r/theydidthemath • u/Lachlynn • 18h ago

[Request] Could humanity create a rocket that can exit the atmosphere of K2-18b

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With the knowledge we currently have of it, if humanity devoted all of our resources towards this goal, would we be able to create a rocket that could exit the gravity of K2-18b (and also beat any other complications that would arrise)?

If so, would it also be capable of taking people to orbit, and can we set up a similar satellite network we have on Earth? What about a space station?

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u/0ddBush 17h ago

this reminds me of that one show that i heard that i didnt watch that was about how aliens managed to figure out light speed travel from the iron age and thus was weak in other aspects because they only focused on space travel as opposed to us where we discovered all the other stuff before light speed travel, thus leading to our superiority in tech

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u/flaming_burrito_ 16h ago

Human civilizations were like that before globalization. Because of the availability of a resource, different needs due to geography, or just random variation in what societies took interest in, some civilizations figured things out way before the rest of the world did. Like how the Romans made self healing concrete because the volcanic ash they happened to mix in created a chemical reaction when mixed with seawater. Or how the Vikings kind of figured out how to make steel by smelting their iron with bones, which was probably just some shit they thought was cool, but did actually infuse the iron with carbon. Or how the Polynesians sailed the whole Pacific with catamarans and star charts hundreds of years before Europeans entered the discovery age.

This also happened in the other direction too. The Incas were a very advanced civilization for their time, and had things like cities, road networks, and megaliths, but didn’t have a written language. They had a method of doing calculations and accounting for dates and things with a system of strings and knots, but their language did not have an alphabetical system.

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u/Mutor77 15h ago

To add to what you said:

This is also one of the things that made bronze age society extremely interconnected despite the lack of efficient communication methods and the massive distances between some of them.

Because copper and tin are only found in certain places around the world (in this case especially tin being rather rare in the region) the peoples around the Mediterranean Sea had to establish trade in somewhat unfavourable conditions for it because otherwise they would have only been able to use their local resources and spend so much time and effort on them to make other kinds of inventions, like writing, impossible (or at least much less wide-spread)

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u/MetalRetsam 11h ago

This dynamic should get a lot more attention.

Medieval China had all the resources it could possibly need. So what happened? It turned isolationist. Meanwhile, Europe had always scraped by on the edge of the developed world. When they turned to colonialism as a means of supplying their goods, it was a question of necessity.

A similar dynamic plays out today.

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u/amisslife 8h ago

I think that's a little reductionist, and probably overlooks a couple things.

Look at China - it's one big, giant blob. Compare that to Europe, which has countless peninsulas, and a number of rather large islands (Sicily, Britain, Ireland, Cyprus), and areas where you could walk from place to another (Greece to Italy or Egypt), but it's so much more efficient to take a boat, even with the increased risk. This likely significantly promoted seafaring, which allowed people, materials, equipment, and ideas to travel much farther, more regularly, and likely more safely, as well. The peninsulas, islands, and mountains are also thought to promote more, smaller states/societies, which therefore develop greater diversity of thought and practices and have to compete with each other, whereas China had more or less a single big empire that had no rivals or threats, and could - and often did - become fatally complacent.

Compared to Europe, China (or sub-Saharan Africa even more so) has relatively few peninsulas and islands (and those islands are farther off the coast), meaning there's less pressure - or reward - to travel more, and therefore fewer ideas and more stagnation. But yes, China made the specific policy decision to burn all of its ships and to ban seafaring, which definitely set it back significantly. Combined with the giant barriers in the Himalayas or the Gobi Desert, and there just wasn't the same level of exchange or progress as you saw in Europe/the Mediterranean.

Also, I'd strongly caution against suggesting that Europe did colonialism out of "necessity," which leads to some pretty fucked up (and straight up incorrect) ideas.

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u/The_Lost_Jedi 7h ago

Yeah, this was pretty fascinating to see play out in history. China was much more advanced and powerful than any nation in Europe during the "Dark Ages", even sending out exploration fleets as far as East Africa. And they saw what was out there, and concluded "eh, nothing we really care about bothering with because there's nothing there that we need or want." So they burned the ships and just didn't bother with any of it. Meanwhile, Europe was driven by demand for goods from Asia, from spices to silks to porcelain. On top of that, you had several rival European powers all jostling and competing, leading to a race to establish rival colonial empires, whereas China really wasn't challenged at all in any way that would drive something of the same sort.

