How much technology has been lost throughout history?

[911]

The loss of knowledge and technology is fast and usually unnoticed.

Remember when we used to be able to do this:

[img=650x450]http://3.bp.blogspot.com/-4vx5PRtim...00/Moon+Landing+1920x1200+wallpaper.jpg[/img]

But were you?

I mean... do you know that most Russians think that Americans never set foot on the moon... just saying... :tinfoilhat:

In any case, if you were, and still are, able to make a flag undulate on a planet without atmosphere, it'd be impressive. The wind coming from??...

I also have my doubts about this. Though I am not completely convinced (more research needed), I lean heavily towards the lunar hoax. I don't have much of an expertise in photography (much of the debunking has come from experts who have pointed out NASA photographic blunders), but I am an engineer. Just to name two issues, and without going on a too big a tangent here:

-On the surface of the moon, a fully loaded astronaut weighs about 58lb (26kg). He should be able to jump 4-5ft with relatively little risk (due to the slower travel speeds), and little effort. Think how high you are able to fling a 26kg weight on earth...

-The Lunar Module weighs nearly 3 tons on the moon (17T on earth), and all its vertical thrust is concentrated on the main central nozzle, which stands very low to the ground. Given the fine, loose dust on the moon, and the slow, prolonged landing with the engine thrust fully focused on the landing spot, there should have been one massive dust cloud that would have submerged the whole area, made a small crater and covered the sides of the module with dust.
https://www.youtube.com/watch?v=hUrA42Js8Zg

/lunar tangent

I think the loss of ancient wisdom is far more centered on works in philosophy, literature and arts than on technology. The problem with ancient technology is that they had to get things done with far bigger constraints, and they had a lot of time to accomplish them (generations). For example, the fact that the Romans used concrete without rebar meant that it had to be stronger (and by default lighter).

There is the aspect of suppressed technological breakthroughs, which some have brought up above. There might have been a lot of this going on in the field of energy, with more efficient combustion engines or power generation methods that were sidelined by energy interests.

 

[samsamsam]

I worked at a NASA center during the development of the Ares-V and Ares-I-X under the Constellation program before it was cancelled.

Holy crap, an actual rocket scientist!

 

[911]

Now we have to figure out who is the forum brain surgeon.

 

[Paracelsus]

-On the surface of the moon, a fully loaded astronaut weighs about 58lb (26kg). He should be able to jump 4-5ft with relatively little risk (due to the slower travel speeds), and little effort. Think how high you are able to fling a 26kg weight on earth...

According to Armstrong they could and did, but since their suits weren't exactly the most robust things in the world they weren't going to screw around with it. Neil Armstrong reported that he was able to jump to the third step of the lunar module ladder, which he estimated to be five or six feet from the lunar surface "I did some fairly high jumps," said Armstrong, "and found that there was a tendency to tip over backward on a high jump. One time I came close to falling and decided that was enough of that". Falling over backward would risk damaging the PLSS. There are frames from the Apollo 11 EVA which are consistent with that jump. They just didn't want to fuck up their suits.

-The Lunar Module weighs nearly 3 tons on the moon (17T on earth), and all its vertical thrust is concentrated on the main central nozzle, which stands very low to the ground. Given the fine, loose dust on the moon, and the slow, prolonged landing with the engine thrust fully focused on the landing spot, there should have been one massive dust cloud that would have submerged the whole area, made a small crater and covered the sides of the module with dust.
https://www.youtube.com/watch?v=hUrA42Js8Zg

Four things:

(1) Dust clouds form in an atmosphere, where the mass of the air itself creates resisting force to dust particles falling. It's why despite Galileo's theoretical calculations, a feather and a bowling ball dropped at the same time from the top of a building don't hit the ground at the same time -- because the air and friction provide resistant force, enough to slipslide the feather around in the air. But there isn't any atmosphere on the Moon, meaning that any dust displaced falls back to the Moon's surface at one-sixth the speed it does in Earth's gravity, but it falls nonetheless.

(2) The LM is standing on solid rock. The layer of dust on the Moon is quite thin and thus any dust blown away from the impact then resettles away from the lander. No blast crater forms.

(3) The lunar module (LM) descent stage engine had a maximum thrust of 9870 ft-lb, but this was throttleable back to a minimum of 1050 ft-lb. Sounds like a lot. But, the diameter of the nozzle was 63 inches, which is an area of about 3120 in2. Dividing this into the force (thrust) and you have a pressure range of 0.4-3.2 ft-lb/in2, otherwise known as psi. This is equivalent to the metric 2760-22,100 N/m2. But let’s stick with psi.

