Friday, 29 August 2014

Sketchy Fact #55: Let the Smallest Bird Bee

The bee hummingbird is the smallest bird in the world at just 5 cm long and 2 grams in weight, that's about as much as 2 paperclips. 


Tuesday, 26 August 2014

The Ice Bucket Challenge: Scientific Considerations

If you’ve spent any time on the internet over the past couple weeks you’ve probably seen a bunch of viral videos of people dumping cold water on themselves to raise money for ALS. Dubbed “The Ice Bucket Challenge” it is a silly activity for a good cause and there is a lot of science involved, so naturally we’ve decided to volunteer our illustrator to take the plunge (donate at http://www.als.ca/en/donate). There are however a few things to consider before engaging in this frozen fund-raiser, so let’s take a moment to get the facts straight.


The Gasp Reflex

According to Beyond Cold Water Bootcamp there are 4 stages of cold water immersion:
  • Cold Shock Response
  • Cold Incapacitation
  • Hypothermia
  • Circum-Rescue Collapse

While each of these is important when you’re pulling unlucky fishermen from frigid arctic seas, only the first really applies to The Ice Bucket Challenge. The cold shock response lasts for about a minute when you’re actually submerged and it can wreak havoc with your body. It begins with a sudden inward gasp that evolution has programmed as a reflex to help us hold our breath. Unfortunately it can also lead to inhaling a bunch of water, so watch out for it.


Icy Heart

The Cold Shock Response also has serious effects on your heart. A sudden influx of cold water makes your arteries narrow in a process called vasoconstriction. The result is that your heart has to work harder to pump the same volume of blood. The lesson here is, if you have a heart condition, maybe leave the ice buckets to the rest of us and just help out with a donation to the ALS association.


Spicing Things Up

As a reader of this blog, you might also be tempted to throw your own flare onto the Ice Bucket Challenge using some clever science twists. You could try The Dry Ice Bucket Challenge. Dry ice is frozen carbon dioxide and has a surface temperature of -78.5 degrees Celcius (-109.3 F). This makes it a pretty bad choice for our purposes. Being that cold, it has the ability to severely damage your skin. Another reason to give it a pass is that as dry ice warms it sublimates, meaning it turns directly from ice into carbon dioxide gas. This has a cool effect at Halloween parties, but it isn’t something you want to be breathing in while you try to go viral.


Another equally bad idea is using liquid nitrogen. With a temperature of -196 C (-320 F) liquid nitrogen is probably the coldest stuff a normal person can get their hands on. However, unless you want your hands to shatter getting liquid nitrogen on them is a pretty bad idea. If you don’t end up effectively turning into glass by freezing yourself solid you might accidentally cryogenically freeze yourself. This isn’t as cool as in the movies. Rather than waking up in the future, your cells will all rupture as the water in them freezes and expands and you’ll just become a very brittle corpse. You do have about a second before it contacts your skin thanks to the aptly named Leidenfrost Effect, but is it really worth the risk?


No Pain, No Gain

Finally, The Ice Bucket Challenge has the potential to cause you some brief pain. In studies of pain tolerance, psychologists and the Mythbusters alike have used tubs of ice water to inflict suffering on their volunteers. In the long-run a little momentary discomfort is nothing compared to ALS, though; so if you don’t have a heart condition and aren’t dumb enough to try our previously mentioned ice alternatives, we challenge you to go for it!

Without Further Adieu…


References:

http://science.howstuffworks.com/life/genetic/cryonics2.htm

Friday, 22 August 2014

Sketchy Fact #54: Follow the Pheromones

Male moths can detect females from up to 7 miles away. Even though they don't have noses, male moths have some of the most sensitive antennae in the business. 


Wednesday, 20 August 2014

Fatally Unfair: The Science of Planet’s Most Venomous Creatures

One of the most exciting things that can happen when you head out into the wilderness is spotting an animal that you wouldn’t see on a typical day. Such sightings, however, often carry with them a risk of bringing you uncomfortably and unintentionally close to the food chain. Depending where you live in the world you could risk being stalked by a tiger, mauled by a bear, or taken down by the bite of a venomous snake.


From the perspective of someone who grew up in a country without many venomous animals, that last option is particularly jarring. Like most Canadians with a penchant for spending time in the woods I have a healthy understanding of what to do if I encounter a certain type of dangerous animal. Given that I am most likely to come across a large mammal like a bear or a mountain lion the options range from playing dead, to climbing a tree (to escape a grizzly), to fighting back and hoping for the best. However, in the face of ambush predators that rely on one quick bite or sting to take you down, all of the tactics I have spent my life learning result in me twitching and dying in the dirt.


