Monday, December 22, 2008

What's Gonna Get You?

How have the leading causes of death in the United States changed since World War I? By compiling values recorded by the Center for Disease Control, I have created graphs of these causes in 1918, 1958, and 1998 for comparison. The first observation I would like to point out is the large percentage of Pneumonia and Influenza deaths in 1918. It was the number one cause of death that year (33% of deaths) and many of the surrounding years as well, yet by 1958 we can see it had declined to a measly sixth cause of death (4% of deaths). It was again sixth in 1998 (3% of deaths). In 1918 nearly four times as many people died from Pneumonia and Influenza than the number 2 leading cause of death, heart disease, so falling from 1st to 6th is a large drop. Why this large defenestration? One solid explanation is the development of antibiotics and vaccines. In 1918 there was a large influenza pandemic and in the 1940's the U.S. military developed the first approved vaccine for influenza, which explains the 1958 ranking. The development of antibiotics did not mature until the 1940's, which explains why Tuberculosis fell from 3rd place to off the charts in 1958, 1998, and hopefully for good in the United States.
Another rather drastic change is the rise of Cancer as a leading cause in death in the United States. In 1918 it was the number six leading cause of death (4% of deaths) yet by 1958 it became the number 2 cause of death (15% of deaths) and remained number 2 in 1998 (23% of deaths). This is due to a combination of two basic factors. The first is probably the most recognized today, and that is the rise in use of machines, materials and foods that give off a significant amount of radiation; this is, however, not an object of real concern because the amount of radiation released is often insignificant and of no real danger. The more likely culprit is the increase in lifespan of individuals living in the United States. Cancer is an old age disease. The reason cancer "didn't exist" hundreds of years ago is that it actually did exist, only nobody lived quite long enough for enough genetic mutations to manifest themselves. As life expectancy went up after 1918, so did incidence of cancer.
The last most apparent observation I would like to point out is the apparent rise and dominance of Heart Disease as the leading cause of death in the United States after 1918. Similar to cancer you could argue a larger presence of heart-weakening factors increases Heart Disease risk, however a more valid explanation may lie in the lessening of risk of the other methods of mortality. As risk of infectious disease goes down, other causes seem to go up, only because they are simply what remains.

The values on the graphs were created based on information compiled by the Center for Disease Control, which may be found on the following online pdf (last checked 11/20/2008):

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Sunday, December 21, 2008

Luke...I am your father.

Think about how many times during the day you use your hands, whether it be to pick up something, to hold something, or to even feel something. Now imagine you no longer have your hands. You no longer have the ability to perform simple tasks like picking up an object. This is the case for millions of Americans who have lost their arm(s) and are unable to perform the same tasks that many of us take for granted every day.

Before the Luke arm, prosthetic arms only had three powered joints as well as three degrees of freedom. A
user could move their elbow, their wris t, and open and close some type of hook where the hand would normally be. The problem with this type of prosthetic is that it is frustrating to control and does not provide that much functionality (IEEE Spectrum). Often people who had lost their arms opted to not even wear this type of prosthetic because wearing the burdensome prosthetic was simply not justified by the small amount of assistance it provided. For as technologically advanced as this world had become, prosthetics was living in the age of the Flintstones. A new prosthetic had to be created that would give amputees’ more range of motion and fine motor control but it also had to be modular, usable by anyone with any level of amputation.

Technology has finally caught up and the Luke arm has been created. The Luke arm is a prosthesis named after the lifelike prosthetic worn by Luke Skywalker in Star Wars and was created by Dean Kamen. The Luke arm is a scientific breakthrough in the world of prosthetics due to its remarkable ability to act like a real human arm and hand. Microprocessors have been made small enough and power consumption has become efficient enough to place control electronics, lithium batteries, motors and wiring into a compartment the same size, shape and weight as the human arm. A human arm has a total of twenty two degrees of freedom, a lot more than the prosthetic arms most people are using now. What makes the Luke arm better than previous prosthetics is the fact that the Luke arm has eighteen degrees of freedom. The Luke arm has many degrees of freedom due to the enormous amount of circuitry inside the arm, which allows for its agility (

The Luke arm has tremendous motor control so that people who use the arm are able to pick up coffee beans one at a time, hold a power drill and even unlock a door.The reason the Luke arm has such fine motor control is the use of tactors. A tactor is a sma
ll vibrating motor-about the size of a bite size candy bar- that is placed against the user’s skin. A sensor on the Luke hand, which is connected to a microprocessor, sends a signal to a tactor, and that signal adjusts the grip strength of the hand. When a user grips something lightly, the tactor vibrates slightly. As the user’s grip tightens, the frequency of the vibrations increase (IEEE Spectrum). This is a non-operative way that allows users to pick up a paper cup without crushing it or firmly hold objects without dropping them.

Another way to control the Luke arm was discovered by neuroscientist Todd Kuiken of the Rehabilitation Institute of Chicago, who has successfully been able to surgically connect amputees’ residual nerves, which connect the upper spinal cord to the 70,000 nerve fibers in the arm, to the pectoral muscles. The patient thinks about moving the arm and signals travel down the nerves that were previously connected to the arm but are now connected to the chest. The chest muscles now contract in response to the nerve signals, instead of the arm muscles. The contractions are sensed by electrodes on the chest and those electrodes send signals to the Luke arm, allowing it to move (IEEE Spectrum). By using the Luke arm, amputees are still able to create signals from their brain to their arm; the only difference is that there is a robotic arm there instead.

Before the Luke arm is available to the public it must first be approved by the FDA, and it cannot be approved until several clinical trials have been performed.

Below is a video demonstrating how the Luke arm works and its capabilities.


Adee, Sarah. (February 2008). Dean Kamen’s “Luke Arm” Prosthesis Readies for Clinical Trial. Retrieved November 25, 2008, from

Chistensen, Bill. (2008, February 3). Luke Arm Robotic Prosthesis. Retrieved November 25, 2008, from



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Saturday, December 20, 2008

Coriolis Effect

The Coriolis Effect is the apparent deflection of a moving object when viewed from a rotating frame of reference. The effect is named after the French scientist who first described it in 1835. The effect is most commonly associated with the rotation of the Earth. Objects that travel in a straight path appear to veer right in the northern hemisphere and left in the southern hemisphere. In actuality the object stays on a straight path and only appears to curve due to our rotating due to our rotating frame of reference on the Earth.

The apparent force causing a Coriolis Effect is a fictitious force because the effect is only obtained in a rotating frame of reference. When visualized from the inertial frame of reference it is apparent that there is not actual force working on the object. However, despite the fictitious nature of the force, it can be describes in mathematical terms.

