Tag Archives: technology

Quest for fire

958 million – 907 thousand years ago

On June 3 on Logarithmic History, our ancestors had gotten as far as steak tartare. Now it’s time for an Eisenhower steak (cooked directly on the coals; see below).

What really distinguishes humans from other animals? We’ve covered some of the answers already, and will cover more in posts to come. But certainly one of the great human distinctions is that we alone use fire. Fire is recognized as something special not just by scientists, but in the many myths about how humans acquired fire. (It ain’t just Prometheus.) Claude Lévi-Strauss got a whole book out of analyzing South American Indian myths of how the distinction between raw and cooked separates nature from culture. (I admit this is where I get bogged down on Lévi-Strauss.)

Until recently the story about fire was that it came late, toward the latter days of Homo erectus. But Richard Wrangham, a primatologist at Harvard, turned this around with his book Catching Fire (which is not the same as this book), arguing that the taming of fire goes back much earlier, to the origin of Homo erectus. Wrangham argues that it was cooking in particular that set us on the road to humanity. Cooking allows human beings to extract much more of energy from foods (in addition to killing parasites). Homo erectus had smaller teeth and jaw than earlier hominins and probably a smaller gut, and it may have been fire that made this possible. Cooking is also likely to have affected social life, by focusing eating and socializing around a central place. (E O Wilson thinks that home sites favored intense sociality in both social insects and humans.)

Surviving on raw food is difficult for people in a modern high-tech environment and probably impossible for people in traditional settings. Anthropologists are always looking for human universals, and almost always finding exceptions (e.g. the vast majority of societies avoid regular brother-sister marriage, but there are a few exceptions, including Roman Egypt and Zoroastrian Iran). But cooking seems to be a real, true universal. No society is known where people got by without cooking. Tasmanians, isolated from the rest of the world for 10,000 years, with the simplest technology of any people in recent history, had lost the art of making fire, but still kept fires going and still cooked.

Recent archeological finds have pushed the date for controlled use of fire back to 1 million years ago (see today’s tweet on Wonderwerk cave), but not all the way back to the origin of Homo erectus. This doesn’t mean Wrangham is wrong. Fire sites don’t always preserve very well: we have virtually no archeological evidence of the first Americans controlling fire, but nobody doubts they were doing it. It could be that it will be the geneticists who will settle this one. The Maillard (or browning) reaction that gives cooked meat much of its flavor generates compounds that are toxic to many mammals but not (or not so much) to us. At some point we may learn just how far back genetic adaptations to eating cooked food go.

An alternative to an early date for fire, there is the recent theory that processing food, by chopping it up and mashing it with stone tools, was the crucial early adaptation.

Whenever it is exactly that humans started cooking, the date falls in (Northern hemisphere) grilling season on Logarithmic History, so you can celebrate the taming of fire accordingly. It doesn’t have to be meat you grill. Some anthropologists think cooking veggies was even more important. I recommend sliced eggplant particularly, brushed with olive oil to keep it from sticking, and with salt, pepper, and any other spices.

On the other hand, Homo erectus probably appreciated a good Eisenhower steak, cooked directly on the coals. (Yes, this actually works pretty well.)

Eisenhower Coal-Fired Steak

Named for the 34th president of the United States, who liked to cook his steaks directly on the coals, this preparation will create a crunchy, charred exterior with rosy, medium-rare meat inside.

Lump hardwood coals work better than briquettes for this recipe because they burn hotter. Be sure you use long-handled tongs. (Sorry, this method is for charcoal or wood grilling only.)

You might find an uneven exterior crust, especially when using lump charcoal, because it is irregularly shaped (unlike the uniform briquette pillows). If that happens, try to position the steak so that it is more directly on the coals and gets an even char. Clasp the steak in the tongs and rap the tongs against the edge of the grill to knock off the occasional clinging ember. If you have some ash, flick it off with a pastry brush.

Make Ahead: The steaks can be seasoned and refrigerated up to 4 hours in advance. Bring them to room temperature before they go on the fire.

INGREDIENTS
  • 1 teaspoon olive oil
  • Two 1 1/2-inch-thick boneless rib-eye steaks (about 28 ounces total)
  • 2 teaspoons coarse sea salt
  • 2 teaspoons freshly cracked black pepper

DIRECTIONS

Prepare the grill for direct heat. Light the charcoal; when the coals are just covered in gray ash, distribute them evenly over the cooking area. For a hot fire (450 to 500 degrees), you should be able to hold your hand about 6 inches above the coals for 2 or 3 seconds. Have a spray water bottle at hand for taming any flames. But use it lightly; you don’t want to dampen the heat too much, and some flames here are fine.

