The Starry Messenger

Fuel Economy

2006-06-01T21:35:00.000-04:00

by Charles Bartlett (Class of '06)

It is a well-known fact that the world has a limited supply of oil. Oil is used in a multitude of ways, but its most lucrative application is in the automotive industry due to its vast amount of stored energy. The oils used in the auto industry are usually derived from petroleum, and much of the world’s petroleum supply exists under some of the most politically instable and fanatical areas of the world. Finally, the emissions from oil and gasoline, which is also derived from petroleum, once the two are used to their potential in the internal combustion engine have been shown to have damaging effects on the earth’s atmosphere and ozone layer.

Do to these problems, some people have long been calling for an alternative to the use of oil and gasoline in the internal combustion engine, or for a different engine all together. This argument gained a lot of strength in the 1990s, due to all of the media coverage that global warming received. As much of the world’s oil supply is located in the Middle East, political and military uncertainty in the region further increases the demand for alternative power. In the last year or so, this demand has become even stronger due to the sharp spike in gasoline sales.

Currently, some promising alternatives to gasoline are the hybridization of gasoline engines to include electric power, and the use of either ethanol or hydrogen as fuel. Gas-electric hybrids have already been released on the automotive market. These cars use both electricity and gasoline or diesel fuel, and the result is much better gas mileage. Though there are many designs, the most common is that used in the Toyota Prius. When the car is at cruising speed, or at any other point when the car only needs a small thrust, the internal combustion part of the motor spins a generator, which either recharges the battery, or powers the electrical apparatus that propels the car. Other charging of the battery occurs during regenerative braking, where the braking system of the car captures some of the kinetic energy that would usually be lost to heat in normal cars. When the battery has been charged sufficiently, the car is able to switch to its electrical means of propulsion, and is thereby able to save immense amounts of fuel.Another promising alternative is the use of ethanol as a fuel. Brazil is leading the way in the use of ethanol, and produces its ethanol from sugarcane. The country recently announced that it no longer depends on Middle Eastern oil for its fuel. The United States is also pursuing the use of ethanol. The U.S. has long been a great producer of corn, and it will hopefully use much of its corn crop in the future to produce ethanol. The engines that use ethanol in the future will most likely be FlexFuel engines that can run on gasoline, ethanol, or any combination of the two.

Though the future of automotive fuel is still in question, the alternatives to gasoline and oilmake for safe and efficient driving in the future.

http://en.wikipedia.org/wiki/Regenerative_braking
http://en.wikipedia.org/wiki/Ethanol#Physical_properties
http://en.wikipedia.org/wiki/Hybrid_electric_vehicle

Black Hole Information Lost Forever? Not Quite, According to String Theory

2006-06-01T19:31:00.000-04:00

by Sam Wass (Class of '06)

One of the most intriguing conclusions found by string theory, the proposed “theory of everything” which unifies the four fundamental forces (gravity, electromagnetism, strong nuclear force, weak nuclear force), regards one of the universe’s most bizarre objects: black holes. String theory applied to black holes suggests that black holes do not necessarily lose all of the information of the objects sucked inside of them. This resolves one of the greatest problems in modern physics, called the information paradox. Classical equations stipulated that the end result of a black hole was always the same, regardless of the matter put into it. However, this violates quantum mechanics, because it stipulates that processes must be traceable.

Black holes are one solution to Einstein’s equations of general relativity. They are the remnants of stars so massive that they collapsed in on themselves after their supernova, a massive explosion of a dying star. These bizarre objects have zero volume and infinite density, and are completely described by their electrical charge, angular momentum, and mass. It was long thought that information sucked into a black hole was lost forever, but string theory suggests that this may not be the case at all.

String theory, as its name indicates, suggests that the universe is composed of tiny “strings”, which are extremely small loops of energy. They vibrate in different ways, in very much the same was as a musical string would be plucked, and these different vibrations produce the different particles that science observes. Because of Einstein’s mass/energy equivalent (E=mc^2), the string at lower energies represent the least massive particles, while strings at high energies represent more massive particles.

If string theory is applied to black holes, then the singularity, or center of the black hole where the laws of physics do not apply, does not become so indescribable anymore. String theorists describe the singularity as a large mesh of strings, rather than a point in space. This mesh, or “fuzzball” as it is often called, would become very stretchy as it becomes more massive in order to create a supermassive object like a black hole. Scientists who tested the diameter of a black hole that would be produced using this method found that their answer closely approximated the diameter of classical equations.

If this postulate is correct, then information about the objects sucked into the black hole can be stored inside, and then reemitted via Hawking radiation, which happens when the black hole radiates its mass in the form of small particles. Until the application of string theory to black holes, it was believed that a black hole would destroy any information stored inside it. In order to justify this loss of information, quantum mechanics, the rules that govern the universe at its smallest scales, was thought to break down in black holes. However, the application of string theory shows that information stored in black holes is not lost, if string theory is proven to be correct.

References:

New Scientist, “Hawking Cracks Black Hole Paradox” by Jenny Hogan
http://www.newscientist.com/article.ns?id=dn6151

“Physics, M-Theory, and Black Holes"

"Information Paradox Solved? If So, Black Holes Are “Fuzzballs”"

Chronic Allergies

2006-05-30T22:33:00.000-04:00

by Joseph Chang (Class of '06)

Currently, over 50 million Americans suffer from allergic diseases. In fact, 54.6 percent of US citizens test positive to one or more allergens, such as dust mites, rye, ragweed, and cockroach, according to a recent national survey. Allergies are already the sixth largest source of chronic disease for Americans and cost the US health care system about $18 billion annually. In addition, the rate of increase of allergy sufferers is about 5 percent per year; specifically, the number of Americans who suffer from asthma has increased over 100% from 20 years ago to about 20 million, today.

Allergies occur when the body’s immune system reacts to the presence of an innocuous substance, such as pollen or dander, as if it were a dangerous pathogen, such as a virus or bacterium. The development of an allergy begins when the body is exposed to a protein in a harmless molecule and recognizes it as a possible danger. On the first exposure, the body produces specific antibodies called immunoglobulin E (IgE) antibodies which recognize the protein. These IgE antibodies then attach to mast cells, which are responsible for creating various chemicals, such as histamine, prostaglandins and leukotrienes, which jolt the body into anti-pathogen maneuvers, including inflammation and mucus production. The first time the body is exposed to these allergens, there will likely be no symptoms; however, the second time the body comes in contact with the allergens, the IgE molecules recognize the offending proteins and trigger the release of the mast cells’ chemicals and cause the typical stuffed nose and headache allergy-symptoms.

One of the major causes of allergies, as with many other ailments, is based on genetics. Studies show that children with one asthmatic parent have greater chances have having asthma than children with no asthmatic parents. Children with two asthmatic parents have even greater chances of having asthma. In addition, pairs of identical twins, who share the same DNA, have asthma more frequently than pairs of fraternal twins, who do not share the same exact DNA. However, genetics alone does not explain the dramatic increase in allergy rates over the past few decades.

A second cause of allergies is the diet. The reduced fresh fruit and vegetable intake and the corresponding low level of antioxidants and minerals in the American diet both increase the risk of getting allergies. In addition, antibiotic use may be helping the rise of allergies by killing of certain bacteria in the intestine which suppress allergy.

Additionally, the environment plays an enormous role in whether or not Americans develop allergies. Environmental pollution, especially airborne pollution, is often cited as sources of allergies. One example of the pollution on allergies is a study which showed that children who live near major highways and are exposed to diesel fumes exhibit increased sensitivity to allergens that they already react to. Another environmental factor that is being considered as a source of allergies is excessive cleanliness. Essentially, this idea of excessive cleanliness causing allergies, called the hygiene hypothesis, states that immune systems must be exposed to certain levels of pathogens when they are young. If developing immune systems do not come in contact with enough pathogens they will be unable to distinguish between harmless substances and true dangers to the body.

References:

“Allergy Statistics.” National Institute of Allergy and Infectious Diseases. http://www.niaid.nih.gov/factsheets/allergystat.htm. May 30, 2006.

Newman, Judith. “Misery for All Seasons; Allergies: A Modern Epidemic.” National Geographic. May 2006.

The Disappearing Act: Florida’s Coral Reeves affected by Warming Waters

2006-05-30T18:48:00.000-04:00

by Michael Grossi (Class of '06)

It is real folks. Global Warming is here to stay. Many people think that Global Warming is characterized by shrinking ice caps, smog, and warmer temperatures. This may all be true, but one of the most unnoticed conditions caused by Global Warming is the destruction of the world’s coral reeves. This problem is hitting close to home as well. Florida is known as a great tourist destination. It has pristine waters and beautiful sea life to explore. However, because of Global Warming, Florida’s Coral Reeves are on the brink of nonexistence. Scientists are frantically trying to import polyps of coral into areas where much of the coral has died.

