Friday, February 14, 2014

What is keeping me so busy

I mentioned in the past that I work with termites.  If any are interested, this is the group I work with.  My current Job is to go to India and Namibia and do the field research for this project that is currently in the news:

http://www.cnn.com/2014/02/13/tech/innovation/termite-robots-aaas/

Wednesday, October 16, 2013

The Storm of Spears and Press of Shields

In the special battle of Marathon anniversary issue of Ancient Warfare magazine I published an article title The Storm of Spears and Press of Shields, wherein I presented a distillation of all of my views on hoplite combat.  I will post some of that article here in the next few posts and supplement it with other information.


"Over the last half century, a schism developed over hoplite combat that has devolved into a bellum sacrum, with an orthodoxy assailed by an increasingly popular heresy.  The orthodox position, championed by Hanson, Luginbill, and Schwartz, portrays hoplites as lumbering masses of men that charged directly into each other and contested the battlefield by attempting to physically push their foes.  Van Wees, Krentz, and Goldsworthy, describe hoplites as closer to skirmishers, fighting in an opened order, and often paired with missile troops.  Any “push” was either a figurative description or uncoordinated shield-bashing.  I believe they are both in some measure correct, and often equally wrong, because this debate has forced historians to stray far from their fields of study.  Their arguments suffer from an insufficient understanding of the physics and mechanics of large masses or crowds.  Group behavior is my field, and, with the context that I can provide for their arguments, I shall make an attempt at syncretism."
That is how the article opened, and I think both sides in the debate will find explanations for things they hold true and the other side denies.  I hope in the end, after reading this, you will see that there really is not such a divide between the opinions of both camps once we cast off what is not physically likely.

Wednesday, March 6, 2013

A discussion of hoplites on youtube- my 15 minutes of fame, stretched to 27

Yes, I have been away for a long time.  Luckily I have good reason.  I had to focus on the six-legged Myrmidons so as to finish my Ph. D. this May.  In July I will be starting a post-Doc working on Macrotermes termites that build huge air conditioned mounds wherein they practice agriculture by rearing fungus in what seems eerily like a Biodome. My job will be to analyze the manner in which the termites build their mounds and help a group of robotisists and physicists model the system and teach robots how to build for us.  The eventual goal is to have robots that we can send to places we cannot easily get to, like mars, go there and construct habitats for us that will be ready-made when we arrive.

I have not been completely away from hoplites.  I am featured on a YouTube channel:

http://www.youtube.com/watch?v=edoGJw8Xg0Q


Thursday, February 23, 2012

What exactly is my field of expertise?

Every now and then I get a comment that I feel would be better answered as a post so that any others with a similar question can easily find the answer.  Recently I was asked the following in response to my last post:

"What exactly is your field of expertise?"

I am an entomologist. One might wonder what bugs have in common with hoplites, but I work in a field called Self-Organization. We study how large groups of individuals (ants, termites, and people) come together and produce specific outcomes without the need for specific top-down planning. In social insects, this includes things like building huge nests and digging extensive tunnel galleries (my specialty), but in humans this encompasses the behavior of large crowds and the self-organization of traffic patterns.
It is the confluence of a chance of birth, my great-grandfather was actually from Sparta, and the fact that in war, and especially in a mass formation like a phalanx that we see humans acting in the most self-organized way that brought me to this.

You might say "war? self-organized? but what of all those officers?" I would counter with the fact that no officer in the history of warfare ever ordered his men to rout and run for their lives, and yet they do so in a highly coordinated manner. This same under-layer of self-organization exists during an advance and in group fighters like hoplites, during battle.

Over the last decade I have been studying hoplite battle. Initially I simply bought the prevailing notions of V.D. Hanson and those on his side of the squabble over hoplite combat, seeing challenges such as those by Van Wees as unfounded. But somewhere along the way I realized that the mechanics they propose for hoplites pushing each other are simplistic. They are based on an extrapolation of what would work best for two individuals colliding and do not produce the maximum force when men push in ranks. From that realization spawned all of the information on my blog. I have attempted to show the most efficient manner of pushing in mass- if hoplites pushed during battle. I write that disclaimer because some level of pushing is my base assumption, and in earlier posts I have shown the features of the aspis that support this notion. If they never pushed in files, then all of this is irrelevant.

