5 ms·

Survivor bias comes up every time this topic is mentioned, but it really has less explanatory power than most people think. If you meet a man born in 1932 who i

Survivor bias comes up every time this topic is mentioned, but it really has less explanatory power than most people think. If you meet a man born in 1932 who is still running marathons and doesn't need glasses, it's probably luck, although he might have some valuable diet tips to share. If you meet a man born in 1732 running the same marathon, it's time to rule out luck, and start collecting blood samples because he might actually be some kind of vampire. Furthermore, the "survivor bias" idea, as an attempt to explain the longevity of Roman concrete as a building material, implies that the buildings that survived were stronger than the ones that did not, so we're just seeing the upper end of structural strength. But that's not even necessarily the case. Many more were lost because they were deliberately demolished for other reasons (honoring the wrong gods, etc). And it's not like these buildings only survived in ideal environments for preservation; as the article mentions, they have survived in many different climates across a vast empire, standing in seawater, through earthquakes, and so on.

moloch-hai 4y ago
Right. Romans experimented with the formula for concrete for centuries, and learned a lot about how centuries-old concrete structures deteriorated. They didn't have modern chemistry, but they had observational skills and were serious about their work. It would not be surprising to find that most structures weren't built to last any longer than ours, but that some were meant for the ages. An important difference today is we don't build the latter sort, excepting maybe the Sydney Opera House. Many people act personally offended that it doesn't have steel inside.
- saalweachter 4y ago
  I wonder if generational reputations and transmission of methods from master to apprentice is sufficient. "Secundus was an apprentice to Marius who was an apprentice to Darius, who built that awesome aquaduct; Marcus was an apprentice to Felix who who was an apprentice to Marcellus, whose shit bridge fell down after twenty years. We're going to hire Secundus instead of Marcus."
  - rerdavies 4y ago
    Real Roman engineering theory came from Marcus Vitruviouss Pollio's De Archetectura. Considered to be the ultimate reference text for building and engineering projects in Rome in 32bce, It's ten volumes cover how to build everything from temples, to aqueducts, to water mills to machines used for construction. A fascinating read, if you're curious how Romans built things. De Architectura provides the sort of long-term perspective required to build and engineer projects that were meant to last for centuries, based on experience gathered from centuries of recorded experience. I'm not sure if De Architectura is the only book that Roman Architects used. But it was certainly the most important. Hundreds of pages of De Architectura list dimensions of older ancient buildings, the dimension and spacing of pillars, and failures encountered during or after construction. Something along the following lines (not actual text): --- The second Temple at Delos was built in 432bce. It consisted of 13 x 29 doric columns, 6' in diameter, 22' high, spaced on 12' intervals, with two rows in the pro-cella. The cella measured ..... The entrance to the cella was 16' high and 12' wide with a granite lintel measuring 16' x 3' x 2'. The lintel above the entrance cracked and had to be replaced after an earthquake in 430bce. The front-right architrave cracked in 329bce, but was not repaired. The temple was subsequently abandoned and collapsed completely after an earthquake in 327bce. The temple of Apollo at Thebes .... The main architrave cracked while it was being mounted, and further construction was abandoned. --- Given a hundred or so such examples, a Roman architect of a new temple could make somewhat informed decisions about how high, how wide, and how thick he would need to build a new temple, and how afraid he should be when he was commissioned to build a new temple that was higher, wider, or taller.
    - jacquesm 4y ago
      That's a combination of 'Risks Digest' and the 'Engineering handbook' all in one. I'll have to go read this, thank you so much for the pointer.
    - yawboakye 4y ago
      as far as i know, vitruvius wasn’t original: he aped the meticulous and more successful greeks. the ten volumes regularly refer to greek knowledge or practice to cement its authority. the method of construction that is uniquely roman is mixing concrete and bricks, usually to produce aqueducts. and here the simple theory was: everything in excess. in fact, the romans may have been unique in their construction of military camps. for more on that see de re militari
- hprotagonist 4y ago
  The cathedral of st. john the divine in new york city has yet to be completed. we just don't build a lot of them.
- imtringued 4y ago
  We build dams to be long lasting.
  - moloch-hai 4y ago
    More of them, anyway, than of other types. Some have not lasted, with typically regretted consequences.
agumonkey 4y ago
meta comment: I'd love to see the stats about all bias and fallacies mentionned in conversations in the last 20 years. Something tells me wikipedia got deep into people's head.
jacquesm 4y ago
> start collecting blood samples because he might actually be some kind of vampire. In which case your first worry would be to make sure he doesn't collect your blood samples.

