On August 20th, 2017 we learned about

Digital farming tools simulate a full season’s growth in a single day

Humans have been manipulating the evolution of plants for ages, but usually at a pace slow enough we barely notice. By planting seeds from specific plants that had attributes we liked more than others, say a more pleasing color, or larger amount of tasty flesh, we’ve transformed many plants into the produce we know today. However, this is a slow process, and farmers are looking for ways to speed things up while reducing the costs associated with experimenting with a whole season’s crops. The solution may be to first grow crops on a in silico, or “in silicon chips,” before ever putting a seed in the ground.

The simulations that are being developed allow for some very specific details to be tested. For instance, will you get a bigger crop yield if you plant your sugarcane in staggered rows, or all lined up? Should they be angled north-south, or east-west? A farmer could plant four different fields of sugarcane to see which did best, although in doing so they might introduce new variables to the mix. It would also be a slow process, possibly risking income for 12 months of work.

The in silico version took all the available data and came up with a prediction in 24 hours. It considered minutiae down to the amount of light that might be blocked by a neighboring plant’s leaves at different times of the day, then produced a 3D visualization to show the expected outcome of each field arrangement.  In this case, staggered plants planted on a north-south axis was predicted to increase yields by ten percent, making that a much safer test to run in the real world for confirmation.

Farming experiments made even faster

As these tools are developed, researchers hope that the speed and depth of the simulations can be improved. Not everyone can tie up a supercomputer for 24 hours to test out a new technique, and the goal is to eventually simulate a whole season’s growth in a minute, making it easier to try out different variables. The number of variables should also be increased to incorporate more data that different labs have been creating over the past decades, but that requires some serious coordination efforts. Not every research team uses the same tools or data structure to archive their experimental findings, which makes integrating existing information about crops difficult.

Still, the developers are confident that all these challenges can be met, partially because they have to. Concerns over population, soil quality and fresh-water availability suggest that farms will need to be more efficient than ever in the coming years. A tool that lets you configure and simulate new ideas in a single afternoon could save everyone a lot of time and resources.

Source: Growing Virtual Plants Could Help Farmers Boost Their Crops by Leslie Nemo, Scientific American

On August 13th, 2017 we learned about

Automated image analysis set to track birds and bats near wind turbines

The outer tip of a wind turbine can move at 180 miles-per-hour. This is slower than a peregrine falcon when it dives, but much faster than the fastest birds (and bats) and move when flying horizontally. It’s a big concern, as flying animals have a bad habit of flying into moving turbines, leading to as many as 320,000 deaths a year. The speed of the blades isn’t the only worry, as stationary buildings also kill hundreds of millions of birds a year. That said, the novelty and expansion of wind-power has people actively looking for ways to reduce animal fatalities, even in the darkness of night.

To reduce the number of animal deaths from spinning turbines, one strategy is to try to deactivate the blades before animals are nearby. Radar is employed to search for flocks of birds, but that doesn’t help smaller groups or single birds. In extreme cases, protected species like the California condor actually wears tracking equipment to provide early warning to the turbine so that it can be turned off as the bird approaches. That’s not practical for every bird or bat in the sky though, and so research is being done to figure out more widely applicable technologies to get stop the turbine blades when necessary.

Vigilance with video

It turns out that some high-tech bird watching is looking very promising. Cameras with thermal imaging, or “night vision” are being augmented with ThermalTracker software to more accurately detect where animals might be flying. The complete package can then look out for birds and bats 24 hours a day, especially in shoreline areas that are harder for people to survey.  The actual observations are carried out by an algorithm that analyzes the movement of an animal’s wings and flight path to determine what kind of animal it is. Tests have found that this system can detect 81 percent of flying birds and bats, correctly classifying them 82 percent of the time.