Recently two different species of coral were added to the endangered species list: staghorn and Elkhorn. “The species have declined 97 percent since the late 70's”
(http://www.nytimes.com/2006/05/22/us/22coral.html?_r=1&oref=slogin).

Scientists believe that one of the main culprits in the murder of the coral is from coral bleaching. Coral bleaching is when the coral shed their colors, turn white and then die. Coral bleaching is directly tied to rising water temperatures which is a symptom of Global Warming. The episodes of Coral bleaching have been occurring with greater frequency over the past few years. While the ocean’s temperature has only gone up a degree or two over the past few years, it is still enough to have a catastrophic affect on the fragile ecosystems the coral reside in.

The National Oceanic and Atmospheric Administration said that “climate change, whether due to natural variability or human activity is central to several of the threats impacting coral reef ecosystems” (www.msnbc.msn.com/id/12631773/). Scientists have linked the rise in water temperature to the rise in greenhouse gas emissions. Global Warming is one of the main forces in the destruction of some of the most beautiful creatures on the planet. “Requiring greenhouse gas emitting industries to consider how their activities are impacting our most productive marine ecosystems is not only scientifically sound, but also eminently sensible,” Plater added. “The destruction and loss of these coral species would result in the loss of billions of dollars to our economy, the loss of an unknown number of medicines, and decimate local biodiversity. It’s just common sense to consider these impacts before it is too late” (www.msnbc.msn.com/id/12631773).

Despite the negative affect that the rising water temperatures have on coral in some places, other places seem to be flourishing. Not all the news is bad. There are fresh stands of elkhorn and staghorn off Broward County, Fla., in waters where such coral would have never been seen two decades ago. Therefore, one can say that in one area there can be death, in another, new ecosystems can be born.

People have to realize the affect that Global Warming has on our planet. Not only does it make the air we breathe unclean, it kills valuable parts of the world. We have neglected this problem for long enough and now it is coming back to bit us big time. With the water temperatures rising, all of the coral is being killed. Global warming isn’t only killing beautiful creatures to observe, but a valuable part of our life as a whole. The coral provides us with medicine, and it keeps the balance in the ocean. Due to Global Warming we are going to lose these ecosystems, and there is no telling how that will affect us in the long run.

References:

http://www.nytimes.com/2006/05/22/us/22coral.html?_r=1&oref=slogin
http://www.msnbc.msn.com/id/12631773/
www.nrdc.org/globalWarming/nflorida.asp

The Possibility of Time Travel

2006-05-29T22:55:00.000-04:00

by Sam Wass(Class of '06)

Time travel is the main theme in works of literature, H.G Wells The Time Machine and works of film, such as the “Back to the Future” series. But is time travel, the concept of physically moving backwards and forwards through time, actually possible? Some prevailing theories used to describe how the universe works, most notably Einstein’s special theory of relativity, do not forbid time travel. Einstein’s theory declares that relative to a stationary observer, time seems to pass more slowly for a faster moving body. For example, if a person were to observe a clock moving close to the speed of light, the movement of the hands on the clock would be so slow the observer would think that the clock was not working at all. Thus time is a totally relative concept, there is no possibility of their being a clock at the center of the universe by which everyone could set their watches. For an alien traveling at the speed of life, our lives on earth could be blink of an eye. Einstein’s theory could allow time travel because unlike Newton’s mechanics which treat gravity as a force, the general theory of relativity defines gravity as the movement of matter along the shortest space in a curved spacetime. Spacetime as a four dimensional model which combines three dimensional space with one dimensional time, a concept first designed by Hermann Minkowski.

Others believe that time travel could possible through manipulating worm holes, hypothetical topological features in spacetime which are possible through solutions in general relativity equations that are solved with substances of negative energy. A worm hole serves as a link between two distant points in spacetime. Hypothetically, with some exotic future technology one end of the worm hole would be accelerated to the speed of light and then brought back to its original location. Due to time dilation, the phenomenon where the observed time rate is different for two unique reference frames, the accelerated end would have experienced less time relative to the stationary end. This would mean that an object that enters the stationary end would come out in the past relative to the time it entered. A significant limitation to this concept is that one can only travel as far back in time as the initial creation for the technology and thus the technology itself cannot move backwards through time.

Many people believe that direct travel into the past is impossible because of the paradoxes that arise. For example imagine if a person were to travel back in time and kill his grandfather. This would mean that he would have never been conceived and thus would not have been able to travel back in time in the first place. Or consider a person who travels back in time a kills Adolf Hitler, thus preventing World War Two from occurring. This person would have gone back in time with the intent of killing Hitler, but if he were to kill Hitler then he would not be able to have the intention of killing Hitler in the first place.

It is very fascinating to ponder what humans will learn on the nature of time travel in the next century to come. In 1895 Lord Kelvin state, “heavier than air flying machines are impossible”, but we now have technology to travel out of the earth’s atmosphere. Hopefully one day all of our questions about the way the world works will be answered.

References:
http://www.pbs.org/wgbh/nova/time/through.html
http://en.wikipedia.org/wiki/Time_travel#The_possibility_of_paradoxes
http://en.wikipedia.org/wiki/Time_travel
http://science.howstuffworks.com/time-travel.htm

Setback in Rediscovery of Ivory-Billed Woodpecker

2006-05-27T17:49:00.000-04:00

by Brian Lipson (Class of '06)

Last year, the hype began when Cornell researchers claimed to have found evidence of the thought to be extinct ivory-billed woodpecker. The main piece of evidence was video footage that captured a grainy, out of focus clip of a woodpecker with very hard to distinguish features. The footage has caused much debate and skepticism. Research teams have taken both sides, some saying that it is conclusive evidence of an ivory-billed and some saying it is just the similar looking pileated woodpecker that is common to the area where the footage was taken. Notable publications include the Cornell team’s original article about their findings in the journal Science and famous birder David Sibley’s refuting of their claim in the same journal several months later. Further evidence includes sound tapes of supposed ivory-billed calls and pecking noises. Those too have been debated widely, also never really being established as solid proof.

While the discussion goes on, research teams have continued to search the Big Woods area of Arkansas where the bird controversy originally started. Many methods using high-tech equipment are being used to try to capture some kind of evidence to prove the existence of the ivory-billed woodpecker. Infrared cameras and sound recorders are hidden all over the forests in eastern Arkansas to try to collect as much data as possible.

Recently, the Cornell team spent two seasons trying to confirm a sighting of the ivory-billed woodpecker. In this second year of searching for the bird, the team did not find any new evidence of the woodpecker, a slight setback that is disappointing for the team. But they aren’t giving up, and as Ron Rohrbaugh, the leader of the Cornell team’s most recent search, puts it, “Just because we've put two field seasons in doesn't necessarily mean that the bird is not there or that we should have found it by now.”

To this point, the public has been almost completely denied access to the area around where scientists think there is a chance there might be an ivory-billed woodpecker. However, after this most recent search, the public is expected to be able to return. In fact, despite the concern that the public’s return would push out any ivory-billed woodpecker that might still be there, the Cornell team is thinking of having next year’s search consist of volunteers.

One last issue that bothers scientists the most is the funding behind conservation efforts for the woodpecker. The best evidence for the existence of the bird is a fuzzy, low quality video, and yet there has been five million dollars in aid for the conservation of the bird. However, the funding was not an increase in conservation money, it was money taken away from other conservation projects elsewhere in the country. The most frustrating part for the scientists whose projects have lost funding in favor of the woodpecker is that they have their near extinct animals in captivity or unmistakable evidence of their existence.

References:
http://www.kentucky.com/mld/kentucky/news/nation/14613990.htm
http://en.wikipedia.org/wiki/Ivory_billed_woodpecker
http://select.nytimes.com/gst/abstract.html?res=F60D17F7395A0C7A8DDDAC0894DE404482 (as of may 26th)
http://www.sciencedaily.com/releases/2005/04/050428094235.htm
http://www.birdingamerica.com/Ivorybill/ivorybilledwoodpecker.htm

Identification Among Dolphins: They're Smarter Than the Average Mammal

2006-05-27T14:37:00.000-04:00

by Elizabeth Bauman (Class of '06)

Scientists have recently found that dolphins communicate using names. Through the dolphin’s whistle and the dolphin’s voice, dolphins can identify each other and interact verbally. This new discovery makes bottlenosed dolphins, like the one who starred in the famous movie “Flipper,” the only known, non-human animal besides the spectacled parrotlets that have the ability to address one another by an individualized name.

