Cleopatra's calendar

Cleopatra VII of Egypt is a historical celebrity for a number of reasons, chiefly her fruitful political and romantic entanglement with Julius Caesar, her doomed political and romantic entaglement with Mark Antony, her subsequent suicide by asp and her status as Egypt's last Pharaoh.*

More recently, she's received more recognition as a wily and ruthless player in the Ptolemys' deadly game of thrones, a political figure in her own right, rather than the caracatured exotic über-seductress of powerful men.

All of this stuff's historically interesting, but I'd say that her most lasting legacy isn't necessarily a dramatic life filled with passion and power politics and its retelling down the ages, but something even more ubiquitous; the calendar which most of the world uses today.

So here's the argument. Most of the world today uses the Gregorian solar calendar. The Gregorian calendar was  introduced in 1582 by Pope Gregory XIII, as a slightly more accurate upgrade to the earlier Julian calendar.

The Julian calendar is, of course, named after Julius Caesar, who introduced it to Rome in 45 BC, replacing the earlier Roman calendar. 

Unlike the transition from Julian to Gregorian, which was a refinement of the same basic calendrical system, the Julian reform was fundamental, substituting a new, solar calendar for the old Roman lunisolar calendar which, by this stage, had some serious issues:

 Around 715BC the twelve month [Roman] calendar was introduced, based on the phases of the Moon. It takes on average 29.5 days between one new moon and the next and so a twelve-month lunar year lasts 354 days but an extra day was added because even numbers were unlucky. The twelve months had between 28 and 31 days in each to make the year last 355 days. February was the shortest month with 28 days and every other year a whole extra month - called Mercedonius which alternated between 22 days and 23 days - was inserted after the 23rd day of February to try to keep the calendar in line with the solar year of approximately 365 days. At the end of Mercedonius the remaining five days of February were taken, so Mercedonius was followed by the 24th of February. But the arithmetic did not quite work - the system gives an average duration for the year of 366.25 days - and the calendar slowly drifted away from the seasons once more. Inserting an extra period to correct the calendar is called an intercalation.

The situation was made worse because the calendar was not a publicly available document. It was guarded by the priests whose job it was to make it work and determine the dates of religious holidays, festivals, and the days when business could and could not be conducted. Through both carelessness and abuse, the intercalations were not made even according to the flawed rules that had been laid down. By the time Gaius Julius Caesar took power in the mid 40s BC the calendar was in a mess and he decided to make a major reform. 

So where does Cleopatra fit in?

Well, back in 48 BC, Caesar, having routed Pompey the Great in battle, had pursued his hard-pressed rival to Egypt. Ptolemy XIII, in a misguided attempt to curry favour with the victorious Caesar, had Pompey assassinated, a gesture which backfired, leading an enraged Caesar to side with Ptolemy's co-ruler and sister, Cleopatra, depose Ptolemy and place his new ally (and lover) on the throne of Egypt.

In 47 BC, Cleopatra bore a son, Caesar probably being the father, while Caesar went off to do more civil war stuff. 

But this wasn't the end of their relationship. In 46 BC, Cleopatra and her little brother (and co-ruler in name only),  Ptolemy XIV, came to Rome and stayed at Caesar's villa. A few things came out of this visit, including Cleopatra entertaining Rome's great and good, Caesar declaring the Egyptian queen a "friend and ally of the Roman people" and a golden statue of Cleopatra being put up in the newly-built Temple of Venus Genetrix.

There was one, more consequential, result of Cleopatra's stay in Rome, according to Pliny the Elder, who identifies the Greco-Egyptian astronomer, Sosigenes of Alexandria, who was presumably part of Cleopatra's retinue, as the guy who actually devised the Julian calendar, proposed by Caesar in 46 BC and introduced in 45 BC. In this context, the radical move from a lunisolar to a solar calendar makes sense, as the Egyptians already used a solar calendar.

So, yeah, you could argue that without Cleopatra, Rome wouldn't have adopted the Julian solar calendar, the direct ancestor of most widely used calendar used in the world today.**

In a world without Cleopatra, the superpower of the ancient world might have refined its calendar along existing lunisolar lines and the modern world's dominant calendar might have had a lot more in common with, for example, the Hebrew calendar.

There are, of course, counter-arguments:

1. We only "know" that Sosigenes devised the calendar from one very short passage (Pliny's Natural History Book 18, 210-212) so it's not certain that Sosigenes really was the calendar guy. Aristarchus of Samos has also been credited as coming up with the Julian calendar, although there's even less direct evidence for this version.