Anyone who owns a car probably knows that this is already significantly less than your tire pressure … by a factor of 10-100. When Apollo 11 landed, the thrust was down to about 1/3 of max, so down to around 1 psi.

Now let’s look at the average adult footstep: The average non-American weighs around 150 lbs. The average human footprint is around 50 in2 (don’t believe me? do the math yourself!). Divide the first into the second and you have the average human footstep exerting a simple 3 psi.

This is 3x larger than Apollo’s engines.

The very fact that the astronauts walking on the moon did not create “blast craters” underneath them should be explanation enough as to why the engine did not create a blast crater under it — the pressure was simply too low.

(4) Saying "the lander weighs 3T on the Moon" is unintentionally misleading. Newton's Second Law tells us that what counts is the amount of force required to bring the lander to a halt, consequent on Newton's First Law of inertia in a perfect vacuum.

Force = mass x acceleration.

Mass does not change (well, in the case of the LM it reduces over time as fuel mass is expended). The LM on Earth is exerting a force that causes our scales to assess its weight as 17 tons. On Earth, acceleration is at least 9.8 m/s squared, which is Earth's gravitational force. Consequently the force required to escape Earth's gravity is at least mass x 9.8 m/s squared (not counting for air pressure or friction).

On the Moon, however, acceleration is 9.8 m/s squared divided by 6, because the Moon's gravity is one sixth that of Earth. Mass does not change - it's still an object that would weigh 17T on Earth - but the force required to counter the Moon's gravity, change the object's velocity, and thus bring it to the ground safely is much, much less, meaning that the fuel and intensity of the burn is also much less than would be required on Earth. (Not that you could see the LM's engine burning anyway - the fuel mix they had was colourless and lightless.)

 

[weambulance]

I also have my doubts about this. Though I am not completely convinced (more research needed), I lean heavily towards the lunar hoax. I don't have much of an expertise in photography (much of the debunking has come from experts who have pointed out NASA photographic blunders), but I am an engineer. Just to name two issues, and without going on a too big a tangent here:

-On the surface of the moon, a fully loaded astronaut weighs about 58lb (26kg). He should be able to jump 4-5ft with relatively little risk (due to the slower travel speeds), and little effort. Think how high you are able to fling a 26kg weight on earth...

-The Lunar Module weighs nearly 3 tons on the moon (17T on earth), and all its vertical thrust is concentrated on the main central nozzle, which stands very low to the ground. Given the fine, loose dust on the moon, and the slow, prolonged landing with the engine thrust fully focused on the landing spot, there should have been one massive dust cloud that would have submerged the whole area, made a small crater and covered the sides of the module with dust.
https://www.youtube.com/watch?v=hUrA42Js8Zg

/lunar tangent

Watching the 1969 lunar landing video, it's pretty clear they are moving around very easily in terms of effort. But one of the astronauts comments that, essentially, his proprioception is off and he has a poor sense of where his center of mass is. It would probably take a relatively long time to become sufficiently accustomed to the conditions on the moon to start jumping around like a jackrabbit, and it's not worth the risk of injury anyway. They still have the same mass, and jumping high, landing wrong and breaking something could be deadly in that environment.

As to the dust issue, well, it's a vacuum. Any dust that was kicked up would fall immediately back the surface because there's no atmosphere full of energetic gas molecules to keep the dust afloat or even local to the lander.

https://www.youtube.com/watch?v=z7uWK0Smq4U < Dust in a vacuum video

My biggest issue with the idea of a moon landing hoax is it would require the complicity of untold thousands of people who are notably not intelligence agents for almost 50 years. That's simply unbelievable.

...In preview I see Paracelsus beat me to it, but that's alright.

-----------

As to the point of the thread...

I think there's a tendency to romanticize ancient works and knowledge and make it sound like the ancients knew all kinds of things that we don't. I don't think that's true at all.

There are many things we don't know the specifics of, like we don't know for sure exactly what Greek fire was, but it's not like we can't make waterproof, floating incendiary weapons with period materials. We don't know exactly how the pyramids were built, but it's not difficult to come up with valid theories for how they might have been built with the available resources. Scientists have replicated moving Easter Island statues without powered equipment. I'm sure if someone wanted to donate enough money to the effort, historians and engineers could build a small pyramid with nothing but muscle power.

