Friday, 29 November 2013

Sketchy Fact #17: The Case of the Missing Oceans

Venus used to have oceans, but a runaway greenhouse effect heated the planet up to 482 degrees Celsius (900 Fahrenheit) and they evaporated into space.

Wednesday, 27 November 2013

Beards and Staches and Sideburns, Oh My! The Luxuriant Science of Facial Hair

Each year men around the world take up their razors against a sea of stubble to participate in what has become an incredible demonstration of crowdsourcing and teamwork. These men grow mustaches and raise tens of millions of dollars for prostate cancer research. The world has come to know this event as Movember.

As noble a cause as Movember may seem, it does have one unfortunate side effect. Try as they might, some “Mo Bros” will inevitably fall short of their facial hair goals, even if their donations do not reflect this. As a service to the follicley-challenged, we at Sketchy Science thought we would attempt to explain why some men will end up looking more like Matthew Broderick than Magnum P.I. come the end of the month.

Facial hair is a product of hormones and genetics. Testosterone is the primary culprit in terms of facial, chest, and all other body hair in both men and women. The level of testosterone in your body is dependent on a number of things including biology, and environmental factors. As we saw in our discussion of epigenetics, even the lives of your recent ancestors might impact your DNA and subsequently alter your ability to grow a mo. Diet also plays a key role with zinc and magnesium needed to get the testosterone manufacturing process started and cholesterol needed to produce the actual hormone. Foods like eggs, spinach, nuts, avocados, and balsamic vinegar are all fine choices if your want to improve your follicle fecundity. Others like broccoli, cauliflower, and cabbage will help by lowering levels of counteracting hormones like estrogen.

Testosterone acts like a messenger from your body to your hair follicles. In the simplest possible terms, testosterone antagonizes the follicle and tells it to grow, grow, grow. It physically changes the “peach fuzz” many of us are born with, making it thicker, coarser, and darker. From there, you’re off to the races.

Unfortunately, you may be stuck in the gate if your genetics don’t cooperate. Studies have revealed that Testosterone isn’t the sole factor involved in facial hair growth. Research involving Japanese men (a group that is generally less able to grow facial hair) has shown that even men with little to no visible facial hair can have levels of testosterone equal to or in excess of their bearded brethren. The explanation lies in a person’s genetics. Testosterone can yell at your hair follicles to grow until it’s throat is sore but if your DNA doesn’t allow you to respond, you will remain baby-faced. Genetics help determine what is called your testosterone sensitivity. High testosterone sensitivity is not without its drawbacks, however. It has been linked to male pattern baldness in addition to facial hair growth, possibly explaining why Bruce Willis is considered a manly action-hero.

Recent research has also shown that, beyond being a good tool for fundraising, a certain amount of facial hair might also help you attract a mate (at least if you’re Caucasian). A team of Australian biologists evaluated ratings of attractiveness and masculinity for men with no facial hair, light stubble, heavy stubble, and full beards. Results indicated that heavy stubble was the most attractive condition, with full beard, light stubble, and clean shaven being less attractive. Men with full beards were rated highest in terms of masculinity. The researchers suggest that facial hair might serve as a signal regarding reproductive health and the ability of a man to protect his family. It needs to be noted, however that all the men being evaluated were of European descent as well has 80% of the women who did the evaluating. Attractiveness ratings were also impacted by the stage of the woman evaluator's  reproductive cycle, supporting the evolutionary explanation offered by the researchers.

Whether or not you can grow a beard Karl Marx would be jealous of, Movember represents a great cause. It is important to remember that the quality of one’s facial hair is far less important than the quality of one’s intentions. Cancer research is a good and noble thing and we at Sketchy Science wish all Mo Bros and Mo Sistas good luck in their fundraising as we close in on the end of this happily hairy month.

If you want to donate to this worth-while cause you can give through the mo spaces of:

Friday, 22 November 2013

Sketchy Fact #16: Let Your Backbone Slide

The Hero shrew and the Thor Shrew are the only two known animals with interlocking vertebrae. Their backs are reportedly strong enough to support the weight of a fully grown man. That would be like a person piggybacking a blue whale.

Wednesday, 20 November 2013

Chinooks: The Good, the Bad, and the Windy

There are a lot of different ways in which weather can ruin your day. You can suffer through ridiculous heat waves, frigid cold, hurricanes, tornadoes, and hale the size of soft balls. The worst part about it all is that predicting the specific behavior of weather patterns is difficult verging on impossible. The last thing you want is to be surprised when you walk out your front door… That is of course unless you live on the Eastern edge of the Rocky Mountains in North America.

The weather on the leeward side of the continental divide is variable to say the least. In Canada, residents of Alberta can vouch for the fact that summers are short and mild while winter can go on for decades and flash freeze the hair on your head. Indeed, the people of the prairie come from a hardy stock. Occasionally, though some of them get to cheat their way out of winter for a few days at a time.