Meanwhile, brush the oil on the both sides of the steaks, then season both sides liberally with salt and pepper.

Once the coals are ready, place the steaks directly on the coals (see headnote). Cook, uncovered, for 6 minutes on one side, then use tongs to turn them over. Cook for about 5 minutes on the second side.

Transfer the steaks to a platter to rest for 10 minutes. Serve as is, or cut them into 1/2-inch-thick slices.

My handaxe

101- 959 thousand years ago

By today’s date, Acheulean tools are well developed in Africa, and found in India too. Sophisticated tools like the Acheulean hand axe probably tell us something not just about cognition in relation to tool making, but also about social cognition. You wouldn’t make a hand axe, use it, and abandon it. Nor would you go to all the trouble if the biggest, baddest guy in the group was immediately going to grab it from you. So there is probably some notion of artifacts-as-personal-possessions by the time Acheulean appears.

Possession is a social relationship, a relationship between two or more individuals with respect to the thing possessed. Robinson Crusoe didn’t “own” anything on his island before Friday came along.

Linguists have noted something interesting about the language of possession that maybe tells us something about the psychology of possession: Expressions for possession are often similar to expressions for spatial locations. Compare spatial expressions:

João went to Recife.
Chico stayed in Rio.
The gang kept Zezinho in Salvador.

and corresponding constructions for possessions:

The Crampden estate went to Reginald.
The Hampden estate stayed with Lionel.
Thag kept axe.

Of course the Crampden estate didn’t go anywhere in physical space, but it still traveled in the abstract social space of possession. In some cases just switching from inanimate to animate subject will switch the meaning from locative to possessive. The Russian preposition y means at/near when applied to a place (People are at Nevsky street) but possession when applied to a person (Hat is “at” Ivan = Ivan has hat.)

What may be going on here: people (and many other creatures) have some mental machinery for thinking about physical space. That machinery gets retooled/borrowed/exapted for thinking about more abstract relationships. So the cognitive psychology of space gets retooled for thinking about close and distant social relationships, or time ahead and behind. In other words, we may be seeing a common evolutionary phenomenon of organs evolved for one purpose being put to another purpose – reptile jaw bones evolve into mammalian inner ear bones, dinosaur forelimbs evolve into bird wings. You can find Steve Pinker making this argument in his book The Stuff of Thought. And Barbara Tversky’s recent Mind in Motion: How Action Shapes Thought seems to make the argument at greater length; I’m looking forward to reading it. For a while most of the evidence of repurposing spatial cognition for more abstract relationships came from linguistics, but there’s now some corroboration from neurology.

And I’ve made the argument for the particular case of kinship: regularities in kin terminology across cultures tell us something about pan-human ideas of “kinship space.” (My kin and mybody parts are arguably the most basic, intrinsic primitive sorts of possessions, since long before my handaxe.) This implies that the evolutionary psychology of kinship has not just an adaptive component (adaptations for calculating coefficients of relatedness and inbreeding), but also a phylogenetic component  (homologies with the cognitive psychology of space).

We’ll see other possible examples, involving e.g. the evolution of speech sounds, as we move along.

Handaxe

1.540-1.42 million years ago

From around 1.4 million years ago, Acheulean hand axes appear in Africa. They will eventually show up in southwest Europe and as far east as India. Hand axes were long thought to be absent from further east, but now have been found sporadically in East Asia. (Bamboo might have been an alternative to stone in the east.) Wear analyses show that hand axes, “the Swiss Army knife of the Paleolithic,” were used for a variety of purposes: cutting wood, slicing meat, scraping hides.

The hand axe implies a great leap forward cognitively from earlier Oldowan tools (although you can flay an elephant with Oldowan flakes). People (let’s call them people) were not just choosing the right material and making the right hand movements, but choosing the right shape of stone, and imagining the hand axe inside it before they started.

Dietrich Stout, an experimental anthropologist at Emory University, has trained students to make modern-day Acheulean handaxes, and monitored their brains as they learn. (The students’ axes, after months of practice, still aren’t as good as the real thing.) See the video below:

Stonecraft as soulcraft

2.63-2.49 million years ago

Until recently the earliest known stone tools dated back to the Oldowan, 2.6 million years ago, although recently stone tools going back 700,000 years earlier were reported. Stone tool use may be a lot older than we thought.

