[HN Gopher] How are Rome's monuments still standing? ___________________________________________________________________ How are Rome's monuments still standing? Author : clouddrover Score : 52 points Date : 2021-12-20 03:42 UTC (19 hours ago) (HTM) web link (www.bbc.com) (TXT) w3m dump (www.bbc.com) | KSS42 wrote: | Here's some great videos on this question from YouTuber | ToldinStone - Garret Ryan | | Author of Naked Statues, Fat Gladiators and War Elephants | | Why was Roman concrete forgotten during the Middle Ages? | | https://youtu.be/dbvvlFHCNn4 | | See also his YouTube series: History of Rome in 15 Buildings | | The Colosseum: https://youtu.be/m6iHR8zqbiM | thinkski wrote: | Does make me wonder what we're building today that will last. I | suppose the engineers who worked on Voyager or Pathfinder have | the best shot of having built something enduring. | rurp wrote: | Tangentially related to this, one of my hobbies is to explore old | long abandoned ghost towns and mining camps in the Southwest US. | It is really impressive how well many of these structures have | held up in harsh climates. One of my favorite parts is seeing how | repairs were improvised in the wilderness using whatever supplies | happened to be available. | | The standard approach to trash back then was to throw it in a | pile nearby. Picking through those dumps can be really | fascinating and a surprising amount of items are still in good | shape. A simple heuristic for how old a glass bottle is is how | thick it is. A modern beer bottle looks paper thin compared to | one a century old. | | Looking at old structures and tools really makes vivid how | disposable many modern items are. | hnplj wrote: | roca wrote: | Did the Romans really know that using certain volcanic rocks | would make their concrete structures last longer? Or did they | mostly just use whatever aggregate was convenient and the | structures that have survived are the ones that used the right | rocks? The latter sounds more plausible to me. | | Of course we can still learn valuable lessons from these | surviving structures. | WalterBright wrote: | Rome lasted for many centuries, so I imagine they were familiar | with what worked and what didn't. | SQueeeeeL wrote: | Jonathan Blow makes a bunch of great points about our | simplified view of ancient people, versus the reality of | their complex achievements which could only be brought about | by lots of ingenuity and iterations. | | https://youtu.be/pW-SOdj4Kkk | bcrosby95 wrote: | The interconnectedness of the bronze age was amazing. To | make bronze required combining metals sourced from | thousands of miles away from eachother. | | In comparison, iron could be made basically anywhere. | simonebrunozzi wrote: | TL;DR: their concrete was different. | | > Roman concrete, on the other hand, is a simpler mix of | quicklime made from baking and crushing limestone rocks and, most | importantly, volcanic rock aggregates of various types, which | were abundant in the region surrounding Rome. In contrast to the | aggregates used in modern concrete, these volcanic materials used | by the Romans are highly reactive and the resulting concrete | remains chemically active for centuries after it first hardens. | | By the way, I don't buy this entirely. Let me tell you why. | | The Pantheon is mostly stones and bricks, and "some" concrete to | keep the bricks together. These large stones are held together by | simple force of gravity, very much like the Pyramids in Egypt | (~4,000 years old, or double the age of the Colosseum or the | Pantheon). | | I'm not a materials engineer (just a software engineer). Can | someone with more knowledge comment on my view? | ardit33 wrote: | It is both..... so both the author and you are correct. | | Modern concrete has rebar, which eventually gets rusted, and | corroded, and fails (in 150-200 years). Also, roman concrete | was just thicker/used more material. | | Also simple stone survives forever, while brick a bit less, and | 'simpler mud bricks' and wood a lot less. | | SO, from Roman times, really only the strongest buildings | survived, and everything else is gone. So, there is a survivor | bias. We are only looking at the strongest buildings, and not | the average one. | mrkstu wrote: | And as their wealth was staggering, they could afford to | build 'strong' more than most ancient civilizations and most | of the conquerors just were assimilated rather than wanting | to tear it down to the dirt. | valarauko wrote: | The Romans weren't any more significantly wealthier than | other contemporary Old World civilizations/empires - China, | Persia, or India, for example. Conquerors being assimilated | is a common theme that runs across most of these | civilizations as well. However, monumental buildings that | survive invading armies just tend to be | dismantled/repurposed by the locals for the building | material over time. I suspect that part of the reason for | Roman monuments surviving is that the fall of Western Rome | lead to an overall decrease in the urban population & | subsequent demand for building materials. China, India, & | Persia likely saw no such population decreases. | _carbyau_ wrote: | Using survivor bias to our benefit though. Evolution for | buildings as it were. | | While the article title is a blanket question on ALL Roman | monuments - which clearly didn't all survive - the article is | about people investigating how the long lasting ones do what | they do. | | Which sounds great to me. | 8ytecoder wrote: | I think we're missing another key factor here. Most "well | preserved" buildings are ones that are in continuous use. So | they get maintained and repaired. A temple in