the human body will encounter complications in low and zero gravity
ftl will never happen
space stations are a scam that rich tech ceo's promise
mars cannot be terraformed
life is probably unexceptional and we will never make contact with others
you will all die on earth
It's not a struggle session when these are all factual and already agreed upon
A real struggle session is "are wormholes real"
Yes, unless our understanding of quantum mechanics is very off.
Are they macro-scale, un-event-horizoned, and traversable is the real question.
Gravity can be simulated by constructing large rotating ships and stations.
FTL probably won't happen, but we might be able to exploit the curvature of space time and jump to far away locations that appear to be tens, hundreds, thousands, millions, of light years away.
Space stations under capitalism, maybe.
Eh. The medium term goal would be to just build large biome structures.
Yeah, probably. We'll find some rudimentary something or another, akin to bacteria or slime molds or whatever.
Alien life most likely won't be green skinned bipeds. That's near-sighted.😢
This is revisionist defeatist propaganda that ignores the struggles of the proletarian masses in establishing the true habitat of Soviet Man among the stars.
Gagarin smiles at everyone except you.
Don't need zeroG compensation if you make a space ark large enough to have its own internal gravity
Ftl isn't necessary on luxury gay space communist generational ships
Space stations are mostly lane but if they're also giant ships they're cool and good
Go further than Mars, get a cooler planet
This one is really true, make sure we aren't being settlers
I'm either dying here or not dying here, 50/50
large enough for its own gravity
Bruh??? How big do you want your spacecraft to be??
If you want a comfortable habitat, you basically need a floating city. I think the typical O'Neil cylinder is about 8km in diameter and 32 kms long. For each module. The more advanced designs typically have two of these that are connected with bearings at the ends and rotate in opposite directions. If you build them this large, you can get earth-like gravity on the cylinder walls by rotating the structure at a speed where (most) people don't get motion sickness. This means your crew doesn't have to put up with the lowered bone density and muscle atrophy that you usually get when you stay in a low g or zero g environment for long periods of time.
Building them this large also means you can have enough plants on board to produce oxygen for the crew, you can recycle waste water, grow your own food etc., there can even be small lakes or rivers on the cylinder walls.
That's largely a concept for space stations, but you could also use these for a generation ship.
oh ok i interpreted your comment as saying "just make your mass so hyuge it's a defacto planet!"
Big. Take the biggest thing and make it bigger. Communism is when things are big, the more bigger the more communister it is.
Because if we can't make the only planet in the universe we are perfectly adapted to work, then I don't think the inhabitable void of space is going to be much better.
Shut up doomer, who's we? Last time i checked me and my mates didnt genocide the congo or deforest the amazon or create the pacific garbage patch. Heehee how can we go to space if we havent fixed eartyh, stfu you can focus on two things at the same time as a species.
i said deforest the amazon and kil the congo, not the other way around. your rhetorical victory is forfeit uwu
i was meaning to say stop shaming the consumer of a capitalist economy for the unnecessary evil the capitalists do. stop saying humanity is at a great fault just because 200 years ago we let people get exponentially rich and create a class all for their own to conquer the earth.
We probably won't colonize other planets or whatever but exploring space is dope regardless. Nothing bad about learning more about the universe n shit.
I definitely think it's awesome for educational and curiosity purposes. The problem is when people are just throwing all their eggs in the Mars or Moon base or whatever idea for some reason and not giving a shit about the infinity of problems under the current societal system on earth.
That goes for a huge chunk of academic work, though. Tying science related stuff too closely to its application is a great way to give people an excuse to kill off whatever isn't "practical" enough. You already see it with the focus on STEM.
Space mining is probably pretty critical to avoiding ecosocialism on the cheap for most people in the world (and that's the best outcome without those mineral resources)
Space just isn't that cool or useful. We were all hyped up on space race nonesense and positivism, but it was a fever dream all along. We could go live on other planets but there's no reason to do so any time soon.
Why would I want to go to space do I look like some sort of nerd
Nah dude Elon Musk will totally nuke the polar ice caps to create an atmosphere and fly us there in his Big Fuckin' Rocket
Seriously, 2020 is too insane to predict next week and y'all wanna rule out space? Get outta here
dreaming will not exist under communism, dreaming is a human coping mechanism to deal with capitalism
That and "It doesn't matter if we suck Earths resourses dry and leave it a husk, because we'll just move on to the next one!"
Notice all the video game sci-fi settings are depressing capitalist hellscapes.
Aliens are here, they're watching us
FTL is possible just gotta find a way to manipulate that Dark Matter baby
Artificial Gravity is also possible gotta find a way to do shit with Graviton particles or something I don't know
Who needs mars when you can build big-ass cylinders in SPACE, THAT GUNDAM SHIT MOTHERFUCKA
Aliens signals are everywhere, we're just too stupid and impatient to catch them, the WOW Signal was alien
I will die in the revolution and my gay children will marry gay aliens 👍
Check-and-Mate
Artificial Gravity neatly solves the FTL problem along multiple axis (wormholes, pocket subspace, alcubierre drives, take your pick) though you need dark energy, not dark matter.