We now know that tool making is not uniquely human. (For tool use in dinosaurs, check out this post, from early April.) But Oldowan tools – including choppers (below), pounders, and scrapers — go beyond anything chimpanzees, or other animals, do. Kanzi, a bonobo (pygmy chimpanzee, who was also taught to communicate with an artificial set of symbols) learned to use sharp stone flakes for cutting, but never mastered the art of striking a stone core at the proper angle to produce useful sharp flakes. Apparently australopithecines (or maybe early Homo or Kenyanthropus) had taken a step further by 2.6 million years ago (or earlier).

oldowan

Early evolutionary theory developed in tandem with the Industrial Revolution and included an appreciation for the importance of manual labor. Darwin, in The Descent of Man, argued for the central role of toolmaking in human evolution, and, not surprisingly, the same point was echoed by Friedrich Engels in 1876, in his unfinished essay “The Part Played by Labor in the Transition from Ape to Man.” Engels was pushing back against the attitude in most traditional stratified societies that manual labor is low class, while symbolic labor (and/or wielding weapons) is high class.

For example the fingernails on this Chinese scholar advertised that he didn’t work with his hands.

fingernail

Nowadays, a common complaint about the post-industrial economy is that so much education and employment revolves around pushing symbols around that manual labor is relatively devalued. The recent book Shopcraft as Soulcraft: An Inquiry into the Value of Work is a statement of this lament. Maybe today is a good time to celebrate the part played by labor in the transition from ape to man — by making something, or mending something.

But if food is more your thing, the next post will suggest a recipe.

The bottomlands

There’s a book from back in 1954, now out of print, called Engineer’s Dreams by Willy Ley (who was most notable as a spaceflight advocate). The book lays out various grandiose engineering projects that people have proposed over the years. Some of these dreams have actually been realized: after centuries of people talking about it, there is now a tunnel under the English Channel.

Others … well …

One project the book discusses is damming the Congo River, creating a huge lake in the Congo basin, then sending the water north to create another huge lake in Chad. (There’s a small lake there now, almost dried out, which was a lot bigger 10,000 years ago when Africa was wetter.) From Lake Chad, the water would be sent further north to create a great river – a second Nile — running through Libya into the Mediterranean. All that fresh water is just running uselessly into the Atlantic now. Why not send it someplace where it’s needed?

Another engineer’s dream is to refurbish the Mediterranean Sea by building a dam across the Strait of Gibraltar. This actually isn’t an impossible project. The strait is less than nine miles across at its narrowest, and about 3000 feet deep at its deepest. A dam across the strait would have some dramatic consequences. The Mediterranean loses more water from evaporation than it gains from the rivers running into it. The difference is made up by a flow of water from the Atlantic. Cut this off, and the sea will start shrinking. You could let the Mediterranean drop 330 feet before stabilizing it, run a huge hydroelectric plant at Gibraltar, and open up a whole lot of prime Mediterranean real estate.

Sadly, whenever people have dreamed great dreams, there have always been small-minded carpers and critics to raise objections. Okay, so maybe the mayors of every port on the Mediterranean would complain about their cities becoming landlocked. And maybe massively lowering the sea level in an earthquake-prone region would lead to a certain amount of tectonic readjustment before things settled down.

So probably the Gibraltar dam will never be built (although Spain and Morocco are considering a tunnel). But we’ve seen already that Mother Nature sometimes plays rough with her children, and it turns out (although Ley couldn’t have known this back in the 50s) that damming the Mediterranean has already been done. The story begins back in the Mesozoic (late March), when the Tethys Sea ran between the northern continent of Laurasia and the southern continent of Gondwanaland. The sea was still around 50 million years ago (April 11) when whales were learning to swim. But it has been gradually disappearing over time. When India crashed into Asia and raised the Himalayas, the eastern part of the sea closed off. And as Africa-Arabia moved north toward Eurasia, a whole chain of mountains was raised up, running from the Caucasus to the Balkans to the Alps. The Tethys Sea was scrunched between these: what’s left of it forms the Caspian, Black, and Mediterranean seas.