F= -2mΩ x v

Where: F is the Coriolis Force; m is the mass of the rotating object; v is the velocity of the particle; and Ω is the angular velocity vector of the rotating object.

Mathematically explaining the Coriolis Effect is important in order to make predictions on the observed path of objects on the Earth. Two common uses of the Coriolis Effect are in long range ballistics and meteorology.

Coriolis Effect on Ballistics

The Coriolis Effect has implications on long range ballistics, such as artillery shells. Due to the rotation of the Earth, the ballistic will appear to hit to the right of the target in the Northern Hemisphere. The ballistic itself is not curving but following a straight path. It is the rotation of the Earth that makes the ballistic miss.

An object that moves longitudinally along the Earth will appear to deflect to the right because of the eastward rotation of the Earth. In order to compensate for this deflection, the artillery round must be aimed to the left of the actual target in order to hit the target.

The principles of the Coriolis Effect are best exemplified on a smaller frame of reference. This animation of two figures passing a ball on a moving carousel demonstrates the principles of the Coriolis Effect as seen on Earth. When the one figure passes the ball from the center of the rotating carousel to the outside, the ball's trajectory will remain straight; however it will miss the recipient because of the rotation of the carousel. When both figures are on the outside of the carousel and pass the ball, the ball will travel straight but will appear to swerve in relation to the figures on the carousel.

Coriolis Effect on Meteorology

Air tends to flow from low pressure areas to high pressure areas. However, when we observe the actual flow of air masses notice a tendency to flow perpendicular to low pressure areas. This phenomenon can be explained by the Coriolis Effect. As the following video shows, we would predict the flow of air to go directly towards the low pressure zone. However, since the Earth is rotating, we observe an air flow perpendicular to the expected path. Meteorologists need to account for this effect when making weather forecasts.

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The development of skyscrapers is a process which had its birth in the ancient world, with the construction of such wonders as the pyramids of Egypt and the Great Lighthouse Pharos of Alexandria. Yet these ancient structures remained the exceptions to the norm of structural height until the dawn of American industrialization. Throughout most of human architectural history, cathedrals and temples were the largest structures to be built, but their heights were limited by the engineering limitations of the time. Today, skyscrapers are an ordinary feature of most modern industrialized cities. There were countless advances in engineering over the centuries which led to the development of modern skyscrapers, but none so influential as those in the late 19th and 20th centuries. I will explore a few main factors which contributed to the ability to build modern skyscrapers which have become such a necessity in modern industrialized cities.
Skyscraper with steel and concrete core: Photo from

The primary factor which has allowed engineers to overcome the boundaries of building tall structures is the use of steel frames. In the past, attaining any significant height required that a structure’s base be wide to compensate for the increase in the force of gravity created by the weight of the upper levels. This situation meant that as the height of a structure increased, its base had to increase by an increasingly larger factor. The layout of modern cities does not provide the space for such buildings to be erected, and so an alternative is necessary. The use of steel frames (preceded by iron frames) allows for very high construction with no need for a large base. A steel skeleton of rails, riveted together with steel plates, and connected to massive steel columns is what makes up the frames of average skyscrapers today. The huge columns, encased in concrete, are what support the brunt of the force of gravity acting on a building. Functioning like a spine at the core they channel the gravitational forces down through the frame and into the piled foundation below, which is supported by the bedrock beneath. The support structure of some buildings, such as the Sears Tower, is located on the outer perimeter of the building. This so-called “hollow tube” design works in much the same way. (Wells 20)
Skyscraper foundation support (several of these hold up the main columns): Photo from

Generally, all of the steel support structure is coated in fire-resistant material to ensure that it is protected from warping under extreme heat. The “flimsy fire cladding” (Wells 19) of the steel structure was a factor in the collapse of the World Trade Center towers during the terrorist attacks of September 11th, 2001. It is believed that the impact of the hijacked airplanes largely stripped away this coating, and exposed the superstructure to fire. Once weakened, the beams gave way and resulted in unequal distributions of weight onto lower beams, which were not designed for the strain and collapsed in a domino effect.

The physics associated with the support systems of skyscrapers is complex and fascinating. Virtually every aspect of this science is applied in the design and construction of the supports. The force of gravity, as mentioned above, must be considered thoughtfully when designing the foundation, so that its surface area distributes the weight of the structure effectively. The frictional forces between the steel and concrete foundations and their surroundings must be assessed as well for the distribution of weight. Compressive and tensile strengths of both steel and other materials used in construction must be known in order to assure their proper use and maintain structural integrity. Thermal expansion characteristics of all the supporting material must be known in every conceivable temperature they may endure.

Additionally, buildings must be constructed so that they can be subjugated to natural forces and still maintain structural stability. Wind is prime among these forces. A building must be able to withstand the forces associated with high winds; a problem which must be addressed with care in the tallest of buildings, as wind pressure increases by a power of three with height (Wells 15). Skyscrapers built in earthquake zones are particularly complex. A thicker, stronger-than-normal internal structure is required, as well as complex dampening systems of springs and flexible materials which absorb and distribute the kinetic energy of earthquakes, maintaining the vertical equilibrium of the building.

Today’s skyscrapers, though enormous, are limited by the imperfections of human technology. We can only build them so high. Matthew Wells describes the theoretical vertical limit of a skyscraper, using current building materials, as being 18 kilometers high. However, due the deficiencies of construction, and the unpredictability of environmental forces, he sets the practical limit at 1.60 kilometers. And yet, as of today, we have yet to achieve more than half that height. The Burj Dubai, still under construction, will be the tallest man-made structure on the planet when completed, and stand at 818 meters or more. That is a formidable accomplishment for structural engineers, and yet it is well below the highest conceivable limit.

Burj Dubai: Photo from

It is easy to imagine going beyond the heights achieved by modern skyscrapers, (science fiction authors do it all the time), but actually building futuristic supertall structures requires overcoming many engineering obstacles. One of these is the fundamental problem of base size. Steel can only do so much, and eventually we reach the point where we need to augment or buttress the base in order to compensate for the increasing force of gravity applied to the foundations by the materials high up. Just looking at the photo of the Burj Dubai above reveals that the engineers still needed to follow a somewhat pyramid-like design even with the most up-to-date building materials.

Going beyond the 1.6 kilometer mark will require strong materials. Talk has been made about the possibility of using carbon nanotubes, which have a tensile strength fifty times that of steel, and a Young’s modulus five times greater than steel. Maybe with this technology, and some radical engineering practices, the human race will one day see that 1.6 kilometer barrier broken. I am not optimistic, however, of seeing such things come about in my lifetime.