Expanding this foundation, there are plans to add further sophistication to this system. Software will be refined so that analysis of the video can happen in real time, allowing recordings to be paused when no animal is in the sky. This should reduce costs, making this kind of tracking more accessible to wind farms everywhere. There are also plans to add second cameras, enabling stereoscopic comparisons of the sky. This enhancement would let the system estimate the animal’s distance more accurately, allowing for better judgments of the creature’s size and species. And thanks to the night-vision thermal imaging, it all works in various lighting conditions.

Searching for better sites

All this collected data can then be used to better inform turbine management, giving people a better picture of what species are active in a specific area. This can be crucial, as poorly-selected wind farm locations are actually thought to be the biggest cause of animal fatalities. Not all patches of the sky are equally trafficked, and so knowing who lives in the neighborhood can make a significant impact on conservation efforts.

Source: Night Vision For Bird- & Bat-Friendly Offshore Wind Power by Frances White, Phys.org

On August 13th, 2017 we learned about

Cow pie biogases now provide fuel for farm’s giant feed truck

The average dairy cow produces around 40,000 pounds of manure a year, most of which doesn’t just disappear into thin air. As a cow pie decomposes, some of that solid waste does become a gas, the most notorious of which is methane. Even though you can’t see all that CH4, it makes a big difference to the world since it traps 23 times more heat in the atmosphere than carbon dioxide. Fortunately, methane doesn’t need to simply waft away, and farms are now using their cow poop to power everything from buildings to the very feed trucks that carry food to cows in the first place.

Prepping poop for generating power

Unfortunately, you can’t just scoop some poop into a gas tank and be on your way. Cow poop is made of a variety of materials which need to be separated so they can be used more efficiently, not totally unlike the refinement processes for crude oil. To make the most of their manure, farms have to invest in a huge container called a digester. The digester helps maintain an optimal temperature for poop to break down, and conveniently contains the unpleasant “barnyard aromas” at the same time. The products of digestion are fibrous materials that can be used as cow bedding or other products, potent liquid fertilizer, and assorted “biogases,” including methane.

Methane burns easily, which is why it’s the primary component of natural gas. Burned in combustion generator, plenty of electricity can be harvested to power farms, trucks, and even surrounding communities. Again, the methane doesn’t simply vanish into thin air though, and burning methane does create carbon dioxide as one of it’s by-products. Still, since carbon dioxide isn’t as potent a greenhouse gas as methane, most people consider this a win. It doesn’t hurt if farms can be more self-sustaining either.

Dung-fueled driving

The amount of power than can be generated from reused cow poop is significant enough that many farms are looking to expand their capacity. Farmers that have made the investment to set up one digester are often interested in setting up a second. The Straus Family Creamery in California took a different approach, and invested in a lengthy retrofitting project with their International Harvester feed truck. After eight years of work, they converted the diesel truck into a zero-emissions electric vehicle so that it could be powered by their poop-fueled generator. Apparently the creamery feels their cows’ poop can provide even more, and they plan to power a delivery truck with methane-produced electricity in the near future.

Source: Poop-Powered Electric Feed Truck Debuts at Northern California Creamery by Tiffany Camhi, The California Report

On August 9th, 2017 we learned about

Racing league looks to push the speed limits of autonomous automobiles

Roborace is coming, but not to your kids’ cartoon lineup. If development continues as planned, the nascent racing league aims will be pitting ten teams against each other to see who can design and refine the best non-human driver. This is because “Robo” isn’t in the name just to attract ten-year-olds, but because the focus of the sport is to push and publicize the upper limits of autonomous cars. While the car designs may look like something that would make Speed Racer reconsider the Mach 5, the larger goal is to show the general public that autonomous cars can safely handle a lot, even our relatively dull trips to the grocery store.

Motors, sensors, but no seats

Currently, Roborace still consists of only four prototype vehicles, all lazily dubbed the “Robocar.” Robocar is powered by four 300-kilowatt motors, and can reach speeds close to 200 miles per hour. It’s unusual silhouette is partially thanks to Daniel Simon, who has helped design vehicles for science fiction movies, but also thanks to not needing a proper cockpit. The only driver on board is made of silicone, and so the usual safety equipment to keep a human alive and functional have been dropped to save space, weight and drag.

