available, from asteroids and comets in our solar system. Except fossil fuels, and we're rapidly using those up ourselves already. And even then, Titan has plenty of methane if memory serves.

(*) No, the only thing that would make Earth a point of interest for an interstellar traveler is the life on the planet. Be that as a somewhat rare subject of study or a source of slave labor or whatever else I'm not thinking of or cannot even conceive of. But the sci-fi trope of biome rarity or resource rarity just doesn't hold up.


As for what aliens might look like, well, that's an entirely different question. Personally, I believe (based on our present knowledge of chemistry) that carbon-based life is the most likely, followed by maybe silicon-based life. It's in the molecular complexity as well as the temperature range where the molecules in question have such a wide range of structural permutation and stability. Unless of course there somehow are elements on the periodic table that we didn't encounter in our solar system that are sufficiently light to do many of the same things. Furthermore, we can surmise that certain societal milestones are a requirement for a civilization to have become an interstellar one in the first place - they'd need to have become the dominant species on their planet, for one, and have the drive to expand at the very least to have done so. As such, at a point where interstellar travel is feasible, expanding to new planets is less feasible than just building new space habitats. I realize this slightly contradicts the part about there being no reason whatsoever to conquer the Earth, and I'll happily concede this point - yes, for a civilization looking for more places to stuff their population, assuming they are very close to us in physical characteristics and living requirements, the Earth would be a good target. Big caveat though, surface acceleration. This is the one variable which can differ a fair bit for Earth-like planets that could feasibly sustain carbon-based life.

What I mean is: we're not going to have a good time of having a Mars colony or a Moon colony until we figure out how to prevent bone and muscle loss. Any alien life coming to Earth would have much the same issue unless coming from an environment extremely similar to our own. Far better to have orbital stations built to spec.

[Vertigo 7]

Olterin has a great point. Without some as yet unknown method of artificially producing gravity, the only method we have of simulating gravity is through centrifugal force. This presents problems for prolonged deep space travel because the craft would have to be massive and would also be incredibly slow moving.

As much as we may want to believe the "science" of Star Trek and the like, it's just not realistic. While things such as cold fusion, anti-matter, dark matter, and such are either theoretical or have been proven, there's no theory for producing gravity. And without that, I'm afraid the negative health impacts on life forms spending years in space would make them incapable of setting foot on this planet without immediately collapsing and dying under their own weight.

[pjknibbs]

Olterin has a great point. Without some as yet unknown method of artificially producing gravity, the only method we have of simulating gravity is through centrifugal force. This presents problems for prolonged deep space travel because the craft would have to be massive and would also be incredibly slow moving.

Why does providing gravity through rotation imply either massive *or* slow-moving? You could have a pretty small craft (say, 50m across) and spin it to provide gravity, just as they did in the movie Interstellar. As for slow-moving, the important thing is acceleration, not speed, given there isn't any drag in deep space to slow you down.

[Olterin]

Why does providing gravity through rotation imply either massive *or* slow-moving? You could have a pretty small craft (say, 50m across) and spin it to provide gravity, just as they did in the movie Interstellar. As for slow-moving, the important thing is acceleration, not speed, given there isn't any drag in deep space to slow you down.

Precisely, it does not. My point was a different one - more likely than not, a species having evolved on another planet would have a different "native" surface gravity than Earth. The bigger the difference, the bigger the problems for them would be, hence my comparison with ourselves and having a presence on Luna or Mars.
With that being said, inertia is a thing, so "slow-moving" for a spacecraft would mean more "very sluggish". As for the scale, volume is a consideration unless it's a TARDIS - you wouldn't build a manned interstellar vessel for just 5 people unless you also had FTL propulsion.

Edit: random thought just crossed my mind - a species having evolved on a 2g surface gravity world would likely have natively more agile craft since they would build for their native surface gravity, or at least with it in mind. Assuming, of course, that the physical limits would scale up due to evolution.

