Science/history challenge: Beat Sputnick

[Stargate525]

4 hours ago, DerekL1963 said:

It means they know the recipes - not the reason why the recipes work, or why they sometimes don't work.   They don't know that adding carbon makes steel, they know "heating in charcoal makes this particular metal harder".   The don't know adding [whatever] makes the material more corrosion resistant, they know "adding a capful of sand collected from the beach of La Mad at high tide will reduce rust".

Knowing how to make something like steel isn't the same as knowing why what you do causes the changes in the materials properties.  The latter is a huge (and largely unrecognized) part of the Industrial Revolution and the modern world - once you know why, you have the ability not only to make material in industrial quantities, but make materials of predictable qualities in industrial quantities.

I understand that. But having the HOW down already makes teaching the WHY a hell of a lot easier. Almost literally, all you need to do is turn 'heating in charcoal' into 'adding a very specific amount of what charcoal is made of.' Your foundry workers don't need to be your chemists, or the ones testing the purity of the metal. You're falling into the trap of thinking that ancient peoples were backwards bumpkins, when they very much weren't. A Roman smith (given the removal of the language barrier) planted into a modern machine shop would be up to speed remarkably quickly. Your biggest issue are going to be the scientists and the scholars, actually, as much of their view on physics and chemistry is based in greek philosophy, and very wrong. There, you need them to unlearn entire lifetimes of knowledge before you can build it back up.

[sevenperforce]

Indeed. Honestly the scholars and alchemists and astronomers are only going to get in your way. I would recommend going straight to the military-industrial complex of the day. "Screw those nerds; give me three legions and let's build a gorram starboat!"

[DerekL1963]

54 minutes ago, Stargate525 said:

You're falling into the trap of thinking that ancient peoples were backwards bumpkins, when they very much weren't. A Roman smith (given the removal of the language barrier) planted into a modern machine shop would be up to speed remarkably quickly.

By modern standards, he *is* a backwards bumpkin.

And a Roman smith would be completely lost in a modern machine shop - because what a modern machine shop does is nothing like what he did.   Even in a modern forge or foundry he'd be lost, as he can't read the instructions, if you ask him to anneal something a 1000 degrees - he doesn't know what annealing is, let alone a degree, etc... etc...  (Doesn't mean he can't be taught those things mind you, only that trying to transform the Roman production process into a modern one isn't going to be a simple one - they lack the basic concepts and skills.)

 

1 hour ago, Stargate525 said:

Your biggest issue are going to be the scientists and the scholars, actually, as much of their view on physics and chemistry is based in greek philosophy, and very wrong. There, you need them to unlearn entire lifetimes of knowledge before you can build it back up.

You should read up on the Luddites sometime.   It's not just the scientists and scholars that resist change.

[StrandedonEarth]

The chemistry is definitely the key. The least complicated booster to make would  be solid-fueled, and the casing could be hammered out of bronze and wrapped in electrum wire, with a clay (or clay-lined) nozzle. The trick is creating a propellant and casting it in the casing. Staging it is merely an engineering problem. Fins for atmospheric guidance and try to get the gravity turn right. The hardest part is getting the orbital insertion burn to actually put the thing in orbit.

[sevenperforce]

You almost want to stick with fins for guidance and merely put two fused RCS rockets in the nose to knock it into a gravity turn and then into a circularization burn.

[micr0wave]

The roman aqueducts were up to 100km or so long, with a constant minimal slope to keep the water flowing which somewhat require to be pretty accurate with measuring things.

As really basic rocket fuel some sugar based one should be doable with pretty simple methods.

 

[Stargate525]

3 hours ago, DerekL1963 said:

By modern standards, he *is* a backwards bumpkin.

And a Roman smith would be completely lost in a modern machine shop - because what a modern machine shop does is nothing like what he did.   Even in a modern forge or foundry he'd be lost, as he can't read the instructions, if you ask him to anneal something a 1000 degrees - he doesn't know what annealing is, let alone a degree, etc... etc...  (Doesn't mean he can't be taught those things mind you, only that trying to transform the Roman production process into a modern one isn't going to be a simple one - they lack the basic concepts and skills.)