The end product of my research is that I can reconcile the two divergent views on hoplite combat. Hanson was not wrong in principle, just unclear on the mechanics. I don’t fault him for it, that knowledge was beyond his expertise, but his presentation was vulnerable to those who wrote against pushing because I believe many intuitively knew something did not work, and some evidence, like spear fighting before pushing, could not be accounted for sufficiently. But for the fact that the “heretics” did not believe in a push by files, they had many features correct. In a sense it is like the heretics had much of the early phase of battle correct, while the orthodoxy understood the end of battle- or at least of many battles.

Obviously there are not all that many of us interested in hoplites, but I would love to see more people with divergent training put that knowledge to use in the study of hoplites.

By the way, Self-Organization has caught the interest of modern armies. Google it and you’ll find many resources. If you do a Google scholar search on me (Bardunias), you’ll see what I normally publish about insects and how they work in groups.

Wednesday, July 27, 2011

Reconciling the Storm of Spears with the Press of Shields

I've just written a long article on the mechanics of hoplite battle for the Marathon Special issue of Ancient Warfare magazine (http://www.ancient-warfare.com/cms/ancient-warfare/guidelines/editorial-plan-2.html).  I will be in good company, because the editors have secured articles by some of the top thinkers on ancient Greek warfare, like Krentz and Sekunda. 

My article, which I think will have the final title, "The mechanics of hoplite combat: reconciling storm of spears with press of shields", is a bit over 6,000 words and crammed with many of the concepts I discuss on this blog.  The goal of the article is to reconcile the increasingly divergent views of the "orthodox" and "heretical" views of hoplite combat.  If you've been reading, then you know that I believe most of the differences evaporate once we understand the mechanics of masses of men in motion.  The heretics in general don't understand how men could survive a physical push by all ranks, while the orthodoxy does not present realistic mechanics for men doing so.  Were it not for the fact that they both veer away from their fields of expertise and into mine, I would have nothing to add to the discussion.  But because they do, often making assertions that they are unqualified to make, I have an opportunity to bring about syncretism.  To paraphrase Dr. Krentz, I have no expectation that my recommendations will be followed, but the argument should reach a larger audience now.

 One thing that I have done in this article is to update the presentation of the crowd-othismos from my 2007 article.  In that earlier article I specifically presented the new form of othismos as a counter to the prevailing orthodoxy.  Because I wrote within the paradigm of the orthodoxy, the earlier article left the impression that battles had to start with a collision.  In this article, I have shown what I have discussed on this blog for some time, that the physical collision of men more likely occurred after a period of spear-fighting.  This is because the density of the crowd is far more important to the transmission of force than the speed of advance.  Hence the storm of spears, then press of shields all formed part of the experience of most hoplite battles.  Often, one side gave way "at spear's length" before othismos, and sometimes I believe there was an initial collision, as during the second phase of Coronea, "a battle like no other", but the threat of both phases of battle was always present.

I haven't posted for a while, but I have been banking up information.  Once the article comes out, there will be a flurry of posts to provide supporting material.  I have many diagrams I did for the article that will find their way into posts.

So, check back over the next month or so because things will heat up.

Tuesday, November 9, 2010

"Reinstating the Hoplite": Adam Schwartz and the failure of the orthodox view of othismos

A few months back, I promised a review of Adam Schwartz's "Reinstating the Hoplite: Arms, Armour and Phalanx Fighting in Archaic and Classical Greece". In this post I am going to specifically address Section 3.4, Othismos. I’ll restate that this book is a remarkable resource. If you own only one book on hoplite combat, own this one. Much of the book is a filtering and restatement of arguments put forth in a series of papers that make up the great “Heresy-v-Orthodoxy” debate, meticulously footnoted. If you have read all of these papers, then much of this book will not seem novel, but it is nice to have all of this in one place and Schwartz’s commentary is often quite insightful.  His description of othismos is a weakness of the book.


This section begins with a description of othismos as “a common effort, ostensibly by a common push…of the entire phalanx…into the enemy in order to drive them back”, following Hanson’s usage. I agree with this definition and we will need to keep it in mind as we go forward, for Schwartz deviates from it in important ways in his presentation. Following the prevailing notion, which you now know to be incorrect if you have been reading my previous posts, he goes on to describe men hoplites in othismos:

The hoplites in the front stemmed their left shoulder against their shield and thrust it against the shields and bodies of the enemy with all their might; and the ranks behind them in turn stemmed their shields against the backs and right side of the man in front in a ¾ stance, as it were.