south India is | about a 1000 years old. It has seen repeated damages - some | intentional during conquests - but survives to this day because | the damages were patched up within a few decades. The "few | decades" it can go - even with damages - is likely from the | material and construction. But the centuries that add up comes | from regular maintenance. | valarauko wrote: | Well, while this is true, there is some level of survivorship | bias here. Plenty of comparable South Indian temples were | torn down, and the ones that survive are mostly quirks of | chance. Even the ones that do survive have seen many of their | gopurams (monumental gates) collapse after a few centuries | due to political apathy in modern times - the one I recall | most recently was at Srikalahasti. | soperj wrote: | Some structures were build without any concrete at all. That | being said, they've build sea walls that have lasted thousands | of years. | FredPret wrote: | We use reinforced concrete, concrete with steel bars inside. | This allows us to built really thin and strong concrete | bridges, balconies, roofs, etc. | | But the steel rusts after a couple of decades. | | Rusted steel is marginally larger than new steel. | | So when the steel bars expand by rusting, it pushes against the | concrete from the inside, causing cracks. Then lots of water | can get in it rusts faster. | | Eventually chunks of concrete fall off and structural collapse | follows. | | If we built like the Romans, it would be more expensive, but | would last 1k+ years. | WalterBright wrote: | It's critical to protect the concrete from water. | smegger001 wrote: | I wonder how long carbon fiber rebar, or plastic coated steel | rebar would last. | Cerium wrote: | Plastic coated rebar is a product. In theory it can solve | the rusting problem, but in practice the coating will get | some nicks during installation that can concentrate | corrosion leading to point weaknesses. There are additional | concerns with the bonding between the concrete and the | coated bar. | tastyfreeze wrote: | Basalt rebar is chemically resistant and doesn't corrode. | It does have a lower tensile strength than carbon fiber but | is suitable for current designs. | mc32 wrote: | There are stainless steel rebar and epoxy coated rebar for | structures exposed to the elements. Stainless steel rebar | appears to be kind of expensive so its use is limited. | dr_orpheus wrote: | I don't know how it compares to actual rebar reinforced | concrete, but we do use fiberglass reinforced concrete. | FredPret wrote: | Interesting idea, but carbon fiber would need to be really | cheap. Would work well until a critter of some sort evolves | that eats plastic | microtherion wrote: | The explanation in the article is fascinating, but I wonder how | much the Romans knew about the durability of their concrete at | the time, and to what extent they just got lucky by the mix of | material that happened to be available in their area. | SQueeeeeL wrote: | I feel like a single human could trial and error their way to | a very good paper airplane over the course of 2 or 3 days. It | seems pretty obvious that a large group of people would trial | and error products in much the same way, especially those so | essential to their civilization. Especially with the large | trade networks that we know to exist back then. | [deleted] | hujni wrote: | I've wondered if maybe the "stones" of the Pyramids were | poured. It wouldn't surprise me given the lack of gaps. | tastyfreeze wrote: | You aren't the only one. | | https://youtu.be/znQk_yBHre4 | kmonsen wrote: | Are there strong counterpoints to this? If that is possible | it seems extremely more likely than aliens or whatever else | people are coming up with. | orwin wrote: | You're right to not buy this entirely. Roman concrete was great | because it could harden while in water. And waterworks was | probably the primary reason why Rome was such an early | superpower (for multiple reasons: hygiene, stronger ports and | also mechanical force, as "free" energy give you productivity | increases. But it had less tensile strength than our current | concrete. | | The reason why multiple structures still hold today and will | hold longer than most of our structures is more simple than | that: they over-engineered the shit of everything that still | hold today. Also for the same reasons, multiple bridges, | castles, church or structures built between the low medieval | era and high med/renaissance will likely last as much as roman | structures did. | atdrummond wrote: | They're not. The Romans built a huge amount and much of their | artistic architectural works remaining today were purposely | preserved, even if reused for some alternative purpose. | | Yes, there are some construction techniques they used that | contributed to better survival rates than some other structure | types. But mostly we've ended up with what was lucky enough to | survive. Replay the historical tape again and we might be | surprised by what didn't survive war, fires, other natural | disasters on the second go round. | cblconfederate wrote: | > for the same reasons we preserve Victorian era buildings. | | Not really, christians destroyed a huge amount and ruthlessly, | and tons of marble was 'repurposed'. The best chance of a | building to survive was being used as a church | atdrummond wrote: | I suppose I just don't find that substantially different than | the National Trust repurposing say Ickworth into a hotel. I | understand that contemporary society places a higher value on | a certain type of "accurate" preservation than many societies | that came before but if people had truly wanted historical | Roman