Chinooks (also known as foehn winds) are a Calgarian’s best friend. Over the course of a few hours, these warm winds can rush in from the mountains and lift the temperature from sub-zero to nearly tropical.  Examples of potent Chinooks seem to break all the rules of Canadian winter. During the winter of 1962 the town of Pincher Creek, Alberta was greeted by a Chinook that caused the mercury to rise by an astounding 41°C (74°F) in one hour resulting in a day-time low of -19°C and a high of 22 (-2 to 72°F). In February 1992, Claresholm, Alberta experienced a high of 24°C (75°F), one of the highest February temperatures ever recorded in Canada. These Chinooks are certainly impressive, but bragging rights in the warm winter wind department go to the town of Loma, Montana where on January 15, 1972 the temperature fluctuated by 58°C (103°F) from a low of -48 to a high of 9°C (-54 to 49°F).

For those of us who live beyond the reach of Chinooks, this is all clearly unfair. Obviously the people in Alberta and Montana and the handful of other places along the continent’s spine that experience nature’s equivalent of a “Get Out of Jail, Free” card have made some deal with Satan. Alas no, the science behind Chinooks is relatively straightforward. 

As warm, moist air from the Pacific rushes up the western edge of the Rockies, temperatures fall and water is dropped off in the form of snow. The remaining dry, cold air crests the mountains and (in the manner of cooled gases) begins to rapidly fall down the leeward side. As the air falls it gets crunched together (becomes denser) and the temperature rises dramatically. It is the same thing that happens in a piston when air compressed so rapidly that it heats up to the point of exploding, only far more agreeable for people who get in the way.

Rapidly condensing air does have its side effects, it must be said. Though it might not feel like it on the level of everyday experience, wind is very heavy stuff.  If you weighed a column of air 1 meter (3.28 feet) in diameter that extended to the top of the atmosphere you could come up with a figure of about 10 tons (22,000 lbs). Consequently, as cold air plummets down the side of a mountain, it tends to pick up speed. Chinooks can reach hurricane speeds. On November 19, 1962 a Chinook blasted through Lethbridge, Alberta at a speed of 171 km/hr (106 mph).

Summer weather in January is a perk that is not taken lightly in the great white north, but having your house blow away will put you at a powerful disadvantage when the arctic air mass reasserts itself, as it inevitably does. There may be a lot of give and take when it comes to Chinooks, but a little heat in the dead of winter is a pretty cool thing.

Friday, 15 November 2013

Sketchy Fact #15: The Windiest Place... In the Wuhrld

Mount Washington in New Hampshire, USA is the windiest place on Earth. The highest wind speed ever recorder there was 372 km/hr (271 mph) in 1934. The guy who went outside to read the instruments was tied to the building with a rope.

Wednesday, 13 November 2013

The Neanderthal Within: The Science of Cousin-Lovin’

One of the most interesting facts in the study of human evolution is that for a very long stretch of time (much longer than modern humans have existed) there were multiple species of humans running around the planet trying to make their way. We (Homo sapiens sapiens) represent the only surviving species on the branch on the tree of life known as Homo.

So what happened to the others? There are too many stories to tell in such a short article but one stands out as being worth sharing. It is the story of our closest cousins. A group with whom we shared the planet for roughly 160,000 years before they vanished about 40,000 years ago. Today we call them Neanderthals (Homo neanderthalensis).

In the same way that people are often hard on their relatives, modern culture has been tough on Neanderthals. We tend to think of them as prototypical cave-people. Hunched over, heavy brows, probably carrying a club, and dumb as a rock. The problem with the Fred Flinstone view is that the evidence contradicts it pretty badly.

The more Neanderthal skeletons we look at and the more sites we examine, the more scientists are realizing that Neanderthals were the equal of their H. sapiens counterparts. In a lot of ways, they even had us bested. First and foremost, they were physically stronger. They were slightly  shorter than modern humans with males reaching an average height of about 5 foot 6 inches and females just a touch over 5 feet tall, but their bone structure suggests that they were more heavily muscled and the injuries they routinely survived imply that they were tough as nails.

That is pretty unsurprising. You would expect a species of human that lived in Europe during an ice age to be pretty tough. The second fundamental difference between our species hits a little closer to the modern human ego. Neanderthals may have been smarter than us.

Not only did the average Neanderthal have a larger brain than a modern human, they also left behind evidence of art and advanced tool making abilities. Some scientists have even suggested that modern humans stoleideas from Neanderthals when it can to making spear points and the like.

Clearly something isn’t adding up here. If Neanderthals were stronger, smarter, and more technologically advanced than us, why aren’t they around today? There are a couple explanations. First, brain size isn’t everything. Recent research has suggested that a greater portion of a Neanderthal’s brain was devoted to processing vision and movement and less was devoted to social networking compared to modern humans. Second, when you factor in brain to body mass ratio, modern humans aren’t left as far behind.