That’s not to say that this is just motorized wheels. To make up for the lack of a human’s eyes, ears, touch and cognitive abilities,  the Robocar is loaded with sensors. These include two radars, 18 ultrasonic sensors, two optical speed sensors, six visual cameras, GPS, and five LiDAR sensors, which are a bit like radar, but with lasers instead of radio-waves. The cumulative data is crunched by an onboard computer handling 24 trillion operations per second. Of course, all this hardware is for naught if the car isn’t making the right operations per second, and that’s where Roborace organizers see the real competition heating up.

Cranking up the coding

Right now, Roborace organizers are planning on sharing the Robocar physical design with every team that participates. That’s because they see the real innovation not coming from better sensors, but from the software that uses those sensors. In that sense, the races will be testing each team’s programming, removing physical differences as variables in the races. This puts the focus on making better algorithms that can handle the complexity of measuring ever-changing spacial relationships and making preemptive course corrections in tiny time increments. Ideally, some of those improvements can then be passed on to more consumer-grade vehicles, since presumably a program that can initiate a maneuver to avoid an obstacle while moving at 200 miles per hour should be able to handle a similar dodge when puttering along at 35 miles per hour.

Right now, top drivers can still out perform the Robocar. A trained human brain can make these kind of calculations pretty well when focused on the task, but there’s hope that this kind of competition will help artificial drivers catch up quickly. At the very least, Roboraces should help the public become more familiar, and maybe even comfortable, with autonomous vehicles. In the mean time, let this be fair warning that sci-fi kids’ shows need to step things up a bit, because Robocars are becoming a reality.

Source: Robots, Start Your Engines! by Jesse Dunietz, Scientific American

On August 6th, 2017 we learned about

Our favorite robots are those with faults and flaws

You may not find the antics of R2-D2 terribly charming, but apparently a bit of bumbling can make a robot much more appealing to the humans that need to interact with it. This may seem counterintuitive, since any robot that’s tasked with assembling our airplanes or fighting fires should perform those tasks as accurately as possible to help keep us safe. However, robots performing more socially-oriented functions, like helping you check in for a flight, are more likely to get on your good side if they make an error or two (and correct it.) This is great news for roboticists, since we’re a long way off from any robot that can handle every social interaction perfectly… not unlike actual humans.

A study from the University of Salzburg, Austria, asked people to perform various tasks with a robot assistant. The tasks weren’t the focus of the study though, as the real variable was how the robot behaved along the way. Some robots performed the tasks as smoothly and flawlessly as possible, and were were generally rated by their human partners as being very anthropomorphic and intelligent. Other robots were programmed to make mistakes from time to time, and while they weren’t rated as being so intelligent, they were nonetheless the most likable robot to partner with. This is important, because people will be more willing to work with an automaton on any project or transaction if they can find it likable in some way.

Our fondness for flaws

Researchers believe that this is a case of what’s known as the Pratfall Effect. It has been demonstrated experimentally by showing people video of a peer successfully answering questions in a game show setting. After getting 92 percent of the questions right, some viewers see this person spill their coffee in their lap, while others don’t. Everyone can agree that this is a highly competent person, which is good, but the people who saw the spilled coffee also find the person to be very likable. Small flaws make a person, or robot, feel relatable and “human.”

Mistakes only make people, or robots, more attractive if they’re already seen as competent though. So a robot can’t do everything wrong and expect to win anyone over. However, perfection isn’t a practical goal, so researchers propose that robots be designed to take advantage of the Pratfall Effect when mistakes are inevitably made. If a robot can read social cues from humans well enough, it may be able to better scrutinize it’s own behavior for mistakes to correct. Correcting the mistake would then show competency, but also “humanize” the robot in a way that would be otherwise hard to plan for.

