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.
Friday, 29 November 2013
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:
The Writer: http://ca.movember.com/mospace/782322
The Illustrator: http://ca.movember.com/mospace/2300458
Their Team: http://ca.movember.com/team/992625
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
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.
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