Many ancient structures were better built than modern things because, I suspect, they operated on a longer time horizon than we do. And of course the structures that weren't well built aren't around anymore, so we're seeing only the best now. It's absurd to imagine that if we wanted to, we couldn't build structures that would last several thousand years*. But we don't want or need to. The world changes too fast and most people don't think beyond their own lifetimes, if they manage to think even that far ahead.

Everything is on a budget, built by the lowest bidder who will probably cut corners, and few things are expected to last more than a handful of decades. Why build a bridge that will last 100 years when odds are its traffic or weight capacity will be exceeded by the local community in only 20 years? Why do the roads in most of the US suck? I assure you it's not because we don't know how to build better roads.

I'm not saying knowledge hasn't been lost or that humans didn't experience civilizational setbacks because of it, I just think claims that ancient civilizations actually knew more than we do--and such claims are common enough--are sensationalist. We might not do things exactly the same way, but I've never heard of anything ancients could do that we literally cannot do anymore by any method, unless you count "look at species in nature that are extinct now".

I do lament the general lack of craftsmanship in the things I see around me, though.

*If you replicated the Parthenon in solid aluminum on quartzite bedrock in a geologically stable region, it would probably last longer than our species.

-----------------------

Now allow me to make my own sensationalist prediction. I think there's a real danger that humanity will be permanently technologically crippled in the next couple centuries.

We're in what I think of as the easy energy window (readily available dinosaur squeezings), and eventually (150 years?) that easy energy will run out. When it does, we're not just losing easy energy. Oil is used in virtually everything. That's okay as long as we have loads of available energy when oil runs out, to power the alternate processes we develop, but if humanity suffers a societal collapse the materials required to rebuild might simply be unavailable because we already used them.

The idea is somewhat explored in the novel The Mote in God's Eye, if anyone is curious. Good book.

If we did have a societal, and thus technological collapse, we'd likely lose most of our accumulated knowledge. It's almost all stored on computers or non-archival paper in books. All it would take is a few decades of low tech and that's all she wrote: most of what we know would be gone.

Another possibility is we'll run out the clock. We'll dither around like retards trying to make the wind blow and the sun shine on command, fail to develop nuclear power, and slowly backslide as energy gets more and more expensive. The rich would keep their toys for awhile, but innovation would halt. I think that is unlikely because Russia or China will say fuck the environmental concerns and develop nuclear power to maturity if we don't.

Some sort of correction will be applied by mother nature before too long (<1000 years, I'd guess), though. We cannot perpetually grow our population. Maybe it will be war, maybe disease, maybe a terrible natural disaster. Maybe Skynet will awake, or we'll all sink into VR and stop living in the real world. Who knows? I just hope humans have built a robust enough civilization, one way or another, to weather the storm when it comes.

Personally, I'd like us to get off planet and establish a colony elsewhere as soon as possible. I don't expect it in my lifetime, but now's the time to get cracking. Wait too long, and we might lose the ability to do it at all.

 

[thoughtgypsy]

I worked at a NASA center during the development of the Ares-V and Ares-I-X under the Constellation program before it was cancelled.

Holy crap, an actual rocket scientist!

Haha, well technically not a rocket scientist. Usually Aerospace and Mechanical engineers fill that role. NASA is also made up of other engineering disciplines like electrical (which handle power generation and transmission, communications, control systems, remote sensing), Systems engineering (which handle integration of the various systems, weight budgets, etc), and chemical and material engineering. There are also other fields that are of various interest in other missions such as geology and meteorology (for science missions), applied mathematicians (for calculating the orbital dynamics and flight paths of missions, or for calculating astronomical phenomena), physicists, chemists, and so on. You'd be surprised how many college students rotate through NASA as a result of their internship and CO OP programs. Most impressive of all are the Test Pilots.

 

[Dalaran1991]

So this is how you draw out the most intellectual guys in the forum!

Awesome contribution people thanks! And I'm just here reading on the Moon landing and the burning of Alexandria instead of being productive

On a serious note, this whole discussion on how easy it is to change history and wipe out "the truth" got me jumping. What if, in Roosh and Samseau's apocalyptic visions, one day all men are actually enslaved by societies and feminists and men's lives can be at the mercy of any fat whore at any moment (save for an elite minority) Lots of predictions like this seem crazy but at back at 300BC people would think you mad if you say Rome would one day fall *Not wanting to derail my own thread*

 

[Paracelsus]

Most impressive of all are the Test Pilots.