[fiksal]

Muscle and bone loss are "features" of our own bodies. If we were to figure out how to turn it off, we would feel much better.

Radiation is problematic, unless we figure out how to make ourselves better, that'll always be one.


As for gravity and non gravity, that also mostly matters for organisms with fluids and a need to pump those fluids. Any more solid life won't care.


As for spinning. Not sure we really want that. Might be more practical figuring out how to turn off the above processes than spinning the whole ship. Even with spinning it will not ever be even close to a gravity : with different rotational speeds at various "heights" - you will never want to jump and standing up might be a dizzying experience.



Something was mentioned before. Why would anyone fly to another star? That's a good point - there is little reason. One maybe would fly if it's a relatively cheap travel, for example, low energy consumption, ability to survive for a very long time, or just being near immortal.

[Vertigo 7]

Olterin has a great point. Without some as yet unknown method of artificially producing gravity, the only method we have of simulating gravity is through centrifugal force. This presents problems for prolonged deep space travel because the craft would have to be massive and would also be incredibly slow moving.

Why does providing gravity through rotation imply either massive *or* slow-moving? You could have a pretty small craft (say, 50m across) and spin it to provide gravity, just as they did in the movie Interstellar. As for slow-moving, the important thing is acceleration, not speed, given there isn't any drag in deep space to slow you down.

So disregarding the movie aspects and focusing on the math, if the desired outcome is to produce 1g along the circumference of a spinning object, the larger the object is, the less angular momentum is required to achieve 1g. It's just like wheels on a vehicle, the larger the wheel, the less RPMs are required to achieve a desired velocity.

In space, things are even trickier because you have to be able to consider navigation. Things wont work like in Babylon 5 where one part of the ship is spinning and the other part is stationary. Law of inertia - an object at rest stays at rest unless acted on by an outside force. So we can't build ships where say the living quarters were on a spinning part and the engines and thrusters were stationary relative to the rest. Spinning any part of the ship will spin the whole thing (Think of a helicopter. If the tail rotor fails, the helicopter starts spinning out of control because the tail rotor was providing counter force to the force needed to spin the blades). Meaning if I have a small ship, it's going to be spinning fast to create gravity. If I need to turn the craft to avoid a hazard it would be difficult to time thruster firings in such a way that the ship can safely navigate.

However, in a larger ship, since it would be spinning more slowly, the thruster timings would be easier to manage and allow for a much greater margin of error.

As for why it would be slow moving, again, law of inertia. The craft would need sufficient thrust to get it moving. Assuming we could ever actually build the things, there's no way they could be launched from the surface of the planet. Think of how much fuel is used just to put a tiny capsule in orbit today. They would have to be assembled in space. Once they get moving, they're basically going to be ballistic. It's not going to be like Star Trek where the ship can just stop on a dime and forget the Expanse, the sheer force of trying to end over end flip something that big and try to counter its momentum with retrograde engine firings would rip the thing apart. Trying to reinforce it for doing something like that would increase its mass and require even more effort just to get it moving forwards.

All of this has been looked at, heavily, by NASA and JPL. There's a really good reason why it's been rejected.

[brucewarren]

The maths says a large station can be spun more much slowly than a small one for the same effective G.

Even without all the technical stuffs there is another reason why you would want a large slow spinning ship/station as opposed
to a small one that span quickly. If you spin the station like a top everyone on board would be throwing up their lunch instead
of getting any work done. If you're planning to spend a long time on the station crew comfort is something that needs to be considered.

[CBJ]

If you spin the station like a top everyone on board would be throwing up their lunch instead
of getting any work done.

This is wrong on a couple of counts. First, they would only get motion sickness if there was a fixed reference point by which they could tell they were spinning. Without one, and with constant rotation, they'd be completely unaware of it. And second, dealing with similar sickness caused by weightlessness is already part of astronaut training; it would be no different if they had to add motion sickness due to rotation to the training.

