Some pirate science on International Talk Like a Pirate Day

Monday, September 19, 2016, 11:04 AM - Happy International Talk Like a Pirate Day, everyone!

As they sailed the seven seas in search of that one big score, pirates had a hard life, but one that actually involved quite a bit of science. It helped them navigate. It healed their wounds and kept them healthy. It even kept them safe from the effects of hurricanes and other bad weather. Here's just a small sampling of 'piratey' science!

Red sky at night, sailors delight...

... Red sky in morning, sailors take warning.

This may be an old folk lore saying, but it has some real meteorological science behind it.

As a pirate standing on the deck of a ship watches the Sun on the horizon, they're looking through maximum amount of Earth's atmosphere between them and the Sun, thus the sunlight is scattered the most by the time it reaches them. In clean air, there is still mainly a blue sky, as blue light is scattered preferentially by the molecules in the atmosphere. However, if you add dust, smoke, pollen and other particles into that air, these particles scatter the light even more. By the time the sunlight reaches the pirate, it will have scattered through all the colours from blue to red.

The air masses that typically have the most particles in them are the stable ones you get with high pressure systems. These are also well known as fair-weather patterns, and thus pleasant sailing for the pirate's ship. Low pressure systems (which typically have 'cleaner' air) are known for more unsettled weather, from just a batch of rain all the way up to a hurricane. It doesn't always work out this way, but typically, low and high pressure systems follow after each other, moving west to east (at least in the northern hemisphere).

So, if a pirate sees a red sky when the sun is setting, they're seeing more light scattered off particles in the air to the west. Thus there's very likely a high pressure system off in that direction, which should bring pleasant weather to where they're sailing. If they see that red sky as the sun is rising, though, the high pressure system is off to the east, and that could mean unpleasant weather is on way.

The eye patch, the peg-leg and the hook hand.

Piracy was a dangerous lifestyle, and loss of an eye or a limb was common enough that it seems no pirate costume these days would be complete without an eye patch, and some even include the wooden leg or the hook hand.

While one can survive losing an eye, and even get by in life well enough, we humans depend on having two to get around and interact with the world around us. The binocular vision we have, where both eyes have overlapping fields of view, gives the ability to tell how far away things are from us. With only one eye, you could reach out for your hat or your sword belt and miss because your brain was off by a few centimetres in it's estimate of the distance.

Loss of a hand or a leg in a sword fight involved some of the earliest use of prosthetic limbs. The ship's surgeon had to be skilled enough to save the pirate's life, which involves quite a bit of science on its own, but once the job was done, the hook and the peg - being common implements on a ship - were a natural go-to when looking for a replacement. 

It's easy to see how losing a hand would cause a person trouble, even a hardened pirate, especially if it was your dominant one. Learning to use the other hand just as well takes time, but it can be done. Losing a leg and having it be replaced by a simple peg would have a big effect on your balance, though. When we walk, it's not just a matter of our foot landing straight down on the ground and then pushing off. The entire foot, from heel to toes, is involved in keeping our balance as we move from step to step.

Scurvy knaves

It wasn't just injury that pirates had to worry about. When you're out at sea for weeks at a time, eating preserved foods, like salted meat, and drinking beer, rum or just water, it's going to result in some serious vitamin deficiencies if you're not getting any fresh fruits and vegetables. Lack of vitamin C was one of the biggest problems, as it caused a condition called scurvy.

A pirate that develops this malady probably just feels a little 'run-down' to start, but in time their gums start to bleed, their teeth can feel loose, and they develop horrible breath. They bruise easily, the wounds from their latest fight are slow to heal and they'll complain of aches and pains. They'll get weaker, sores will develop on their skin, and they can get bloated and puffy. Eventually, they'll come down with the fever, and without help they can quickly die. 

The reason for this is that without vitamin C - also called ascorbic acid - the body can't make or maintain the collagen that's goes into forming skin, tendons, ligaments, bones and other tissues like the walls of blood vessels. The vitamin C a pirate does get from their food gets stored up in the body, but if they have to go without for a long period of time, once they've whittled through that store, their body can't make any more collagen. So, as the collagen in their tissues continues to break down, just as a consequence of everyday life, the results are all the horrible symptoms of scurvy.

The discovery that lemon juice could keep sailors from suffering this debilitating illness was a big boon to the pirating trade, as long as you could keep your crew supplied with enough fruit to last the journey.

Walking the plank!

Supposedly a favourite way of getting rid of unwanted prisoners, mutineers, or the captain (should such a mutiny actually succeed), was getting them to walk the plank. This involved extending a wooden plank out off the side of the ship's deck, and forcing the victim out onto it so that they would eventually fall into the water and be left to drown. The purpose of it, supposedly, was pure psychological torture, as it served no real practical purpose, and would actually be rather difficult to pull off. The reason for this? Science!

Extended out from the side of a ship, a plank would essentially be a lever, with the edge of the ship's deck acting as the fulcrum point. Since the plank wouldn't be a permanent fixture on the deck, sailors would need to stand on it or hold it down so that the victim could walk out and still be supported. However, with the fulcrum so close to the pirates end of the lever, it would take several of them to hold it down.

For example, take a 3-metre long plank and extend 2.5 metres of it beyond the deck. Put a 90 kilogram man out onto the end of it, and just by the laws of physics, it would take 450 kilograms (at least 5 pirates the same size as him!) to hold him out there for any length of time - even more if he decided to jump around a bit. A lever definitely gives the advantage to the person who's farthest from the fulcrum (although, while jumping around might upset the pirates, it would just result in you going into the water faster).

All in all, it seems like an awful lot of effort just for a little entertainment. It's no wonder that - contrary to modern depictions - this was actually an extremely rare form of punishment at the time.

X marks the spot!

Stealing gold and precious gems from merchant caravels and treasure vessels not only took careful navigation to find the shipping routes and lanes, but you also needed to be able to find your way back to that hidden cove, or tiny island beach, in order to dig up your buried treasure once you were certain you'd gotten away with the crime. On a vast ocean that can look nearly the same from horizon to horizon for days on end, how do you find your way around with that kind of precision?

It would take more than just a map and a compass. Pirates (and other, more law-abiding seafarers) used astronomy!

During the day, it would be a simple matter to use a sextant (or the much simpler mariner's astrolabe) to note the angle of the sun in the sky and use that to find their latitude. At night, the stars would offer even more exact navigation, as the pirates could note the positions of specific stars in the sky, and their angle from the horizon and even from the moon ('lunar distance').

As long as they kept track of how the position of the stars changed based on the time of the year, they could easily plot their position when they buried their ill-gotten gain and very precisely find their way back at a later date.