What The Universes Behold

Catalina M Ramirez Nazario

The universe we have learned about since we were little in school is very limited. It expands to horizons and immensities that we might have never imagines. Recently the thought has been present that, what if it is not just one universe… What if there is a multiverse! A lot of people haven’t even heard of concepts of black matter, black energy or about a false vacuum, which are concepts that are needed to understand the different theories and thoughts on parallel worlds and multiverses. This is a reason that may lead people to think that they are not well prepared or not capable enough to learn about the new thrills and discoveries of the Physics community. On the book Parallel Worlds, Michio Kaku takes readers by the hand into a tour of several theories, history and physics concepts that will make the reader be able to grasp an understanding of the out coming theories on the multiverse. 

The book divides all the information into three major categories: the universe, the multiverse and escaping into hyperspace. In the first part, Kaku explains to readers about theories on how the universe was created, like the big bang, things that can make up the universe, new discoveries and also specifies the phases of the universe throughout its creation up to now. In the second part of the book we go into depth about the concept of a multiverse and all its meaning. This is a good transition because we are aware of what makes up and important concepts of our universe in specific, so we can truly appreciate and understand a bigger picture where there are more universes besides the one we live in. Here, Kaku introduces the concepts of super symmetry, time traveling, String Theory, M-Theory, among other concepts. In the third and last division of the book, Kaku discusses and escape to hyperspace. This consists of utilizing the concepts discussed earlier in the book which say that in a distant future our universe might end to be as we know it, and so, a future generation of society will have to device a way of surviving, and Kaku discusses the possibilities of using parallel universes as the solution. 

The concepts in this book may not be the easiest to understand for someone with a minimum background in Physics, but the way that Kaku lays it out and explains the concepts is easier to grasp. He makes it simple because he explains basic concepts that make it easier to understand the main concept that he wants to make accessible to people. Even if you do not have an immense knowledge in Physics, you will be able to understand what Kaku wants us to learn through his books. This is a book that I would recommend for anyone who has a striving curiosity to expand their universe to a possibility of many universes After you have read it, you will be aware of a world of theoretical physics that will stimulate your curiosity, knowledge and imagination to the fullest extent. 

Reference: 

Kaku, Michio. Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos. New York: Anchor Books, 2006. Print. 

Transformers: From dream to reality?

Catalina M Ramirez Nazario

The generation that is cursing the university right now, has possibly grown with the image of cars and planes transform into alien robots and fighting to protect the human race.  The transformers TV series, had most kids I know go crazy with the changes and the fights; but what is it that keeps this series alive? Even when you grow up, you still have that excitement and thrill when you see Transformers. Now, the real question is: how possible is it really to have transformers that resemble the one in the series and the movies? It is possible! A transformer in the series is an alien robot that resembles humans, but can change its shape from a car into this giant robot. If we were to turn this into a more realistic term of calling a robot a “transformer, then we could say that it is a robot that can change its shape to perform different tasks. 

In actuality, building a transformer would not be impossible, but it would be highly improbable. We first have to define that there are three factors to consider as basics to the possibility of building a transformer robot like in the movies: size, energy and biped walking. We will first start of by explaining the size factor. Making a robot just as big as the ones we see in the movie is one of the challenges of design, but it is also a design to their wallets. Constructing a plan just for them is not a bad idea, they just need more men to execute and a little more of planification. Another aspect to be considered is how to provide energy to such a big object. There are many different ways to obtain energy: coal, gas, wind, tidal, etc. This all need to be considered thinking specifically which can produce enough energy for a 16 feet or 28 feet transformer robot? A good option to answer this question is to utilize hydraulic energy. This source of energy can be powerful enough for a robot of this magnitude, but there are several complications to implementing the systems such as tubes and pumps that will move the water throughout the robot. One very big complication is that the hydraulic systems will have to be implemented alongside the electrical wiring and pieces, without having the water damage them, even when the robot transforms and moves all of its parts to adapt to its shapes. This is not a problem for the movie characters because they have their own alien power source that gives them “life” and energy; which is called the cube. Another fact to consider is how to make a robot walk like a biped for a prolonged period of time. Experts in engineering and physics have been trying to work out this problem, with several prototypes; but the farthest they have gone has been Honda with a robot called ASIMO. This is a robot that walks like a biped, but his approximate height is 4.3 feet and his walking speed is 2.7km/hr and can run up to a speed of 6 km/hr. This is the farthest technology has gone in creating a biped robot, and it can only function for a time of 40 minutes to 1 hour. If we compare this to the size of a Transformer, we see that our actual technology is far from making this a possibility in a near future. 

 Figure 1: Honda’s ASIMO robot, walking down the stairs. 

Although making a Transformer of the magnitude of those in the movies and the series is, at the present time, very difficult; there are several robots in science which are designed to transform to perform several functions or to adapt to their surroundings. These types of robots are divided into three main areas: self-configuring robot, chain robots, and lattice robots. Describing a self-configuring robot, we see that the robot is made up of a lot of small modules that move together to form a robot that adapts to different surroundings, but their usually only program to be good at doing specific tasks. A good example for this type of robot is the concept used for the Mars Rovers. Chain robots are a series of modules or robots which are joined together; they look mostly like a spider or a snake. An example of this type of robot is NASA’s Snakebot. 

Figure 2: NASA’s Snakebot

Now, for the last classification for robots, we have the Lattice robots. This type is composed of a lot of small robots that have their own way of functioning, but combine to work as a bigger robot. An example of this is more of a Terminator T-1000 or a bank of fish uniting to form a big arrow in the Nemo movie; it is not so much seen as a Transformer like in the movie, but it does fulfill the purpose of the transformer. 