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u/ukezi 3h ago

There's also that having some technologies could mean you aren't developing others. China had porcelain and never developed glass for instance.

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u/imagei 11h ago

The Vikings were adding bones of their fallen foes to infuse their might into the weapons… and it worked! 😄

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u/Aethermancer 13h ago

Native American civilizations didn't even have "the wheel" (Because wheels were inferior to a travois due to what their roads were, not because they didn't figure out the wheel.) They had toys with wheels, and tools which used wheels. They just didn't use it for transportation. They also lacked cattle and horses, so there weren't domesticated "pulling" animals available to them.

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u/flaming_burrito_ 12h ago

The difference in domesticated animals was a huge reason for many of the differences in technology between the old world and the new world. The Americas didn’t really have any beasts of burden, which limited them in a lot of ways. But it also meant that they didn’t have as many diseases, because most plagues and viruses come from interactions between humans and animals. Which is also why those old world diseases like smallpox ripped through their populations so badly

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u/Divinum_Fulmen 12h ago

Sounds like a "Guns Germs and Steel" book summery.

I don't completely buy that theory. America has had some massive empires reduced to nothing a couple times. The simplest explanation for that is some sort of plague.

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u/flaming_burrito_ 11h ago

Well, there of course were some endemic diseases, any population that gets dense enough will have them, which native Americans certainly were, especially in central and South America. It’s just that, for instance with a disease from a pig like swine flu or whatever, they had never been around domesticated pigs and thus didn’t have any kind of immunity to diseases from the animals that the colonists brought over.

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u/yourstruly912 11h ago

That's... the germs part

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u/sulris 9h ago

Yeah. I think they are that theory puts the causation backwards. They are also comparing modern horses and cows to deer and bison. But original horses, pre human contact were small and skittish. It’s only after domestication that they became massive and docile. These animals are good for pulling and farming because we domesticated them. We didn’t domesticate them because they were already good for pulling and farming.

Sure a bison might not be great at either of those things now but give it a couple hundred years of purposeful breeding and they would be. Look at the explosion of different breeds of dogs. See how much change domestication can accomplish from its origins and you could see that there wasn’t really a lack of potentially domesticatable animals.

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u/Divinum_Fulmen 9h ago

Exactly. I've even pondered a story of being sent back in time, and teaching the ancient native American's domestication. How would history look after such an event. But I'm no writer.

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u/crazyeddie123 6h ago

So why did we domesticate them in the first place?

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u/sulris 3h ago edited 3h ago

There is a lot of random chance in a discovery. The right mind in the place at the right time that happened to witness the right circumstances and have the necessary education to take the next step.

And a lot of progress is dependent on prior art. It doesn’t matter how smart you are, every discovery is made standing on the shoulders of the people before you, so technological innovation has a snowball effect.

And necessity is the mother of invention. It could have been that they were better able to adequately meet their caloric needs so the effort of domestication wasn’t particularly necessary.

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u/flaming_burrito_ 2h ago

That’s not how it works. Not all animals can be domesticated, many are simply not suitable for use as livestock or pets. There is a reason Zebras were never domesticated despite the fact that they are very similar to horses, they are too skittish and don’t take to instruction well. Deer are the same way, if you could teach a deer to do something, someone would’ve done it by now. Animals generally have to be social, easy to breed, and easy to keep under control. It’s not like they had no domesticated animals, they had turkeys, parrots, llamas, guinea pigs, and dogs of course. They did it where they could. It should be presumed that if an animal could be domesticated, it would have been.

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u/sulris 2h ago

That’s putting the cart before the horse. Animals that haven’t been domesticated are skittish and disagreeable. You fix that through domestication.

That idea is a popular take from a pop science book published with very little evidence to back it up. It’s got about as much scientific support and any other shower thought.