Man, what I wouldn't give to hear the thoughts of a NASA Test Pilot.

 

[debeguiled]

I watched the Monuments Men film recently. It struck me as poorly-made, too diffuse, too much a collection of anecdotes, but it wasn't until roughly the final third of the movie that I realised exactly what its problem was: the moviemakers and the actors didn't believe European culture was actually worth saving.

Great insight. I don't remember having any thoughts after this movie except it made me curious to see the Ghent Altarpiece, which I knew nothing about, and I realized that even though this movie talked about art, it did very little to actually express a real appreciation of art.

In case you saw the movie, and feel you are missing out on the Ghent Altarpiece, here it is:

[img=640x400]http://www.thehistoryblog.com/wp-content/uploads/2012/02/open-altarpiece.jpg[/img]

This is not the derail it seems. Maybe appreciation of fine art is on its way to being a lost technology.

 

[debeguiled]

As to the point of the thread...

I think there's a tendency to romanticize ancient works and knowledge and make it sound like the ancients knew all kinds of things that we don't. I don't think that's true at all.

There are many things we don't know the specifics of, like we don't know for sure exactly what Greek fire was, but it's not like we can't make waterproof, floating incendiary weapons with period materials. We don't know exactly how the pyramids were built, but it's not difficult to come up with valid theories for how they might have been built with the available resources. Scientists have replicated moving Easter Island statues without powered equipment. I'm sure if someone wanted to donate enough money to the effort, historians and engineers could build a small pyramid with nothing but muscle power.

Many ancient structures were better built than modern things because, I suspect, they operated on a longer time horizon than we do. And of course the structures that weren't well built aren't around anymore, so we're seeing only the best now. It's absurd to imagine that if we wanted to, we couldn't build structures that would last several thousand years*. But we don't want or need to. The world changes too fast and most people don't think beyond their own lifetimes, if they manage to think even that far ahead.

Everything is on a budget, built by the lowest bidder who will probably cut corners, and few things are expected to last more than a handful of decades. Why build a bridge that will last 100 years when odds are its traffic or weight capacity will be exceeded by the local community in only 20 years? Why do the roads in most of the US suck? I assure you it's not because we don't know how to build better roads.

I'm not saying knowledge hasn't been lost or that humans didn't experience civilizational setbacks because of it, I just think claims that ancient civilizations actually knew more than we do--and such claims are common enough--are sensationalist. We might not do things exactly the same way, but I've never heard of anything ancients could do that we literally cannot do anymore by any method, unless you count "look at species in nature that are extinct now".

I do lament the general lack of craftsmanship in the things I see around me, though.

This is a great point, and it is making me wonder if the important technologies we are losing aren't really the tangible scientific ones, but the big picture ones.

Is it too much of a stretch to say that something like a taking the long view, and thinking of generations that will come, counts as a technology, or is it more of a mindset?

It seems to me that, rather than asking what medieval Englishmen insulated their houses with and comparing it to the spun glass of today, it is much more important to ask ourselves why do we choose to build houses that (coincidentally) fall apart the minute the 30 year mortgage is paid?

Look at the roads and bridges, as you say, that are falling apart, and you are right, we have all the technology in the world, but they were built with the assumption that the economy would continue to expand forever and ever, so why not, along with the politicians, kick the can of rebuilding them further down the road?

These are far more intractable problems than comparing the roofing products of today with say, a bit of rope twisted from straw to hold up the thatching from Stuart England. (I saw a bit of this rope from the 1600s in a documentary. Because the thatch had kept it dry, it was still as strong as the day it was made, but that's a side issue.)

If family homes get abandoned by the kids at 18 as a matter of course, how are you going to interest people in paying for stairways like this:

Why not just slap up something like this:

I think a return to ideas of craftsmanship, and longevity are not only aesthetic ideals, they are practical ones. And if your kids don't want your carefully built house, you could just dismantle it and sell it to someone, as I am sure in the future, anything that is made to last will be selling at a premium.

