Sketchy Fact #29: Kitty-Vision

Cats are physically and behaviourally designed to survive high falls. They instinctively spread their limbs to increase wind resistance and, as a result, fall much slower than a human or whale would. One study found a cat that fell out of a 32nd  story window and only chipped a tooth and collapsed one lung.

Garbage Island: Floating Fun with the North Pacific Gyre

Last year we at Sketchy Science were fortunate enough to find ourselves on the Hawaiian island of Oahu for 10 days of fun in the sun. We explored every corner of the island looking for fun stories to share and were not disappointed, from extinct volcanic craters, to epic surf, to amazing wildlife, Hawaii proved to be a hot bed (if you’ll pardon the pun) of science gold. However, one of the things we discovered was bigger than all the rest. We never actually saw it because, as you will read, it’s not easily detectable for land-dwellers; but we did spend the better part of 5 hours flying over it.

The Northern Pacific ocean is home to one of humanity’s great shames. Due to the collision of currents and the durability of certain man-made detritus, there now exists a floating patch of garbage twice the size of the continental United States stretching from 500 nautical miles off the California coast nearly to Japan. It goes by several names, but we like to call it Garbage Island.

Garbage Island is a joint creation of human wastefulness and the clockwise-spinning network of currents call the North Pacific Gyre. This massive area in the world’s most massive body of water is an oceanic desert, home to few large fish but brimming with microscopic phytoplankton. The rotating nature of the Gyre causes any drifting material to get caught up in the middle of the ocean for what can turn into an immense amount of time. Fortunately most natural materials break down in a few years. Unfortunately, humans have invented plastics, which basically last forever.

Give anything on Earth enough time and it will eventually find its way into the ocean. That is just how things work. The problem with plastic is that no natural process exists to break it down into simpler compounds. Instead of biodegrading, plastic photodegrades; slowly fracturing into hundreds or thousands of smaller and smaller pieces. These tiny bits of plastic are called nurdles, or (if you are the poetic type) mermaid tears. Roughly 70% of nurdles sink, the rest get caught up in surface currents and float around for an indeterminate amount of time. What this all means is that garbage island isn’t actually an island. It is more of a conceptual blob of sparsely packed filth in a vast expanse of water, which is way less fun.

It may not seem like such a big deal. After all, there isn’t much wildlife in an oceanic desert. Unfortunately, large animals like whales, sea turtles, and birds travel through the North Pacific looking for food. They end up swallowing garbage which clogs up their innards and eventually kills them. If that isn’t enough, there is another indefatigable law of nature: Whatever ends up in the ocean eventually ends up on your plate. As plastics float about, they absorb chemicals like mercury and pesticides like DDT that people continue to dump into the oceans. Those compounds get more and more concentrated as they work their way up the food chain. Humans are at the top of every food chain there is, so this bioaccumulation is bad news for us if we plan to keep eating fish.

This is all pretty upsetting, I am aware. So what can be done to fix it? Fortunately, many countries around the world are taking steps to reduce unnecessary consumption of plastic. You may have noticed that your local grocery store now makes you pay for plastic bags, or, at the very least, encourages you to use reusable ones. Many restaurants are also moving away from plastic forks and knives in favour of metal utensils that are actually capable of spearing and cutting food.

Cleaning up the Pacific is something that we still need to figure out. Collecting billions of tiny pieces of plastic without hauling up a heap of plants and animals along with them is a daunting task. Until engineers solve that problem, we will have to rely on common sense to avoid making the problem worse. Do your part to recycle and to produce as little waste as you can. It’s the least you can do to help eliminate the world’s biggest landfill. At worst, just aim to be better than the countless tourists we encountered on Oahu who watched in stunned disbelief as their air mattresses blew out into the ocean without making the slightest attempt to retrieve them.  If a simple lack of idleness isn’t enough for you, grab a snorkel and a biodegradable trash bag, then meet us in Hawaii.