The research was led by Vincent Janik of the University of St. Andrews in Scotland, and it tested the differences in response of the dolphins between a dolphin’s whistle and a dolphin’s “voice.” The scientists recorded the dolphin’s whistles, stripped them of the intonation and sound that would identity the dolphin’s “voice,” and replayed the whistle through an underwater speaker to observe the responses of the dolphins. The scientists found that close relatives of the dolphin would react strongly to the whistle, while many unrelated dolphins would also react to the whistle, indicating that the dolphin’s whistle, regardless of its voice, does provide a means of identification for the dolphin.

The researchers found that dolphins develop their signature whistle as infants and use their personal whistle throughout their lifetimes. Other dolphins repeat the specific whistle back, which shows that they are calling the dolphin by its individual name. In addition, since each dolphin’s blowhole creates a unique and distinct sound, dolphins are able to recognize each other’s voices. Voices are distorted by water pressure, however, so personal whistles are another conclusive means of identification.

Dr. Janik reported from his research, "Bottlenose dolphins are the only animals other than humans to have been shown to transmit identity information independent of the caller's voice."

The interest in dolphin voice recognition began in the 1960’s when researchers noticed a specific set of whistles among captured dolphins. The theory of communication among dolphins was controversial for years and was only recently tested and proven correct. While it is clear that dolphins communicate through personal voice and identifying whistles, scientists are unsure if communication between dolphins can be considered language.

"Language by the standard definition must have syntax-or structuring of words- and reference," said Dr. Laela Sayigh, an investigator at the Woods Hole Oceanographic Institution and the co-leader of the study. "Dolphins do have the ability to use artificial signals to refer to objects, but it is unclear at present if their vocalizations involve syntax."

Scientists are also unclear if dolphins have different accents and dialects in different regions of the world, which could be identified through different patterns and frequencies of the whistles.

"Dolphins in Australia do seem to produce more simple whistles, while Florida dolphin whistles appear to be more modulated," Sayigh said. "Right now, we don’t know why that happens."

The research on communication between animals is continuous and productive. The recent evidence about dolphin voice and name recognition sheds new light on animal interactions. Dolphins’ brains have evolved to an almost human level of intelligence.

References:
http://dsc.discovery.com/news/briefs/20060508/dolphin_ani.html
http://www.physorg.com/news66448409.html
http://www.newscientist.com/article/dn9128.html
http://www.ens-newswire.com/ens/may2006/2006-05-09-02.asp
http://www.theaustralian.news.com.au/story/0,20867,19056713-30417,00.html

Allergies: How They Work and Why We Suffer

2006-05-26T15:24:00.000-04:00

by (Class of '06)
By Hannah

Do you struggle with allergies? Are you allergic to certain foods? Or do you get congested, have itchy throats, or sneeze simply from walking outside? Why do we get allergies, and what makes us suffer?

Allergies are triggered because of a hypersensitive immune system. In a hypersensitive immune system, harmless substances are mistaken to be dangerous and are then attacked.

Lymphocytes which are white blood cells are present in the immune system. Two types of lymphocytes exist throughout the body; B-cells and T-cells. A lymphocyte’s job is to protect the body from foreign substances like bacteria and viruses. However, in a hypersensitive immune system, Lymphocytes can not always distinguish whether something is a threat and make mistakes, causing an allergic response.

Lymphocytes identify surface markers on molecules to determine if they are foreign to the body. When a lymphocyte cannot identify a substance, the B-cell (lymphocyte) which is capable of producing antibodies, travels to the lymph node where it transforms into a cell and produce IgE antibodies which fight the threat. The IgE antibodies fight foreign bodies and ultimately cause allergies and allergic reaction like hives, itching, runny nose, sneezing that many people suffer from.

When the B-cell mistakes a foreign substance as dangerous the B-cell, as explained earlier, produces IgE antibodies which fight the intruder. The IgE antibodies attach themselves to white blood cells that contain histamine. Histamine is a substance that helps fight infections in the body. The process of attachment is called Sensitizing Exposure, and the process takes about ten days to complete. Once the process is complete however, the next time the lymphocytes recognize the intruder a process known as the allergic cascade occurs.

In the allergic cascade, the IgE antibodies (lymphocytes that are there to protect the body from foreign substances) that are bound to the white blood cells containing histamine recognize the surface markers on the foreign body. The antibodies then attach themselves to the surface marker of the allergen (foreign substance detected by the lymphocytes). The attachment between the antibodies and the surface marker of the allergen alerts a group of proteins known as the complement complex. A primary protein attaches to the site and starts a sequence of protein attachment. The intruding cell is defeated once the sequence and chain of proteins is finished.

Destroying the intruding cell however, also destructs the white blood cells containing Histamine that were attached to the intruding cell.

When the white blood cells are destroyed, the histamine that the cells carry is released into the body’s tissues and blood. When the histamine is released, the surface blood vessels become dilated, resulting in lowered blood pressure. The dilation enables fluid to fill the gaps, causing the allergy symptoms that we all know and love.

Other, more serious allergic reactions like anaphylactic shock, which depending on the situation and reaction, can result in troubled breathing, swelling, organ damage, and blocked airways, is caused by a systematic reactions. In systematic reactions, the release of histamine causes capillaries all over the body to dilate, instead of in just one area of the body.

It is amazing what goes on in our bodies. It is at least comforting to know that our allergies are the result of an immune system overly eager to keep us safe.

References:

http://health.howstuffworks.com/allergy1.htm

Gore's Return to the Headlines

2006-05-23T19:33:00.000-04:00

New Blockbuster Movie Focuses on Global Warming
by Robbie Havdala (Class of '06)

Remember Al Gore? He's about to hit the headlines...again. And it's not even for a run at a presidential election. It's for a movie.

Starring in his own film, the documentary An Inconvenient Truth zooms in on Gore's emphasis on global warming in his unsuccessful '00 campsign. The film itself has already received awards from the Sundance Film Festival. It depicts Gore in a new light: a humorous yet concerned man. Ever since his failed campaign, Gore has put his time and energy in a last ditch attempt to save the planet from what he views as "no longer a political issue." His devotion to fighting global warming flourishes in the film famous before it even hits theaters on Wednesday.

Throughout the movie, Gore cites evidence many people would have difficulty rebuking. His main point is that global warming has become a problem of humanity, not of politicians. No longer is it a future threat: it is imminent. One example he brings up: in the past 20 years, global temperatures have been readily increasing. The hottest year? 2005. Another point he makes is Mount Kilomanjaro. Long ago it used to be covered in snow and ice. Within the decade, no snow will be left.

Nor is this simply a problem of natural beauty, notes Gore. He points out the havoc that Hurricane Katrina caused, which may have been helped by warmer ocean waters. Then, Gore claims, consider if glaciers continue to melt at the current rate, coastlines across the earth will be underwater. Manhattan will be submerged. Florida will be half underwater. Recall the number of flood refugees caused by Katrina: now multiply that number by 1000.

While the intent of the movie is to inform, it almost seems to act as a horror film. Yet, the horror of the film is reality. Though only time will tell whether it succeeds at the box office, it will certainly open some people's eyes to the imminent threat that the world seems to keep ignoring.

References (all as of 5/23/06):

http://www.climatecrisis.net/aboutthefilm/

http://www.climatecrisis.net/thescience/

http://www.climatecrisis.net/blog/

http://festival.sundance.org/filmguide/popup.aspx?film=6556

http://movies.yahoo.com/movie/1809257809/info

The Real Story of Pluto

2006-01-30T13:21:00.000-05:00

by Elizabeth Bauman (Class of '05)

Recently, there has been fiery debate amongst astronomers about whether or not Pluto, one of the nine titles that students memorize in grade school, is indeed a planet. New discoveries and found statistics have led astronomers to contemplate whether Pluto should remain considered a planet or be “demoted” to a lesser status.

Pluto was named the ninth planet in our solar system in 1930 by Clyde Tombaugh in the Lowell Conservatory. According to some astronomers, however, Pluto, if found today, would not be named a planet. The definition of a planet, unfortunately for astronomers, is arbitrary.

"It's something of an embarrassment that we have no definition of what a planet is," wrote a professor in the Berkeley News. "People like to classify things. We live on a planet; it would be nice to know what that was."

Some claim Pluto is too distant from the Sun to be considered a planet, but is more similar to Trans Neptunian Objects. Trans Neptunian Objects, called TNOs and discovered in 1992, are small objects composed of rock and ice and are considerably distant from the Sun. These TNOs have characteristics quite similar to Pluto’s and even have a subset of TNOs called Plutinos, or little Plutos.