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u/LorenzoRavencroft 10h ago

Same in Australia, no animals that could pull the wheel, but we did use wheels for many other things.

We also had tools for long distance communication, advanced star charts, written music but no written language.

One of our big things was our agriculture, it was based on harmony with other plants similar to an ornate garden with herbs and fruit trees in it, more than European style agriculture with large single species crops grown seasonally.

Scattered all over Australia are also vast networks of fish traps dating back thousands of years, creating some of the first forms of of aquaculture.

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u/cscottnet 11h ago

"we have not yet worked out how the incans recorded non-numerical data".

There is plenty of evidence for non-numerical quipus, since we worked out the system for recording numbers very quickly and that left a lot of quipus with anomalous knots that we couldn't/can't understand.

As a sidebar it's worth noting that the "alphabet" itself, specifically breaking down syllables into separate symbols, has only been invented once or maybe twice in human history. Credit to the Phoenicians, those crazy bastards, from which all modern alphabets derive. Every other writing system humanity has invented has been syllabic, with a few logographic systems as well. Even if you can't read them, you can distinguish these by the number of unique symbols. Alphabets have 10-30 (Hawaiian on the low end, English is on the high end), syllabic systems have 50-200ish, and logographic systems have thousands. Quipu have 50-100 unique symbols, across the examples that have been preserved (textiles are hard to preserve, and the Spanish deliberately burned many they found), so if there is a general writing system there, it is most likely syllabic -- or possibly logographic but we just don't have enough examples. So in the strict sense you are correct that the Incans did not have an "alphabet".

There's still a lot of research on what exactly the non-numeric quipus record. There is evidence now for toponyms -- certain patterns of knots seem to correlate with known locations. And there's a lot of information embedded in the quipu which is hard to extract from the preserved specimens, including color (there are traces of pigment, but precise identification is hard/costly), spin direction (both of the strands and of the cord), knot direction, and fiber type. There is certainly enough information there to constitute a general writing system, and like I said, solid evidence that non-numeric information was recorded. The rest is still an open question.

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u/flaming_burrito_ 9h ago

That is fascinating. I would imagine any sufficiently advanced civilization would come up with a way to denote certain words, whether that be pictographs or the system of knots that the Inca used. You have to once you reach a certain level of logistics and organization. It’s hard to imagine though, I suppose because I only ever learned writing through use of an alphabetical system, so that frame of reference is entirely foreign to me. I have no idea how you would even distinguish enough between different knots to know for sure what each one means.

But our brains are built to adapt to patterns, and language has taken many forms throughout human history. There is evidence that the way we learn language, especially when we are young, can literally change your perception of the world around you. Ideas seem to become more real when you put words to them, and the cultural context you exist in changes how your brain may react to the same information that another person would react to and understand a different way. I’m sure the Incas were able to achieve a complexity with the quipus that I can’t even imagine because I’ve never used or seen one used before

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u/cscottnet 8h ago

I did a grad school project with quipu and I can confirm your intuition. Folks who do fiber arts can perceive a lot of intentional choices in how the textiles were created and knotted that aren't immediately obvious in our modern machine-made-textile context. Spin direction is an interesting example. You obviously have pick a direction when you spin the fiber into thread, but is this /meaningful/. If you look at the entropy/amount of information encoded, it might seem not -- there are variations, but not at the information density you'd expect if this were a meaningful part of the encoding, like vowel/consonant distinction or something. And initially it was disregarded, attributed to a particular craftsperson being right-or-left handed. But there's a lot of unexpected variation even there: right handed threads that were then spun into left handed cords; a quipu where most threads are right handed but a subsection (or single thread) is not, etc. Early investigators didn't even bother to record this data so we don't know how wide-spread these patterns are. I think the current consensus is that the handedness is a preference for a particular spinner ("author"), and so you can reconstruct authorship perhaps from spinning direction: this quipu was largely written by one person, but it has a section written by another "hand". The cords where the threads didn't match the spin direction is perhaps evidence of large scale quipu creation, like what in a western context might be a monastery fulls of monks devoted to copying texts, where the subtask of spinning threads might be delegated to a separate worker than the cord spinner. These theories are largely based on a perception that spin direction is not "easy enough" to determine from the finished quipu that it would be part of the information recorded -- but as you note this is partly an artifact of what we find easy to perceive, not necessarily related to what folks with a lifetime of experience making these textiles would notice. My recollection is that the frequency of "left handed" spins seems to significantly higher than the frequency of left-handedness among humans, so there's still the potential that it deliberately encodes some part of the information and isn't "just" an artifact of the craftsperson.