The rest is correct and what Korolev was aiming for. Planets are Petty Bourgeois. Culture Orbitals are Proletarian.
Anti space-doomer post.
FTL will never happen and that's ok. We can get around that.
Mars cannot be terraformed and that's ok. We didn't need it anyway.
It's worth considering that there are enough metals in this solar system to create enough 1G rotating cylinder habitats to provide more surface area to live on than all the habitable planets in the galaxy combined. If we just lived here in the solar system we could provide for trillions of humans.
At that point we could probably manage to gather enough energy fire some of them out to other solar systems. Give them enough fuel to slow down then just laser the fuckers in the direction of other stars.
Or heck it's possible to turn our own star into an engine by basically reflecting all the light in one direction and riding a beam of photons to get closer to other star systems over the course of a million years.
Legit if we started building some serious infrastructure in orbit around earth and the moon, I think people will be surprised what we are capable of.
Like a generation ship? Interesting concept, the only issue I see is getting access to all the metal in the solar system, it's a lot of metal. And then assembling it, although I assume you could put it together in space
The truth is that reality is stranger than science fiction, and when you look at non-FTL travel you start to think about pretty wild and massive concepts that are done on the scale of thousands or hundreds of thousands of years. Even without FTL, if you built enough generation ships around our star and then fired one to every single suitable star system in our galaxy at the same time, it would only take just over 100,000 years for all ships to arrive and for the galaxy to be colonised.
"Generation ship" really depends on how fast you shoot it out of the system. If it's going fast enough it's not a generation ship from the passengers perspective. They'll arrive in 100,000 years but for the passengers it could be less than a lifetime of subjective time, plus and on the scale of the universe, 100,000 years isn't a long time. Supposedly it 100,000 years for our ancestors to leave Africa and settle all corners of Earth.
It just means that without FTL we all become time travelers while in transit.
Don't need a generation ship if you solve old age (or accelerate fast enough to relativistic speeds)
Also dismantling Venus would get a decent Ringworld/Dyson swarm going. The Asteroids alone could vastly outstrip Earth's area.
well low earth orbit satellites have the benefit of eventually falling into the atmosphere and burning up so Elon's skynet isn't an issue there
FTL is unnecessary. But not because of generational ships like @Shmyt said, but because there's no speed limit in the universe. Yes, you read that right, relativity does not actually impose a limit on how fast you can go, only in how long it will take the information to get back to Earth. Not only that, relativity actually helps you: the faster you travel the more space squishes in your direction of travel.
The squishiness is given by the "Lorentz factor"
γ = 1/√(1 - v²/c²)
where c is the speed of light, 299,792,458 m/s, and v is the relative velocity between you and whoever is measuring your speed, Earth probably. So for example if your velocity is v=0.99995c, γ ≈ 100, and from the point of view of the spaceship all distances are 100× shorter, while from the point of view of Earth everything inside the spaceship moves 100× slower than normal.
So let's say you want to travel to the other end of the Milky Way, which is about 100,000 light years away. Let's brute force the problem and attach a massive rocket to the spaceship that accelerates at 9.8 m/s², and when we're midway through we rotate the ship 180° and decelerate at 9.8m/s². This is convenient because the ship can be organised as a tall building with gravity equivalent to the Earth's.
The Lorentz factor we reach at the midway point is[1]:
γ = ad/c² + 1
Plugging in a = 9.8m/s² (1.032 light-years/year²) and d = 50,000 ly, we get γ ≈ 50000. So suddenly our eternal 100,000 light year journey is squished to 2 light years, and we're travelling at 0.9999999998c from the point of view of the Earth.
Calculating the total time from the point of view of the spaceship, including the time to accelerate to almost the speed of light, is involved so I'll just drop the formula from [1]:
T = 2c/a acosh[ad/(2c²) + 1]
And the table of how long it will take to reach certain landmarks:
d (ly) Stopping at γ T (years) 4.3 Nearest star 3.2 3.6 12.2 Luyten b (nearest potentially habitable planet) 7.3 5.2 30000 Centre of our galaxy 15500 20 100000 Opposite end of our galaxy 50000 23 2000000 Andromeda Galaxy 1000000 29 So we can reach the other end of our galaxy within a single person's lifetime without any speculative technology like wormholes or whatever.