Starting about 6 million years ago, the story takes a really dramatic turn. The continents were in roughly there present positions, but the northern movement of the African tectonic plate, plus a decline in sea levels due to growing ice caps, shut off the Strait of Gibraltar, sporadically at first. With water from the Atlantic cut off, the Mediterranean began drying out. By 5.6 million years ago, it had dried out almost completely – the Messinian Salinity Crisis. (The Messinian Age is the last part of the Miocene Period). There were just some hyper-saline lakes, similar to the Great Salt Lake in Utah or the Dead Sea in the Near East, at the bottom of an immense desert more than a mile below today’s sea level. The Nile and the Rhone cut deep channels, far below their current levels, to reach these lakes. This lasted until 5.3 million years ago, when the strait reopened and a dramatic flood from the Atlantic restored the Mediterranean.

All this was happening just around that time that hominins were committing to bipedalism. Did the cataclysmic events in the Mediterranean basin have some influence on hominin evolution in Africa? At this point we can’t say.

Harry Turtledove, prolific writer of alternative history, has a novella, Down in the Bottomlands, set on an alternative Earth in which the Mediterranean closed off, dried out, and never reflooded. In the novella, terrorists are plotting to use a nuclear weapon to reopen the Mediterranean desert to the Atlantic – sort of Engineer’s Dreams in reverse.

Coals to Newcastle

289-275 million years ago

It seems like Gaia really went on a bender in the late Carboniferous, getting drunk on oxygen. By some estimates, the atmosphere was over 30% oxygen back then, compared to 21% today. Living things took advantage of the opportunity. Insects apparently face an upper limit in size because they rely on diffusion through tracheas instead of forced respiration through lungs to get oxygen into their bodies. With more oxygen in the air, this limit was raised. The Carboniferous saw dragonflies with a wingspan up to 70 centimeters, and body lengths up to 30 centimeters, comparable to a seagull.

dragonfly

This happened because plants were turning carbon dioxide into organic matter and free oxygen, and the organic matter was accumulating. With carbon dioxide being removed from the atmosphere, the late Carboniferous and subsequent early Permian saw a reduced greenhouse effect, and global cooling. This was another Ice Age, with ice caps around the southern pole.

A lot of organic carbon ended up being buried. Much of the world’s coal, especially high quality anthracite, has its origin in Carboniferous tropical forests. Western Europe and eastern North America lay in the tropics at the time, and got a particularly generous allotment of coal. Three hundred million years later this bounty would fuel the early Industrial Revolution. (Thanks partly to some of my Welsh ancestors, who helped dig it up back in the day.)

coal age

Green revolution

September 1970 – March 1974

The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate.

Paul Ehrlich. The Population Bomb. 1968

Ironically, it was just around the time that Ehrlich wrote this that production of rice and wheat in India, the Philippines, and other countries was booming thanks to the Green Revolution – more productive plant varieties that could take advantage of fertilizer and pesticide inputs. It’s true, as Malthus pointed out long ago, that exponential population growth can eat up any conceivable increase in agricultural output. But the Green Revolution bought the world some breathing space until birth rates began to come down. It probably also eased some of the paranoia about food supply that played a part in two world wars.

Whoever makes two ears of corn, or two blades of grass to grow where only one grew before, deserves better of mankind … than the whole race of politicians put together.

Jonathan Swift

Steam engine time

1716-1732

The steam engine was a child of seventeenth century science; the Scientific Revolution gave birth to the Industrial Revolution. That’s not at all the conventional story, but David Wootton’s recent book The Invention of Science: A New History of the Scientific Revolution makes the case.

According to the conventional story, the steam engine resulted from the work of generations of inspired tinkerers, ingenious craftsmen with no particular scientific training and no great scientific knowledge. Indeed, according to one historian, “Science owes more to the stream engines than the steam engine owes to science.” (After all, the steam engine did inspire Carnot’s thermodynamic theory.)

But Wooton traces a path from scientific theory to practical application, beginning with the seventeenth century science of vacuum, air and steam pressure. The pioneering scientists here were not just theorists. They built (or at least designed) a number of devices for making use of differences in gas pressures, including an air gun (Boyle), a steam pressure pump (della Porta), and a vacuum-powered piston (von Guericke). Huygens took up the last idea, using an explosion to empty air from a cylinder, through a valve, and then using the partial vacuum to move a piston. This in turn was taken up by Denis Papin, a French Protestant medical doctor and mathematician, who worked as an assistant to Huygens, and then to Boyle. Papin combined scientific knowledge and engineering experience to design several steam engines. None of these was very practical – sadly Papin ended his life in failure and poverty. But the first of them was very similar to the first commercially viable steam engine, produced by Newcomen in 1712 – so similar that many historians have been convinced that Newcomen must have been familiar with Papin’s design.