Size is also a gray area for Pluto. Pluto is twenty-five times smaller than Mercury and its mass is one-fifth of that of the moon. However, Pluto is also nine times larger than Ceres, the largest object in the asteroid belt, and its mass is over ten times that of Ceres. Pluto, while one hundred times more massive any other TNO, excluding its satellite Charon, has diameters closer to those of TNOs than of other classified planets.

Some persist that since Pluto is spherical and not egg shaped like many smaller objects, it would be automatically considered a planet if it were simply closer to the Sun. Such beliefs, however, would entitle the asteroid Ceres and Kuiper-belt objects of Varuna and Quaoar to also be named planets.

Some astronomers disregard these objections to Pluto’s status, waiting for a more concrete distinction between planets and TNOs. "Until there is a consensus that one of the physical definitions is clearly the most useful approach in thinking about the solar system, the IAU will not 'demote' Pluto or 'promote' Ceres," says the International Astronomical Union (IAU).

While the IAU currently denies any plans of change, a commercial opportunity is about to take place. Astronomers will soon name their ten thousandth asteroid discovery, and there are rumors that Pluto will be entitled number ten thousand and a TNO.

Astronomers at Caltech suggest that a planet is a body whose mass is greater than the total mass of its surrounding bodies. By this definition, Mercury is a planet because few asteroids are in its region. Jupiter, too, is a planet because its mass is sufficiently larger than the sum of the Trojan asteroids. Pluto, inevitably, is not considered a planet in this theory because its mass is less than half of the total of the Kuiper Belt Objects.

Currently, without further definitions of and distinctions between planets and TNOs, Pluto will remain a planet. "There is no plan to 'downgrade' or 'demote' Pluto. It will stay as a planet," Brian Marsden, head of IAU’s Minor Planet Center.

Bibliography:

Cauchi, Stephen. "Pluto may Lose Planet Status." Sydney Morning Herald. 11 Jan. 2006.

Cuk, Matija. "Is Pluto a Planet?" Cornell.edu. 11 Jan. 2006.

Hajian, Allie, John Cannizzo, and Laura Whitlock. "Ask an Astrophysicist." NASA. 11 Jan. 2006.

Whitehouse, David. "Pluto will have 'dual citizenship'." BBC News. 11 Jan. 2006.

Development and Utilization of X-Ray Technology

2005-11-17T15:46:00.000-05:00

by David Smoot (Class of '05)

X-Ray technology is a form of medical imaging utilized around the world to evaluate diagnoses and cure disease. Each day, hundreds of thousands of diagnostic X-Rays are performed in the United States. X-Rays were originally invented and created by Sir Wilhem Roegntan in 1897. He developed the X-Ray by making a special cathode ray tube that emitted a new wave frequency or energy packet. Once the X-Ray was produced, it was then illuminated onto a special type of film making an image. Doctor Roegntan decided to experiment with his X-Rays and used a person’s hand in one of his experiments. When the film of this X-Ray was produced, Doctor Roegntan realized that the resulting image was a picture of the bones in the hand. Interesting enough, when the Doctor took the X-Ray, the person involved in his experiment was wearing a wedding ring. Doctor Roegntan recognized that the X-Ray could not penetrate the ring and was the reason why the film came out white around the man’s wedding ring finger. A new technology was born. All of a sudden people could see what was going on inside the mysterious human body.

X-Ray technology is a fancy form of photography. Just like photography is about light exposure, X-Rays are about light exposure and density. Depending upon the different densities and the level of transparency, the X-Ray beam’s encounters will determine the darkness of the image produced. For example, lungs appear black and the bones appear white. The lungs appear black because the X-Ray energy can pass through the lungs density and therefore the image can be developed. The bones are extremely dense and the X-Ray energy cannot pass bone thus not allowing the film to develop where the bones are. A black and white image is made, and due to the organ densities, radiologists can determine which organ is which. This is the basis of X-Ray technology.

Today there are many other sophisticated methods of producing an X-Ray image. Instead of using black and white film, X-Rays are now taken digitally and viewed on high-resolution computer screens. How ironic? Now that we are in the digital camera era, we have decided to go digital in the medical fields. In addition to the digital methods is a method that involves three-dimensional imaging. Three-dimensional images can be utilized using CAT (Computer Assisted Tomography) Scan techniques. In this technique, an X-Ray tube is rotated around a person or any type of object. The tube is rotated in a continuous fashion. A computer then collects all of the images that are made. This information is then plugged into a special mathematical algorithm that then produces a three-dimensional image. As most people predict, a 3-D image provides an exponential amount of diagnostic information as compared to a 2-D imaging system. All of a sudden, internal organ relationships are shown in complete detail. Regular X-Rays only show an image in a XY plane and are therefore less diagnostic.

X-Ray technology is a little over 100 years old. The utilization of X-Ray’s in medicine has revolutionized the physician’s ability to make an accurate diagnosis.

References:

RSNA.org
Sandy Smoot (M.D.)

1600 x 1200? No Problem!

2005-11-17T15:32:00.000-05:00

Vector Graphics and their applications

by Paul Reny (Class of '05)

Ever find an image online somewhere, and think “Wow, that would look good as my desktop background!” only to find that alas, when the image is stretched to cover your beautiful 1600 x 1200 pixel display, it is distorted and blocky. Well, that problem is easily solved with vector graphics. Distorted images be gone, vector graphics are the way of the future, despite the fact that they are still somewhat in their infancy.

Vector graphics, also known as object oriented graphics, are images that are completely described using mathematical definitions. They are constructed using mathematical formulas describing placement, shapes, and colors. Unlike Bitmap images, vector graphics contain shapes, lines, text, and curves, which all together form a picture. Each individual line is made up of a few control points that are connected using Bezier curves. A Bezier curve in its most common form is a simple cubic equation that can be used in any number of ways. Originally developed in 1970 by Pierre Bezier for computer aided design, it has become the foundation of the entire Adobe PostScript drawing model. Using the minimal amount of control points to draw curves, this model is a very space efficient way of drawing images.

In addition to the simplicity with which they are drawn, altering vector graphics is a very simple process, as the shapes and components within them can easily be ungrouped and edited separately. Due to their use of mathematical formulas, vector graphics based images are easily scalable without any loss in quality, up to 6400%. This is a vast improvement over bitmap images, where the slightest enlargement starts to distort the image greatly, even given recent improvements in anti-aliasing. Therefore vector based images are ideal for logos, maps and other objects which are resized frequently. However, due to the nature of the way data is stored in vector graphics based images, they are not well suited to complex images such as pictures. The lack of well defined shapes and lines makes it very difficult to create vector graphics based images from photograph type images. This is the one major shortcoming that vector based graphics images have. An additional minor problem with vector based images is that there is not one uniform file type, such as GIF or JPEG file types for bitmaps, which is used for all vector graphics. Fortunately, it is relatively easy to convert vector based images into bitmaps, although much more difficult to do the opposite conversion.

Since vector based images only need to store instructions for drawing an image, i.e. the data for the few points of the Bezier curves, and not data for each individual pixel, a vector graphics file is significantly smaller than a bitmap file. Often, vector data stored in EPS format, which includes a bitmap preview in addition to the Bezier data, is actually smaller than th e preview data. Other vector graphics formats are PICT, EPS, and WMF, in addition to PostScript and TrueType fonts. Common programs used to draw vector graphics images are Adobe Illustrator, Corel Draw, and Macromedia FreeHand. While bitmaps will continue to dominate the photo image industry, vector graphics are by far a superior choice for simple, scalable, compact size images.

References:

Bitmapped vs. Vector Art. 16 Nov. 2005.
Bitmap vs. Vector. 16 Nov. 2005.
Bitmap vs. Vector-based Graphics. Adobe Web Tech Curriculum. 16 Nov. 2005.
Vector Graphics Terminals. 16 Nov. 2005.
What are Bitmap and Vector based graphics? 16 Nov. 2005.

Light Pollution

2005-11-17T13:58:00.000-05:00

by Sarah Flannery (Class of '05)

Astronomers and stargazers worldwide face the threat they will no long be able to see their beloved night sky because of light pollution. Light pollution is defined as the “glow of light we see at night above cities and towns,” according to the Ontario Hydro Leaflet on Light Pollution. (Ontario Hydro is a progressive electrical utility for Ontario, Canada. It’s caused by poorly designed outdoor lights, such as street and parking lights. The light spills to the side and glows upwards, making the stars less visible. If lights were designed to minimize upward light leakage, light pollution would not be a problem. Light pollution consists of five main components: glare, light trespass, clutter, energy waste, and urban sky glow. Glare blinds us and harms visibility. Light trespass is when somebody’s outdoor lights spill out, or “trespass” onto other people’s property. Finally, urban sky glow destroys our view of the universe. Light pollution has the potential to blot out the night sky in just a few generations from now if we do not do something. Fortunately, there are many steps that even the average person can take to stop light pollution from taking the beauty of the night sky away from us.