2. If Pliny was right, and it was Sosigenes, then it would be more accurate to call it Sosigenes' calendar, not Cleopatra's, which would give my post title way less name recognition.

3. Name-checking Cleopatra might also make this a version of the questionable "great man" version of history (in this case "great woman", obviously). In a counterfactual world where Cleopatra, or Julius Caesar, or both of them, had never been born, it's likely that Rome would still have dominated Ptolemaic Egypt as a client state before absorbing it completely, so Greco-Egyptian scholarship and the eventual adoption of a calendar based on the Egyptian calendar might have been on the cards anyway.

But it's still at least plausible to think that the world's most widespread calendar might not be preeminent had chance not led to Julius Caesar meeting Cleopatra. And it's about as good an illustration of the Cleopatra's nose theory of history as I can think of.

*Roman pharaohs don't count.

**Not something I'd thought about until I came across a reference to the Egyptian influence on the Julian calendar in this video.

Paleoart: the next generation

The past is a foreign country; they do things differently there. The deep past is so weird and wonderful it's practically another planet. I've enjoyed the sheer otherness of artists' attempts to recreate scenes from deep time since I was a kid. Here's an illustration of "early forms of life" from the pages of the Odhams Encyclopaedia for Children I was given for my 6th birthday. The artist was one John Rignall:

It's the sort of busy scene, packed with weird and wonderful detail which might appeal to a child, and it did. Looked at from a half century later it shows how far and fast reconstructions of the Mesozoic world have changed. From the kangaroo-posed therapod to the offended-looking tail-dragging sauropod to the absence of feathery dinos that aren't Archaeopteryx, the ancient creatures all have a retro look.

OK, it's an impressionistic overview for kids, including an assemblage of plants and animals most of which lived many millions of years apart from one another. But even the more "realistic" dino books I had as a kid featured reconstructions like this one by Zdenek Burian, of semi-aquatic Brachiosauruses adopting a watery lifestyle to take the enormous weight off their feet:

Some people are, apparently, a bit fed up that the dinosaurs they thought they knew as kids have been superseded by new best guesses at what these creatures looked like in life. Personally, I find a lot of the new paleoart keeps the sense of wonder I had as a child new and fresh.

For a taste of what I mean, I can warmly recommend a visit to Dr Mark Witton's wonderful paleoart-themed blog. It's full to the brim with strange, beautiful and astonishing visions of past life by Mark and many others. From my personal favourite for their sheer weirdness, the giant azhdarchid pterosaurs, to bizarre big-headed predators from the Triassic, or Diplodocus, there are wonders on every page. And also discussions of why (scientists think) these critters look the way they're illustrated. 

 There is, for example, an interesting post on lips versus exposed teeth in illustrations of extinct carnivores. That post seemed, at least to this non-expert, to make a pretty solid case for assuming lips in all but a very few cases. Interestingly, John Rignall's therapod dinosaur from my childhood encyclopaedia, although its teeth are showing slightly, looks as if it has lips. At the very least, Rignall has made it ambiguous and not as boldly and ostentatiously toothy as many lipless carnivorous dinosaur illustrations of the time:

Also interesting that, from all the big, fierce , famous, carnivorous dinosaurs he could have chosen, (T Rex, Allosaurus, Megalodon), Rignall chose the obscure Antrodemus, a contested name for what most paleontologists would call bits of an Allosaurus. Although Rignall might be up there with modern paleoart with what seems to be lips on his Antrodemus/Allosaurus, the kangeroo posture and palms-down hands is definitely retro dino - compare and contrast with this modern reconstruction of the posture of Allosaurus jimmadseni:

Image credit: Scott Hartman (Creative Commons Attribution)

The other great thing about Mark is that, although there's lots of solid science in there, he doesn't take himself too seriously and he's generous with the playful pop culture references; see What Daleks, xenomorphs and slasher movies tell us about palaeoart and here, on his Twitter feed, Mark imagines what a gorilla the size of King Kong might actually look like, (given the biomechanics of very large animals, not much like a gorilla):

"It was skeletal and circulatory weakness killed the beast. We've come up with a patch for these issues with the release of Kong 2.0."

This is fantastic (in both senses of the word), but it's worth remembering that scientist's current understading of the constraints on the size and shape of animals is built on some old and well-established principles. As Stephen Jay Gould once noted:

Galileo first recognized this principle in his "Discorsi" of 1638, the masterpiece he wrote while under house arrest by the Inquisition. He argued that the bone of a large animal must thicken disproportionately to provide the same relative strength as the slender bone of a small creature.