Up to recently there’s been no convincing account of how Newcomen could have learned of Papin. But now Wooton has discovered the likeliest link, a book by Papin with the unpromising title A Continuation of the New Digester of Bones. The book has been neglected by historians, not surprisingly, but sold well in its own day. It gives plans for a pressure cooker (hence the title). But it also contains detailed descriptions both of vacuum powered piston, and of the use of steam condensation to produce a vacuum: just what Newcomen needed to put together to build his first engine. Wooton writes:

Newcomen’s steam engine is a bit like a locked-room plot in a detective story. Here is a dead body in a locked room: How did the murderer get in and out, and what did he use as a weapon? … We cannot exclude the possibility that Newcomen went to London and met Papin in 1687 … But we do not need to imagine such a meeting. With a copy of the Continuation in his hands, Newcomen would have known almost everything that Papin knew about how to harness atmospheric pressure to build an engine. … From this unintended encounter, I believe, the steam engine was born.

He concludes:

Historians have long debated the extent to which science contributed to the Industrial Revolution. The answer is: far more than they have been prepared to acknowledge. Papin had worked with two of the greatest scientists of the day, Huygens and Boyle. He was a Fellow of the Royal Society and a professor of mathematics. … Newcomen picked up … where Papin began. In doing so he inherited some of the most advanced theories and some of the most sophisticated technology produced in the seventeenth century. … First came the science, then came the technology.

A cycle of Cathay

The innovations which make their appearance in East Asia round about the year 1000 … form such a coherent and extensive whole that we have to yield to the evidence: at this period, the Chinese world experienced a real transformation. … The analogies [with the European Renaissance] are numerous – the return to the classical tradition, the diffusion of knowledge, the upsurge of science and technology (printing, explosives, advance in seafaring techniques, the clock with escapement …), a new philosophy, and a new view of the world. … There is not a single sector of political, social or economic life in the eleventh to thirteenth centuries which does not show evidence of radical changes in comparison with earlier ages. It is not simply a matter of a change of scale (increase in population, general expansion of production, development of internal and external trade) but of a change of character. Political habits, society, the relations between town and country, and economic patterns are quite different from what they had been. … A new world had been born.

Jacques Gernet. A History of Chinese Civilization, pp. 298-300

Scholars contemplating the sweeping economic, social, and political transformation of China under the Song dynasty (960-1279) seem compelled to draw analogies with later dramatic occurrences in Europe – with the Renaissance (as in the quote above) or with the Economic Revolution in England on the eve of the Industrial Revolution.

The changes are dramatic. Population roughly doubles, from about 50 million to about 100 million. Cities grow. Both internal and external trade boom. The division of labor advances, with different households and different parts of the country specializing in “goods such as rice, wheat, lighting oil, candles, dyes, oranges, litchi nuts, vegetables, sugar and sugarcane, lumber, cattle, fish, sheep, paper, lacquer, textiles and iron.” In a number of fields of technology – iron production, shipbuilding – China reaches heights which the West will not attain for many centuries.

With changes in the economy come changes in the relation between society and state. Taxes come to be mostly collected in cash rather than kind, Eventually revenues from taxes on commerce, including excise taxes and state monopolies, will greatly exceed those from land tax. A Council of State will put constitutional checks on the power of the emperor.

Yet Imperial China will ultimately follow a different, less dramatic developmental pathway than Europe. Some reasons why:

The nomad brake. By 1000, Western Europe has largely tamed its barbarians, folding them into a settled, stratified, Christian society. But the civilized folk bordering the Eurasian steppe, in Eastern Europe and continental Asia, are in for a rougher ride. During the whole Song period, China faces a threat from nomads to the north. In the Northern Song period (960-1126), the Khitan empire, founded by steppe nomads, occupies Mongolia, Manchuria, and part of northern China. In the Southern Song period (1127-1279), the Song lose all of northern China to a new barbarian dynasty, the Jin. Finally, the Song dynasty ends when all of China is conquered by the Mongols under Genghis Khan and his heirs, with the loss of about a third of the population. For all the wealth and sophistication of the Song, the succeeding native Chinese dynasty, the Ming, does not regard them as a model to be emulated.