Works Cited

Wells, Matthew. Skyscrapers: Structure and Design. New Haven: Yale, 2005.
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Michael Phelps has the record for most gold medals in a single Olympic games, was voted Sportsman of the Year in 2008 by Sports Illustrated, and holds world records for the 200m freestyle, 200m butterfly, 200m medley, 400m medley, 4x100m freestyle relay, 4x200m freestyle relay, and the 4x100m medley relay (Wikipedia, 2008). Michael Phelps truly is great at swimming; no one can deny it. However, is it really viable to say that his technique is the sole reason for his continued success in breaking records?

If we look at men’s and women’s 200m butterfly world records since 1959, we notice that the men’s times have dropped 17.9% whereas the women’s times have dropped 20.9% (see figure). There has not been a particular standout female swimmer in the past 50 years who everyone claims has changed women’s swimming, so then why is Michael Phelps considered to be the cause of the incredible decrease in men’s race times seen recently? American swimmer Mark Spitz improved upon the record by 5 seconds and broke it seven times from 1967-1972; from 2001-2008, when Michael Phelps broke the record seven times, it decreased by a mere 2.55 seconds, only half of the decrease achieved by Mark Spitz. Limits exist in all things, so does this mean that we are approaching the limit for the fastest possible time in the 200m butterfly? Have we already surpassed the actual physical limit and now it is only changing because of technology? I don’t know, but let’s take a look at the technology of the swimsuit Phelps used in the Beijing Olympics, Speedo’s LZR Racer Swimsuit, to see how the swimsuit helped him and the other swimmers who raced with it.

This video from explains how the LZR swimsuit works to improve efficiency of movement through water, which is what the swimmers are looking for. In order to get better times, they need to increase their efficiency, be it through better technique or a better suit. This Speedo suit decreases drag by 24% and makes the body more streamline, increasing the efficiency of the swimmer (Brain, 2008). All athletes are looking to improve their times and technology facilitates this. The big controversy is whether or not the LZR swimsuit is the same as doping in other sports. On one hand, the swimsuit increases efficiency; on the other hand, the swimmer still needs to perfect his or her technique in order to perform at the elite level. It’s up to you to decide.


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Flying Buttresses

Flying buttresses are an architectural feature mainly seen used in medieval cathedral designs. First developed in Romanesque architecture and later perfected in Gothic architecture, flying buttresses are built projecting from the walls of a structure down to the foundation in an half arched shape. The purpose of such projections is to support the weight and horizontal thrust of the high arches and domes spanning the interior space. The flying buttress serves as a bridge, carrying the lateral thrust produced at the base of the arches and domes due to their weight, across to the outer buttress, which is massive enough to absorb the pressure (Watterson 103). The stability of the entire building depends upon the balance of pressures and with the existence of flying buttresses, cathedrals were able to be built taller and more glorious than ever before (Statham 370).

(Photo Above: Flying Buttress,

Flying buttresses originated from the idea of internal buttresses used in Romanesque architecture dating back to the 10th century. Buttresses were used for support on the inside of the church walls because it was thought that such large flat structures were unfitting to be seen on the outside of the churches. Towards the end of the Romanesque period, as architects challenged one another to build churches and cathedrals higher than ever before, the use of flying buttresses on the outside of these structures became necessary. With the beginning of the Gothic period, flying buttresses not only became used more for their function, but for their appearance as well. Gothic architecture began in the 12th century in France and lasted until the 16th century. Mainly used in the construction of cathedrals, abbeys, and churches, the Gothic style is characterized by the pointed arch, the ribbed vault, and the use of flying buttresses.

(Photo Above: Notre Dame Cathedral in Paris, France,

One of the first, and most famous, cathedrals to incorporate the use of flying buttresses was the Notre Dame Cathedral in Paris, France. Its construction began in 1163 and the cathedral was finally completed around the year 1345. Many different architects and ideals went into the construction of Notre Dame. Flying buttresses were incorporated into the architecture for the primary use of balancing the pressure produced by such vaulted spaces. Another very important reason flying buttresses were used in the Notre Dame Cathedral was to allow adequate sunlight into the building (Temko 127). With such high walls and lack of windows the cathedral proved to be quite dark. Architects then realized that with the addition of more flying buttresses, they could place large stained glass windows along the walls of the cathedral to allow in more light. The incorporation of these large windows would further weaken the stability of the walls; however the strength of the flying buttresses solved such issues.

(Photo Above: Flying Buttress of Notre Dame, Paris,

Influenced by the architecture of Notre Dame, the architect of the Chartres Cathedral in France utilized the flying buttress to reorganize the whole appearance of the interior church structure and achieve a look of simplicity and coherence (Henderson 111). The cathedral was begun in the 12th century and went through a multitude of disasters including multiple fires before its final completion and dedication in 1260. Chartres stands with a nave of 120 feet, a south-west tower of 340 feet, and a north-west tower of 370 feet and contains 176 stained glass windows. This magnificent feat and defiance of gravity was made possible by the abundant use of flying buttresses.

(Photo Left: Flying Buttresses of Chartres Cathedral,


Henderson, George. Chartres. Penguin Books. Baltimore, Md. 1968.
Statham, H. Heathcote. A Short Critical History of Architecture. Charles Scribner’s Sons. New York, NY. 1927.
Temko, Allan. Notre Dame of Paris. The Viking Press. New York, NY. 1955.
Watterson, Joseph. Architecture: Five Thousand Years of Building. W.W. Norton and Company Inc. New York, NY. 1950.

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With regard to shampoo, the qualities expected by today’s consumer exceed the basic function of cleansing, as there are products for every texture, color, and length of hair. With so many products available on the market, there must be chemical differences to make each one unique, which is where the problem lies. What is actually in these products that are rubbed into our scalps and skin daily and what affects do they have on our bodies?

In the United States, chemicals are being dumped into the products that we use daily with the intent of cleansing ourselves, while in reality these products are disturbing our bodies’ natural pH balance and introducing compounds whose effects on the human body are deleterious, still unknown, or not fully understood. The cosmetic industry has fought resolutely throughout the past several decades to avoid strict regulation by the FDA and we, the consumers, are suffering as a consequence. The FDA does not require safety testing of cosmetic products before their introduction to the public and does not have firm rules for the cosmetic labeling process (Schapiro 2007). Without stringent controls in place, the cosmetic industry is allowed to ignore the potential deleterious effects of cosmetic ingredients. Some companies knowingly use carcinogens or developmental toxins and continue to use them because there have not been specific complaints related to their products. Other companies use chemicals that are untested and could possibly have harmful effects but nobody knows whether or not they do.