The problem: fuel
I said this was a brute force solution. Accelerating constantly a 9.8m/s² takes an absurd amount of energy. More precisely, if we're carrying the fuel with us and we have a 100% efficient antimatter engine that annihilates all its fuel using the good-old E=mc², we need:
M = exp(aT/c) − 1
to accelerate at a for time T from the point of view of the spaceship. We can then substitute how much matter-fuel we need to carry along with a tiny 1000 kg spaceship to these landmarks:
d (ly) Stopping at Rocket fuel for 1 ton payload 4.3 Nearest star 38 tonnes 12.2 Luyten b 210 tonnes 30000 Centre of our galaxy 960 million tonnes 100000 Opposite end of our galaxy 10 billion tonnes 2000000 Andromeda Galaxy 4.3 trillion tonnes It gets much better if we don't need to carry the fuel with us. In this case we only need:
E/c² = 2 m (γ - 1),
twice the relativistic kinetic energy of our vessel. We could build galactic highways that push spaceships with lasers, the energy requirements would be quite modest because of how the energy of the lasers gets multiplied by the γ factor.
The other problem: Heat
You usually think of the universe as a cold place, and hear that its temperature is 2.725 K. This is the temperature of the cosmic background radiation, which is essentially the Big Bang, as we can see it still occurring in the edges of the observable universe. The Big Bang was originally very very hot, but as the universe expands it is stretched and "redshifted" into cooler radiation. When you accelerate to almost the speed of light you undo this, and the Universe starts feeling hotter and hotter, linearly with the Lorentz factor[2].
So at γ = 110 the Universe feels like a comfy 300 K (27 °C, 80 °F), but at the γ=15500 you'd reach travelling to the centre of the galaxy the Universe in front of your spaceship is a bright, 50000 degree hell that vaporises any known material. You may see it as "space friction". Maybe somebody will come up with a "cosmodynamic" design that deflects the heat from the front into the 0 K cold of the back.
And what does this have to do with communism?
I think the obsession with FTL travel in fiction is bourgeois ideology. It is only really necessary to build a sort of centralised galactic empire. The physicists that figured out relativity saw it as enabling space travel, not as an impediment: A loosely coupled "fully automated" galactic federation sees no real problem with communication delays of thousands of years.
This is great stuff.
Ian Banks and many others have come to the same conclusion, that even with life extension interstellar imperialism is basically impossible at STL speeds. Even with FTL it is difficult, The Culture is certainly a (somewhat diverse) cultural union, but states proper don't exist and it's pretty much impossible to stop secession.
The Player of Games establishes that the (rather small) Empire they found is the second centralised interstellar state ever discovered in Galactic History (and Culture history alone goes back 6000 years). And it uses 99.9 percent of its resources keeping itself together
Karl Schroder does make one that exists by forcing people on the colonies into increasing amounts of cold sleep to sync travel times.
Damn, this is some gourmet shit.
Seriously though, really nice calculation and an interesting perspective on FALGSC.
v>c is not allowed, but v here is the speed of anything from the point of view of something else in an inertial frame of reference. And "speed" is defined something like "if this thing was a mirror, and I sent two light pulses towards it 1s apart, how far apart would I see reflections of it". In a similar way "time" is defined as "if this thing was two mirrors 1 light-second apart, with light bouncing between them, how long does it take a photon to bounce from one mirror to the other and back". You can picture why there is time dilation if you imagine the two mirrors moving, and the light bouncing diagonally between them. Because of geometry the diagonal path is longer than a straight path—this is where all the square roots in the formulae come from—, but the speed of light is fixed, so "time" stretches out. These geometric definitions sound pedantic but they are actually useful and accurate with respect to the more formal definition that uses a non-euclidean metric space.
If you instead define "fast" from your own point of view, as in "how far away it is / how long it would take you to reach it", then you can be arbitrarily "fast".
The loophole is space contraction / time dilation: you will never see the speed of your destination be higher than c as long as you are in an inertial frame of reference, that is, not accelerating. But as you accelerate you'll find all distances between all objects become less than they used to be before you started accelerating. So the apparent speed of your destination will be
v_apparent = v_inertial + Δγ/Δt * d.
Since Δγ/Δt depends only on your rocket, v_apparent can be arbitrarily large.
So in the middle of your trip towards Andromeda, 14 years after you departed, from the point of view of the Earth you will look like a compressed, redshifted blob moving at almost the speed of light, that left 100000 years ago and still has 100000 years to go.
From your point of view, the Earth below looks like a compressed, redshifted blob approximately 1 lightyear away. It is vertically mushed together along with most of the Milky Way. Andromeda is also approximately 1 light year away and looks compressed and blueshifted.
From the point of view of your destination in Andromeda, 14 years ago a relatively bright, blueshifted thing came out of the Milky way and has already moved halfway across. In 14 more years it will arrive. If you defined speed as apparent distance / apparent time it'd look like you're moving faster than light, but if Andromedans know about the speed of light, they'd know you're not actually moving faster than light.
You can't actually see coming something that moves faster than light. If you were, when you arrived you could look behind you and see yourself from the past, moving backwards as the light from your ship arrives after you did.