The average person can help by investing in quality, efficient lighting for their homes. The light from inside buildings is one of the six major causes of light pollution. Good lighting is well-shielded, so that the light uses just enough light but not too much, and uses lighting sources that are energy efficient. Other things that will help are turning off flights when they are not needed, and using night lighting only when it is really necessary. Since most of the problem of light pollution lie outdoors, local governments and businesses have a big responsibility to reduce light pollution, because they can do the most to help reduce it.

Five out of the six major causes of light pollution can be prevented by businesses or governments. These five causes are: public, street lighting, the lighting from cars, the floodlighting of advertising signs and buildings, the floodlighting of sports stadiums, and security floodlighting. To start with, outdoor light should be regulated, so that the glow does not go to an extreme. If noise pollution can be regulated, then light pollution should be regulated as well. Outdoor fixtures should be shielded just like indoor fixtures are, to prevent spillage of light into the night sky. Billboards and signs should be lighted from the top down instead of the bottom up. When installing outdoor lighting , some things to keep in mind are to make the illumination even, and to only use light where and when it is needed. These are all simple solutions to a massive problem.

References:
All info obtained from information sheets on www.darksky.org

The Evolution of Robotic Surgery--Success and Possibility

2005-11-16T15:41:00.000-05:00

by Hannah Shakartzi (Class of '05)

Who ever thought that surgeons would be able to perform surgery from around the world? Developments and the evolution of robotic surgery over the last five years have improved medicine and have made telesurgery possible.

Robotic surgery first made its debut as part of the da Vinci Surgical System. The da Vinci System first enabled surgeons to perform endoscopic- minimally invasive surgery, without physically maneuvering surgical tools.

It did so with the use of a viewing and control console along with a surgical robotic arm unit which performed the surgery.

A surgeon was able to look at the viewfinder to see magnified 3D images of the surgical site and control the surgery, while sitting at the console. The 3D images were provided by an endoscope, a small surgical camera in the patient controlled by one robotic arm. The surgeon used foot pedals to control the camera, and used hand movements to adjust and reposition the remaining two, robotic arms, performing the surgery. Electrical signals enabled the robotic arms to mimic the surgeons hand movements.

The Zeus Robotic Surgical System is another surgical aid that has also contributed to the advancement in medicine and the idea of telesurgery. It was cleared in October 2001.

The Zeus Robotic Surgical System consists of three robotic arms that are mounted on an operating table. It has a computer work station, video display, and hand controls which move the three robotic arms that maneuver the surgical instruments. One of the robotic arms is called the Automated Endoscopic System for Optimal Positioning, or otherwise known as the AESOP. The AESOP, like in the da Vinci System, maneuvers the endoscope. However, unlike the da Vinci System, the AESOP and the robotic system itself is voice-activated. The two systems are similar in the way that they function.

The two systems have improved medicine in a variety of ways. Both of the robotic surgery systems provide greater precision and control when dealing with surgical tools. The system provides a greater depth perception and viewing of the surgical site than a human eye could see due to the magnifying lens of the camera. The robots enable smaller scale work which conventional surgery permits, and also eliminate tremors from fatigued surgeons. Fewer surgeons are also needed in the operating room because of the robots assistance. Another benefit is that robotic surgery requires less incision, lowering blood loss, reducing trauma, ultimately resulting in a quicker recovery.

The da Vinci Surgical System, the Zeus Robotic Surgical System and the AESOP, have most importantly led to the development of telesurgery.

Scientists soon began to realize that if surgery could occur from meters away, than it was also possible from miles and even continents away. With the use of the Zeus Robotic Surgical System, and high speed fibre optic networking, a surgeon in the United States removed a gall bladder of a sixty-eight year old woman from over 7,000 miles away, in Strasbourg France, on September 17, 2001. Operation Lindberg was the first telesurgery operation in the world.

Operation Lindberg was a medical success. It showed that people would be able to receive surgery from surgeons around the world. Telesurgery could serve beneficial to people living in impoverished nations, and could lower the price of healthcare due to minimizing travel. It could also serve as a model to provide astronauts with surgery on long missions, along with aiding wounded soldiers in battle.

The da Vinci Robotic System and the Zeus Robotic System served as the basis for the advancement of surgery around the world and has provided science and medicine with endless possibility.

References:

Is Global Warming Good For Business?

2005-11-16T15:32:00.000-05:00

by Brian Lipson (Class of '05)

Global warming is steadily melting the Arctic ice cap each year with some surprising side effects. The ice cap reached its lowest level ever recorded this last summer, and as the ice melts, new land and seas become uncovered. The newly exposed lands are potentially hiding valuable resources. Arctic nations are competing to claim the territory, fighting for possible new waterways for trading routes and oil drilling sites. However there is a rule about claiming territory. Countries are only allowed to claim territory that is part of the continental shelf off each respective coast. As a result, Arctic nations are scrambling to explore and map the topography of the ocean floors in the Arctic to find ocean floors with elevations that can be considered part of a continental shelf. The countries involved are the United States, Russia, Canada, Denmark, and Norway (the only countries with coasts on the Arctic Ocean). The expeditions sometimes include icebreakers to explore possible drilling sites, while others include sending scientists to map out the topography of the ocean floor for claming territory. Currently, Canada and the U.S do not agree on the ownership of the Northwest Passage, a potential major trading route in Northern Canadian waters that could open up due to melting ice. Canada claims it is theirs while the U.S. says it is international water. Canada is making efforts to reconnect with indigenous villages in the arctic to rally them in support of Canada's claims to the new lands. If it weren't for global warming, Canada would be paying no attention to its arctic lands, but due to the potential financial gain, the Canadian government now is taking measures to secure its northern territories. Norway is especially eager to claim oil-drilling sites in order to become a huge supplier of oil to countries in need like the United States.

Overall, there are several possible benefits of the melting ice. On the business side, new waterways that open up for trading vessels could make trade much more efficient. For instance, a trip from some ports in Russia to midcontinental North America usually takes around 17 days, taking a route through Canada via the St. Lawrence River and the Great Lakes. However, if ports like the one in Churchill, Manitoba (on the coast of Hudson Bay) have longer shipping seasons, ships could take advantage of the route that only takes about eight days (as is the case in Churchill). From there, railroads could transport goods the rest of the way. In the process, Churchill would become a hub for trading vessels, vastly improving the economy and business there. Also, if oil sites were discovered, major sources of new oil would make gas prices drop. The new and faster trade routes would reduce product costs because of more efficient trading and would increase business in new port locations. Cruise companies would have new routes to send customers on. Some indigenous villages in the arctic would have more visitors due to the longer shipping seasons. Tourist visits to arctic villages are vital to the economies, sometimes garnering as much as $40,000 American dollars per visit. As of right now, these tourist visits are rare, and only about five come annually. A continued thawing could increase the visits. A positive environmental side effect could be that new sources of oil could decrease the need for oil drilling in places like Alaska and end political arguments over drilling on fragile land on the North Slope.

It is only fair however to mention the negative consequences of global warming. Increased shipping in areas makes oil tanker accidents more likely. Not only are oil spills catastrophic for the environment, but on the business side, fishing communities such as ones in Norway are worried that an oil spill would wipe out the fishing industry (especially because oil spills take longer to clean in cold water due to less wave action). If the ice in the arctic continues to melt each year, ocean levels could increase to the point where coastal human settlements could be flooded. In addition, other more urgent effects like severe weather and changing climates could be having serious impacts on humans and animals. Many animals rely on the winter ice pack for food. For instance, polar bears use ice packs to hunt seals, but significantly reduced ice packs are starting to starve polar bears. A possible negative business side effect is that severe weather and climate changes could ruin crops and agriculture in general. Also, migrating fish, namely salmon, are moving farther and farther north for cold waters. Fisheries may have to relocate and move north to keep up with the migrating fish. Finally, in addition to the toll on humans that severe storms have, the cost for insurance and recovery efforts from severe storms could total around 150 billion U.S. dollars per year in the next decade alone.