The potentially harmful chemicals that are used in cosmetics enter the body in large amounts as base ingredients, seeping in directly through the skin, going straight to the bloodstream, and accumulating, rather than being digested and filtered like trace contaminants in water or food (Skin Deep 2008). One chilling fact is that more than one-third of all personal care products contain at least one ingredient linked to cancer (EWG 2007). These possible carcinogens have the potential to spread throughout the body and accumulate significantly, especially when they are rubbed on the skin and lathered into the scalp on a daily basis. Currently the problem with the cosmetic industry is not the ingredients in shampoo that are labeled. Obviously, if there was an ingredient listed on a product’s label that has been shown to be unsafe, it would send up a red flag and no one would purchase it. The problem actually lies within the ingredients, such as phthalates and 1,4 dioxane, that are not included on the labels due to loopholes.

Independent studies found that more than 70% of health and beauty products tested, such as shampoos, contain chemicals called phthalates. Phthalates are used in cosmetic products as alcohol denaturants, film formers, plasticizers, solvents, and fragrance ingredients. These phthalates are classified as “fragrances” on the label or are part of trade secret formulas, both of which are exempt from federal labeling requirements and are not required to specifically be included on the ingredient labels. The problem with leaving phthalates off the labels is that consumers buy these products not knowing what they are spraying, brushing, or rubbing on their bodies, which can be harmful. These phthalates are known to cause problems with the kidneys, liver, lungs, and blood clotting, but the main concern is underdevelopment of the male reproductive tract (Aggregate 2002). A study that was conducted testing 136 women and their sons between the ages of 2 and 36 months found that the mothers’ increased urinary concentrations of phthalate metabolites and subsequent prenatal phthalate exposure were correlated with decreased anogenital distance and impaired testicular function in the boys after birth (Swan 2005). These lab results indicate that a significant percentage of cosmetics companies may be hiding phthalates on store shelves within the containers of their products, with no warning for pregnant or potentially pregnant women who might want to avoid purchasing products that contain chemicals linked to birth defects.

Another problem with labeling is with contaminants. Many companies have attempted to reformulate shampoo so it does not contain sodium lauryl sulfate, the chemical that causes shampoos and soaps to have a lathering effect, which also potentially damages the lipid layer of the skin and has associated health risks (Malkan 2007). This chemical is too harsh for hair and strips away the natural oils in hair over time, leaving hair frizzy and dull with split ends and breakage (Schulman 2007). In the process of chemically removing this harsh foaming cleanser, it is converted to sodium laureth sulfate in some shampoos. This change looks better on the ingredients labels, but one thing that is overlooked is the fact that this process of converting the lauryl to laureth produces a byproduct called 1,4 dioxane, which is a petrochemical linked to cancer (Malkan 2007).

All of this information can certainly be overwhelming and people may not know how to go about making changes for a healthier lifestyle. There are a few solutions that can be combined to change the face of beauty products in today’s market. Ideally, companies should publicly pledge to voluntarily remove phthalates, sulfates, and other potentially unsafe chemicals from their products, manufacturers should clearly label all phthalate-containing products on the container that can be read easily before purchase, and manufacturers should test cosmetics ingredients and final products thoroughly, only marketing products that meet rigid safety standards, just as is the case with food products (Houlihan 2002). But honestly, without strict regulation none of this is ensured to happen because it requires research and change, both of which cost money. Therefore, the next step is for the federal government to set strict safety standards for personal care products, which would call for a change in the way the cosmetic industry does business; companies would have to reformulate their products to exclude ingredients that could potentially be harmful to people, whether it be because they have been found to be detrimental or because there is no toxicity data available for them. Consumers could also live a healthier lifestyle by doing their part. When reading the labels on beauty products, people cannot even pronounce half the words, let alone know what these ingredients do and how they affect the human body. Researching specific products, finding manufacturers than can be trusted who follow reputable standards, and decreasing the number of products that are used are key steps in reducing the risk of encountering harmful chemicals in beauty products. When choosing shampoos it is important to remember that the consumers are the ones who drive the market, and without their support and purchases, companies and products mean nothing. Demanding better quality means getting better quality because the industry wants what you want — customer satisfaction.

Some people may be wary of the claims of toxicity and danger in personal care products, stating that the levels of the chemicals are not high enough to experience problems or that the hazardous claims are just false. But when looking at the larger picture, what harm could be done in being cautious? Why use chemicals that may be associated with some risk when it is not necessary? In my opinion, it is worth taking the European approach to cosmetic safety, banning ingredients that have ever been shown to have deleterious effects on the body, even if it is just for peace of mind (Shapiro 2007). There is a reason why people still use the phrase “it’s better to be safe than sorry”.

Watch the video clip above of Stacy Malkan, the author of
"Not Just a Pretty Face", on News 7 discussing the harmful
effects of common beauty products.


"Aggregate Exposures to Phthalates in Humans". Health Care Without Harm. July 2002

Environmental Working Group, “Skin Deep”.

Environmental Working Group. 2007.

Houlihan, Jane; Brody Charlotte; Schwan, Bryony. "Not Too Pretty: Phthalates, Beauty Products & the FDA". July 2002

Malkan, Stacy, "Not Just a Pretty Face". Gabriola Island, Canada: New Society Publishers, July 2007.

Schapiro, Mark. "Exposed: The Toxic Chemistry of Everyday Products and What’s at Stake for American Power". White River Junction, VT: Chelsea Green Publishing Company, 2007.

Schulman, Audrey. "The No 'Poo Do". The Boston Pheonix. May 25, 2007.

Swan, Shanna H., "Decrease in Anogenital Distance among Male Infants with Prenatal Phthalate Exposure". Environmental Health Perspectives Volume 113, Number 8, August 2005
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First off, I feel like I should explain myself. You see, most of what you hear on the news and read in newspapers about Global Warming is wrong. And when I say "wrong", I mean an outright fabrication of facts. Unfortunately, whenever I try to tell people about this, the general reaction goes something like this: "What?! You don't believe in Global Warming?! You're worse than Hitler!!". Alright, so maybe that's slightly hyperbolic, but only slightly. So, in the interest of setting the facts straight, I present 4 popular misconceptions about Global Warming and the actual realities.

4) What You Thought You Knew:
Polar Bears Are About To Become Extinct

In Reality:

No, they aren't. Polar bear populations have increased by almost 50% in less than a decade, from 1480 animals in 1992 to 2272 animals in 2001 ( That data comes from the U.S. Fish and Wildlife Services. Prior to that, polar bear populations had indeed been decreasing, largely due to over-hunting, but after polar bear hunting was curtailed, the bears made an amazing comeback. So, the next time someone says they're worried about polar bears, tell them that the bears are fine and that they should worry about all the animals that are really becoming extinct.