 

[Parzival]

Whats more interesting, what did we achieve in the last 40 years? After we got to the moon, whats next? Not so much. Even more, whats the fastes plane in the world? Still an old one from the 70s the Blackbird. Sure our computers got faster and we have internet. But did this put on more value to our lives? We got rid of all the dirty labour, at least in some parts of the world, people live longer and poverty went down. With some of this modern technology, our minds still stick in the past of industrialisation. Thats how they plan and construct societies. The knowledge is not only technology, its wisdom. Did we gain more of this? We are just bigger apes with better rocks in our hands. With all the possibilities in some level we stay the same. The computers and the internet just create more pressure, we compare now with machines. We are not smart enough to use them to our benefit. Automation, Digitalisation, it could solve so many issues and still we think like 150 years ago.

 

[Paracelsus]

It seems to me that, rather than asking what medieval Englishmen insulated their houses with and comparing it to the spun glass of today, it is much more important to ask ourselves why do we choose to build houses that (coincidentally) fall apart the minute the 30 year mortgage is paid?

The shortest answer is planned obsolescence.

Take your average incandescent lightbulb. Edison is not the inventor or the only historical producer of electric bulbs; like Henry Ford, he's merely the guy who was the most successful at selling them and finding a bulb that would keep him in business. Edison's first lightbulb only lasted 13.5 hours, but in months he had built one that lasted 1,200 hours ... that is, three years of continuous burning.

But Edison's bulb is not the best. The best one is the one that's stood the test of time, the bulb that Adolphe Chailet built, one of which has been burning for more than a century non-stop. Note in the story that they trialed several different bulbs from several different companies with increasing voltage. While every other bulb -- including Edison's -- burst as the voltage increased, Chailet's bulb took it without flinching and just kept getting brighter.

How is it that the earliest light bulbs lasted for decades longer than they do now?

In brief, the Phoebus Cartel, something that sounds like the title of a Robert Ludlum novel but which was deadly serious. The lightbulb companies got together in the 1920s, realising that as their designs got better and better, their sales dropped off further and further.

Per that page I've linked to:

As technological advances improved and pushed out the life span of incandescent bulbs, sales volumes would be negatively impacted. Fewer, infrequently burnt out bulbs meant less need for replacements – less demand for their products. While price fixing was a natural result of cooperation in an imperfectly competitive market, the Phoebus cartel strived to do more than hike prices. They went beyond limiting product innovation – over the gradual course of a few years, manufacturers actively lower the life span of light bulbs. The industry standard of 2,500 hours in 1924 would eventually drop to 1,000 hours by 1940. Light bulbs were deliberately made more fragile, and competitors would be closely monitored (and if necessary, fined) to ensure strict adherence to product degradation. The Phoebus cartel would eventually dissolve due to increased external competition and the disruptions of World War II, but it had successfully demonstrated a very important point. Stifling innovation and product quality was a feasible means of sustaining consistent consumption and profits.

Couched within this time frame would be the Great Depression through much of the 1930s. Whilst the most famous economic contribution of the time would come from John Maynard Keynes in the form of Keynesian economics, one other man suggested an idea that would eventually be much more pervasive in our social mentality. In 1932, Bernard London proposed that to solve the Great Depression, all goods were to be produced with planned obsolescence – that everything would only be useable for a finite time before rendered obsolete. Obsolete goods would be forfeited to the government, and consumers would have no choice but to go and buy new goods, as a means of creating demand and stimulating the depressed economy. This farfetched proposal understandably failed to gain traction, due to its unpopular and rigid nature, but his musings did not fall on deaf ears.

What was shot down in the 1930s would adapt and come back stronger in the 1950s, thanks to industrial designer Brooks Stevens. With an ideology that centred on designs that felt ‘new’, his influential status in America directed the focus of consumers to the way products looked. Distanced from the notion of a product’s functional obsolescence, Stevens would rather push to instil in the consumer the willingness to chase the latest trends, to sooner abandon their old products in favour of the newest design. This propensity to purchase the latest novelties would be a big force in developing a consumerist society, one that has carried on to something we still strongly subscribe to today.

Planned obsolescence forces us to buy more shit earlier because it doesn't last as long, but Brooks Stevens' insight attacked the Western psyche and made us our own psychological slaves to planned obsolescence: he played on us not being forced to buy a new product when it burned out, but rather created/played on our thirst for something newer than what we have. This is where the loss of craftsmanship really lies: because we were fooled, as a society, into thinking that because something was new it was automatically better. You can see the results of that mindset in the idiot hordes who queue up for the newest shitty iPhone that does exactly the same thing the old one does. Planned obsolescene is one of the fathers of our consumerist society.