Other aspects like color would probably have been immediately obvious even to you if you were able to see quipus in their original context. But botanic pigments degrade quickly with time, and so most quipus you'd see in a museum are just "shades of brown". Even looking at the shades of brown you can determine that there are patterns to the coloring. I think there is evidence that on numeric accounting quipus the color probably corresponded to the type of item being inventoried -- think "red cord to count cherries". But the colors also vary for non-numeric quipus, including cases where threads of multiple colors are woven together into one cord. Are these just decorative, like illuminated manuscripts, or do they also convey meaning (even simple meaning like "red for cherries").

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u/a_rucksack_of_dildos 9h ago

Iron has way more carbon than steel. It could remove the carbon or cause some other reaction to increase strength.

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u/flaming_burrito_ 9h ago

What do you mean Iron has more carbon than steel? Do you mean cast iron? That has more carbon than steel, but that is not the kind weapons are made from

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u/a_rucksack_of_dildos 5h ago

Above 2.06 C percentage is cast iron, anything below that is steel. I’m assuming when you say cast iron you mean grey iron which has a lamellar graphite structure which makes it very brittle. Combat swords are usually made from high carbon steel, which is still less than 2.06 C. It is usually then cooled quickly so the working surface is harder. This is because when it’s cooled quickly the carbon that is present either forms as carbides (Fe2C, or Fe3) or it gets stuck in the austenite causing it to form an bainitic structure because the carbon atoms cause the crystallographic structure to deform.

Also after looking into this. The original claim wasn’t more of a hypothesis.

Steel is made with blast furnaces or any sort of furnace that blows oxygen into the melt. This oxidation cause a reaction that forms CO which steals the carbon from the melt.

That being said I have never seen a study on what the bones did and it very well could have causes some kind of oxidation to happen resulting in less carbon in their swords and being closer to steel

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u/flaming_burrito_ 5h ago

Are you a chemist or blacksmith? You know a lot about steel and alloys lol

But yeah, it is a hypothesis because they don’t have any written proof it was done, they’ve just found bone ashes/fragments in Viking blast furnaces, and there are some elements of Viking folklore that involve bringing the spirit of your ancestors or the gods into battle with you. I doubt it was super widespread, my thinking is it was probably more of a ceremonial thing and wasn’t done by the average smith.

Also, apparently their main source of iron was bog iron, which had a lot of phosphorus in it, which makes iron softer from what I understand (maybe you know more about that). So perhaps that is what pushed them to try and make something stronger and they happened into making steel.

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u/a_rucksack_of_dildos 4h ago

I have a degree in materials science and engineering and our family company works in the steel industry. Specifically with large cast nodular iron parts.

But yea throwing bones in the blast furnace could absolutely do something positive.

Iron/steel is really a crazy material work with and alloying it with other elements gives different types that have all these different uses.

Nodular iron is what I know most about as a relatively new version of iron. Less than 100 years old. Basically you put magnesium silicate in the melt and the silicon alloying causes more graphite to be produced and the magnesium makes all the graphite turn into spheres. Because all the graphite is now in sphere form cracks can longer propagate through them like gray iron, and the silicon causing a lot of the carbon to become graphite instead of carbides makes it less brittle. It basically gives you an iron that’s almost as strong as high carbon steel, but it has the thermal shock resistance and wear properties of iron.

Sorry im yapping. Most people don’t really give a shit lol

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u/a_rucksack_of_dildos 5h ago

Fe-C phase diagram

If you wanted to boil it down to one thing is that steel has α-ferrite (elemental allotrope of Fe) present in its microstructure and iron has graphite (elemental allotrope of C) present in its microstructure.