3) What You Thought You Knew:
Melting polar ice caps are going to flood coastal cities.

In Reality:
It may surprise you to learn that the movie Waterworld did not, in fact, have a sound scientific basis. Between 1986 and 2000, Antarctic valleys cooled 0.7 degrees celcius per decade, with serious ecosystem damage (including cute little penguins) resulting from the cold ( In fact, Antarctic ice is increasing at 26.8 gigatons per year, reversing the melting trend that has been in place for the last 6000 years (;295/5554/476?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=positive+mass+balance+of+the+the+ross+ice+streams%2C+west+antarctica&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT). In case you didn't know, a gigaton is one billion tons. And the fact that Antarctica had been melting for the past 6000 years seems to suggest that people may not be the only influence on climate.
Surprisingly, not science.

2) What You Thought You Knew:

Global Warming is causing more hurricanes, like Katrina.

In Reality:

Total hurricane strikes in the U.S. are at an all-time low. There were more hurricanes in the 1850's than the 1990's, and during years in between, the hurricanes go up and down, but generally down ( Obviously, hurricane Katrina has colored all our opinions, but the fact is: you have less chance of being hit by a hurricane than people did 150 years ago.

"Hurricanes don't care about Global Warming"
1) What You Thought You Knew:
That this graph:

....showed something significant.

The Reality:

This graph shows nothing. I'm sure you've seen it before, or others like it. Have you ever actually taken a good look at it? It looks like it shows the planet in the midst of exploding, but it actually shows an average temperature increase of 0.8 degrees C. As you read above, Antarctica has cooled by nearly that amount every decade for the past 25 years.
What We've Learned:
That you can't believe everything you hear about Global Warming. There are many more holes in the theory, from the drops in global temperature between 1940 and 1970, the reliability of the data, the urban heat island effect, and countless more. I urge you to go out and research these things, and verify what I've posted, because peer review and proper interpretation of data is essential for science to be taken seriously. At the end of the day, Global Warming might be a political issue, or a social issue, or an economic issue, but without proper consideration as a scientific issue, it means nothing.

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The heart truly is an amazing organ. It alone is responsible for circulating blood to every organ and cell of the body, and from the moment it starts beating, it does not cease until death. It is regulated to increase its beats per minute during exercise, and to slow down after exercise ceases. It responds to the body’s need for nutrients and oxygen by increasing circulation of the blood. Here are a few facts about this life sustaining organ that most people don’t know.

1) Even at rest, the muscles of the heart are contracting harder than the leg muscles in a person sprinting.
2) There are roughly 5.6 liters of blood in the human body; the heart is able to circulate this volume of blood 3 times around the human body in a minute.
3) The average heart beats about 100,000 times a day, equal to 35 million times a year and 2.5 billion times in an average lifetime (70 years).
4) The system of blood vessels in the human body (including arteries veins and capillaries) is over 60,000 miles long, and the human heart is able to supply blood to every inch of it.
5) The heart pumps enough blood during its lifetime to fill 3 super tankers.
6) The heart is able to accomplish all these amazing tasks, and only weights between 8 and 10 ounces in a grown adult.

The primary responsibilities of the heart are to transport oxygen and nutrients to organs and cells throughout the body, and pick up and rid the body of carbon dioxide and wastes from these cells. The nutrients are transported in the blood’s medium, plasma, while the oxygen is bound to the incredibly important protein hemoglobin, found in red blood cells. Each of these hemoglobin molecules can bind 4 oxygen molecules, and there are over 270 million molecules of hemoglobin in each red blood cell. Therefore red blood cells are able to transport very large amount of oxygen. These red blood cells give the blood its characteristic red color, and are pumped throughout the body at an astonishing rate by the heart.

With each beat the heart pumps two to three ounces of blood into circulation. For the heart to work efficiently the blood passes through a series of chambers in the heart, the blood first enters either the right or left atrium, then is pumped into the right or left ventricles to be pumped to the lungs or throughout the body. There are several valves in the heart to prevent backflow of blood that would otherwise occur due to the high pressure that the blood is subjected to in order to speedily and effectively travel throughout the body.

The contractions of the heart are actually controlled by an electrical signal that travels along the heart. The first signal originates at the SA node which causes both atria to contract and force blood into the ventricles, this signal travels down the heart to the AV node located on the other side, where there is a pause while the ventricles fill with blood, then the AV node signals both the ventricles to contract. This electrical system accounts for the rhythmic beating which allows blood to be pumped most effectively. The resting phase of this system is called diastole, while the contracting phase is called systole. The flow of blood through the heart causes the valves talked about earlier to open and close, giving rise to the lub-dup sound of the heart beating.

The pulse is usually an accurate reading of the heart rate of a human adult, it is a result of arterial expansion due to the increase in pressure of the blood during systole. This wave of arterial expansion begins as blood leaves the heart and travels the lengths of the arteries in the body, gradually weakening in strength as it goes. As you place your fingers on your artery you can feel the expanding and shrinking of the artery as the blood passes through it. A chart of average pulse rates is given below:

Blood pressure is a measure of the systolic and diastolic pressures of the blood traveling through the human body. Blood pressure is measured in millimeters of mercury, a common unit for pressure, and is measured by wrapping a cuff around a person’s upper arm and inflating the cuff to a high pressure and gradually releasing the pressure in the cuff. When blood is first able to pass through the artery collapsed by the inflated cuff this is the systolic pressure, because it is at a higher pressure. When blood is no longer able to be heard passing through the artery using a stethoscope this is the diastolic pressure. As we mentioned before systole is when the heart is contracting, and diastole is the phase when the heart is resting. A chart of blood pressures ranging from optimal blood pressure to stage 3 hypertension (high blood pressure) is given below:

Many factors can affect both blood pressure and pulse, exercise being the first that comes to mind when most people are asked. Exercise increases the number as well as the strength of heart contractions because the body has a higher need for oxygen and nutrients in its muscles. This therefore increases both pulse and blood pressure. Obesity affects both of these as well because, in people who don’t exercise, the heart is out of shape and does not pump as effectively, and therefore must beat more times than the average person to reach all areas of the body. Blood pressure is increased by obesity as well.

The heart truly is a miracle of the human body. It pumps an astonishing amount of blood throughout the body every day and never takes a moment of rest from the time it starts beating until death. Without this amazing organ life would not be possible.