 

You should read up on the Luddites sometime.   It's not just the scientists and scholars that resist change.

Let me rephrase. He isn't STUPID, he is NOT AS HIGHLY EDUCATED. He was not given a comprehensive education from age 5 and schooled for at least 13 years to attempt to give him a broad base of all knowledge available.

Telling him to 'anneal something to 1000 degrees' is jargon, and you know it. It would literally be a matter of telling him 'this dial tells you how hot your forge is. Get this metal to 1000, keep it there for a bit, and let it cool slowly.' He'll have a name for that process already, and from that point forward will know YOU call it annealing.

And I specifically said that if you ignored the language gap. Put him in a modern forge with latin or greek writing, and an untrained uptimer with their language of choice, he will be the one able to turn out better work more quickly, every time.

[kerbiloid]

Arc welding of the heavy machinery and the alumina electrolysis are available only since WWI.

[magnemoe]

15 hours ago, StrandedonEarth said:

The chemistry is definitely the key. The least complicated booster to make would  be solid-fueled, and the casing could be hammered out of bronze and wrapped in electrum wire, with a clay (or clay-lined) nozzle. The trick is creating a propellant and casting it in the casing. Staging it is merely an engineering problem. Fins for atmospheric guidance and try to get the gravity turn right. The hardest part is getting the orbital insertion burn to actually put the thing in orbit.

Now hopefully somebody will do some calculations on this. ISP, trust and weight of one booster.
Added issue that making large solid fueled rockets are an new thing, yes artillery sized ones are old but they are small compared to that needed here, 
V2 was liquid fueled even if an solid fueled rocket with similar performance would be cheaper as its easier to scale up liquid fuel. 

https://en.wikipedia.org/wiki/Solid-fuel_rocket
In short forget black powder, the composite ones require aluminium. The candy ones sounds plausible and have 130s. 
 

[wumpus]

1 hour ago, magnemoe said:

Now hopefully somebody will do some calculations on this. ISP, trust and weight of one booster.
Added issue that making large solid fueled rockets are an new thing, yes artillery sized ones are old but they are small compared to that needed here, 
V2 was liquid fueled even if an solid fueled rocket with similar performance would be cheaper as its easier to scale up liquid fuel. 

https://en.wikipedia.org/wiki/Solid-fuel_rocket
In short forget black powder, the composite ones require aluminium. The candy ones sounds plausible and have 130s. 
 

Black powder: see what if #24 (rocket resembles the Great Pyramid).

Composites: need electricity and access to Iceland for (smelted) Al.  I'd be surprised if you could make composites any other way.  Building electricity up from lodestones will be tedious (though probably not as bad as the rest of the chemical issues).

Candy: Grab the entire roman honey supply?  Get the Aztecs to grow sugar cane (presumably they need to conquer the islands first)?  Sounds easy at first, but the details are killer.

Double Base: this jumped out to me.  Needs mid-19th century chemistry, so I haven't a clue how they get their precursors.  ~200 Isp, I'd expect this to work.

One other thing: consider ceramic sides to your SRB.  To get the ideal radial symmetry required (forget about anything except spin stabalization), at some point you will have to lathe your rocket.  Doing this with ceramics (i.e. a really big pottery wheel and each stage done separately) sounds easier than lathing a steel rocket.  Also consider the Chinese empire due to typically being more advanced for the time, ceramic use, and being at least as large as the Romans.

* note: if you are dead set on using mining records to locate precursors and sweep them up near the ground, Mayans (various tribes of Mexico), Incans, and Mississippi (mound building) people lived on land that often wasn't mined until recently.  -Note: obviously the Mayan & Incans did lots of mining (although the Incans are said to have left an entire silver mountain  for the Spanish) for silver and gold.  Not so much iron and the weird stuff needed for space travel/chemistry.

Edited February 24, 2016 by wumpus

[micr0wave]

Chemistry to get materials is easier than it seems to be at first glance. This example illustrates the basic process, which works for a wide range of other endproducts as well.

You'd be surprised what can be made at home. Considering you have a whole empire working for the project it shouldn't be a big problem to get sufficient quantities of materials. Speaking of ancient empires ... i bet there'll be enough 'volunteers' to take a ride

Steel has less than ~2% carbon and is known since ~1000BC or so, i'm pretty sure the producers knew what they were doing.