Rice economics. Rice is the main food crop in southern China, the most populous and developed part of the country. Here’s a basic fact about rice versus wheat production (hat-tip pseudoerasmus): diminishing marginal returns to labor are less pronounced with rice than wheat. In other words, with rice, you can produce a lot more if you’re willing to put in a lot more work. With wheat, you more quickly reach a point where additional labor yields little additional production. This simple fact has far-reaching implications. Imagine an economy with two sectors, agriculture and manufacturing. And imagine that population expands up to a Malthusian limit. Under these assumptions, and given standard economic reasoning, it makes a big difference whether the principal crop is rice or wheat. With rice (diminishing marginal returns less pronounced), equilibrium population density is greater, output per capita is less, and more of the labor force is in agriculture, less in manufacturing.

So an economic model incorporating information about labor productivity of rice and wheat seems to account for some basic differences between China and the West. But rice cultivation may have more subtle implications.

Rice psychology. An older generation of humanist scholars was willing to generalize about Chinese thinking.

It is quite clear to all those who have been in contact with this world that it is quite different from the one in which we ourselves have been moulded. … China does not know the transcendent truths, the idea of good in itself, the notion of property in the strict sense of the term. She does not like the exclusion of opposition, the idea of the absolute, the positive distinction of mind and matter; she prefers the notions of complementarity, or circulation, influx, action at a distance, of a model, and the idea of order as an organic totality. … Chinese thought does not proceed from an analysis of language. It is based on the handling of signs with opposing and complementary values.

Gernet p. 29

Within the social sciences, sweeping pronouncements like this are suspect. To hard-headed materialists and quants they look hopelessly impressionistic and unscientific. To post-colonialist critical theorists, they reek of old-fashioned, condescending Orientalism. But there is now a substantial body of research demonstrating real differences in cognitive style across cultures, and between the West and China (and other East Asian societies), in line with the quotation above.

Of note here: there is also regional variation within China. Rice paddy farming requires high levels of cooperation, including joint work keeping up irrigation systems, and reciprocal labor exchanges. And research shows that there are differences in psychology as well between wheat and rice growing regions in China. Chinese from rice growing regions are more inclined to holistic, context dependent thinking. Chinese from wheat growing regions have a more independent, individualizing cognitive style. In other words, the expansion of rice cultivation in China may have reinforced some of its characteristic cognitive inclinations.

In conclusion: the history of the Song period poses in particularly clear form the “Needham puzzle” of why the Industrial Revolution did not originate in China. The answer, it seems, is complicated, combining (at least) political and social responses to external threat, the nature of agricultural economies, and more intangible (but still measurable) differences in cognitive style.

Weaving history

832-676 BCE

The association of particular plaid patterns (tartans) with particular Scottish highland clans is a phenomenon of the last several centuries. But the Celt-plaid connection goes back a lot farther than that.

plaid

This picture shows a scrap of fabric associated with the Iron Age Hallstatt culture of central Europe. The culture lasted from 800-500 BCE, and is ancestral to later historic Celtic cultures. In fact, traditions of plaid weaving seem to go back a lot further. We find similar plaids being woven at roughly the same time, but thousands of miles away, in what is now Xinjiang province in western China. Linguistic evidence (from later writing) and genetic evidence (from mummies) suggest that some of the inhabitants of Xinjiang at this point were speakers of Tocharian languages, a branch of Indo-European, deriving from the western steppes. (Both Tocharian and Celtic probably branched off the Indo-European tree long before Indo-European-speaking chariot riders rode south to Iran and India.) We know that Proto-Indo-European had words for weaving. The Celtic and Tocharian plaids are similar enough (according to those who know such things) that it seems likely that IE speakers were also weaving plaids from early on.

The Mediterranean developed its own culture of weaving. In Mycenaean Greece, slave women worked under factory-like conditions to produce cloth for ordinary wear, some of it exported. Aristocratic women too were weavers. They might work with spindles of bronze, silver, or gold, weaving story cloths – tapestries that illustrated family histories. The shroud that Penelope wove by day and unwove by night was presumably one such.

Mycenaeans used writing for bureaucratic record keeping, not story-telling. Remembering the past was the business of female weavers and male bards. When literacy disappeared during the Greek Dark Age, historic memory, such as it was, was kept going by weavers, and by bards – often called weavers of words.