Source: Why Humans Find Faulty Robots More Likeable, Scienmag

On July 27th, 2017 we learned about

Glue inspired by slug-slime aims to beat stitches at sealing wounds in soft tissues

Few things make a boo-boo feel better than a kiss and adhesive bandage, particularly if that bandage has cool cars or aliens on it. While countless kids have demanded their scrapes and cuts be covered with these magic curatives, scientists from Harvard University are working on something that will likely be well received as an improvement— medical slug glue. Based on the defensive mucus secreted by dusky slugs (Arion fuscus), this new polymer promises to be a considerable improvement over today’s medical glues, stitches and sutures, although until they make it with pictures of cartoon slugs Band-Aids might still prove useful.

Dusky slugs make their mucus to glue themselves to trees or rocks when they sense danger, hoping to make themselves immobile so a predator can’t swallow them. Thanks to these life-or-death stakes, their secretions are both flexible and durable, which is a big reason they caught the attention of researchers. Nobody is proposing we start harvesting goo from scared slugs though, as scientists have been formulating their own gel that used the mechanics of the slug slime as a starting point.

Sticking and stretching across the soft and squishy

The current gel now boasts a number of properties that make it attractive for a range of medical interventions. It doesn’t bond as quickly as current medical glues, which would allow doctors to adjust positioning more carefully while it’s being applied. It should also be less toxic to different cell types than glue, and there are plans to make sure the final product will dissolve over time on it’s own. The long, polymer chains that make up the bulk of the gel are extremely flexible, stretching as far as 14 times it’s initial length before failing in a lab test. It also bends with the soft tissues of the body and can even be secured on wet surfaces, such as skin or even hearts covered with blood. In fact, an injectable form of the adhesive even patched a hole inside a pig heart, hanging on even as the heart continued to beat.

All of this would be a huge improvement over today’s glues and stitches. Sewing skin closed leaves the body more exposed to pathogens, drying, scarring and more. Skin and other organs should all benefit, with the one tissue missing from the menu being bone. As great as this all sounds, it’s only been proven in experimental conditions thus far. We’ll have to wait for full FDA approval before we can take care of our wounds with a squirt of Slug-Aid.

Source: From goo to glue: slug slime inspires new wound-mending surgical adhesive by Nicola Davis, The Guardian

On July 26th, 2017 we learned about

Learning about train wheels through the lens of Thomas the Tank engine

We all pretty much “get” wheels, right? From the time we’re babies, we see wheeled objects rolling around us on a regular basis, and it’s not long before the functionality of a wheel and axle can be taken for granted as just another part of almost every vehicle out there. So when my four-year-old recently looked up from his heap of toy trains and wooden track to ask about a particular wheel on a particular train, I had to admit that I really didn’t have an answer. The train in question is known to Thomas the Tank Engine fans as “Emily,” and she stands out among her peers with an oversized wheel each side of her boiler, rather than the more common set of small wheels under the locomotive. Fortunately, behind the expressive faces and somewhat snarky attitudes found on Thomas characters, there is some factual basis for many of the engines, and in this case Emily’s giant wheel does indeed have an explanation.

Which wheels provide power?

To make sense of how this character’s design connects with real life engineering, it’s helpful to embrace your inner four-year-old and familiarize yourself with how train wheels work. Locomotives generally have a battery of wheels, but like a two-wheel drive car, only a few wheels are actually being driven by the engine, appropriately called the driving wheels. The other wheels are there to distribute the weight of the locomotive, and stabilize it as it moves down the track. Wheels in front of the drive wheels are the “leading truck” and those behind the drive wheels are the “trailing truck.” Drive wheels could then be coupled together with the coupling rods you often see on the outside of train wheels, joining them together to share and distribute the power from the engine.