Mahalo

Sketchy Fact #28: Prodding the Depths

According to National Geographic, 2010 was the most dangerous year on record for unprovoked shark attacks with 79 being recorded; begging the question, how many attacks were provoked?

A Vitamin D-lemma: The Formerly Racist Science of Skin Pigmentation

One of the most accessible bullets in the chamber of anyone who denies science is the fact that scientists don’t always (or even often) get things right on the first try. We all know that there were times in the past when people thought the sun revolved around the flat earth and that if a woman weighed as much as a duck she was probably a witch. In truth, science in vindicated by the fact that it is willing to change its collective mind in the face of new evidence. Occasionally though, there are topics where people should have known better a whole lot sooner than they did. Skin pigmentation is one of those topics.

Most famously in the blunders department, scientists (if it isn’t too much to call them that) used to use skin pigmentation to classify groups of people into “races.” Most of us are more than passingly familiar with the categories they came up with. Black, White, Asian, Latino, Brown, and Native American are the major denominations that tend to arise when we think about race. Historically, these divisions have been really bad news for most people. Actually, pretty much only white people made it through history free of persecution. 

For much longer than it made sense to believe so, people thought race was at the heart of who a person was. In fact we now know that race is entirely an artificial construct. As you move across the world and meet people from all its corners (spheres don’t have corners, it’s just an expression) you quickly realize that not only is there a complete continuum of people  between every stereotypical skin colour, there is also more variation within these so-called races than there is between them.

The reason that the illusion of races persisted for so long is because skin pigmentation is dictated by geographic location. Specifically (and very generally) groups of people with lighter skin have spent a lot of time living in areas far from the equator. As you move closer to this imaginary dotted line, you are likely to find groups of people with darker skin.

There are two-easy-to-understand reasons for this. Firstly, people get sunburns. As our ancestors moved out onto the hot African plains in search of food they needed to evolve a mechanism through which to expel excess heat. Over time, our ape-like ancestors lost most of their body hair and evolved the ability to sweat (as sweat evaporates it cools the skin). Unfortunately, as hair receded skin became more susceptible to UV radiation. As hilarious as it is to slap someone’s freshly reddened back when they are least expecting it, constant pain and the threat of skin cancer is no way to run a species. To cope with heightened exposure to the sun, human skin began to produce more melanin. 

Melanin is nature’s sun block. It protects the skin from burning and reduces the risk of cancer following exposure. It also darkens the colour of your skin. When normally pale people get a suntan, they are experiencing the same kind of transformation that all humans did in the distant past, it is just happening on a limited scale. No matter how long a white person stays in the sun, they will never look like Tyra Banks.

The problem with melanin is that occasionally it does too good of a job blocking the sun. As it turns out, exposure to UV light isn’t always a bad thing. In fact, it is one of the easiest and most reliable ways for a body to produce vitamin D. Vitamin D is essential to the normal growth of bones and the prevention of developmental problems like rickets (the softening of bones in young people). Since having softened bones is arguably worse than getting skin cancer (if you don’t have a strong skeleton, you aren’t likely to live long enough to get skin cancer), evolution needed to find a balance.

People who live far from the equator have to deal with seasons, and with seasons comes reduced daylight hours as we saw a few weeks ago. If your skin is full of melanin and you live at high-latitudes, you are likely to be vitamin D deficient and at high risk for rickets. To combat this, the bodies of people who live in such places have adapted and tend to produce less melanin, making them appear lighter in skin tone. This also explains the nice continuity in skin pigmentation we see between the equator and the poles.

So there it is. Skin colour, like every other characteristic we possess, is an adaptation; not a convenient indicator of personality traits. With the advent of sunscreen, vitamin supplements, and air travel it is also probably an adaptation with an expiry date. In another thousand years, we will probably all just be beige anyway. 

Sketchy Valentines 2014

Instead of a fact we at Sketchy Science decided to give you, our readers, the greatest gift of all: Sketchy Valentines from us to you! Or from you to your special someone... assuming they are a nerd. Feel free to print and distribute at will!

Happy Valentine's Day!

