Physics of snowboarding (2) Mar 20, 2009
Whenever I zoom past people on a snowboard, I wonder if my speed is a result of my recklessness, or if it's because of my weight.  The answer to this lies in the fun and exciting world of physics, which attempts to explain complex phenomena by assuming the world is ideal.  And away we go! 

If we treat the skier or snowboarder as an object on an inclined plane, we can simply sum the forces in each direction.  If we assume the direction of motion is x and the direction perpendicular to the hill is y, we have: 
Fx:  W*sin(theta) - Ff - Fd = m*ax
Fy:  Fn - W*cos(theta) = m*ay

W = weight = m*g
Ff = friction force = mu*Fn
Fd = drag force = 0.5*rho*cd*s*v^2
Fn = normal force

m = mass
g = acceleration due to gravity
theta = slope of hill
mu = coefficient of friction between snowboard and snow
rho = density of air
cd = drag coefficient of human
s = presented area of human
v = velocity
Since there's no motion perpendicular to the hill (unless you're jumping), the forces in the y-direction are zero.  Solving for normal force and doing some algebra, we get the acceleration in the x-direction as a function of several terms: 
a = g*sin(theta) - mu*g*cos(theta) - 0.5*rho*cd*s*v^2/m
These three components are gravity, friction, and drag.  If we take drag out of the equation for a moment (since it depends on velocity and doesn't contribute much for slow speeds), a snowboarder's motion down the hill is simply a function of gravity, slope, and coefficient of friction, which means it's not a function of mass, i.e. heavier people don't go faster. 

However, coefficient of friction is a tricky thing.  It depends on the amount of surface area in contact as well as the specific materials involved.  For example, if one ski contributes X amount of friction, two skis will contribute 2X.  And then there's the fact that skis and snowboards are rarely in full contact with the ground.  Also, board length and rider stance can each have an effect.  Finally, snowboard material, finish (including wax), and snow consistency all play a role.  Suffice it to say rider mass has an effect, whether or not it's significant or measurable. 

Getting back to drag, we can further assume that air density and drag coefficient are essentially constants (cd technically varies with velocity and body shape, but the values are all pretty close), which leaves just a few variable terms: 
a ~ s*v^2/m
Simplifying it even further, it can be shown that mass and area vary inversely and almost equally, i.e. a heavier person tends to have more surface area than a lighter person.  And since one is in the numerator and one is in the denominator, they essentially cancel out.  This leaves us with: 
a ~ v^2
In human terms, this says that a person's acceleration varies inversely with the square of their velocity, which in even more human terms means that the slower a person is going, the faster their acceleration will be, which doesn't necessarily say much, but it does say one thing:  Speed doesn't depend on mass.  So no, I don't go faster because I'm heavier.  I probably go faster because I'm a moderate adrenaline junkie and my enjoyment on a snowboard comes through speed, not carving back and forth down a mountain.  That being said, my weight has an effect on the coefficient of friction between my board and the snow, and while it's hard to quantify, can be assumed to have at least some affect on speed.  How's that for a non-answer? #science
Funny because funny Mar 19, 2009
It's my belief that some things are funny simply because another person finds them funny.  They're funny because they're funny.  Such is the case with many puns.  Not many people will actually laugh at a play on words, though I'm one of the few people who will.  And because of this inescapable fact, people will laugh along with/at me because they think it's funny that I think it's funny.  Hey, whatever works. #sociology
GE commercials (1) Mar 18, 2009
I think it's funny how GE advertises their aircraft engines, diesel locomotives, and medical imaging systems on their very own TV network, NBC, as if the people who watched their sitcoms on weeknights had any kind of ability to buy such things.  I guess they're trying to advertise their brand, not just their products, but it still comes across as odd. #entertainment
Too much chivalry (1) Mar 18, 2009
Some people complain that there's just not enough chivalry these days.  Where are the men who open doors for women?  Who carry heavy objects for women?  Who hail a cab, give up their seat, or pay for dinner? 