Emily’s enormous wheel

So where does that leave our giant mystery wheel on Emily? Emily appears to be based on a class of steam locomotive called a Great Northern Railway (GNR) No. 1 Stirling Single. The important bit of all that is the “Single,” as it refers to the single, gigantic drive wheel on the side of the locomotive, which received all the power from the engine via a large piston on the outside of the wheel. This design was put into service in 1870, and was a way to balance concerns about speed versus stress on the axle. The record-holding 96-inch wheel could move the train along at a good speed while not needing to rotate as fast as a small wheel would. The catch is that a large drive wheel is slower to accelerate, and only goes fast once it’s had time to get moving. These factors made for a train well-suited for express trips between York and London, generally traveling around 50 miles per hour.

Gordon goes faster

At this point, Thomas the Tank Engine fans might be pointing out that Emily is not in charge of the express trains, as that’s Gordon’s job. Conveniently, Gordon is also based on a real locomotive, the London and North Eastern Railway Gresley A1. These locomotives were first built in 1922, and had six drive wheels to get them moving. They were heavy but powerful, and engineering improvements would eventually get them up to 108 miles per hour over short distances. It’s not clear on my son’s toys, but the drive wheels on this locomotive were all 72 inches in diameter, making them only slightly smaller than what was found on a Stirling Single. The wheels just have a harder time standing out when proportioned on a 70-foot-long locomotive.

Thomas’ torque

While Thomas himself was never referred to as being especially huge or fast, it’s worth noting the utility of this cheeky little engine as well. Thomas was based on the London, Brighton and South Coast Railway’s A1 Class locomotive, often referred to as “Terriers.” These tank engines were often used to shunt cars around freight yards, and had excellent acceleration thanks to their six smaller drive wheels. When not using their torque to push other cars, they were used on branch lines since they could get up to speed quickly between stations, completing routes on tight timetables, just like in the children’s books.

The accuracy of these trains isn’t an accident, as The Railway Series was created by a family of train enthusiasts. Wibert Vere Awdry worked primarily as a clergyman, but he also worked for years on England’s Steam Railway Heritage. Christopher Awdry, the son who Wilbert invented Thomas for, also worked with trains, volunteering on the Talyllyn Railway in Whales between writing more Thomas stories. I don’t recall any stories about Emily winning long-distance races, but clearly there was an appreciation for engineering got these engines moving.

Source: Steam Engine Wheel Arrangements, H2G2

On July 4th, 2017 we learned about

Engineers look to Lepidoptera for lessons on manipulating light

Butterflies and moths are masters of light manipulation. Their bodies have evolved specialized structures that allow them to reshape light in ways we can, at this point, only envy. Researchers are doing their best to emulate them though, building new materials based on molecular structures found in these insects’ wings and eyes. With any luck, we’ll soon have new ways to bend and trap light, improving everything from the ways we cool our buildings and stare at our screens.

Skipper butterflies in the family Hesperiidae might not have the saturated oranges or blues of other species, but small flecks of white on their wings have been catching researchers’ eyes. As with blue, there’s no pigment that makes the wings white. To send white light to your eye, the butterfly’s wings are instead covered in tiny scales that are bent or twisted at different angles to control how the light is refracted. The angle of each scale then plays a role in the color produced, which can apparently be manipulated in a why a static pigment can not.

In the case of skipper butterflies, the white dots on the outside of their otherwise brown wings can display more than one color of white. Close examination found that these spots seem to be a key signal to other butterflies, and their wing scales can control just how reflective or dull the white appears. The degree of control can even very between being dependent or independent on the viewing angle of the wing.

This kind of control would be great to build into various technologies, starting with glass and paints. Since white light is made up of all the colors from the visible spectrum, reflecting white light is a good way to keep sunshine off an object. People in hot climates often paint roofs white to try to keep buildings cool, a strategy that could be greatly enhanced if the paint could incorporate some of butterfly scales’ light-bending properties.

Seeing more with less light

Sometimes reflecting light isn’t what you’re looking for. In those cases, moth eyes may provide a good model for how to bend light in order to trap it. Moths evolved specialized structures in their eyes to help keep them from reflecting ambient light at night, which might make them visible to predators. Human eyes really only experience this a problem when a camera flash goes off, but the underlying principles may be very helpful in the design of LCD screens, like those found on your phone.