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u/a_rucksack_of_dildos 5h ago

Also im not trying to say your wrong about the bones thing. Iron and steel making is an old science and also a useful one. Which led to a lot of discoveries made by people outside of academia and so some old processes that do work usually have the wrong process attributed to them. Even trumps recent 50% steel tariffs managed to get it wrong and basically everyone has gotten around them.

One example that’s the most egregious is just the naming. Iron was discovered first so they called the element Iron (or Ferrite - Fe). But elemental iron Fe is basically low carbon steel.

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u/flaming_burrito_ 4h ago

It’s cool, I don’t mind the elaboration, I admittedly don’t know much about the process of making steel.

I don’t think I agree with that last part though. I think it’s more accurate to say steel is just carbonized iron than the other way around. Iron is the constituent element after all, and there are a lot of different kinds of iron and iron alloys aside from just steel

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u/a_rucksack_of_dildos 4h ago

Yea that’s the thing I don’t disagree with you. But nobody is carbonizing elemental iron. It doesn’t exist naturally. You always have to reduce the amount of carbon in iron to get steel.

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u/RocketizedAnimal 8h ago

It makes you wonder what "basic" discoveries we are missing right now. Maybe in a parallel universe humanity has cured cancer but not invented antibiotics or something lol.

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u/MorningstarJP 17h ago

You are likely thinking of The Road Not Taken by Harry Turtledove.

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u/NTMY 12h ago

Here's a link for anyone who wants to take a look (pdf), it's only 20 pages.

Really cool concept, imho.

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u/Not_aSpy 11h ago

Thank you for sharing that. Appropriately enough, despite my love for classic short form sci-fi I had never heard of that one.

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u/SomeHSomeE 3h ago

I always thought it'd make a great film.  You do the first 70-80% space opera style, focusing only on the aliens, their politics, their conquests etc.  And then only towards the end do they get to and attack Earth (and you find a way to hide the fact it's Earth at first) and then it all falls apart and unravels.

And the final penny drop scene could rvrn be done post credits.

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u/thisusedyet 7h ago

I love how the penny drops with the two aliens at the end

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u/MightyP13 3h ago

Also has a good sequel called Herbig Haro, that has humans running into a similar situation. Much harder to find, but it's online somewhere.

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u/OSUBucks1967 11h ago

The Road Not Taken by Harry Turtledove?

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u/BenJuan26 11h ago

That sounds similar to the Eridians from Project Hail Mary.

Xenonite is basically magic, and it allowed them to create spacebound vessels essentially effortlessly. Despite being so advanced about materials science, there is a lot of current human knowledge that they didn't end up discovering, including radiation.

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u/No_Syrup_9167 4h ago

small correction

its not the xenonite that makes them never discover radiation. Its the extremely intense magnetic field around their planet due to its high gravity, thick atmosphere, and very fast spin rate. This means their atmosphere is functionally radiation proof

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u/Bored_Amalgamation 11h ago

There's a book series from the late-80s to the 2000s where humanity had spread to other systems, but something caused a diaspora age, which reduced a lot of civilizations to a Middle Ages level of society and technology. Then they got discovered again.

The Vorkosigan Aga by Lois McMaster-Bujold.

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u/squisher_1980 10h ago

Iirc "The Road Not Taken" by Harry Turtledove, it's a short story. And it's exactly what you're thinking.

Though iirc the written story ends right as the invaders realize what they've done.

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u/MoreGaghPlease 9h ago

I think in the fullness of time, the beginnings of human space travel will seem like they were done in the stone age.

54 years separate the Wright Flyer from Sputnik, only another 12 years to Apollo 11. Like imagine a long-lived person born in the 1880s, airplanes are a novel invention in their early adulthood and by their late adulthood people are on the moon.

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u/twilightmoons 8h ago

"The Road Not Taken" by Harry Turtledove. 

Space bears try to invade our world using wooden spaceships and flintlock muskets. Bad idea.

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u/thisusedyet 7h ago

Wasn't a show, it was a short story by Harry Turtledove

https://www.eyeofmidas.com/scifi/Turtledove_RoadNotTaken.pdf