My complaint is that there's actually too much chivalry, and it's annoying.  I'm saying this from my male perspective, as the recipient of several acts of chivalry by other men.  I don't mind that a fellow man holds the door for me or helps me carry a heavy object.  But men shouldn't be giving up their seats for other men.  They shouldn't be insisting on paying for meals.  A line has been crossed, and depending on the circumstances it's either creepy or emasculating.  I appreciate the sentiment of respect and genuine care, but insisting on paying for my meal makes me feel like a little girl. #psychology
Future president (1) Mar 17, 2009
I look forward to the day when our country is run by an attractive, unoffensive, relatively neutral, mentally stable, likable man or woman backed by the best minds in fields like economics, business, and science.  I picture a celebrity like Matt Damon or Oprah enlisting the help of Bill Gates, Michael Bloomberg, and Stephen Hawking.  The president him/herself would merely be a figurehead, capable of speaking well in public and looking good on camera.  The real brains of the operation would be the real brains of the operation.  I guess that's essentially how it's done now, but I still feel like we're forced to choose between a car without wheels and a car without a battery.  Can't we get a complete car?  (To be fair, this Obama fella isn't all that bad.)  Also, we often don't know the people behind the scenes, both because they're behind the scenes and because they're not famous people.  If Michael Bloomberg can generate billions of dollars and then run the city at the center of the universe, I think he should be in the oligarchy that runs the country.  And Oprah should be his spokeswoman. #politics
Deal or No Deal Mar 16, 2009
Deal or No Deal might be the stupidest TV show ever created, though I might be just as stupid for watching it.  To be fair, I've only seen it a couple times and I don't fully understand the concept, but I was thoroughly disappointed by what I saw.  How can Howie Mandel, with all his fashionably bald, soul-patchy coolness fail to impress?  Easy; make a game of chance into a primetime network TV show.  And most times, the "chances" are less than flipping a coin and getting heads.  At least Wheel of Fortune requires the ability to spell.  They could easily cut an hour-long show down into about five seconds.  "Will you will a million dollars?  *flip*  Nope."  One thing that stands out about the contestants is their incredibly selfish, pigheaded greed.  I mean that in the nicest possible way, of course.  Several times throughout the show, the contestant is offered a sum of money to leave the show, oftentimes rejecting that offer in the hopes of winning the million dollar grand prize.  The episode I watched had a woman reject five or six separate offers for over $250,000, then tearfully explain how a million dollars would help her family get out of debt, pay the mortgage, and support the kids.  The offers kept going up until they hovered just under half a million, as the woman continued to shut off her critical thinking skills and follow her foolhardy greed.  I found myself wanting to actually jump through the TV and smack the woman in the face, in the hopes that I could convince her to use a tiny part of her brain to think about the situation for two seconds and realize that half a million now is infinitely better than the less-than-50% chance of one million later.  She ended up accepting the next offer, which was lower though still over $400,000, and finding out that if she had continued playing the game, she would've won the million dollars.  If I was on the show, I'd probably accept the first offer that popped up, likely in the range of $5000, making me perhaps the worst possible contestant, though also $5000 richer.  Easiest $5000 ever. #entertainment
K-Rock died (2) Mar 16, 2009
Last week, I was surprised to find out that the radio station 92.3 K-Rock in New York City died, or more accurately, it switched to a top-40 station.  This came just over three years since the station (and many others around the country) switched to Free FM, and then switched back after about 18 months.  This most recent switch was equally as unexpected and unwelcome, and it's really thrown a wrench into my morning commute.  I used to listen to a talk show that kept me entertained just long enough for my 30-minute commute.  But now I'm forced to look for other music on the radio, and it just once again hammers home the point that I don't like "accepting" whatever is broadcast.  I'd rather have a choice, and that choice isn't radio.  For the moment, I've allowed myself to settle on NPR, though I'm morally obligated to financially support it, and I'm not sure that I want to be "a supporter of NPR" a.k.a. "a card-carrying liberal".  In the future I see myself getting more into audiobooks and podcasts and anything else that can occupy my time in nice little 15- or 30-minute intervals. #entertainment
Mother of invention (1) Mar 16, 2009
They say necessity is the mother of invention, but I would argue that laziness is an important factor too.  Do we really need TV remotes that change channels by sending infrared signals through the air, or do we just not feel like getting up?  Do we really need those Roomba robotic vacuum cleaners to vacuum our floors, or do we just not feel like doing it ourselves?  (On a side note, I would argue that many of the inventions that involve robotics are essentially centered around laziness and some guy in a lab saying, "I don't feel like doing this.  Maybe I can design a robot to do it for me.") 

Another mother of invention turns out to be sports and leisure.  I noticed this as I was on a ski lift going up a mountain in Vermont this past weekend.  Huge machines that looked like scorpions were carving snow with their "tails" to make a giant half-pipe.  It was immediately evident that these machines were designed and created exclusively for this purpose, so that skiers and snowboarders could spend their winter weekends doing tricks and avoiding catastrophic head injuries. 

I guess it just amazes me that entire industries are formed and countless dollars are spent in the advancement of science and technology, often for questionable gain.  But I don't mind; the half-pipe keeps all the dirty teenagers busy so they take up less space on the rest of the mountain.  It's a win-win. #technology
Pixel count vs. pixel size Mar 10, 2009
When it comes to digital cameras, everyone's always talking about megapixels.  In an attempt to summarize several links about this topic, here's the main idea:  Pixel count (i.e. the number of megapixels) in a digital camera doesn't matter as much as pixel size.  And in some cases, more megapixels means worse quality pictures.  I've read that five or six megapixels is really all most people need, even for printouts and enlargements.  The only time it would be beneficial to have more than that is if you tend to edit your pictures by cropping or cutting out and magnifying a certain part.  So if you take a picture of the entire Manhattan skyline and only want to print out the section with the Empire State Building, it might be good to have lots of megapixels.  But again, just because your camera says "15 megapixels" on the front, doesn't mean it'll take a better picture than the guy standing next to you with the 5-megapixel dSLR. 

Pixel size is what really matters, and I'll attempt to illustrate this with a picture. 
[Image: imagesensors.png]
These are examples of image sensors.  The image sensor is what actually records a digital version of what is physically visible.  The one on the left is what's typically found in handheld point-and-shoot cameras.  The one on the right is what's typically found in dSLR cameras.  Both image sensors have the same number of pixels, but it's easy to see that the larger sensor has larger pixels.  Larger pixels mean better color depth and better light capturing.  This doesn't mean you can't take a great picture with a small camera.  It just means that pixel count isn't the only way to compare two cameras.  There's also the issue of pixel quality, i.e. image sensors made by Company A are better than those made by Company B, but that's a whole different animal. #entertainment
Lunatic ninja (1) Mar 10, 2009
An Australian man, upon being awoken by an intruder breaking through a window and jumping on his bed, had this to say:  "My initial thought when I was half awake was, 'It's a lunatic ninja coming through the window.'"  He was later relieved to discover it was merely a kangaroo, which had to be wrestled outside in a state of confusion and panic. 

The reason I'm posting this is because the only reason someone would say something like that is so that people like me would link to his story on the internet.  So there you go, sir. #nature