moloch-hai 4y ago

Right. Romans experimented with the formula for concrete for centuries, and learned a lot about how centuries-old concrete structures deteriorated. They didn't have modern chemistry, but they had observational skills and were serious about their work. It would not be surprising to find that most structures weren't built to last any longer than ours, but that some were meant for the ages. An important difference today is we don't build the latter sort, excepting maybe the Sydney Opera House. Many people act personally offended that it doesn't have steel inside.

saalweachter 4y ago
I wonder if generational reputations and transmission of methods from master to apprentice is sufficient. "Secundus was an apprentice to Marius who was an apprentice to Darius, who built that awesome aquaduct; Marcus was an apprentice to Felix who who was an apprentice to Marcellus, whose shit bridge fell down after twenty years. We're going to hire Secundus instead of Marcus."
- rerdavies 4y ago
  Real Roman engineering theory came from Marcus Vitruviouss Pollio's De Archetectura. Considered to be the ultimate reference text for building and engineering projects in Rome in 32bce, It's ten volumes cover how to build everything from temples, to aqueducts, to water mills to machines used for construction. A fascinating read, if you're curious how Romans built things. De Architectura provides the sort of long-term perspective required to build and engineer projects that were meant to last for centuries, based on experience gathered from centuries of recorded experience. I'm not sure if De Architectura is the only book that Roman Architects used. But it was certainly the most important. Hundreds of pages of De Architectura list dimensions of older ancient buildings, the dimension and spacing of pillars, and failures encountered during or after construction. Something along the following lines (not actual text): --- The second Temple at Delos was built in 432bce. It consisted of 13 x 29 doric columns, 6' in diameter, 22' high, spaced on 12' intervals, with two rows in the pro-cella. The cella measured ..... The entrance to the cella was 16' high and 12' wide with a granite lintel measuring 16' x 3' x 2'. The lintel above the entrance cracked and had to be replaced after an earthquake in 430bce. The front-right architrave cracked in 329bce, but was not repaired. The temple was subsequently abandoned and collapsed completely after an earthquake in 327bce. The temple of Apollo at Thebes .... The main architrave cracked while it was being mounted, and further construction was abandoned. --- Given a hundred or so such examples, a Roman architect of a new temple could make somewhat informed decisions about how high, how wide, and how thick he would need to build a new temple, and how afraid he should be when he was commissioned to build a new temple that was higher, wider, or taller.
  - jacquesm 4y ago
    That's a combination of 'Risks Digest' and the 'Engineering handbook' all in one. I'll have to go read this, thank you so much for the pointer.
  - yawboakye 4y ago
    as far as i know, vitruvius wasn’t original: he aped the meticulous and more successful greeks. the ten volumes regularly refer to greek knowledge or practice to cement its authority. the method of construction that is uniquely roman is mixing concrete and bricks, usually to produce aqueducts. and here the simple theory was: everything in excess. in fact, the romans may have been unique in their construction of military camps. for more on that see de re militari
hprotagonist 4y ago
The cathedral of st. john the divine in new york city has yet to be completed. we just don't build a lot of them.
imtringued 4y ago
We build dams to be long lasting.
- moloch-hai 4y ago
  More of them, anyway, than of other types. Some have not lasted, with typically regretted consequences.

agumonkey 4y ago

meta comment: I'd love to see the stats about all bias and fallacies mentionned in conversations in the last 20 years. Something tells me wikipedia got deep into people's head.

jacquesm 4y ago

> start collecting blood samples because he might actually be some kind of vampire. In which case your first worry would be to make sure he doesn't collect your blood samples.