A lot of things which seem to require some hightech at first glance are things found in nature, asbestos for example.

[Laie]

35 minutes ago, micr0wave said:

Chemistry to get materials is easier than it seems to be at first glance. This example illustrates the basic process, which works for a wide range of other endproducts as well.

(saving you a click: the example is electrolysis of water) Oh, great. This merely leaves the issue of liquefaction & storage, piece of cake.

We really need to clarify the rules of this thought experiment. Are we to build the rocket with the available tech at a given era, or is this an excercise in equipping an ancient civilization with an industrial base?

Because clearly, both romans and chinese had it in them to build rockets... Eventually they pulled it off on their own. Tossing a couple of eggheads and textbooks at them (and magically changing their priorities) might shorten this to a century or three, but by the time the rocket gets built they'd have little in common with the civilization you started from. I'm remined of Nippon, c.1860-1910.

[micr0wave]

yeah, it was just meant to illustrate the basic mechanism, but it can be used, without much hightech, to have the needed materials to make better ones.

The hydrogen and oxygen is just one example of a wider range of possible uses, be it making bases or acids or purifying metals and other things.

 

I thought of the chinese too, i wonder if maybe silk and some resin might be some medieval Kevlar-ish material to build things with.?

 

 

 

[sevenperforce]

1 hour ago, Laie said:

(saving you a click: the example is electrolysis of water) Oh, great. This merely leaves the issue of liquefaction & storage, piece of cake.

We really need to clarify the rules of this thought experiment. Are we to build the rocket with the available tech at a given era, or is this an excercise in equipping an ancient civilization with an industrial base?

You can equip the ancient civilization with whatever industries are necessary in order to build the rocket, but you only have your own lifetime to do it in. Which means you'll need to limit yourself to stuff which can be done rapidly, without a lot of precursors and development and construction time. Basically stuff where manpower is your limiting variable...because that's where ancient civilizations have the edge.

[Laie]

In that case, again, I think it's possible to hammer out a rocket (including some clockwork for guidance) from bronze & brass. The clockwork will probably take the longest, your artisans will have to familiarize themselves with the concept through much trial and error. No matter how many legs-up you give them, in the end they have to learn it themselves.

The rocket may probably be no larger than a Redstone, if that.

Im clueless about possible fuels. All chemistry will probably be batch processing, producing perhaps a few dozen kilos per run. Therefore chemicals should be storable at ambient temperature and a quality control that's based mostly on look and smell will have to do.

The fun part is that the big picture barely changes between 500BC and 1600AD. You might get better and smaller clockwork, or pipes and fittings that are actually tight, as well as other small stuff that's probably mission-critical. But I don't see them build a bigger rocket or brew better propellant until well into the industrial age.

[QuesoExplosivo]

Keep in mind how heavy bronze and brass are, with respect to their strength.

For an oxidizer, nitric acid is relatively easy to produce. It has the bonus of being hypergolic with certain fuels (aniline comes to mind).

Quality control of fuel is actually important: bad fuels can cause coking/fouling of nozzles.

[Laie]

8 minutes ago, QuesoExplosivo said:

Keep in mind how heavy bronze and brass are, with respect to their strength.

I know that they are worse (hence my arbitrary Redston size limit -- a bronze vessel of that size seems quite ambitious in my layman's eyes) but I don't know how much worse they are. However, I recently came across this nice chart:

Propellant	Rocket Percent Propellant for Earth Orbit
Solid Rocket	96
Kerosene-Oxygen	94
Hypergols	93
Methane-Oxygen	90
Hydrogen-Oxygen	83

Same source gives a soda can as 94% content / 6% container. Now, staging will improve this by quite a bit but I wouldn't trust my artisans with a mechanism that will ignite a liquid rocket motor in space. Leaving me with solids for circularization, which probably have to be quite small and inefficient (gunpowder?) -- so yeah, prospects are bleak.

They may have made fine steel blades as early as 100BC but I don't think you can forge a tank on an anvil -- you want sheet metal from a steel mill for that. One lifetime won't suffice.