 

[samsamsam]

I worked at a NASA center during the development of the Ares-V and Ares-I-X under the Constellation program before it was cancelled.

Holy crap, an actual rocket scientist!

Haha, well technically not a rocket scientist. Usually Aerospace and Mechanical engineers fill that role. NASA is also made up of other engineering disciplines like electrical (which handle power generation and transmission, communications, control systems, remote sensing), Systems engineering (which handle integration of the various systems, weight budgets, etc), and chemical and material engineering. There are also other fields that are of various interest in other missions such as geology and meteorology (for science missions), applied mathematicians (for calculating the orbital dynamics and flight paths of missions, or for calculating astronomical phenomena), physicists, chemists, and so on. You'd be surprised how many college students rotate through NASA as a result of their internship and CO OP programs. Most impressive of all are the Test Pilots.

Nice try to humble your way out this one. Expect a PM from me when I try to recreate a V2 in backyard.

 

[Blobert]

Extinct animal species. Most clearly in domestic animals, the biodiversity of cattle breeds now compared to a 100 years ago is huge. A lot of breeds bred for survivability and toughness in adverse conditions have simply died out since they can't compete in a mass farm environment where you just sit on your ass all day.

Wild extinct species we've not had a direct hand in shaping, can count as a technological loss in a sense too - imagine your ancestor was a mammoth hunter and he ran out of mammoths, shit, he better come up with a new lifestyle. And he'll also forget what he knew about hunting mammoths, and how to treat one's corpse. When the shit hits the fan you might wish you had some Neanderthal pals to cover your back.

But who knows, maybe we can bring back some dead species in the near future, and of course create new ones much more efficiently with gene editing... Like some ancient engineer who created the Cheetah to be an ultimate pet.

 

[thoughtgypsy]

Nice try to humble your way out this one. Expect a PM from me when I try to recreate a V2 in backyard.

I would not recommend that...

And something I'll pass on to my firstborn son:

 

[Dalaran1991]

Bumping this thread because I've been thinking a lot about human knowledge.

One thing that strike me is, in the event of another "fall" (apocalypse, huge world war, whatever), just how likely it is for most if not all the technology we have today to be suddenly lost?

A vast majority of guide and manual we have now is on the net, and let's suppose the net is gone, humans are scattered into small bands (so typically your vanilla apoc scenario)

Which one among us here knows how to jury-rig a radio? A phone line? A computer? A TV? Let alone building them from the ground up.
Again, let's suppose that you only have 1 radio / computer left and if you mess it up you are done with the tech.

We take our computer for granted, but if you look at it another way, a screen that lights up on commands, playing images and sounds is freaking magic to me. Sure, most of us here know the general theory about how it works. But take a computer all apart, and I mean taking even the smallest part on the motherboard apart, how many of us can reassemble it without a manual?

Inspired from this piece of warhammer literature which has become popular here:

The Mechanicus does NOT have the technology. They haven't been living on some fancy paradise planet since pre-Fall. Mars is an anarchic nightmare shithole the moment you leave the safe zones into the kilometers of labyrinthine corridors beneath it full of rogue machinery, self-aware and malevolent AI from before the Fall, and the daemon programs of the Heresy. EVERYTHING in the databases is fucked. The databases are fragmented over the entire surface to the extent that it would be impossible to see one tenth of the total files in the ludicrously extended life of a Magos even assuming that they are completely safe to visit. And they are not.

The files have been corrupted into madness by the Fall, and the unleashing of the most potent informational warfare systems ever to exist to defeat the Iron Men. Nearly all of Mars was rendered uninhabitable, what they live in now is built on the top of the ruins. They send archeotech expeditions in to find shit, nearly all of them never come back. The sheer number of rogue war machine running around in there is sufficient to rape the mind. Then came the Heresy, which was not earth-exclusive. Mars as the second most critical planet in the Imperium was the site of fighting nearly as ferocious as on Terra, with Mechanicus loyalists and Hereteks fighting tooth, nail, and mechadendrite everywhere. Ancient machines were unleashed, viruses both normal and daemonic unleashed into all the computer systems. Towards the close of the Heresy, Rogal Dorn sent some Space Marine operatives to wipe the planet clean of all life. Nearly every single stored record on Mars was rendered unusable, and those that survived are half the time self-aware and don't like you, or daemonic and actively try to kill you.