Love and Other Tricks of Chemistry

Like it or not, the greeting card companies have won. Mid-February has become and will remain a celebration of love and coupling and chocolates and gift-giving. Whether you’re the type who can watch The Notebook ten times in a row and still get choked up, or an emotionless automaton you are likely to see otherwise normal people making googley eyes at each other on park benches and in restaurant windows for the rest of the week. But what is going on with these people? Are they possessed by a mystical, spiritual, connection with their one true soul-mate or is something more scientific going on?

Given that this is a science website, you won’t be surprised to hear that it’s the latter. Love, the feeling that drives us to do crazy things like build empires and spend our Saturdays at Bed Bath and Beyond, is nothing more than a trick of psychology and brain chemistry.

It all starts with infatuation. You look across a crowded room and your heart starts to beat faster as you first lay eyes on… someone who probably looks either like you or one of your parents. Yes, as gross as it may seem, research has suggested that our template for attraction is often shaped by the people who raised us. It makes sense when you think about it. Our first feelings of love are directed at our parents, so why not stick with what works? People are also attracted to versions of themselves that have been morphed into members of the opposite sex. One study found that when given a selection of pictures and told to choose the most attractive person, participants picked out a computer-morphed version of their own face over the faces of strangers nearly every time, even though they didn’t recognize the faces as their own.

So you and your doppelganger are now dating. You likely have a few things going on chemically in your body. First, your estrogen and testosterone levels have probably surged, increasing your sex drive. When you see your new partner, dopamine begins to stimulate the reward centres of your brain in much the same way as it does when you win a hand of blackjack at the casino. Norepinephrine (a cousin of adrenaline) is coursing through your brain and body just like that time when you nearly crashed your car. Only this time, you've convinced yourself it is good excitement.

You’re pumped, you’re happy, and you’re primed for some lovin’, it’s no wonder that this surge of chemicals is so addictive. Research scanning the brains of people in the early stages of love look eerily similar to those of alcoholics and drug addicts, lusting for their next hit of the good stuff. Having your brain resemble that of a problem gambler is the least of your worries, though; you are also very likely experiencing low serotonin levels comparable to those of people suffering from obsessive compulsive disorder. That explains why you literally cannot stop thinking about your partner (Sandori, 2001).

If you decide to give in to your sex hormones you may just exacerbate the problem. During sex your brain and the brain of your partner will release oxytocin, which leads to feelings of close attachment (Carmichael, Humbert, Dixon et al., 1987). Fortunately, if you get enough oxytocin, you will begin to transition back to a closer approximation of your normal self as you enter the stages of long-term love. If your relationship emerges from the initial euphoria and you don’t find your partner’s suddenly apparent flaws to be a deal-breaker, your body will begin to amp up production of vasopressin. Vasopressin has been linked to long-term, monogamous love and actively interferes with the dopamine and norepinephrine that make infatuation so much fun. You may not be as excited and horny, but you probably feel more relaxed.

The general sense of calmness and well-being you feel is being fed by a constant stream of endorphins. Congratulations, you are no longer a crazy person. Over time you can even begin to exit your love-den and re-enter society. If you’re really lucky, you might even find yourself in a situation where you’re only paying for half the rent on your one-bedroom apartment. This love thing isn’t so bad after all.

And that is pretty much it. Love isn’t a mysterious force of the universe that binds us together; it can be explained with a little psychology and a cocktail of neurochemicals. It makes sense when you think about it, evolution has programmed us to fall in love to ensure the species continues. If acknowledging that fact takes some of the romance out of love for you, you’re probably coming at it from the wrong angle. Rather than living in awe of love as the wondrous spiritual outcome of two people overcoming the odds of probability to come together and form a connection, maybe we should all just marvel at the complexity of the process and feel lucky that we have brains capable of experiencing it at all.  That is a fact worth sharing a box of chocolates over.