I'm fully aware that impure fuel may cause problems. You need something that easily seperates from other reaction products, and/or is quite forgiving. 80% ethanol should be comparatively easy, for example, and nitric acid should be doable. Unfortunately, those two won't work together.

Side note, hemp-and-resin seals and nitric acid, what could possibly go wrong?

[magnemoe]

14 minutes ago, Laie said:

I know that they are worse (hence my arbitrary Redston size limit -- a bronze vessel of that size seems quite ambitious in my layman's eyes) but I don't know how much worse they are. However, I recently came across this nice chart:

Propellant	Rocket Percent Propellant for Earth Orbit
Solid Rocket	96
Kerosene-Oxygen	94
Hypergols	93
Methane-Oxygen	90
Hydrogen-Oxygen	83

Same source gives a soda can as 94% content / 6% container. Now, staging will improve this by quite a bit but I wouldn't trust my artisans with a mechanism that will ignite a liquid rocket motor in space. Leaving me with solids for circularization, which probably have to be quite small and inefficient (gunpowder?) -- so yeah, prospects are bleak.

They may have made fine steel blades as early as 100BC but I don't think you can forge a tank on an anvil -- you want sheet metal from a steel mill for that. One lifetime won't suffice.

I'm fully aware that impure fuel may cause problems. You need something that easily seperates from other reaction products, and/or is quite forgiving. 80% ethanol should be comparatively easy, for example, and nitric acid should be doable. Unfortunately, those two won't work together.

Side note, hemp-and-resin seals and nitric acid, what could possibly go wrong?

About making an large steel plates, its an reason why plate armor was idiotic expensive in medieval time. Roman armor used strips of metal as it could be forged. 
Bronze is easy to handle but its heavy compared with steel. Solid fuel rockets also need an strong and light casing so you can get decent chamber pressure. 
 

[sevenperforce]

How hard is it to crack vegetable oil into ethanol and mix that with sugar and lots of iron oxide?

[Stargate525]

8 hours ago, wumpus said:

Candy: Grab the entire roman honey supply?  Get the Aztecs to grow sugar cane (presumably they need to conquer the islands first)?  Sounds easy at first, but the details are killer.

Beetroot. fields upon fields of the hardy vegetable. Cheap and easy sugar, and that'll keep your economy going as refined sugar would sell its weight in gold.

[magnemoe]

1 hour ago, sevenperforce said:

How hard is it to crack vegetable oil into ethanol and mix that with sugar and lots of iron oxide?

Easier to just distill vine, making moonshine is ridiculous simple, even high quality one. A bit weird it was not discovered before medieval times. 
Sugar from roes iron oxide is also easy. 

[sevenperforce]

12 hours ago, magnemoe said:

Easier to just distill vine, making moonshine is ridiculous simple, even high quality one. A bit weird it was not discovered before medieval times. 
Sugar from roes iron oxide is also easy. 

Added benefit: you don't have to worry about filtering out methanol.

What kind of ISP would an ethanol/methanol/iron oxide/sugar rocket get?

[Mad Rocket Scientist]

Pre-1600.  If you could convince the Chinese to make as much gunpowder as possible, you could get into a solar orbit.

[sevenperforce]

2 hours ago, Mad Rocket Scientist said:

Pre-1600.  If you could convince the Chinese to make as much gunpowder as possible, you could get into a solar orbit.

A fascinating possibility. What kind of ISP could that develop, and how would you stage/contain it?

[micr0wave]

I only found values for Ethanol+O₂, was around 2700 Ns/kg, for comparison the H₂/O₂ combination had 3800 Ns/kg.
Saturns 2nd stage with H₂/O₂ had an Isp of 420. Since i have no real idea how to find the way from the specific impulse of the fuel to the final Isp of the motor maybe someone could show how to do the math.
Considering having a whole empire to work for the rocket and there were numbers of like 60.000 tons iron for the romans mentioned, i think there should be some more e.g. sugar than that available within a short timeframe.
60.000 tons iron sound sufficient too, we don't want to build the empire state building, just a simple rocket.
Ethanol is easy to get, and a bottle Jeb Daniels can't hurt either