3 ms·

It's a seductive idea, that we can see into the past so accurately in such a way. The article suggests weaknesses though that seem to be being brushed under the

It's a seductive idea, that we can see into the past so accurately in such a way. The article suggests weaknesses though that seem to be being brushed under the carpet. The biggest problem is with the economics and the history rather than the science of measuring lead in ice cores. The article states: Yet for all these coins, it remains unclear how Rome managed its money in a modern sense ... and that seems to be a problem because the theory asks us to believe something implausible; that during times of war coin production went down. Everything we know about both modern and ancient governments tells us that rulers routinely inflate their currencies to pay soldiers. During a time of war, when desperation is at its peak and there is a need to win at any cost, furiously minting coins to fund the fight is extremely common. Yet according to these graphs coin production goes up during times of peace and down during times of war. Really? The story falls apart in other ways further down the article: That said, the lead record does not seem to mark a few major events in Roman history. The Plague of Justinian, which may have killed half the population of Europe in 541 and 542 a.d., does not seem to feature prominently in the record OK, so their entire thesis is that the Roman economy can be measured using lead in ice cores, yet an event that more than decimated the population appears to have had no impact on economic activity at all? Either the measurements are wrong, or the historical understanding of the plague is wrong, or the understanding of what lead in ice cores means historically is wrong. But it's hard to see the theory as presented as anything but implausible when such gaping holes exist in the data. It gets worse: Nor does the record encompass the full scope of the Roman coin-minting operation: Many important silver mines sat near Greece and the eastern Mediterranean, and their emissions probably did not make it to Greenland. So lead in the air can make it from Spain to Greenland, about 2700 miles, but not from Greece to Greenland, a distance of about 3100 miles? They're nearly the same distance apart. Does lead in the air have a magic cutoff beyond which it cannot travel on the wind and if so, why does the article not talk about this? Finally, the article does note that this new study contradicts an earlier study that concluded the opposite. This is explained by saying the new study has more data. But this still seems odd to me - it's saying the old study had such bad luck that the ice cores they studied were totally misleading to the extent that they presented the opposite of the truth. How did that happen? Is it really plausible and if so what other studies should be invalidated as a result of not taking enough core samples? I find myself wondering how much of this article boils down to curve fitting and munging the data to fit what we are sure we "know" about Rome, to create a nice story that doesn't rock any boats.

chimprich 8y ago
> So lead in the air can make it from Spain to Greenland, about 2700 miles, but not from Greece to Greenland, a distance of about 3100 miles? I have no domain knowledge about this, but I assumed the difference was in atmospheric circulation. Happy to be corrected by anyone who knows about this stuff, but I'd have thought there was a relatively clear pathway across open ocean from the Iberian peninsula to Greenland. I'd expect the route from Greece to Iceland to be significantly more chaotic as far as wind is concerned; more land, mountain ranges, and opportunities for rainfall and mixing of currents.
- fapjacks 8y ago
  Just to add something, we can make some guesses about the circulation of the ocean and wind currents during Roman times because we know that the Roman Warm Period approximated the climate we enjoy today, for several reasons. For example the locations where date palms are grown and dates harvested. We have at least one account which mentions that date palms can be planted in e.g. Greece but that dates will not fruit there (which is the case today), but that dates can be grown and harvested in Judea, which was not the case between the time of the Roman Empire and today because of the colder climate. Medieval scholars weren't sure what to think of that.
vincebowdren 8y ago
Yet according to these graphs coin production goes up during times of peace and down during times of war. Really? Well, the republican era wasn't a very peaceful time; Rome was pretty much continuously at war in one way or another for centuries. The late republican crisis was unusual because the roman legions were fighting each other, instead of non-roman forces.
zhdc1 8y ago
> ... and that seems to be a problem because the theory asks us to believe something implausible; that during times of war coin production went down. This doesn't really surprise me. Lead production during the first downturn was controlled by the Carthaginians, who were effectively wiped out by the Romans (which is why there was a sharp reduction in lead emissions when the Carthaginian Empire fell, followed by a sharp increase after the Romans restarted lead production). The second and most severe dip happened during the crisis of the third century, which destroyed Roman trade and kicked off the transition from a quasi-market economy to a feudalist economy. The Plague of Justinian happened after the western empire had already collapsed. The eastern empire did control some of the Spanish coast around that time, but it's plausible that mining had already been reduced to a minimum, since most of the Spanish mines were located in what (as far as I can tell) were effectively frontier regions.

chimprich 8y ago

> So lead in the air can make it from Spain to Greenland, about 2700 miles, but not from Greece to Greenland, a distance of about 3100 miles? I have no domain knowledge about this, but I assumed the difference was in atmospheric circulation. Happy to be corrected by anyone who knows about this stuff, but I'd have thought there was a relatively clear pathway across open ocean from the Iberian peninsula to Greenland. I'd expect the route from Greece to Iceland to be significantly more chaotic as far as wind is concerned; more land, mountain ranges, and opportunities for rainfall and mixing of currents.

fapjacks 8y ago
Just to add something, we can make some guesses about the circulation of the ocean and wind currents during Roman times because we know that the Roman Warm Period approximated the climate we enjoy today, for several reasons. For example the locations where date palms are grown and dates harvested. We have at least one account which mentions that date palms can be planted in e.g. Greece but that dates will not fruit there (which is the case today), but that dates can be grown and harvested in Judea, which was not the case between the time of the Roman Empire and today because of the colder climate. Medieval scholars weren't sure what to think of that.

vincebowdren 8y ago

Yet according to these graphs coin production goes up during times of peace and down during times of war. Really? Well, the republican era wasn't a very peaceful time; Rome was pretty much continuously at war in one way or another for centuries. The late republican crisis was unusual because the roman legions were fighting each other, instead of non-roman forces.

zhdc1 8y ago

> ... and that seems to be a problem because the theory asks us to believe something implausible; that during times of war coin production went down. This doesn't really surprise me. Lead production during the first downturn was controlled by the Carthaginians, who were effectively wiped out by the Romans (which is why there was a sharp reduction in lead emissions when the Carthaginian Empire fell, followed by a sharp increase after the Romans restarted lead production). The second and most severe dip happened during the crisis of the third century, which destroyed Roman trade and kicked off the transition from a quasi-market economy to a feudalist economy. The Plague of Justinian happened after the western empire had already collapsed. The eastern empire did control some of the Spanish coast around that time, but it's plausible that mining had already been reduced to a minimum, since most of the Spanish mines were located in what (as far as I can tell) were effectively frontier regions.