In this way, a tremendous pressure could be generated and conveyed through the entire phalanx from the rearmost rank, its force increasing on the way.

 Right away, Schwartz has unwittingly presented us in these two sentences with contradictory mechanics. This is the most glaring problem with the current portrayal of othismos, and the focus of my campaign to correct our understanding. You cannot both stand at a “¾ stance” and sustain “tremendous pressure”. A ¾ stance is one in which your body is held at a diagonal behind the shield, which is facing flush to your foes. The arm is bent, with the arm and body forming an acute angle. This is the natural stance for just about all combat sports, from Asian martial arts to renaissance fencing. Hoplites probably stood this way when engaged in spear fencing. I will do a full post on stances and weapons grips used in hoplite combat at a later date, but for now it is important to understand that in this pose, the only thing holding the shield away from the front of your body is the strength of your arm and shoulder. Were I to grab you by the right shoulder with one hand and the shield with the other and try to force your shield to touch your chest, it is easy to see that very little of your musculature resists my pushing.

Now, even the biggest weight lifter cannot resist “tremendous pressure” with the strength of his arm and shoulder alone. Remember that less than 10 men can generate 1,000 lbs of force or more. So if we take the description of men at ¾ and apply anything approaching the force that can be generated by files of hoplites, the end result will be that the hoplites collapse into the bowl of their shields, chest to underside of the shield rim. Once they collapse into the shield in this way, they occupy less space than they did in the ¾ stance. Thus, as the file closes in there is no room to move back into ¾ stance again unless the files spreads out.

This is important because the current orthodoxy posits a stance with the left shoulder inside the bowl of the shield, pushing on the inner shield-face. Many have interpreted Arrian, the Roman tactician, describing this in a section of his Tactica (16.13). Arrian of course was not a hoplite and the passage in question does not exist in earlier sources for his tactia. He did on the other hand live at a time when Romans formed shield-walls, later called a fulcum, wherein men with very different, single gripped, shields may well have pushed standing sideways at far lower pressure than a hoplite with an aspis could survive.

If we toss out the ¾ stance when pushing, then we can also eliminate the notion that the depth of the aspis was to allow the shield to be rested on the shoulder while pushing. I won’t go on here, but look back to my previous posts to learn how hoplites stood with their shields and a further examination of why the “shoulder rest” function was a side benefit and not the purpose for the depth.

At 3.4.2, the book moves on to describe arguments for and against a literal othismos defined as above. This section is a good distillation of the various viewpoints, but in rebutting the opinions against othismos, Schwartz goes awry. He specifically addresses two arguments: 1) the tremendous force generated by deep files of men would cause a squeeze that would be “distressing to contemplate” in Fraser’s words (1942), and 2) the great pressure would impede weapons usage.

Schwartz is failed here by his reliance on Franz (2002). I must be clear that Franz wrote in German, a language I do not read, so I am only commenting on Schwartz’s translated quotations from that work. With that in mind, what is attributed to Franz shows a lack of understanding of how force is generated in groups of pushing men. He is quoted as writing:

The mass pressure was not achieved by the weight of the warriors, but by their muscles…the mass of the hoplites played a relatively minor role. It came into play chiefly when brief, thrusting impulses were transmitted from one warrior to another.

Schwartz focuses on this and tells us that it “corrects a common enough oversight in the othismos debate.” In fact, Franz, via Schwartz, is propagating a misunderstanding of crowd forces while at the same time being represented as an authority on the subject. Mass is the most important factor in transmitting forces through dense crowds. It is through “leaning” and resting your weight on the man in front, more than “pushing with the legs” that force adds cumulatively in crowds. Members of crowds stand for the most part upright and lean into each other with the upper body angled to some degree. The amount of pressure that can be generated in pushing with the legs is restricted by the angle the legs make with the ground- the closer to perpendicular the less pressure you can generate, with an optimal angle at something acute like 45 degrees depending on how well your feet grip the substrate.