References:

Sandroni P (October 2001). "Aphrodisiacs past and present: a historical review". Clinical Autonomic Research11 (5): 303–7. doi:10.1007/BF02332975

Carmichael MS, Humbert R, Dixen J, Palmisano G, Greenleaf W, Davidson JM (January 1987). "Plasma oxytocin increases in the human sexual response". The Journal of Clinical Endocrinology and Metabolism 64 (1): 27–31. doi:10.1210/jcem-64-1-27

Sketchy Fact #27: It's Krillin' Time

By weight, Antarctic krill are most abundant wild animals on earth. If you put them all on one scale their biomass would be approximately 379 million tonnes. By comparison, the biomass for all humans is estimated at 350 million metric tonnes. 

The Heat Beneath Your Feet: The Toe-Tingling Science of Geothermal Energy

A few months ago we learned about using the sun as a source of energy and were impressed by how convenient it is to have a super massive power plant in the sky. The trouble with the sun is that unless you have homes at the north and south poles that you can travel between, it is only available for half the day. Renewable energy is fantastic and it will eventually save the world, but people are going to want to be able to recharge the batteries in their electric cars while they sleep. That being said, we have to branch out from solar power alone.

Fortunately, there is another molten ball of pure energy that is a little closer to home than the sun. While the sun steams along at an insanely blistering 15 million degrees C (27 million degrees F) in its core, the alternative, our home earth, is a relatively chilly 4,200 degrees C (7,600 F). What it lacks in heat, it makes up for in proximity. If you want to find this potential source of limitless energy, all you have to do is start digging.

It’s not something that we think about on a daily basis, but every moment of your life will be spent on a thin sheet of rock surrounding a ball of magma. At its thickest, the Earth’s crust is barely more than 50 km thick. If you take a bite out of an apple and look at how thick the peel is in relation to the size of the whole fruit, you will have a reasonably good idea of what separates you from volcano juice. Luckily, our tenuously insubstantial barrier provides a great advantage for anyone looking to escape the use of fossil fuels. It’s called geothermal energy, and it combines the Earth’s heat with the water that flows through the crust to create useful energy.

There are three main ways to use geothermal energy. The first is the easiest and involves piping water from hot springs (pools of heated water that seep to the surface) directly into homes and buildings to provide heat. If there isn't a hot spring nearby you will have to build a geothermal heat pump, which takes water from a few feet under the ground (this water has a consistent temperature of 10 to 15 degree C (50 to 60 F)) and circulates it through pipes. The relatively minor amount of heat from the water can be transferred to homes using electric compressors and heat exchangers. In the summer, the process can even be reversed to draw heat from the home and put it back into the ground to cool things off. The third option is a geothermal power plant which pipes hot water and steam from deep within the Earth through turbines, making them spin, creating electricity in the process. 

The last of these options offers significant advantages where it is practical. We humans may appreciate a warm house in the winter, but we really appreciate electricity sucking things like iPods and televisions. Sometimes we even use electricity for worth-while things. I bet you didn’t realize that up to 30% of the electricity produced by people is used to treat and distribute clean drinking water. Now imagine if we could use clean, renewable, geothermal power to do that same job.

Fortunately you don’t have to imagine too hard, because engineers in British Columbia (BC) already had that idea. BC is home to Canada’s largest water filtration facility, called the Seymour Capilano Filtration Plant (SCFP). BC is also Canada’s most geologically active province, with the Juan de Fuca tectonic plate slowly crashing into the North American plate, creating heat as it goes. The SCFP takes advantage of this happy coincidence by employing an underground geothermal exchange system that saves the facility enough energy to power 160 homes per year. And if you think that’s impressive, hop on a flight over to Reykjavik, Iceland where 95% of the buildings are heated and powered by that country's abundance of volcanic awesomeness. 

Of course, we don’t all live on a fault line or next to a volcano, so the opportunity to build a geothermal power plant isn't always available. However, we can all dig a few feet underground and install a geothermal heat pump. Domestic systems can be built for around $30,000 US and they save enough energy to pay for themselves in 5 to 10 years… Maybe it’s time we all got a little bit more Icelandic.