For more speculation on the biology of oversized apes (in this case of the human variety), this video on the biology of giants by YouTuber Trey the Explainer also has some fun with the topic of biological scale:

I'm liking this stuff very much. Almost as much as this awesome poster for the, sadly unmade, Hammer movie Zeppelins v Pterodactyls. Yes, I know I've shared this image before but honestly, just look at this thing. As Dr Johnson almost said, when a man is tired of pterodactyl-on-Zeppelin action, he is tired of life.

Props to the bros

Relative to the average YouTube vid, the one embedded below is a bit long (50 mins+), and it's quite a deep dive, but it's also worth your time for the way it unpacks an interesting tale of historical and technological contingency.

tl;dr*: the Wright brothers were the first to fly a heavier-than-air craft** and did so using an engine which was, by subsequent standards, pretty feeble (12-16hp). One innovation which helped them to translate this miserly amount of power into powered flight was figuring out how to build an efficient propeller.

On the other side of the Atlantic, aviation pioneers in France were struggling with stumpy, inefficient paddles for propellers, but building ever more powerful, efficient engines in an attempt to overcome this limitation and get their creations off the ground.

Then, in 1908, Wilbur Wright rocked up in France to demonstrate one of his aircraft. French customs unpacked the machine for some sort of check and managed to damage it in the process. Wright had to get his aircraft repaired and rebuilt with the help of locals, some of whom had been working with French aviation pioneers. This was the moment when the secret of the Wright's propeller technology stopped being a secret.

The fortuitous combination of Wright propellers and powerful French engines quickly became one of the main drivers of the aviation firsts of pioneers like Louis Blériot and Henri Farman, the early French dominance of the aviation industry and the swift evolution of the aeroplane from astonishing novelty to a useful device with practical applications.

It's an interesting tale, far more so than the abbreviated list of "firsts" in less detailed accounts and I like the way it both does justice to the Wrights' genius and the contribution of French engine makers who, in struggling to overcome the limitations of primitive propeller design turned a disadvantage into industry dominance.

*I guess the video equivalent should be tl;dw.

**Not Alberto Santos-Dumont - the video examines the claims that Santos-Dumont was the first to achieve powered flight and demolishes them pretty convincingly. What I particularly like about this video is that it treats Santos-Dumont's actual achievements with seriousness and respect, rather than dismissing him completely for not having achieved this world-changing first.

Before the Ever Given

The cost of one ship blocking the Suez Canal for a week, plus the resulting backlog is being estimated at some $1bn (£730m), according to Akshita Jain in the Independent.

It could have been worse. A lot worse. 

Imagine an event which blocked the canal for eight solid years. 

I shouldn't have to imagine, because this is an actual thing which happened in my lifetime. Until the canal came back in the news, I'd wholly forgotten that a second Suez crisis affected maritime traffic for far longer than the 1956 debacle. The canal was closed due to the Six Day war in 1967 and wouldn't re-open again until June 1975, after Israeli forces had withdrawn from the Sinai Peninsula and the Egyptians had cleared the canal of sunken ships and mines. 

Here's a nice summary of the long blockage, including the story of the ships which were navigating the canal when the Six Day War broke out and were trapped for eight years:

It's a historical event which gets comparatively little attention, which is a pity, because as a natural experiment into the effect of introducing trade barriers into places where trade previously flowed freely, this feels pretty damn relevant right now, especially here in Global Britain™.

Breaking news: Bus blocks major trading route! pic.twitter.com/K6xWDYSYIN

— MrProgressiveAlliance 🇬🇧🇫🇷🇩🇪🇪🇺🌍 (@MrYesWeCan) April 1, 2021

While we're on the subject of historical blunders by wannabe global powers that turned out to no longer be quite as awesome as they thought, there's one other Suez-related tale that's worth re-telling. Namely, one of history's most bizarre tragicomedies, the hellish 18,000-mile (29,000 km) journey that Russia's Second Pacific Squadron took from the Baltic to the Tsushima Strait off Japan and one of the most consequential naval defeats in Twentieth Century history. The Russians could have had a much shorter voyage had they not upset the entity which really was "Global Britain" back in 1905 and which closed the Suez Canal to the hapless Russians. 

Here's a very good telling of the whole globe-spanning organisational and logistical nightmare:

And, for the sale of completeness, the final catastrophe that ended the epic voyage:

One of the participants in this naval omnishambles survives to this day as a floating museum in St Petersburg; the protected cruiser Aurora, which, more than a decade after taking part in the Battle of Tsushima, fired the shot which signalled the attack on the Winter Palace and the start of the Russian Revolution.