[Mightysword]

To be honest, though, as somebody already pointed out, we're suggesting that aliens have a human-like way of thinking, which is probably unlikely. What if they grew and evolved on a planet with a sulfuric atmosphere? What if they lived and evolved in a gas giant and they eat palladium?

I have to agree, tech progress doesn't strictly speaking mean morality progress.

Regardless of how a civilization think, for one to progress their survival instinct had to outweigh their destructive instinct no matter what. It's not something that's based on a moral code. That's why I said the Sith Empire doesn't make sense because it's not even a bout being evil (by our standard). Regardless of what it is, simply the fact a civilization doesn't destroy itself with it own technology speak "something" for their ethic.

Same is going to happen to space exploration, or a new form of energy which incidentally can be used for huge booms. Technological progress doesn't mean moral growth for us, why would do for an alien race?

I disagree. If you want to hold everything in a "everything or nothing" manner against an ideal standard, than yes our current moral is still far from perfect. But put it in relative context against history, it had improved a lot. From cavemen, to tribal to the first civilization like Babylon or ancient Egypt, to Roman empire, to the city states and dynasties during renaissance era and to now, each era improves the human's conscious and ethical understanding greatly - again, comparing to the previous era, not to a gold perfect standard. In fact, I would say it's almost mandatory, not even hand and hand but ethical evolution is a prerequisite for technological advancement.

The only truly sensible and fairly universal means of measuring their level of advancement is the amount of energy available to them (Kardashev Scale).

Yes, that is another point I wanted to mention. Right now nuke is the most powerful form of energy for us, but even simple physic would prove it's no where enough to drive FTL travel. Meaning an interstellar civilization would have access to even a more powerful form of energy source, which can be assumed even more destructive as a weapon. However, this would also mean they had solved the very basic needed of a civilization - energy need, which I believe would go great length in pacify most conflicts with the alternative is to destroy yourself with it.


Unless ... their advancement is biological rather than technological. So an alien could be something like the Tyranid ... in that case may the Emperor help us.

[red assassin]

If you spin the station like a top everyone on board would be throwing up their lunch instead
of getting any work done.

This is wrong on a couple of counts. First, they would only get motion sickness if there was a fixed reference point by which they could tell they were spinning. Without one, and with constant rotation, they'd be completely unaware of it. And second, dealing with similar sickness caused by weightlessness is already part of astronaut training; it would be no different if they had to add motion sickness due to rotation to the training.

Spin artificial gravity is identifiably different to natural planetary gravity due primarily to Coriolis forces (but also tidal forces), and it does make people ill. There's quite a lot of disagreement in the literature about the extent to which people can tolerate this and how much they'll adapt, and some authors find quite practically sized spun sections are tolerable, especially if you're just trying to produce some gravity and not fully 1G, but it's definitely not as simple as sticking people in a spinning tube and hoping for the best!

[mr.WHO]

If you spin the station like a top everyone on board would be throwing up their lunch instead
of getting any work done.

This is wrong on a couple of counts. First, they would only get motion sickness if there was a fixed reference point by which they could tell they were spinning. Without one, and with constant rotation, they'd be completely unaware of it. And second, dealing with similar sickness caused by weightlessness is already part of astronaut training; it would be no different if they had to add motion sickness due to rotation to the training.

Unfortunately this is not true - for small radius, high speed spinning stations the "gravity" difference between feets and head is so noticable that human brain can't really process process the motoric situation (your head feel different gravity, but try to apply to your feets that are at different gravity) - you will risk serious injury when trying to move (even more confusing if you will change/move in different directions to station rotation) or even simply by turning your head.
You can "feel" similar but lighter issues when you're on high speed carousel and turn you head around.

The bigger stations with slower rotation reduce this problem to neglible level.
Someone on YT did the math and station from Space Oddysey is nearly good.
On something like Stanford Torus or O"Niel Cylider you wouldn't even notice anything unless you would play specific ball sports like Volleyball or Tennis (you woud notice that the ball would fly differently than in Earth condition).