It just seems so much less sporting. With a large predator at least you know what got you and can do something to stop it. In that sense, venom is nature’s most unfortunate pull of the slot machine. It's that inherent unfairness that makes venom so fascinating.

First off, it is important to know the difference between venom and poison. Poison is nature’s passive form of toxicity. Poisonous animals will definitely cause you some harm, but you have to bring it on yourself. By contrast, a venomous animal actively seeks to cause trouble. Venomous animals bite and sting and for that reason tend to be predators (ex. snakes, jellyfish, spiders). Poisonous animals are more often prey that use there poison as defense against predators (ex. frogs, beetles, and plants).


One of the more fun questions a person can ask in any discussion of venom is “Which animal has the world’s deadliest venom?” Unfortunately, like all seemingly simple questions in the world of science, this can be a tricky one to answer. The most common method of rating the potency of toxins is determining their LD50 (Lethal Dose 50). This is the dose of the toxin that is lethal for 50% of animals that receive it. Given in milligrams of toxin per kilogram of body mass, LD50 is a good starting point but is far from perfect. Animals react differently depending on where in the world the toxin originated, how it is administered, and a host of other variables.


It may not be foolproof, but it is the best option we have if we want to find the world’s most venomous creature. Now that we have a method we need to narrow down our search geographically. Fortunately this isn’t at all difficult. There is one place that we can go with a reputation for being crawling with the world’s deadliest versions of every poisonous animal. Pack your bags, we’re off to Australia.


We won’t get into why Australian animals are so venomous because that is something even scientists have a hard time answering. Let’s just take it as a fact that Australia is about the last place in the world you want to get bitten or stung by something. Near the top of the list of animals you don’t want to cuddle with is the box jellyfish. Small, unassuming, and nearly transparent but for a faint tint of pale blue these invertebrates pack a serious punch. The venom of a box jellyfish has an LD50 of 0.04 milligrams/kg of body mass. Keep in mind that with LD50, lower numbers equal stronger toxins. For comparison, the LD50 of coral snake venom (one of North America’s most venomous animals) is 1.3mg/kg. Adding insult to injury, the jelly’s venom has the ability to kill skin cells. That means if you don’t end up dead, you can at least count on some pretty gnarly scars.


As troublesome as box jellies may be, however, there is one Australian critter that makes even them nervous (assuming they have emotions which they probably don’t). You may be surprised to learn that the creature most scientists agree is the world’s deadliest is actually the cone snail. This marine snail may look a lot like it’s cousins that kids pick of leaves in their grandparent’s gardens but rest assured, this ain’t your gamgam’s brand of mollusk. Not even close. With a mind-blowing LD50 of 0.012mg/kg, cone snail venom usually kills the snails prey animals (mostly fish and other snails) before their nervous systems can even react to being stung.


Say what you will about my pal the grizzly bear, at least it has the decency to let you hit the ground and have a look at it before finishing you off.


References:





Friday, 15 August 2014

Sketchy Fact #53: Fighting Fingers

Your fingers don't have any muscles in them. When you move your fingers you are actually tugging their tendons using the muscles in your forearm.

Wednesday, 13 August 2014

Giant Boat-Knives and Other Bad Decisions: The Tale of the Basking Shark


Our friends at The Starfish asked us to drop some knowledge on basking sharks for Shark Week. Ask and you shall receive:

The ocean is full of monsters. That is a pretty well established fact. Any parent who has ever told an insomniac child, awake and trembling at 3AM, that there is no such thing has clearly never seen a picture of a giant squid or an angler fish. Sea monsters range from the very small (jellies) to the unfathomably enormous, but few are as impressive as the basking shark (known to science by the delightfully gladiatorial name of Certorhinus maximus).

Basking sharks fall into the “sea monsters” camp mainly because of their size. They are the second largest fish in the ocean (after whale sharks), reaching lengths of up to 33 feet and weighing as much as 8,000 pounds (3,600 kg). They also look unmistakably ferocious in that classic sharky way. They have dorsal fins that stick high out of the surface of the water, streamlined bodies, and (scariest of all) enormous mouths. You could swim into a basking sharks mouth pretty easily without ever touching the edges.


The thing about basking sharks though, is that they aren’t ferocious at all. Like so many of the biggest things in the ocean, they are almost comically gentle. They cruise around at around 3 mph (5 km/h) with their mouths agape, swallowing tiny plankton and filtering out massive amounts of water. They love to hang out in the sun right at the surface of the water, hence their name.


Unfortunately, this affinity for sunshine and their ridiculous size has caused some trouble between us and them, but not for the reasons you might think. Whereas humans normally hunt things as impressive as basking sharks for trophies or meat, these lumbering beasts are actually pretty useless as a commodity (unless you’re one of the 3 people alive who enjoy Icelandic hakarl).