buildings gone, they would be. | cblconfederate wrote: | tons of pagan roman and greek statues were destroyed. | what's left today is only a tiny amount | atdrummond wrote: | I agree? My original reply's point was we have a very | small minority of what the empire constructed. And much | of that is because it was purposely preserved, if for | alternative reasons. | sandgiant wrote: | Destroying symbols of a previous rule was (is) commons | practice. Constantine realized that some building and | monuments were worth preserving and repurposed them as | "Christian", thereby ensuring their preservation for | hundreds, or even a thousand of years. | Pigalowda wrote: | I recently found out about this sad column repurposed in 608 | AD as an honor to the Eastern Roman Emperor, Phocas. | | https://en.m.wikipedia.org/wiki/Column_of_Phocas | | The city had been sacked multiple times at that point and I | suppose it was the best they could do. | atdrummond wrote: | What's crazy there is that by the mid-1800s, sketches would | only show a portion of the column due to the rise in ground | level over the intermediate period. | peoplefromibiza wrote: | Nope. | | Romans invented concrete, and it was so good that still today | the average concrete can't compete with it (its resistance to | cracks is one example) | | Rewind history and roman buildings would still be there. | | They are thought to be one of the few things that would survive | human extinction. | | The only thing that would outlast them are Giza Pyramids. | | https://en.m.wikipedia.org/wiki/Roman_concrete | dehrmann wrote: | There might be some truth to Roman concrete still being | reactive leading to its longevity, but I'd be really careful | about dismissing survivorship bias. | atdrummond wrote: | I don't have the energy to revisit the arguments about Roman | concrete that come up every time it is mentioned on HN. | Needless to say, the notion that their "superior" method was | "forgotten" is a massive oversimplification of what actually | happened. | | Another comment made my point better than I did - which was | that Roman buildings that remained standing did so because | they were useful for some purpose, often an alternative one | (such as a church). It speaks to their value specifically as | architecture and is mostly orthogonal to their construction | techniques. There are plenty of old buildings (such as Horyu- | ji, Ruwanweli Maha Seya, Mousa Broch, etc) that don't use any | kind of magical construction techniques but have stuck around | because of their value to the surrounding society and active | efforts at preservation and/or repurposing. | peoplefromibiza wrote: | > which was that Roman buildings that remained standing did | so because they were useful for some purpose, | | that's a fallacy. | | A lot of buildings were useful back then, it wasn't easy to | build them nor cheap. | | But most of them collapsed, because they weren't strong | enough. | | You get roman buildings everywhere in Europe and Northern | Africa, a lot of civilizations lived there in the past 40 | centuries and their remains are scarce at best. | | It is like saying that Amazon beat many other startups of | its times because they got lucky, it's simply because their | execution was better than the competition. | User23 wrote: | > There are plenty of old buildings (such as Horyu-ji) that | don't use any kind of magical construction techniques but | have stuck around because of their value to the surrounding | society and active efforts at preservation and/or | repurposing. | | This is true, but rather misleading. Horyu-ji burned down | and is probably around 80-90% new material. | | The Roman concrete structures on the other hand survived | this long with their original construction materials. | Linosaurus wrote: | The article did bring up some ways modern concrete is | superior in the shorter term: | | "Among the biggest obstacles to wider adoption of the Roman | recipe are its long curing time - it can take up to six | months to reach full strength, compared to standard | concrete's' 28 days - and lower strength (Perucchio said it's | approximately 10 times weaker than modern concrete)," | JSavageOne wrote: | You respond to an article detailing the superiors durability of | Roman concrete with "they just chose to preserve these | buildings" and "they just got lucky", cite no sources, and this | is the top comment on this thread? | | Seems HN quality has gone downhill since what I last remember. | cblconfederate wrote: | They didn't use javascript? | [deleted] | agumonkey wrote: | They did https://rome.tools/ | basementcat wrote: | Rome wasn't written in a day. | bennysomething wrote: | Surely it should be "why are Rome's monuments..." Or am I | mistaken, I'm not actually sure | freefal wrote: | Either reads fine to me. | emmelaich wrote: | 'how' sounds a bit wrong to me, too. But it's popular in the | USA. | nraynaud wrote: | one very impressive feat is the Pont du Gard, this thing has been | in disuse for 1500 years, and lots of stones have been looted | over the centuries. And its aspect ratio is somewhat thin. | wsinks wrote: | Survivorship Bias | | The ones that are still standing were built really well. Each | will have its own reason for standing so long. | noyeastguy wrote: | I wonder if there will come a time when society decides it's | better to fix ruins such as the Colosseum and the pyramids | instead of letting them just rot away. | i_have_an_idea wrote: | What would be the practical purpose of "fixing" something like | the pyramids? Vs. just preserving them as-is. ___________________________________________________________________ (page generated 2021-12-20 23:00 UTC)