If you come back with a schematic, it is almost certainly gibberish, and if it isn't, it's probably corrupted into uselessness. If it does come back whole it was probably malevolently fucked with so that instead of a Lasgun power cell it's a fucking grenade set to detonate the second you finish building it. Why do you think they want off-world STCs so damned much if they had them all here? The fucking Heresy is why. Off-world they only have to contend with the Fall's war and its effects on the machinery plus twenty thousand years of degradation with no maintenance. But at least off-world it'll probably just not work instead of actively seeking to kill you.

Why do you think they seek to placate the Machine Spirit? It's because it exists. The fragments of trillions of self-aware programs, flourishing during the Dark Age of Technology and shattered by Man in his war with the Iron men, imprisoning the few who had not set themselves irrevocably into the machinery, a prison smashed wide open by the Heresy. Everything that can hold programming in the Imperium has a shard of a program in it. EVERYTHING. And you'd better fucking please it or it will do everything in its power to make your day shit. Sure, if it's a Lasgun it'll just not work or start shooting off rounds by itself, but if you piss off a Land Raider you can say bye-bye to half a continent. They apply these principles to things without spirits by habit, since they're so used to dealing with tanks that if not talked to just right might go rogue and annihilate the Manufactorum before they can be killed.

This is why they do not like ANYONE fucking with technology, because it is so rare to find anything that just works it is critical it not be compromised. That, and they do not have the actual knowledge to fuck with it intelligently, just through experimentation, which inevitably leads to slaughter. Pressing buttons to see what works is fine in a 21st century computer, but it is a very stupid thing to do at the helm of a 410th century starship with the destructive power to end solar systems. The entire knowledge base of humanity was lost. Not forgotten, but outright lost. Everything at all, poof. Nobody knows anything because the Fall fucked everything up and the Heresy double-fucked it. To rebuild the theoretical framework needed to design new technologies that don't kill everyone near them would require starting from the ground up. They don't have the time, they never have, and they never will.

This gets on to the point of war and what it does to technology. Someone will parrot that it makes it go much faster. Yes, it makes practical applications of technology go much faster. It also utterly stops all research on the scientific theories behind those technologies. This means that when war chugs along for a decade or two things get done. It means when it goes on too long you run out of theories to turn into technologies, and then you run out of technologies to apply. You stagnate. When you have been fighting in a war for survival in a drastically overextended empire, this is what happens. You are desperate for any extra materiel that can possibly be produced. Half your entire fucking military might went rogue, smashed the half that stayed and a whole swathe of the logistical side of your society, leaving you with the tattered shreds of a war machine to keep hold of an empire that was reaching straining point with an army far larger. There is no time for the sort of applied research programs that took Man twenty five thousand years to develop, in a time of unprecedented growth and prosperity.

 

[Leonard D Neubache]

There's a school of thought that if we suffer a serious decline that we can never recover beyond subsistence agricultural living again.

That's because all of the "easy" resources that we built our civilisations with are completely tapped out. You don't find oil at ten feet anymore, and if the drilling rigs all fall into disrepair then what kind of technology tree would you need to get them started again, and how is it possible when the energy surplus of an oil based society was what allowed us to drill to thousands of feet, miles offshore no less?

And that's just one of a thousand supply chain issues that a true collapse would bring about.

The theory goes that the inhabitants of a planet have just one shot to build a civilisation that will take them to the stars, and if they fuck that up then the next civilisation elsewhere in the universe which is successful will inevitably find the fuckups tending their fields as they'd done for hundreds of thousands of years (assuming their planet wasn't a radioactive wasteland).

 

[Svoboda]

It's not just ancient technology getting lost or in disuse. It's 14 years since the last commercial supersonic passenger flight. Concorde ran for almost 3 decades.

 

[debeguiled]

Do values count as technology?

 

[weambulance]

There are quite a few projects that are preserving human knowledge. The problem isn't knowledge, it's the supply chain, as Leonard suggests. I can design a (simple) computer from first principles, but that's not very useful if I don't have the materials to build it or the electricity to run it.

There's so much high tech junk made today that could be repurposed and reused that I think it would take multiple near extinction level events over multiple decades to really screw things up to the point where we couldn't recover, though. That is subject to change with time, as devices are made more disposable, less durable, and less maintainable every year in the name of continuous economic growth.