References:

The New York Times: "As Polar Ice Turns to Water, Dreams of Treasure Abound." By Clifford Krauss, Steven Lee Myers, Andrew C. Revkin and Simon Romero. Part 1 of "Big Melt" series, from October 10, 2005.
The New York Times: "Old Ways of Life Are Fading as Arctic Thaws." By Steven Lee Myers, Simon Romero, Clifford Krauss, and Andrew C. Revkin. Part 2 of "Big Melt" series, from October 20, 2005.
Wikipedia: "Global Warming (effects)"
The Boston Globe: "The Heat is on." By Beth Daley, Globe Staff November 14, 2005

How do hydrogen fueled cars work?

2005-11-16T14:22:00.000-05:00

by Gareth Lewis (Class of '05)

Fuel cells have been in the news a lot lately. According to news reports, we may soon be using the technology to generate electrical power for our cars. The technology is appealing to people because it offers a means of making power more efficiently and with less pollution. But how does it do this is the question?
What is a Fuel Cell?

A fuel cell is an electrochemical energy conversion device, or a device that converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. Another electrochemical device that we are all familiar with is the battery. A battery has all of its chemicals stored inside, and it converts those chemicals into electricity. This means that a battery eventually dies and it needs to be thrown out or recharged. With a fuel cell, chemicals are constantly flowing into the cell so it never dies. Most fuel cells in use today use hydrogen and oxygen as the chemicals. A hydrogen car uses hydrogen as its primary source of power for locomotion. There are two main methods: combustion or fuel cell conversion. Fuel cell conversion is what has been in the news most recently and is expected to power the cars of the future.

In fuel cell conversion, the hydrogen is turned into electricity through fuel cells, which then powers electric motors. The proton exchange membrane fuel cell (PEMFC) is one of the most promising technologies. It transforms the chemical energy liberated during the electrochemical reaction of hydrogen and oxygen to electrical energy. A stream of hydrogen is delivered to the anode side of the membrane-electrode assembly. At the anode side it is catalytically split into protons and electrons. This oxidation half-cell reaction is represented by:

H₂ _ 2H⁺ + 2e^-

The newly formed protons filter through the polymer electrolyte membrane to the cathode side. The electrons travel along a circuit to the cathode side of the membrane-electrode assembly. This creates the current output of the fuel cell. Meanwhile, a stream of oxygen is delivered to the cathode side of the membrane-electrode assembly. At the cathode side oxygen molecules react with the protons permeating through the polymer electrolyte membrane and the electrons arriving through the external circuit for form water molecules. This reduction half-cell reaction is represented by:

4H⁺+ 4e^- + O₂ _ 2H₂O

How a fuel cell works: Simplified

At a glance these equations look relatively simple. They are however not easily done and not easily explained, as you just read. This is a simple way of explaining the reactions. On one side (Anode side), hydrogen is channeled through to the anode. An anode is the electrode in a device that electrons flow out of to return to the circuit. At the same time oxygen from the atmosphere is channeled into the other side called the cathode side. A cathode is the electrode at which electrons go into a cell, tube or diode whether driven externally or internally. A reaction in the anode side causes the hydrogen to split into positive ions (H⁺) and negatively charged electrons (e^-). A membrane allows only the positive ions to pass into the cathode side. The electrons travel along an external circuit to the cathode. This external circuit is what creates the electrical current that powers the engine. When the electrons and the positive ions combine with the oxygen it creates water.

Chemistry of a Fuel Cell
Anode side:
2H₂ => 4H⁺ + 4e^-
Cathode side:
O₂ + 4H⁺ + 4e^- => 2H₂O
Net reaction:
2H₂ + O₂ => 2H₂O

References:

Adams, Victor. "Fuel Cells." Physics World. July 1998. Physics Web. 4 November. 2005.
Ford, Royal. "Out Of Thin Air." Boston Globe 31 October. 2005, Business. ed. : E6+E4.
"Fuel Cell." Article. 15 November. 2005. Wikipedia. 4 November. 2005.
"Fuel Cells Basics, how they work." Basics. The Online Fuel Cell Information Resource. 4 November. 2005.

Hayabusa on Mission to Discover Origins of the Solar System

2005-11-16T09:15:00.000-05:00

by Geoff Counihan (Class of '05)

The Japanese launched the Hayabusa spacecraft on May 9th 2003 from their Kagoshima launch site. The spacecraft was meant to rendezvous in mid summer 2005 with the near earth asteroid Itokawa and bring back samples to earth in June 2007. Since asteroids are left over material from the formation of the solar system, these samples hopefully will help us determine what elements comprised the early solar system.

Itokawa is a 600-meter long potato shaped asteroid, which named after Hideo Itokawa, an early Japanese rocket scientist. The goal of the mission is to land on the surface of the asteroid, bring back samples from the surface, and to parachute them into Woomera, Australia. This will let scientists study the minerals that compose the asteroid and better understand the early composition of the universe. In addition to this primary objective, the mission is also to prove the electric propulsion engines, an autonomous navigation system, the sample collection system, and re-entry equipment.

During Hayabusaís flight two of the three reaction wheels, and the solar panels were slightly damaged by solar flares. This delayed the arrival to the asteroid until September 2005. These problems have required the scientists to rely more on Hayabusaís chemical propellant thrusters to maintain control of the spacecraft. It has also caused the scientists to be much more concerned about fuel conservation.

Since September, Hayabusa has been circling a few miles from Itokawa and has been collecting data on the asteroid. The entire surface has been examined with cameras and x-ray spectrometers to map the terrain and identify mineral composition. It has also been taking detailed pictures to identify the best landing site. There are two possible locations both generally smooth ñ almost all the rest of the asteroid is covered in jagged rocks and rough terrain. These two potential sites are now being thoroughly examined to determine which is best for Hayabusa.

On November 4th the Hayabusa ran into trouble during its practice landing session in preparation for the planned landings on November 12th and 25th. Scientists shut down the practice mission due to unusual signals from the spacecraft and have not yet rescheduled a landing.

When Hayabusa does land on Itokawa, it will release an ultra small Micro/Nano Experimental Robot Vehicle for Asteroid, known as MINERVA. MINERVA is a hopping robot lander with three, color cameras. Two of which are for stereoscopic close ups, and one is for distance. An interesting fact about the design of this 1.3 lb. lander is that it will hop around on the asteroidís surface transmitting data back to the hovering spacecraft.

During the landing, the Hayabusa will shoot a marker into the landing area that will reflect light back to the spacecraft. Then it will use a laser ranging device to descend to the asteroidís surface. Once there it will quickly sample the surface, launch MINERVA, and take off.

The most difficult part of the mission is clearly landing on the asteroid and gathering samples. The communication lag from the asteroid to earth is 10 minutes, meaning that the spacecraft will have to make most of the important decisions alone, without direct control from the scientists on earth.

References:

Formation of Stars

2005-11-15T22:22:00.000-05:00

by Sam Wass (Class of '05)

Stars are the fundamental components of space. While scientists have proved that stars are “self gravitating balls of mostly hydrogen gas that act as thermonuclear furnaces to convert hydrogen into heavier elements of the periodic table” (1, p1), they have been unable to formulate a strong model regarding star formation. For the much of the last 50 years, observation of the star forming process has been severely impeded by the fact that most stars form in dark clouds that optically block the process. Infrared and millimeter-wave technology has significantly expanded our knowledge how stars develop.

The dark clouds that make up the band which splits the Milky Way (when observed on clear sky) are the locations of star formation. These clouds are primarily made up of very cold hydrogen gas. The actual creation process occurs in the dense centers of these clouds. If an otherwise stable dense core is sufficiently unbalanced or loses internal support, the core’s dusty material collapses and thus starts the creation process. Any disturbances, including supernovae and spiral density waves have the potential to offset cloud equilibrium. Scientists have calculated that the molecular core must collapse to a size nearly ten orders of magnitude smaller than the original dimensions of the core in order to be dense enough to develop into a protostar, the first stage of star development. As particles contract closer to the core, their gravitational energies decrease. This results in an increase in temperature through the conversion of gravitational energy to thermal kinetic energy.

Once the protostar is born, the forming star enters the accretion phase of stellar evolution. During this time the star’s core slowly gains mass through the accretion of material being pulled into the core. Once the embryonic core achieves a mass of roughly .2 to .3 solar masses, the core’s temperature is sufficiently high enough to begin deuterium burning nuclear reactions. Once the core achieves a temperature of 10^6 Kelvins, hydrogen fusion commences and for a low mass star, the core commences the main sequence of stellar evolution.

The conditions that determine the main sequence evolution of a future star are the protostar’s mass, radius, and luminosity at the point where accretion stops. Once all of the material floating around a protostar is accreted, the protostar becomes visible to the telescope. The continued hydrogen burning within the star increases the star’s internal pressure to balance gravity. The star will begin a long phase of equilibrium along the main sequence of the stellar life cycle.