When light hits the glass of your phone, some of it is reflected back at your eyes. When it’s coming from a source brighter than the screen, like direct sunlight, it can overpower the image the screen is trying to show you, leaving you nothing to see but glare. To compensate, devices crank up their screen brightness, but that takes a lot of power, draining your battery faster. With a moth-inspired film on the outside, the sunlight wouldn’t be reflected, and the screen could remain dimmer without a problem. Engineers are hopeful that this will be available to phone manufacturers soon, but some issues like durability are still being worked out. For all their subtle ways of controlling light, moths and butterflies aren’t the most rugged insects out there.

Source: Penn collaboration produces surprising insights into the properties of butterfly wings

On June 29th, 2017 we learned about

Frozen waffles and a flaming, melted plate teach us about toasters and microwaves

“Mommy! Daddy! There’s a fire!”

This is not how you want to start your day, but it wasn’t completely surprising when we heard it at 6:30 Tuesday morning. After all, just the night before we’d told our eight-year-old that if she wanted to cook a frozen waffle she was allowed to use the toaster. We told her where the waffles were and how long to cook them for. We reminded her to be careful with the hot toaster, and to get help if there was any sign of a fire. She was, therefore, just doing exactly as we told her.

The problem was what we hadn’t told her: Plastic plates can go in the microwave, but not the toaster.

The fire was contained, although at the coast of one Ikea plastic plate (dishwasher, microwave, but not toaster safe!) and the toaster itself. The plate’s flames were actually rather persistent, requiring some effort to be fully extinguished. Our daughter wasn’t actually too phased by all this— she just wanted to know why a plate could be used in one metal cooking box, but not the other?

Warmed from the inside by water

A plastic plate can survive your microwave because microwave ovens heat water, not plates. A magnetron behind the oven’s buttons generates microwaves that are then piped into the main compartment where your food is. Those microwaves are a lot like high-energy radio waves, but with shorter wavelengths. The wavelength is important, because it can affect what the microwaves will be blocked by, interact with, etc. In this case, the wavelengths are just below five inches long, and they’re kept contained by the metal shielding along the sides of the oven, bouncing around like light bouncing off a mirror.

When the microwaves hit your food, they primarily interact with water molecules your food contains. It will cause those molecules to vibrate in place, and some of that activity creates friction between molecules. As with other cases of friction in the world, that friction converts the initial source of energy into heat, and warming your food. In a way, the water molecules are doing the actual heating here, and so drier food (or plates) don’t get warmed very much, while water-filled items like pie filling can become scaldingly hot very quickly.

Cooking with heated air and coils

A toaster oven heats food through convection. Electric coils are pumped full of energy so that some of that energy can start heating the air in the oven. Warmer air rises, triggering a bit of circulation to eventually give you a very hot pocket of air in your metal box. All ovens heat food through convection heating, but some ovens (and even our replacement toaster) now bill themselves as “Convection Ovens.” These ovens include a fan to circulate hot air faster, making the warming process a bit faster, although sometimes drying out food more in the process.

Just as hot coils give away heat to the cooler air in the oven, hot air transfers heat into your cool food. Under ideal conditions, the temperatures would eventually equalize, and no heat would need to be transferred further. However, since the heat is being transferred from the outside in, thicker pieces of food need to wait for the outer layers to warm up before the insides warm up. The upside is that this “outside-in” heating can give you crunchy crusts and crispy skins in a way that a microwave will never do.

What pans go where?

Circling back to my daughter’s confusion over plates, plastic can go in a microwave, but only a few plastics can survive an oven. Because the plate doesn’t get heated as much as the food in a microwave, its temperature isn’t likely get hot enough to melt or ignite.  Metal is a big problem though, because it can reflect microwaves back at your magnetron and damage it, or build up an imbalanced electrical charge that results in dramatic sparking and arcing. That can damage the shielding of your microwave, allowing it to “leak” microwaves when you use it. Those microwaves can then harm body parts that have a hard time shedding heat, like your eyeballs.

