Wasting garbage Sep 3, 2009
I feel bad about using and wasting the following things that end up in the garbage: 
  1. Paper towels.  They do a great job of drying things up, but sometimes they simply soak up water.  Clean water.  I feel bad using paper towels to dry my hands after washing them because I could just as easily use a washable towel or my pants.  All three objects perform the same function equally well, but only paper towels end up in a landfill.  Thankfully paper towels are biodegradable, so they won't sit around forever.
  2. Plastic bags.  On at least two separate occasions in my lifetime, I threw out a bag full of other plastic bags, simply because I had no use for that many plastic bags and they were taking up space.  This is still something I sort of regret, because plastic bags have a tendency to sit around in landfills for eternity.  And most times, they perform the stupidly simple purpose of transporting objects from one location to another.  You could use a billion other things to perform that function.
  3. Styrofoam cups.  I like me some smoothies, but smoothie-makers feel the need to package their products in landfill-destined polymer cups (which also stay around for eternity) because they keep things cold.  I personally wouldn't mind plastic (recyclable), metal, or even wood containers to transport my blended fruit semi-beverage from the store counter to my mouth.  I'm not that picky.
Wendy's a hippie, and it's rubbing off on me. #science
Recorded voice Jul 29, 2009
Popular Science answers the question of why you don't like the sound of your recorded voice: 
"When you speak, the vocal folds in your throat vibrate, which causes your skin, skull and oral cavities to also vibrate, and we perceive this as sound," explains Ben Hornsby, a professor of audiology at Vanderbilt University. The vibrations mix with the sound waves traveling from your mouth to your eardrum, giving your voice a quality -- generally a deeper, more dignified sound -- that no one else hears. Through a loudspeaker or recording device, you pick up sound only through air conduction.
Entertainers and public speakers have a knack for getting over this. #science
Too much AC Jul 17, 2009
Last week it reached a mild 75°F during the day in NJ and dropped down to the high 50s at night, yet the people who live in the house next to mine had their air conditioner on all day and all night.  Maybe it's because I grew up without air conditioning (a habit I still largely keep to this day), or maybe it's because I can use half an ounce of brain power and realize how wasteful it is, but all I could think when I walked out of my house in the morning and heard their stupid air conditioner still churning was:  Open a damn window, ya sissies. #science
Idling planes Jul 16, 2009
As my plane sat on the runway at the end of a long line waiting to take off from Newark Airport last week, I couldn't help but think how futile it seems to own a car that gets good gas mileage, to have installed new windows to better insulate my house and further cut down on energy usage, and to turn off the light in my hallway when I'm not there for five seconds, all the while fifty gigantic, energy-sucking jets sit idling on a runway waiting around for god-knows-what so they can take off.  The power of one = zero.  Change needs to come from above.  (Sorry if that sounds ridiculous and sensational; I couldn't think of a better way to write it.) #science
Blue and green on pink Jun 25, 2009
The blue and green seen in this picture are actually the same color. 
[Image: bluegreenpink.gif]
Discover Magazine says, "our brain judges the color of an object by comparing it to surrounding colors."  If you zoom in and cut out all the other colors in the picture, it's true, they're the same.  This scares me, because I thought my brain was smarter than that.  It turns out it can be easily tricked.  (via Neatorama) #science
Improper measurements (1) Jun 24, 2009
I get confused when the wrong method of measurement is used to quantify something, as in, "The human body is X liters."  Generally you expect measurements concerning the human body to be in weight or height, not volume.  The volume of a solid is hard to visualize, as is the weight of a liquid.  Such is the case with this news report about an overturned beer truck:  "Police say a truck carrying 40,000 pounds of beer overturned in Vermont and closed a highway for several hours."  How much is 40,000 lbs of beer?  I have no way of comparing that to something I know.  I understand a pint.  I understand fluid ounces.  But pounds?  I'm assuming either the police or the reporter simply read the number on the side of the truck that referred to how much weight it was carrying.  It could've been 40,000 lbs of metal or 40,000 lbs of water.  Either way, the truck couldn't carry more than 40,000 lbs of anything.  And yes, I realize that, knowing the density of beer is something close to water (~1 g/cm3), I can calculate that the volume of 40,000 lbs of beer is somewhere around 4800 gallons.  But I wouldn't have to do that calculation if, like every other liquid on earth, this beer was measured in volume. 

It's the same with ketchup.  A bottle of ketchup lists its weight in ounces, which again is odd because I would consider ketchup a liquid, not a solid.  And yes, that's ounces of weight, not fluid ounces, which further points out the ridiculousness of English units. #science
Green Onion Apr 21, 2009
I like The Onion's advice for making your house a little greener: 
Hot water heater:  Go off the grid by making your own clean-burning natural gas.  Simply collect organic material, superheat it, and compress it over several million years.
If The Onion had a customer complaints department, I would work there. #science
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
Big kids fall hard Jan 29, 2009
Gravity tells us that all objects, regardless of weight, when dropped from the same height, travel at the same speed and thus hit the ground at the same time (or rather, this is what would happen if air resistance didn't decelerate objects that weighed less and/or had a larger cross-sectional area, hence why a bowling ball would hit the ground before a feather if dropped from the same height). 

The problem with this idea (not that it's incorrect) is that it only accounts for speed, while ignoring mass.  This becomes painfully obvious as we humans grow taller/larger.  It's fun to watch little kids ski down a mountain or tackle an opponent on the football field, and then get up as if nothing happened.  When we adults try this, we end up with big bruises on our hips and knees, and we're left blaming it on age.  I don't think age is the culprit.  And I don't think it's gravity.  I think it's mass. 

This can be proved with one of two physical quantities, (1) force and (2) kinetic energy.  Force is defined as (mass × acceleration).  Since acceleration is the same for everybody because of gravity, the difference is mass.  Let's say I'm ice skating, and when I fall, I fall on my hip/butt.  Let's also say that I weigh three times as much as that little kid who just zoomed past me (e.g. 150 lbs vs. 50 lbs).  Assuming all my weight falls on that one body part, the force of my hip bone hitting the solid ice is exactly three times the force of that little kid's hip bone hitting the same ice.  Similarly, kinetic energy is the energy associated with a moving object, and it's defined as (½ × mass × velocity²).  If we assume the velocity of a falling child (that's a funny thought) is equal to the velocity of a falling me, that leaves the same relationship:  I have three times the kinetic energy as that little kid.  Maybe that's why it takes longer for me to get back up. #science
Four-stroke vs. two-stroke engines Dec 22, 2008
What's the difference between a four-stroke engine and a two-stroke engine?  This topic seems to come up every once in a while, so I'll record the answer for posterity: 

Four-stroke engines are in pretty much all cars and trucks driving on the road, whether gas or diesel or sporty or work-y or anything else.  The "four-stroke" refers to the four parts of a cycle:  Intake, compression, combustion, exhaust.  HowStuffWorks has a great article with an animation. 

Two-stroke engines are generally in lawn mowers, leaf blowers, chain saws, and dirt bikes.  The "two-stroke" refers to the two parts of a cycle:  Compression and combustion.  Again, HowStuffWorks has a great article with an animation. 

Why use either one?  Two-stroke engines produce more power and weigh less, but they're also louder, require a mixture of oil and gas, don't last as long, aren't as fuel-efficient, and produce more pollution than four-stroke engines.  The reason they're used is because of their power and weight properties. #science