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Why Do We Exercise?

After class yesterday, I walked back to my dorm and threw my book bag on my bed and headed for the couch. Just a typical afternoon; class followed by a long date with TV and food. During the third episode of the Everybody Loves Raymond marathon, I came to realize something- it seems as though every commercial was lecturing me.

(Left: Everybody Loves Raymond Cast

Every 30 seconds a new commercial appeared selling me some instant weight-loss supplement to help me "LOSE 20 LBS INSTANTLY!" or featuring some celebrity talking about the new foundation they started promoting active and healthy lifestyle for kids. I felt almost guilty for indulging in my Bullet Hole chicken nuggets and fries meal while watching fit kids run around on a playground. I felt worthless watching my third straight episode while Bowflex commercials assaulted me.

With this said, I am a college student. I have to defend myself and my actions against those who deem themselves "correct"-those companies that are telling me that being fit and active are the adjectives of a healthy lifestyle. So I ask them - why do we exercise?

...Ok, so I will never get a response from the TV, so I decided to go out and investigate the benefits of exercise myself.

Why Do We Exercise?

I have come to the conclusion that we exercise for three reasons:

Exercise is good for our health.

Exercise feels good.

Exercise improves our appearance.

Your internal engine is your heart. And like all engines, we must keep it in mint condition in order for it to work at maximum performance for a very long life. The only way to maintain a healthy heart (besides eating correctly) is by pushing it to do more work - conditioning it- forcing it to pump more blood through your body in a shorter time period. This is where exercise comes into play.

(Below: A heart, )

Exercise, whether it be cardio or strength training, puts stress on your body (mainly your muscles), forcing your heart to pump more blood through your circulatory system, to feed your muscles with oxygen. In doing so your heart is conditioning itself and if done consistently, will improve its efficiency. Each contraction will be stronger, and as a result, more blood will be pumped through your body with less effort and less contractions.

The normal resting heart rate for healthy adults is between 60-80 beats per minute. Athletes have a lower resting heart rate because their hearts are stronger and better conditioned, enabling them to pump more blood through their bodies with each contraction. Those of us who sit around all day, eating junk food and watching re-runs of Everybody Loves Raymond, typically have a resting heart rate in the neighborhood of the upper 90s or even 100s. This forces our hearts to do more work (even when we are resting)- putting it under more, unnecessary stress. Basically, a more conditioned heart can increase your longevity.

The second reason for why we exercise comes from the well-known feeling among athletes called the "runner's high". Supposedly, long distance runners and all athletes for that matter, gain some-sort of euphoria following a long-distance jog or some sort of long-term physical activity. Medical specialists credit the feeling to the anadamine levels that rise during strenuous activity. This substance is able to cross the highly impermeable blood-brain barrier, increasing the dopamine levels in the brain (Chris, 2005).

Exercise-induced release of anadamine is a cost-free way of receiving a high.

Lastly, we exercise to look good. In a world that focuses too much on our outer appearance, being in good shape means a lot. Exercising helps you lose unwanted fat (bad) and helps you build lean muscle (good), hopefully exposing that six-pack hidden under your college keg.

(Below: Cover of Men’s Health Magazine, )

I don't even have to explain why a physically fit appearance is desirable- just go to any local store and glance over the cover pages of magazines. Fit men and women grace the covers with bold captions telling you to "READ INSIDE TO SEE HOW TO LOOK LIKE THIS!" We are molded to understand that looking good feels good and leads to success, and as time progressed it has come to be known as fact that when we look good, we feel good. So why not go out and get a little exercise?

Many companies actually hire personal trainers to work with employees one on one. The idea (supported by many years of experiments and data) is that these employees will be happier in the office and thus increase their productivity. The company can then increase its overall productivity just by hiring a personal trainer.

You can't say that hiring a personal pastry chef would have the same effect.

Some companies actually provide exercise facilities for employees because employee’s efforts in the gym will result in decreased medical costs. A recent publication on the New York Times website discussed a few companies who have taken steps to improve the overall health of their workers.

At Great Lakes Industry, President Larry Shultz cleaned up a storage area in order to make room for a few exercise machines. He hopes that employee’s increased health will decrease the company’s healthcare costs.

At another company, “Mike Shirkey, president of Orbitform Group, said, ‘If [employees are] not healthy and alert, they can't do things like designing projects.’ The company has installed a fitness center with exercise machines and showers that workers can use at lunchtime and before and after work” (

One of the most important reasons to exercise is to drastically reduce your risk of acquiring chronic and genetic diseases. By exercising frequently you reduce your risk of…

· High Blood Pressure by 30 – 50%

· Diabetes by about 58%

· Heart Disease

· High Cholesterol

· Stress

…and many other dangerous life-style oriented health hazards. I have included a video that gives you every reason to start exercising on a regular basis if you haven’t yet, and every reason to keep exercising if you have already started.

THAT is why we exercise.

Work Cited:

Chris, 2005. Informative Blog Post at

Retrieved Data from WebMD's Page

Retrieved Statistical Data from UCLA's Public Health Page

Slide Show information (
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· The main reason that people build skyscrapers is because they are very convenient. They serve to fit a lot of floor space in a comparatively small amount of ground surface because of their immense height.
· The challenge in building a skyscraper is building vertically and fighting the downward pull of gravity. As the building gets taller and taller, there is more of a downward force all of which is supported by the base of the building. This is similar to the construction of a pyramid. The reason they are built as they are is because they had to build a wider, sturdier base in order to support all of the weight bearing down from the rest of the pyramid.
· The advancement of iron and steel production was a huge reason that constructing skyscrapers became a reality in the United States. Prior to that, no buildings were more than a few stories tall.
· Iron and steel beams that were relatively lightweight, could support much more weight than brick and concrete while taking up significantly less space.
· Skyscrapers are supported by their steel skeleton. Their weight is supported by a group of vertical steel columns. Each individual floor of the structure is supported by horizontal steel girders between the vertical columns. Many buildings also have diagonal steel beams to supply extra support.