The difference in technology can be explained by necessity. Modern humans evolved in conditions that were less demanding than Neanderthals. While they were chasing mammoths through blizzards, we were running around in the warm climes of Africa. We had a lot of the same problems to solve, but they had more of them overall.

Eventually when humans showed up in Europe we managed to overtake Neanderthals in terms of population. It may have been luck, or it may have been ingenuity. What is incontestable is that we edged them out, but we may have not wiped them out. Recent analysis of Neanderthal DNA and comparisons with our own genetic code strongly suggest that once we had them outnumbered, we began absorbing them through interbreeding.

That is one of the great things about science. Just when you think you have things figured out, you get an M. Night Shyamalan  twist that leaves you questioning your whole perception of things. It becomes a lot harder to think of Neanderthals as club-carrying knuckle-draggers when you find out that the DNA of your average person of European descent is 2.5% Neanderthal.

It looks like the branches on the tree of life are bit more tangled up than we originally thought.

Friday, 8 November 2013

Sketchy Fact #14: Papua New Gatsby

The native people of the Papua New Guinea Highlands were first contacted by modern civilization in 1933, eight years after The Great Gatsby was published.

Wednesday, 6 November 2013

Volcanoes: Flatulence of the Earth

If I had to take a guess at what really got the whole idea of “science” going, and if that motivator was some singular event, I think the safe money would be on a volcanic eruption. I imagine some early human scratching his head and looking on with an expression of dumbfounded awe as a pyroclastic flow swept past at 100 km/hour, simultaneously burying him in a heap of ash and debris and cooking him at a temperature up to 700 degrees C.

Whether they are entombing cavemen, spewing lava into the air, or simply dominating the horizon volcanoes are one of the few things that both the average person and the most devoted nerd can agree are just plain awesome.

Volcanoes come in three main varieties: spreading centre volcanoes, subduction zone volcanoes, and intraplate volcanoes. Each is the result of intense pressure deep within the Earth and the mechanics of tectonic plates.

To really understand volcanoes you need to understand plate tectonics. Since this article is meant to focus on the former, I will sum up the latter in a single sentence: The Earth’s surface is made up of enormous plates that fit together like a badly made jigsaw puzzle, moving around and smashing into each other to produce all the features of the planet’s landscapes.

When plates pull apart from one another, hot rock from beneath bubbles to the surface and you get a spreading zone volcano. 

When two plates smash into each other, one is forced beneath the other (AKA subduction) where the pressure and friction cause the rock to melt. Eventually that rock finds its way up through cracks in the surrounding material to the surface and you get a subduction zone volcano. 

When you have a plate with a weak spot and some particularly hot and motivated magma beneath it, you get an intraplate volcano.

Beyond that, volcanoes don’t like it when you try to come up with general rules about them. Spreading zone volcanoes tend to be the least explosive, but Iceland is really just a combination of these sorts of volcanoes and explosive eruptions there have halted global air traffic and cost the world economy billions of dollars. Intraplate volcanoes tend to be the most destructive, but the Hawaiian hotspot has been quietly erupting more or less constantly for at least the past thousand years.

Clearly, volcanoes are full of surprises. Unfortunately they are rarely the kind of surprises that you look forward to. In 1980, volcanologists in Washington state watched and waited while Mount Saint Helens swelled and rumbled, expecting either an impressive vertical eruption or for the volcano to slowly go back to sleep. No one predicted the lateral (sideways) explosion of ash and debris that killed 57 people and flattened 200 square miles of forest.

The most recent surprise that volcanologists have unearthed is one that they seemingly should have discovered quite a while ago. On September 6, 2013, scientists announced that they had discovered the largest volcano on Earth (so far). Tamu Massif as the peak is known rises 3.5 km from the sea floor about 1,600 kilometers east of Japan and occupies an area of 310,000 square kilometers, making it about the size of the British Isles. The volcano formed over millions of years as eruptions piled up one on top of another and collapsed outwards and upwards, although the summit still lies about 2,000 meters (6500 feet) beneath the waves.

Tamu Massif is being compared to another massive volcano called Olympus Mons which is found on Mars and still holds the title of “biggest volcano in the solar system.” Until now, mountains as big as Olympus Mons were not thought to exist on Earth. The reason is took so long to find the behemoth volcano is that the world’s oceans are one of the few things that are less well understood than volcanoes themselves. Also, scientists originally thought the formation was the result of multiple volcanoes joining together. The recent breakthrough was in establishing the existence of a single vent responsible for forming Tamu.

It’s pretty incredible to think that something like the world’s biggest volcano could exist beneath the ocean, unknown to people, until the 21st century. It really makes you wonder what other incredible things lay hidden by water and question whether or not it’s a good idea to keep dumping radioactive waste and movie directors into the depths.

Friday, 1 November 2013

Sketchy Fact #13: DNA in Spaaaaaaaaaaace!

If you stretched the DNA from a single cell into a fine thread it would be 2 meters (6.6 feet) long. All the DNA from all your cells arranged in a line would be twice the diameter of the solar system.