This is important because, as we have seen in crowd data that I presented previously, high pressures within crowds can be maintained for long periods of time. It is in fact the duration of pressure even more than the sheer amount that causes asphyxia in crowds. So, contra Schwartz, the pressure in ranks of hoplites would be “impossible to resisist” without an aspis to protect the diaphragm. His mention of armor as protection against asphyxia, even if true (some reenactors of ECW push of pike battles tell me that the breast and back does help) becomes problematic when we consider the rise in the era of deepest ranks of the organic corslet, sometimes called “tube and yoke” or linothorax.

Schwartz further quotes Franz about what occurs in crowds:

When people behind sense that the pushing does not bring about any immediate advantage, they stop pushing. The result is a kind of reverse thrust.
This statement shows a fundamental difference in a “crowd” of pedestrians and a “crowd” of hoplites in othismos. The hoplites want to generate lethal levels of forces, while crowds do so only accidentally. If we start from the definition of othismos presented at the beginning of this post, then the goal of opposing ranks is to produce the maximum pushing force that they can. What he describes is true for pedestrian crowds, and this behavior is also why we don’t see othismos in every other battle-line in history. Once the front of the file gets squeezed to their limit, they push back on their own men, causing the file to open. In hoplites this did not happen until the pressure became enormous because of their ability to withstand being squeezed without suffocating.

An analogy to what happens between men in Franz’s depiction would be you walking down a hall and pushing against a closed door. If the door does not open, you stop pushing, the feedback telling you it is locked. But if you know the door is locked and your goal is to break down the door, then you do not stop pushing even when the same exact feedback tells you it is locked. You push harder in order to bust it opened. This is what hoplites did. Their “crowds” were meant to push against resistance and overcome it.

Schwartz touches upon this in mentioning crowd disasters, but does not connect the crowd of hoplites to the type of crowd that ends in deaths from asphyxia because he cannot describe why hoplites could survive this. My own examination of the aspis’s role in protecting against crushing of the diaphragm can. There is no reason to expect a group of motivated pushing hoplites to be “like any other crowd moving in a particular direction.”  They are intentionally attempting to generate the maximum sustained force against their opponents, and could generate sustainable forces far in excess of those which occur accidentally in crowds of similar size.

A bit further on, he discusses that othismos could not last long. This has been an objection of many: “How can you push for an extended period?” The answer again comes from an understanding of crowds. Pressure can be maintained within crowds at rock concerts for long periods.  Force will vary over time, but not in the quick oscillations Schwartz envisions.  There could be "lulls", the force reducing as men simply unpack to catch their breath, perhaps even pulling completely apart and engaging at spear range again.

At the end of this section, following the prevalent notion of hoplites charging directly into othismos, he brings up the fact that many units charge, even when occupying positions of superior height. He portrays them as abandoning tactical advantage for momentum. I won’t dwell on this, but Polybios specifically describes the problem with not charging downhill during the battle of Sellasia (2.68), and it has nothing to do with momentum for othismos.

The second objection he addresses is that weapons cannot be used in othismos. He quotes Cawkwell’s statement that men would “better be able to use their teeth than their weapons”. I’ve addressed this at length, and I was glad to see that Schwartz also saw the utility of the short sword in the press of othismos. He correctly sees the limitations of the spear in othismos and presents the overhand grip as the exclusive strike for use within the phalanx as well. I’ll delve into that deeper in a future post.

He also does a great job of showing the folly of van Wees’s notion that the aspis cannot be used to push because it was held up at a slant and only the bottom rims would collide. Obviously, the men would simply collapse into their shields as they push and Schwartz points this out. Unfortunately, he did not see that this same logic applies to men standing at ¾ stances as I described above.

He also twists Xenophon (Cyr. 7.1.33) to mean that the aspis was rested on, not against, the shoulder. The clear reading of the passage is that the shield was rested against the shoulder/upper arm, and this can certainly be read as a description of the way I portray hoplites as resting the rim against the front of the shoulder, on the broad shoulder piece of the organic corslet. Note that some depictions show these stiff shoulder pieces extending wider than the shoulder, so if you push with the shield on the shoulder the stiff pad gets jammed into your neck!

Section 3.4.3 is an examination of the morale effects of added ranks, which are in no way incompatible with othismos, but works alongside it. In 3.4.4, he discusses the need to maintain cohesion. Goldsworthy’s notion of depth as a means of maintaining cohesion in the presence of broken terrain is mentioned, but as I have shown previously, there is no record of 25 or 50 rank phalanxes deploying from this depth into a shallower, broader line. Unless these men are meant to stand idle until the front ranks somehow break through, getting more men into the area is not helpful unless they can move to a shallower formation and engage the enemy.