This discussion outlines the current model of star formation, but can only be applied to fairly unique star forming conditions. The model cannot represent stars that form in clusters or massive stars larger than eight solar masses. Solving these problems requires learning more about the mysterious formation of dark clouds and thus will require more critical observations and modeling. The study of star formation continues to be a major concentration of astronomical study. Fully understanding this complex phenomenon will hopefully expand our overall understanding of the formation of the universe.

Works Cited (active November 15, 2005):

New Orleans Levees and Floodwalls

2005-11-15T15:56:00.000-05:00

by Dianne Kim (Class of '05)

The havok and destruction wreaked by hurricane Katrina brought into question the effectiveness of the levees put in place to combat such natural disasters. The levees were designed to block storm surges of category 3 storms and katrina entered New Orleans as a category 4 storm. Before redesigning a levee, engineers must consider this: Is the Mississippi Delta still capable of serving as a buffer that can absorb surges and rising ocean levels or has it been washed away beyond repair, necessitating a 300-mile wall to hold back the Gulf?

The hurricane also has a significant impact on nature and wildlife. Environmentalists had filed a suit at the U.S. District Court in New Orleans, claiming that bottomland hardwood wetlands must be spared if the Lousiana black bear is to survive and that the lands serve as breeding grounds for many species of birds in lower Mississippi. For years, environmentalists have condemned levees as artificial barriers to nature, “robbing the river of its ability to sustain itself by disrupting the natural flow and deposit of the Mississippi River’s sediments. The levees installed at the mouth of the MS river spared New Orleans but starved the wetlands of the sediment, nutrients and freshwater they need to survive.

Could the destruction of Katrina been prevented? Researchers say yes. Upon arriving at the scene one month after the hurricane left, they found more breaches throughtout the levee system than they had anticipated. The storm surge eroded sols from the base of the landward side of some levee section. If this wasn’t the scenario, water percolated under the sheet plings through layers of peat, sand and clay, and bubbled up on the other side. These levees were driven only 10 feet into the ground, whereas levees driven 25 feet into the ground kept the water at bay.

In 1998, scientists and engineers proposed a $14 billion dollar plan called Coast 2050, which outlined strategies to revive the delta and control flooding. It was rejected by Congress but considering the rate of wetland loss, land subsidence, seal-level rise and increasing frequency and severity of storms, the proposed should be on the table.

Coast 2050 proposed several different strategies: one such plan proposes connecting the barrier islands and outer marshes with levees, dams and floodgates. This would essentially create a continuous rim, or circle of safety, if you will, around the delta.

The Dutch goverment used this network but to prevent the loss of marshland, they erected an extensive series of sluices whose doors remain open yearround and close when storms approach.

Venice, the sinking city, will rely on mobile floodgates as well, but there’s a spin to it. The mobile floodgates will lie flat on the seabed under normal conditions and rise only during extremely high tides. All these efforts are put in place to appease environmentalists.

Engineers need a new vision to revive LA. The region produces one-third of the country’s seafood and wintering for 70% of the nation’s migratory waterfowl. And still, at least 25 square miles are receding every year. Katrina didn’t help either. The excess salt probably “baked” the soil, and is expected to kill off marsh grass.

So what are the lessons we need to draw from Katrina? Global-warming models show that sea level will climb 1-3 feet this century and increase the frequency and intensity of storms. Some may argue that we are currently going through a cycle but cycles run for 25-30 years and we are only 8 years into the current one. The Coastal Vulnerability Index, a fun-tuned formula made by the USGS, predicts how at risk an open coast-line is to high seas.

Though politicians are trying to save face and are in a scramble to act fast, a long-term plan is needed. Instead of working against nature, we need to work with it.

References:

Scientific American, November 2005 "Protecting Against the Next Katrina."
www. csmonitor.com, "Greens vs. Levees"
www.fas.org CRS Report for Congress, "Hurricane Damage Protection"

Picking: A Delicate and Furtive Pastime

2005-11-15T15:41:00.000-05:00

by Connie Wang (Class of '05)

It's cold, it's late, and you're locked out of your house. What to do? If this weren't your house, a brick through a back window would do. However, because you don't want to be grounded for the rest of your high school life, you need to find a resourceful way of letting yourself in quietly without causing any property damage or waking up your parents.

Luckily, you happen to keep a set of professional lock picks in a spiffy black leather case in your back pocket. The dark light on your front porch prevents you from being able to see what you're doing, so you must rely on your well-honed instincts to intuitively guess what's going on inside the lock. The locks on front doors are generally of the deadbolt variety, and use a cylinder (or pin) lock. A typical pin tumbler is a cylinder within a cylinder, with one rotating inside the other. A full rotation of the inner cylinder, also called the plug, turns the cam, which in turn physically unbolts the lock. Without a key, however, the full rotation is blocked off by a series of pins placed in an uneven line around the circumference of the cylinder. There is a set of pins at every point of resistance. A set of pins consists of two components: the uppermost pins are all of the same size, whereas the pins at the bottom are of varying lengths. In the context of the plug, there are small shafts for each pin set, with a spring at the top to hold the pin sets in place- the pins connect the inner plug and outer cylinder.

You have two main tools: a pick and a tension wrench. Picks are long, slender bits of metal that are curved or bent at the end, and you use these to reach into the opening of the lock to push the pins up. The tension wrench can be thought of as a delicate flathead screwdriver. Think of the tension wrench as your key, only without the ability to push the pins the right way. Whenever the tension wrench is pushed up against a set of pins, you must, with your pick, gently force that one set of pins up above the shear line. This set of pins has been successfully "picked." The process continues until all of the uppermost portions of the pins are up above the shear line, allowing the plug to rotate freely and unbolt the door.

You begin by putting the thin head of the tension wrench into the opening of the lock. Apply pressure gently in the direction in which you would rotate the key, turning until you can feel resistance. Without reducing the pressure, use your other hand to hold the pick. Feel around for the first set of pins that is obstructing your path. When you find the set of pins, use the bent end of the pick to delicately force up the bottom pin. You know you've succeeded when the spring yields, and the uppermost pin is resting in the outer cylinder while the bottom pin is in the inner cylinder. Now you are free to turn the tension wrench even more in the same direction as previously determined (that is, the same direction as how you would turn the key). Continue turning the tension wrench until you encounter resistance. Perform the same steps a few more times until you are allowed to rotate the entire plug, unbolt the lock, and slip in unnoticed to your quiet house.

References:
1. http://www.lysator.liu.se/mit-guide/mit-guide.html
2. http://home.howstuffworks.com/lock-picking.htm

Sea Walls: Retention Comprehension

2005-11-15T15:31:00.000-05:00

by Charlie Bartlett (Class of '05)

With so many people wanting to live near the water, it is no surprise that many attempts have been made to control the sea and rivers, and to increase inhabitable coastline. The most common technique in both residential and public construction is to build a seawall or a retaining wall. Seawalls come in many forms, but they all have the same basic purpose: to create more livable and safer areas near the coast. Retaining walls do the same along riverbanks, channels, etc. But do these attempts succeed? Can the forces of something as powerful as an ocean really be controlled by human construction?

A seawall is something that tries to slow the forces of erosion. In the short term, seawalls can be very successful at accomplishing this. If the material used to construct the seawall is durable enough, it can provide a shielding effect for the part of the beach behind the wall. It does this by absorbing and deflecting the forces of the waves, forces that could eat away at the shore.

However, the problem with a seawall arises in the long term. While the seawall does in fact deflect the force of a wave, the force is not lost. This force of a wave creates a backwash off of the wall. The backwash in turn, along with crosscurrents, up currents and other factors, creates what is known as erosion (erosion is also increased by such influences as wind, water level, etc.). This generates a problem when all of the sediment in front of the sea wall has been taken out to sea.

When the beach in front of the wall has been eroded, the property owner is in the most danger. At this point, the ocean will proceed to erode the seawall, and the wall will ultimately crumple. When this happens, not only is a smaller and more vulnerable section of the beach exposed, but also the pieces of the seawall will now aid in the erosion. The pieces of the wall will be moved and churned with the waves, and as a result, will cut away more at the sand underwater, and will quicken erosion.

A retaining wall is similar to a seawall, but it is usually meant to control a river instead of an ocean. A retaining wall does not have to deal with the effects of erosion to the extent of a seawall, as the water does not undercut the structure. However, the problem with a retaining wall is presented when the force and height of a river increase.