The problem with basking sharks is that back in the 1940’s and 50’s they routinely got caught in fishermen’s gill nets by mistake. You may think that a basking shark would make a good catch for a humble fisherman, but the only sellable part of the great fish is its liver. I say “sellable” instead of “valuable” because in the mid 20th century basking shark livers sold for 3 cents a pound (about $35 per shark) whereas the nets they destroyed with their massive bodies cost roughly ten times that much.


This inevitably led to fishermen hating basking sharks and complaining to the government. In 1949 the Canadian government gave in and labeled basking sharks marine pests and set to work at killing them. The method of choice was either ramming them with boats or slicing them in half with a huge makeshift blade mounted on the bow of a boat. In the 1950’s a giant boat-knife was an impressive thing, at least impressive enough to be featured in the November 1956 issue of Popular Mechanics magazine.


The giant knives proved remarkably effective and in a matter of decades basking sharks were nowhere to be found. Nowadays there is about one sighting per year off the British Columbia coast. Ask someone at the Department of Fisheries and Oceans where they went, and you will likely get a sheepish, embarrassed look in return.


However, the news isn’t all bad. In 2010, Canada followed the lead of countries like Ireland and Great Britain and declared the basking shark endangered. A recovery strategy was finalized in July 2011 and the people who once drove the knife-boats have since been at work mashing the ocean’s CTRL+Z key. Only time will tell if they’ve changed their minds in time.


Wednesday, 6 August 2014

The Alpha Myth: The Real Science of Wolf Packs

People and dogs have had an interesting and complicated relationship since the dawn of civilization. Ever since the first wolf worked up the courage to take food out of a person's hand our two species have been trying to figure each other out. We have moulded the original overly-tame wolves (and yes, all dogs are descended from wolves) into hundreds of different dog breeds of all shapes and sizes. We know which dog to call on to herd sheep, the best for hauling in fishing lines, and which dog to put front and centre in a fire engine. However, for everything we know about the dogs we have created; we have been historically deficient in knowledge of the animals we have left behind.

Considering how much we love dogs, wolves have had a surprisingly rough go. Throughout history people have grown to fear wolves and have hunted them to the brink of extinction. Flip through any animal-based fairy tale book and you will find a disproportionately large number of stories featuring wolves as villains. We have been happy to think of wolves as ruthless killers, ignoring the fact that they are essentially just bigger, more skittish dogs that are trying to make an honest living in the wild.


If you don’t believe that we have been wilfully ignorant of wolves until very recently, consider the fact that the one thing that most people know about wild wolf packs is blatantly wrong. Ask the average person about the social structure of a wolf pack and you will likely get a vague explanation involving the Greek letters alpha and beta. Alpha wolves are the pack leaders; they lead the hunt and keep the betas in their place. They eat first, breed first and are the kings of the castle. The trouble is, they don’t exist.


The alpha wolf theory is based on an observational study undertaken in the 1940’s by biologist Rudolph Schenkel. The theory gained popularity in the 1970's when L. David Mech published his book The Wolf: Ecology and Behavior of an Endangered Species. Unfortunately, most scientists (including Mech himself) know that they alpha theory is based on faulty extrapolation. Mech has actually been trying to get the book out of print for a number of years

You see, when Rudy Schenkel was watching wolves and making notes, he overlooked one important fact: the wolves he was studying were in captivity. Their pack was not the kind that formed naturally in the wild; it was made up of adult wolves forced to live together and compete for resources. Not surprisingly these wolves fought a lot and the dominant ones got their pick of food and mates. This study has been compared to learning about the behaviour of human families by observing people living in refugee camps



In truth, when a male wolf meets a female wolf, they mate, and they raise their offspring together. A pack is just a family. When the offspring get old enough, the males leave to find mates from other packs and start the cycle over again. There are no alphas and betas, only parents and children. Occasionally packs will come together to hunt a particularly large animal or take advantage of a concentrated resource, but usually a pack is just a family unit with older offspring rotating out as new ones are born.


This simple revelation has had dramatic consequences for the way people think about training dogs. Generally speaking, people fall into either the dominance camp or the positive reinforcement camp. Unfortunately, when you stop talking about wolves and start talking about dogs, emotions run a lot hotter. No one wants to believe their method of training is cruel, but that is the word that tends to get thrown around. We won't branch out into the world of offering dog training advice. The message we want you to take away from all of this is that things are generally more complicated than they appear, and that wolves are actually a lot more peaceful than you have been led to believe… But you still shouldn't get up in their space… Unless they raised you.

Friday, 1 August 2014