Personally, I really hope that SpaceX will boost the commercial lauch capacity to such extend that we will have small spinning station within decade or two.
Aparently thre were plans to have test spinning module on ISS, but it was never completed.

[Vertigo 7]

https://www.artificial-gravity.com/sw/SpinCalc/

Found this calculator that can show the differences in relative comfort of occupants based on size and angular velocity of a spinning station/ship. Granted the "comfort" level is conjecture from several different authors but they do all tend to agree that the bigger the spinning thing is, the less discomfort the occupants will feel.

Anywho, based on this calculator, the best experience for the occupants isn't achievable until the object has a radius of about 250 meters.

[CBJ]

Well there you go; I learned something. Apologies are in order to brucewarren then!

[pjknibbs]

Granted the "comfort" level is conjecture from several different authors but they do all tend to agree that the bigger the spinning thing is, the less discomfort the occupants will feel.

Well, yes, that's pretty obvious--the larger the object the slower it needs to spin to provide an effective 1g at the edge. Question is, though, when you're talking about a long duration space mission, at what point does the discomfort of spinning the ship work out better than the discomfort of living in zero gee? I think we're comparing how comfortable it is to living on Earth, here, and it's never going to get close to that until you get to full-on spinning space station.

By the way, I'm not sure why you think the B5 "have part of the ship spinning, but not all" approach wouldn't work. They also used that concept in 2001: A Space Odyssey, only in that the spinning part was essentially a drum inside the ship that was used for exercise due to the long duration of the mission; in the sequel (2010) the Discovery is tumbling when they find it, because friction between the drum and the ship has caused it to transfer the spin to the ship. In a ship that's not derelict you just need a bit of extra manoeuvring fuel to stop the spin, or else have a counter-rotating mass designed to compensate for the spin.

[Mightysword]

Question is, though, when you're talking about a long duration space mission, at what point does the discomfort of spinning the ship work out better than the discomfort of living in zero gee?

I think it's more than just a matter of comfort but long term health issue as well. Astronauts who spent months in zero G suffer muscles decay and need to go through rehab so they can move around normally again. Having gravity, even if it's not a full G like Earth would do wonder to long term sustainability of space travel.

By the way, I'm not sure why you think the B5 "have part of the ship spinning, but not all" approach wouldn't work. They also used that concept in 2001: A Space Odyssey, only in that the spinning part was essentially a drum inside the ship that was used for exercise due to the long duration of the mission;

I think it would actually easier to do 'work' in zero G anyway, especially heavy labor work (i.e mechanical maintenance). Seeing a good chunk of effort in those kind of works down on earth is about lifting and scaffolding, which is rendered moot in zero G.

Not sure if anyone here played the latest mechcommander game released a few years back called Battletech. The player's flagship is called the Argo and I love how the designer put some thought in on the design. The working area of the ship is still zero G, but the 3 living quarter "pods" are designed to have gravity most of the time. During travels, they fold alone the body of the ship, and use the linear acceleration from the engine to generate gravity. When the ship is stationary or orbiting a planet, they open up and rotate around the ship axis and use centrifuge force to generate gravity. It's probably one of the best design I've seen about space travelling aside from the magic gravity device (ala starwar/startrek ship). Here are 2 pics of the 2 mods:

travel mode

stationary mode

[BrasatoAlBarolo]

For very long trips (years and up), you need some sort of cryo-pods to store people and avoid them age on their way to destination.
If aliens come to Earth, their trip from home may be very short (Dune style), quite short (Star Trek style, so perhaps in the magnitude of weeks / months), or very long (decades / centuries), depending on how fast they can move and the means of transport (warp, wormhole, fart-drive and so on). Even if they were immortal beings, centuries on the void waiting to come here and be bombed / eaten / sexually harassed (depending on my first contact scenarios) would be pretty boring, so I'd expect them to have some sort of "sleep mode".