· By building this grid, called the super structure, all of the weight is transferred to the vertical columns in which there is a downward force at the base which is supported by the substructure.
· A skyscrapers substructure supports the vertical beams in a cast-iron plate which sits on top of a grillage (stacks of horizontal beams laid side by side). The grillage sits on top of a level concrete surface. Once this substructure is completed, it is entirely covered with concrete to ensure stability.
· Skyscrapers were not only made possible by the advancement of steel production, but also after the introduction of elevator technology. After you build something a few stories tall stairs are problematic. In most skyscrapers, elevator shafts are placed in the core of the building so they can supply additional support to the structure.
· Skyscrapers have become more and more popular in the world today as the demand for location grows but availability of land decreases. Skyscrapers make it possible to fit a large amount of building space in a small amount of land area.
· The first ever skyscraper was built in Chicago, Illinois in 1885. It was called the Home Insurance Building and it was 10 stories high and 138 feet tall.
· Today, the largest skyscraper is the Burj Dubai in Dubai, a city of the United Arab Emirates. Although it has not yet been completed, it has 160 floors and stands at a whopping 2320 feet, nearly 17 times the height of the first skyscraper.

Burj Dubai

Home Insurance Building

· When demolishing a skyscraper, explosives are the most commonly used methods because they are both efficient and safe. More often than not, skyscrapers are surrounded by other buildings so you can’t just simply knock it over or blow it up…most demolition is done through a process called implosion.

· An implosion is an inward collapse of the building so that it all crumbles down on top of itself and does not disturb the buildings surrounding it.

· In order to pull off a proper demolition, you must place explosives on the supporting beams so and several floors of the skyscraper so that the building can no longer support itself and collapses floor by floor until it is reduced to nothing more than a pile of rubble.

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Friday, December 19, 2008

Tides Are Neat

Many People understand that there is a high tide and a low tide but few know what actually causes these tides and that there are different patterns of tides and tide cycles. There are two main forces that causes tides: the first is the gravitational forces of the Moon and Sun acting on the Earth; the second is the inertial (centrifugal) force due to the Earth's rotation about the center of gravity of the Earth moon system. The Moon's rotation around the Earth combined with the Earth's own rotation causes the ocean's water to bulge in the direction of the Moon. This is called the Equilibrium Tide Theory; the Moon's gravity causes a bulge on the facing side of Earth, and the centrifugal force causes a bulge on the opposite side of Earth. (2) The Sun has a gravitational pull on the Earth, which coincides with the pull of the water surface towards the Sun. The Sun has a smaller effect on tides because its distance from the Earth is that much greater than that of the Earth and Moon.
The cycle between a high tide and a low tide is roughly 13 hours. High tide and low tides occur approximately one hour later each day because as the Earth completes one rotation, the Moon has progressed 12 degrees along its orbit around Earth in the same direction. (1) So high and low tides are directly related to the position of the Moon relative to the Earth.
The two different types tide cycles are neap tides and spring tides. These are explained by the positions of the Sun and the Moon relative to the Earth and the corresponding affect on the tides. (See Illustration) A spring tide is when the Sun and the Moon align themselves with the Earth. (2) This increases the gravitational force acted on the oceans and increases the amount that the tides rise and fall. A neap tide is when the Sun and Moon align themselves in a 90-degree angle relative to the Earth and more equally distribute their gravitational pull on the oceans. (2) The time between a spring tide and a neap tide lasts about seven days.
There are three different types of tide patterns: diurnal, semidiurnal, and semidiurnal mixed tides. (2) What makes these tide patterns is how many times a high tide and low tide occur during one day and the level that those tides reach. A diurnal tide is when there is one cycle between high tide and low tide during the day with a moderate change in water level. This occurs when the Moon is aligned with either the North or South Pole. A semidiurnal tide pattern is when there are two cycles of tides during one day with a moderate change in water level (two high tides and two low tides). This happens when the Moon is aligned with the equator. A semidiurnal mixed tide is when there are two cycles of tides in one day but the tides occur at different levels. This means that there is one elevated water level high tide and one moderate water level high tide along with one elevated water level low tide and one moderate water level low tide.
Tides are also partially responsible for waves, erosion, currents, and animal migration and mating. (1) What makes them even more complicated and hard to predict is the relationship between where the ocean meets land and how fast the ocean floor drops away from the continental shelf. As you can see, there are many different factors that determine the dynamics of tides, the formation of tides, and who are effected by tides.

1) ocean, (2008) In Encyclopaedia Britannica. Retrieved December 1, 2008, from Encyclopeadia Britannica Online:
2)Sverdrup, K.A., and Armbrust, V. 2006. An Introduction to the World's Oceans 9th edition

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Brief Background:
Albert Einstein was born in Germany in 1879 to a Jewish family (Albert Einstein, Nobel Lectures 1967). He was an average student at the Swiss Federal Polytechnic School in Zurich. While in school many professors strongly disliked Einstein. He also met and married his first wife, classmate Mileva Maric during this time (Einstein’s Big Idea, 2005). He graduated in 1896 with a degree in teaching mathematics and physics (Albert Einstein, accessed 2008).
After graduation Einstein began working as a clerk in a patent-office in order to support his wife and children, but this really wasn’t enough. During this time Einstein wrote numerous scientific papers on theoretical physics, and had a few published. It was a paper submitted in 1905 to obtain his doctorate that earned Einstein success and fame (Albert, accessed 2008). While Einstein is most well-known for his E=mc2 work he did not win the Nobel Prize for this. In 1921, he won the Nobel Prize for his paper on the theory of the photoelectric effect (Albert, 1967).

Einstein married Mileva Maric in 1903, and they had three children. Einstein was a very solitary person, and created an ultimatum document for Maric to sign. The document contained things such as; she must bring him food to his study, she could only speak to him when he wanted to be spoken too, and that she could not expect him to be
affectionate. She chose not to sign the ultimatum, and moved out with the children. They did not divorce right away, and Einstein actually bribed Maric into divorce. The bribe was that he would give her and the children the prize money if he were to ever win the Nobel Prize (Einstein, The History channel, 2008). After the divorce in 1909, he remarried within the year to his cousin Elsa Lowenthal (Albert Einstein, 1967).

Einstein published three significant papers in the year of 1905. The year of 1905 is sometimes referred to as the “miracle year” for Einstein. The first paper he published in 1905 described the photoelectric effect. The photoelectric effect is when metals emit electrons when hit by a particular wavelength of light. He based his theory on Planck’s work that described electromagnetic radiation. Planck had discovered that light energy was proportional to frequency of radiation, but Einstein further interpreted this to show that light energy was formed by a collection of radiation (Albert, accessed 2008). Einstein received the Nobel Prize for his work on this paper.