He describes the Argive predilection to run too early into the charge and notes that this tore holes in the formation between them an adjacent units. Interestingly, he goes on to describe Spartans foregoing the charge, but does not seem to realize that this too must result in gaps between them and adjacent units that did have a running charge. The whole line cannot have arrived simultaneously against the enemy line if part walked and part ran. This has been overlooked by everyone to my knowledge.

Following the common model of othismos, he mentions hoplites charging 50 m (later 20-25m) in order to impart “a maximum of penetration power at the collision”. The real cause of the charge has more to do with the “tremendous nervous pressure” he also describes, because it takes only a few yards to achieve the “ramming speed” suggested by the orthodoxy. Any distance in excess of that simply causes fatigue and a loss of cohesion for no gain of momentum. In fact, the whole notion of a charge like an un-horsed medieval knight imparting maximum pressure is a fallacy, as I have previously demonstrated. Dense packing is far more important for a strong and sustainable force even if it occurs at slow speed.

It is in the final section, 3.4.5, that Schwartz’s portrait of othismos falls apart. He again draws on “observations of crowd behavior” to portray othismos as a “phenomenon occurring at intervals”. He applies what I is think a wildly inappropriate reference on Spartan leaders having trouble keeping the rear ranks from pushing forward to initiate the charge to show that rear ranks could push forward when locked in combat. I do believe that they did push forward within the file, but this reference cannot be applied. Cavalry were famous for “chomping at the bit” to rush into the charge as well, but there is not corresponding push when engaged in combat.  Using an innapropriate reference gives ammo to the foes of othismos.

Inexplicably, he abandons the ¾ stance, where men push their shields into the back of those in front, for Luginbill’s “T” shaped, side-on stance where men push into the side and right shoulder of those in front. Then he has the file leaders being propelled into the enemy ranks by the file behind them “killing left and right”. Far more likely is getting “killed from left and right”. More importantly, the overlapping of shields within each succesive rank make any single file pushing through the stacked ranks and out of formation, then into the enemy’s overlapped ranks, unlikely.

He states that: “Such othismos may have occurred in short bursts, and at random intervals, as the rear ranks felt they might help their comrades by applying pressure. And not all 7 ranks need to participate in shoving simultaneously…” This is a radical departure from Hanson's “a common effort, ostensibly by a common push…of the entire phalanx…into the enemy in order to drive them back”. In fact, what he goes on to describe is nothing unique to hoplites. Romans and pretty much any linear formation in ranks surely had disorganized pushing by eager men behind the front ranks. This interpretation makes “othismos” so common in the history of warfare that it hardly warrants a special term in the Greek context. This commonality also goes a long way towards unraveling all of the arguments for the form of the panoply being derived from the need to be effective in the “push”. Any Roman with a scutum could do what Schwartz advocates and frequently did.

Part of the problem is that Schwartz is in a bit over his head. I do not say this disparagingly. I applaud him for attempting to bring in concepts from crowd mechanics even if he ultimately does not sufficiently understand them. A statement that hoplite battles were “essentially chaotic” is ironic, because I agree with him, but my understanding of chaos is clearly far different from his own. The phrase “no one to direct the movements of the enormous organism” is so close to what I believe the truth, but we need to add an understanding of how order emerges from seemingly ‘chaotic’ interactions within groups. The study of how this occurs through what is called self-organization will ultimately yield a clearer understanding of hoplite combat. Groups of men, like flocks of birds or schools of fish, can achieve a great degree of cohesion and coordination through simple interactions between men in a bottom-up fashion, and do not require the top-down direction of generals for much of what occurs in combat. Thus, we do not need “a referee with a whistle” as Holladay (1982) said would be needed to move from one phase to another. Such “phase transitions” can arise simply from the interactions of individual hoplites in the absence of specific orders.

Monday, October 25, 2010

Sword use in Othismos

In an earlier post, I wrote that hoplites in the crowd of othismos could strike with short swords over their shields into the necks of their foes in a truly brutal manner. I happened to find an image that shows what this strike would have looked like and where it would have been delivered. Obviously the artist is not depicting othismos, but the arm position of the hoplite and the insertion point, along side the neck into the chest cavity(but on the left), are similar.