In a convection oven, metal’s just fine. It can easily conduct heat from the air to your food, presumably without hitting its melting point. For aluminium, that’s 660° Fahrenheit, and 1200° Fahrenheit for a cast iron pan, both temperatures that would probably make a mess of your meal. Since common plastics like ABS can get squishy at 88° Fahrenheit, and ignite at 416° Fahrenheit, it’s makes sense that my daughter’s plate couldn’t handle the toaster. From here on out, hopefully the toaster will only have to deal with waffles.

Source: Microwave ovens by Chris Woodford, Explain That Stuff

On June 28th, 2017 we learned about

A brief history of ships sharing statements by hoisting and waving signal flags

Even though we like to romantically think of the ocean as a serene, relaxing place, it’s actually pretty noisy. Between the wind and waves, anyone talking on the deck of a ship is competing with around 85 decibels of splashing and spraying, which is close to the equivalent of a standing 100 feet away from a 45-mile-per-hour diesel locomotive. You could probably raise your voice enough to talk to someone next to you, but since Ancient Greece people have been trying to come up with ways to communicate between different ships at sea. This was often to coordinate military action, but today includes a variety of statements that might need sharing over moderate distances when speaking isn’t an option.

Hoisting preset signals

Sound can travel pretty far through the air, but from the deck of a ship it can’t really compete with light. To compromise, ancient naval commanders would hoist special flags above their ships that signaled to others that it was time to come over and speak face to face. This obviously has some scheduling limitations, and so people tried putting more information into the flags themselves. Different colors, shapes and positioning was used to build up a vocabulary of commands that could be posted so that other ships could view them from larger distances, whenever their view was clear.

Eventually the details of reading these flags evolved into more elaborate codes, complete with numbers, letters and ways to make substitutions if your available flags didn’t include two copies of a certain signal. Using what amounted to three sets of flags, a ship could basically broadcast around 1,000 different signals. In many systems, any message that didn’t have a dedicated flag combination could just be spelled out, letter by letter. There have been many revisions of these systems, some peaking at 70,000 possible signals, but today things have been simplified a bit. The current International Maritime signal-flag vocabulary can still use combinations of flags, but many of the most commonly used messages can be shared as a single flag for convenience. These include important messages like “I have a doctor on board,” or “I am taking on or discharging explosives.”

Sharing with semaphore

Like all forms of technology, there’s never been a single standard for flag-based communication. In the seventeenth century, Robert Hooke started designing the precursor to semaphore flags, which didn’t actually involve the ocean at all. Semaphore towers were tall buildings set as far as 150 miles apart, each with a pivoting crossbar on top. Each end of the crossbar was fitted with an extension that could be arranged to make the entire shape resemble, a line, an “S”, an “L”, or more. Arranging the angles of these bars allowed for 196 distinct positions, each corresponding to a character that could be seen from a great distance. The system allowed for thousands of signals to be sent faster than a horse could deliver a message.

The towers were successful for many years, even delaying the initial adoption of telegraph wires in France. However, they found a more permanent home on board ships, where the crossbars and beams could be replaced by a human holding two red and yellow flags. By adopting different poses with one’s arms, a message could be sent fairly quickly, although it needed to be seen at the right moment, since nobody wanted to be standing on deck waving flags all day long.

Flags, lights and voices

Flags still have their place on ships today, but they do face a lot of competition. Flashing lights signaling Morse code were one earlier alternative to flags, with the big advantage of being visible at night, and maybe even in poor weather conditions like rain. From a military standpoint, radio transmissions are superior to all of the above, since flags and light beacons are not only visible to your own crews, but to nearby enemies as well. Codes could be used to make things more opaque, but being able to communicate directly with your voice is now a much faster, detailed way to say “hi” when out on the water.

Source: Signaling at Sea by Joseph McMillan, Sea Flags