The second paper of 1905 proposed the special theory of relativity, and the third paper provided evidence of atom-sized molecules. His work on the theory of relativity was based off of Hendrik Antoon Lorentz’s theory of electrons and also on Maxwell’s equations of thermodynamics. He based the theory on the knowledge that equations describing the motion of an electron could be used to explain the motion of any particle or rigid body moving with a constant velocity. The theory of relativity describes time dilation, and how mass and energy are related. He also later wrote that in a certain way mass and energy could be considered as the same (Albert, accessed 2008). This notion that mass and energy are related is what led to the famous E=mc2 equation. This equation explains/hypothesizes that mass would be equivalent to energy if all the mass was turned into energy based on the relation of mass to the speed of light (c). His paper on the evidence of atom-sized molecules was based on calculating the average trajectories of particles during random collisions with other molecules as a fluid or gas (Albert, accessed 2008). It was these initial papers that started Einstein’s career of discoveries, theories, and equations. He later would become famous for his E=mc2 equation, and his general theory of relativity that are still being proven today,

Einstein was also known for his anti-war beliefs during World War II. He did not renew his German citizenship when he returned in 1919 from Switzerland and moved to the United States in 1933. Once he moved to the United States Einstein began to urge the development of nuclear weapons, more specifically an atomic bomb before Germany did. His correspondence with President Roosevelt at this time persuaded Roosevelt to fund the Manhattan Project. The Manhattan Project was simply the project to develop the first nuclear weapon during WWII that was supported by the US, United Kingdom, and Canada. He later became involved in efforts towards nuclear disarmament during the 1950’s (Nobel Lectures, Physics, 1967). He became chair of the Emergency Committee for Atomic Scientists in (The Nuclear Age II, 1996), and stated,
"Here, then, is the problem which we present to you, stark and dreadful and inescapable: Shall we put an end to the human race or shall mankind renounce war? People will not face this alternative because it is so difficult to abolish war."

Einstein was very dedicated to his
stance on the war, and the use of nuclear weapons only when absolutely necessary, as well as many other civil rights issues.
Einstein died in April 15, 1955 in Princeton, New Jersey (Nobel Lectures, Physics, 1967).

Albert Einstein,

(n.d.). Retrieved November 24, 2008, from Famous Physicist and Astronomers:

Nobel Lectures, Physics. (1967). Noberl Prize Foundation. Retrieved November 24, 2008, from

NOVA. (2005, June). Retrieved November 24, 2008, from PBS:

The Nuclear Age II. (1996). Retrieved December 1, 2008, from The Center for History of Physics:

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Thursday, December 18, 2008

Physics of Cow Tipping

On a late night with nothing to do but hang around cow pastures, the idea of cow-tipping may easily cross your mind. Assuming there is a cow asleep and standing up, you next want to figure out how much force is required – if applied perpendicularly – to tip the cow over.

(image on right is from

The Statics of Cow Tipping has provided approximate values and has performed calculations. Here, we will discuss the process undertaken as well as a critique of the work.

First, let us approximate the following dimensions of a cow:

Body (rectangular prism) = lwh = 2.5*2.5*6 = 37.5 ft3

Head (cylinder) = pi*r2*h = 3.14*.52*1 = .785 ft3

Legs x4 (rectangular prism) = lwh = .5*.5*2.5 = .625 ft3

From here, we can find the center of mass for each body part. Shown below is the table from The Statics of Cow Tipping (source).

Center of Mass

Part Volume XCenter YCenter ZCenter X(V) Y(V) Z(V)
Body 37.5 1.25 3 3.75 46.875 112.5 140.625
Head .785 1.25 6.5 5.5 .98125 5.1025 4.3175
Leg 1 .625 .25 .25 1.25 .15625 .15625 .78125
Leg 2 .625 2.25 .25 1.25 1.40625 .15625 .78125
Leg 3 .625 .25 2.25 1.25 .15625 1.40625 .78125
Leg 4 .625 2.25 2.25 1.25 1.40625 1.40625 .78125
Total 40.785 ---- ---- ---- 50.98125 120.7275 148.0675

In addition to leaving out units (which I have added in), the site fails to explain where exactly the body parts are located and to what point are the Center values relative. To the left is my own rendition of the cow, which is drawn more closely to scale and includes the point of relativity, noted as the origin point (0,0).

Continuing on in the table, the columns labeled X(V), Y(V), and Z(V) are found by multiplying each part’s volume by its respective XCenter, YCenter, and ZCenter distances (columns 3-5). Of course, this is assuming that the density of the cow is uniform. In reality, the density is not uniform, thereby changing where the center of gravity is located for each part. However, we will ignore reality for this analysis. The volume components of each part are totaled and then divided by 40.785ft3, the total volume of the cow. These answers signify what distance the overall center of gravity is from the point of relativity. The distances are as follows:

XCenter = 1.25 ft

YCenter = 2.96 ft

ZCenter = 3.63 ft

Now we move on to equilibrium/torque calculations. We will assume the same given values as The Statics of Cow Tipping:

mass of cow = 1400 lbs

height of horizontal pushing force = 5 ft

horizontal pushing force = 300 lbs

force of friction = 1400*.45 = 630 lbs

(the cow won't slide)

Although we’ll use the same equation, torque = force*radius, our radius will assume that the cow’s left hind and fore leg remain on the ground. Shown below are two images. The force vector schematic on the left is editted from The Statics of Cow Tipping (source) and includes the forces due to friction, pushing, and gravity on the cow. For the image on the right, the radii are labeled as follows:

r(f) = force radius

r(c) = cow radius

To find the correct radius, we need to consider the moment arm of the force. Since the moment arm is the perpendicular distance from the axis of rotation to the extended line of force, we see that r(f) is indeed perpendicular to the pushing force and r(c) is indeed perpendicular to the force of gravity on the cow.

We can easily find that r(f) = 5 ft and r(c) = 1.25 ft. Now the difference in torque is 1400*1.25-300*5=250 lbs/ft. We need the torque to be less than zero for the pushing force to be sufficient enough to overcome the cow's turning force, so it is clear that one person is not enough to tip a cow.

We're determined to tip the cow, so let's add more people. Assuming the people have identical pushing height and force and will stand in a way so as to push the cow in a uniform manner, then we can calculate that the minimum number of people required to tip a cow is 1400*1.25 < n="2.

Our results agree with The Statics of Cow Tipping. However, we must also consider some real life truths. Most likely, a real cow's legs will move or tilt when the cow is pushed. On the plus side, this moves the center of gravity, making it easier to tip the cow as the shift will shorten r(c) with time while r(f) remains the same. Unfortunately, the cow would sure counter-balance, making it more difficult to tip. Even so, these calculations are still good approximations and as such, leave the myth of cow tipping open to testing!

(above image is from


Semke, Matt. "The Statics of Cow Tipping",


Author unknown. "Google Image Search on cow tipping",

Semke, Matt. "The Statics of Cow Tipping",

Author unknown. "Google Image Search on cow tipping",

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