When the river height rises, there is the possibility of flooding, as the river could rise above the wall. When the force is increased, the wall could break, causing a similar problem. The only seemingly certain way to stop this threat would be to create a massive, extremely thick wall. This, however, is very impractical and very unsightly, and will probably not be instituted in most areas.
This is all well and good, but who cares? This is applicable in one way or another to many areas of the country, but it become immeasurably important to an area such as New Orleans. When an area such as this is below sea level, one the coast, and next to a major river, all of these factors come into play. Hopefully, the area will learn from its mistakes and correct the problem in the future.

References:

Stem Cells in Cancer Treatment

2005-11-15T15:22:00.000-05:00

by Sharon Ron (Class of '05)

Chemotherapy, as a treatment for high-risk cancers, is most commonly coupled with a bone-marrow transplant. However, provocative new evidence shows that patients that undergo peripheral blood stem-cell transplantation opposed to bone-marrow transplantation experience fewer complications, speedier recoveries and have improved relapse and survival rates.

The treatment of chemotherapy kills off cancer cells, however in the process it also kills of hematopoietic stem-cells. These stem cells are essentially immature blood cells produced in the bone marrow and can develop either into red blood cells, white blood cells or platelets. These cells are essential to life so when they are killed off in large amounts during chemotherapy the patient is put at risk for life-threatening infections. This is why procedures such as stem-cell transplantation are vital.

While it is true that all that is needed for a patient is some sort of stem-cell transfusion, research is finding that the stem-cells in bone-marrow are not as effective in stowing off disease as those from peripheral blood. In a study done on small cell lung cancer (SCLC), 18 patients were treated by means of chemoradiotherapy and then received two cycles of treatment with chemotherapy drugs followed by an infusion of peripheral blood stem cells collected from the bloodstream. The typical symptoms seen after chemotherapy, such as higher toxicities, diarrhea and kidney problems arose infrequently. Another study led by Clinical Research Division found that out of 172 patients evaluated, the survival rate for cancer patients transplanted with stem-cells was 65% while the rate of survival for bone-marrow transplantation was 45%. “The results are exciting because most strategies aimed at reducing relapse are associated … with more complications and higher mortality,” says the scientist leading the study, Dr. William Bensinger. He suggests that the difference may lay in functional differences between marrow stem-cells and stem cells from peripheral blood. Bensinger speculates that stems-cells are more abundant in peripheral blood than in bone marrow, although not enough sufficient research has been done to prove this.

The stem-cell collection process might prove to be key in discovering what accounts for this substantial difference. Stem-cells from bone-marrow are removed via a large syringe, injected into the donor’s hip bone until the correct amount or marrow has been collected. However, the process of collection from peripheral blood is to stimulate stem-cell growth through drug injections and then after a few days to collect the blood. The process used separates and collects only the white blood cells because these cells contain all the stem-cells of the blood. Therefore, patients undergoing a transplant of peripheral blood stem-cells also receive a large amount of t-cells.

The patients treated with stem-cells from peripheral blood rather than bone-marrow are clinically proven to have quicker recoveries and less relapses, complications, and deaths. With evidence such as this it seems a change in the chemotherapy recovery process is imminent.

References:
Active (all) as of 11/03/05)

1-866-GRO-BONE

2005-11-15T10:53:00.000-05:00

by Zoe Philip (Class of '05)

The Stryker Biotech division of Stryker Corporation has made a giant step forward in the regeneration of human tissue. Their studies are focused on the renewal of various human tissues that have been damaged through disease or injury. Currently, their lead drug on the market is a protein called Bone Morphogenic Protein 7 (BMP7). It is approved in thirty different countries including the European Union, the United States, Australia, Canada, and Switzerland. The presence of BMP growth factors, a molecule capable of stimulating the renewal of cells, was first hypothesized in the mid sixties by an orthopedic surgeon, Doctor Marshall Urist. By the seventies BMP7 had been discovered, and Stryker acquired the rights to study and manufacture the protein by the early nineties.

BMP7 is capable of stimulating the regeneration of bone. The protein can stimulate fractures to heal and can create bone fusions, in areas such as the spine. All it takes is a local injection (injection at the site of injury) of the protein. The protein then reacts with receptors on mesenchymal stem cells. These stem cells are present in adults as cells designated to manufacture more of a mesenchymal tissue, such as bone. The purpose of the protein is to attach to the ACTII receptors, which stimulate the Smad pathway. The Smad pathway is the pathway within the bone cells whose job it is to tell it to make more cells. In some people, fractures just will not heal because their stem cells are not being stimulated to produce more tissue. When BMP7 is injected into a person, it provides them with the necessary protein to trigger regeneration. BMP7 is just the first step towards discovering and manipulating others proteins that can regenerate other tissues besides bone.

Three components are needed to regenerate tissues: stem cells, a signal to stimulate the stem cells, and a matrix, a substance onto or into which the new cells can grow. The stem cells are already present in most tissues from birth. In the case of re-growing or creating bone, the signal for the cell to begin producing more tissue is the BMP7 protein. In order for the injection of BMP7 to work Stryker Biotech has created several different matrices. One of them is called Bovine Collagen and is used for healing fractured bones. Another, Tricalcium Phosphate, is used in spine fusions. Through the production of these materials, Stryker has made it possible for tissues to heal.

In recent pre-clinical trials, BMP7 has shown that it is capable of regenerating cartilage. If the studies show that the protein is capable of consistently producing new cartilage, then it could be used to cure Degenerative Disk Disease and Ostero-Arthritis, and heal sports injuries. Unfortunately the process of getting a drug to the market is time-consuming and expensive. A new drug must be proven to be safe, effective, and able to be manufactured consistently. On average it takes about 15 years and about 800 million dollars to bring a drug to market. Despite the time and the cost though, the efforts are worth it, bringing relief to patients in pain.

References:

Interview with Dr. Mark A. Philip
http://www.stryker.com/orthobiologics/

Venus Express Takes Off

2005-11-14T16:37:00.000-05:00

by James Cassettari (Class of '05)

November 8th 2005 marked the date in which the Venus Express satellite will be launched by the European Space Agency. It will photograph and analyze areas of the harsh, hot, dry planet in an orbit that will last over a year. This will help in answering the speculation of possible traces of life in the clouds of Venus.

The mission will be the first Venus exploration done by the European Space Agency (ESA). There is a fascination with Venus and it is even considered the Earth's Evil twin because its size and mass are extremely similar. This is interesting to scientists because it can help provide new insights into what happened that made the two environments so drastically different.

The Venus Express is a continuation of the Mars Express mission that the ESA had put together previously. One major exception is that they needed to account for the fact that Venus is about twice as close to the Sun as Mars. The satellite used in the Venus Express Mission is virtually the same except for accommodations that were made to increase its strength and resistance against higher amounts of heat that surrounds the Venusian area.

Years of planning have been involved with the project as it was started in 2001. Its testing finally came to a conclusion in September of 2005. With its final electrical testing, it was ready for shipment to its launch site: Baikonur Cosmodrome in Kazakhstan where it will be launched by a Russian Soyuz Fregat rocket. On November 5th 2005 it was moved to a launch pad, where it will take off for a very important mission for the ESA.

There was a minor setback and delay when the initial launch date was postponed due to a contamination of the satellite's very important insulation. Due to this inconvenience the launch date was changed from October 26th to November 8th. It will take the Venus Express an estimated 153 earth days to complete its trip from Earth to its orbit around Venus. When it finally does make it to the orbit it will take the equivalent of five earth days to complete a good orientation to the planet. It is going to spend 500 days gathering data in its orbit of the planet, but it will not be landing. There have been a few landings on Venus and unfortunately its harsh climate that includes temperatures of around 464 degrees C (864 degrees F) and acid rain have made landing missions difficult. The satellite will collect samples from the dense clouds and photograph different areas.

The photographs and samples that the Venus Express is collecting will be sent via the VaRa Venus Radio, that bounces data transmissions back to earth with radio waves. The photos taken will be of the highest quality from the wide angle Venus Monitoring Camera (VMC). The VMC is capable of capturing still and moving images, and is equipped with ultraviolet, thermal, and visible settings, which means it will take pictures that focus on different aspects on the planet, such as heat and light.

All in all the data that is recovered by the Venus Express will provide very detailed and important information regarding Venus' extremely complex and unforgiving atmosphere. It will be a very big acomplishment for the ESA and will provide valuable information to the world.

References:

Venus Mission Will Reveal Some Surprises, good as of 11/14/05
Venus Express, good as of 11/14/05
http://en.wikipedia.org/wiki/Venus_Express, good as of 11/14/05