Transformers are a child’s dream for a lot of people. While scientists have contemplated the different ways to make Transformer, it is not viable or it does not have a greater reason to spend the kind of money it needs to be done. Transforming robots exist already and are definitely possible! It is up to tomorrow’s physicists and engineers to turn some kids dream into a reality. 

References: 

Wilson, Tracy V. How Real Transformers Work. How Stuff Works; A Discovery Company. Internet. http://science.howstuffworks.com/real-transformer2.htm

HSU, Jeremy. NASA’s Shape-Shifting Robot Is “Real” Transformer. LiveScience. June 25, 2009. Internet. http://www.foxnews.com/story/0,2933,529059,00.html

Claytronics: Programmable Matter

Omar A. De La Rosa Oliveras

Imagine holding your common portable phone which fits perfectly into the palm of your hand, and being able to transform it at will, within seconds, into a fully functional 20 inch portable computer, or turn your car into a motorcycle at will. Seems highly improbable right? Well, in theory, all this and more will be possible with the development and research of a new technology known as programmable matter. The main Idea is based on creating individual nanometer-scale building units which can be arranged and rearranged at one’s will. 

These building units would actually be tiny computers, or micro robots, called Claytronic atoms or “catoms” which will be able to interact with one another. They will act sort of like atoms in the sense that they will be the basic building units of the object which will be formed from them. The position arrangement of these catoms will be controlled by programming, in theory, making it possible for the object composed from them to take any shape desired. Catoms will move in three dimensions in relation to other catoms, adhere to other catoms to maintain a 3D shape, emit variable color and intensity of light, communicate with other catoms in an ensemble, and compute state information with possible assistance from other catoms in the ensemble. The current state of this technology is a bit bulky compared to the final vision of the initial concept. 

  

The current catom is a 44 millimeter diameter cylinder equipped with 24 electromagnets arranged in a pair of stacked rings. These electromagnets are the ones which make possible the interaction between the catoms. In the current design, these can only move in two dimensions relative to each other.  To move, a pair of catoms must first be in contact with another pair. Then, they must appropriately energize the next set of magnets along each of their circumferences. These current models can beat the horizontal force due to friction while in movement with no problem, but downscaling will result in less force having to be applied by each catom to lift its weight and that of the others around it within an ensemble. A future model of less complexity is being developed to lower manufacturing cost and make it easier for mass production. These new models will only have the essentials for working within the ensemble which means they must work cooperatively with others in the ensemble to move, communicate, and obtain power. Today, extensive research and experiments with claytronics are being conducted at Carnegie Mellon University in Pittsburgh, Pennsylvania by a team of researchers. Reseachers believe this technology will be on its final stages within the next four decades. 

Some current ideas for uses of programmable matter are for being able to display and reproduce moving three-dimensional scenes or images like the one seen in the picture above and for aircrafts to be able to change the shape and profile of their wings according to the different flight conditions. The phone and the car examples I gave at the beginning of the article may be ideas a bit too complex for the time being considering they consist of many complex internal mechanisms, but as this technology is being developed we will be getting closer and closer to making these ideas into possibilities. 

Zakin, Mitchell. “Programmable Matter - The Next Revolution in Materials.” Military Technology, 32.5 (2008): 98-100. Academic Search Complete. EBSCO. Web. 28 Apr. 2011.

Goldstein, Seth. Campbell, Jason. Mowry, Todd. “Programmable Matter” Invisible Computing, June(2005):99-101.Web.27 Apr. 2011.

Flaherty, Joseph. "Claytronics – Programmable Matter." Replicator. N.p., 26 July 2009. Web. 27 Apr. 2011. 

Maglev trains revolutionizing 21st transportation

Yrret Marie Maldonado

Can you imagine traveling in a train that is suspended in a cushion of air and that can reach speeds that are up to twice as fast as those of a traditional engine powered train? Well thanks to the principles of electromagnetism, such a train exists and is called the Maglev train, which names mean magnetic levitation that refers to the ability of this train to suspend over a guideway using the basic principles of magnets. The powerful and innovative use of magnets and electromagnetic physics knowledge enables the Maglev train to become a high speed train, capable of revolutionizing transportation in the 21st century.

The basic physic principle behind the Maglev train is electromagnetism which is considered the branch of physics that deals with electricity and magnetism and the interaction between them and it was first discovered in the 19th century.  Electromagnetism which is defines as the force that causes the interaction between electrically charges particles, and the areas in which such interaction occurs is called electromagnetic fields. There are two types of electromagnetic fields: electric field and magnetic fields, however, they are both manifestation of different aspect of electromagnetism and therefore are intrinsically related. In the way, that a changing electric field generates a magnetic field; conversely a changing magnetic fields generates an electric field. This effect is called electromagnetic induction. Also, Electric fields are the cause by electric potential  and electric current and magnetic fields are the cause of the force associated with magnets.  This knowledge of one of the most fundamental physical forces at work, the electromagnetic force gives way to the use of electromagnets like the ones that can be found in Maglev trains. 

The underlying principle behind the working of the electromagnet is the use of electromagnetic induction. The basic idea is to create a magnet by running electric current through a conductor medium (like a wire), creating a magnetic field. Like regular or “permanent” magnets, the electromagnet attracts things made of iron or steel and fallows the fundamental law of all magnets: Opposite attracts and likes repel. The only difference is that electromagnets are temporary; they will exist only if electric current is flowing. The most conventional way to generate high intensity electromagnets is to wind a core substance, usually a ferromagnetic material like iron, nickel or cobalt with many coils of wire. Once this is done, electric current is passed through the magnets, which induces a magnetic field in the ferromagnetic core and is the basis of operation for marvel trains and electrical generators, induction motors, and transformers. 

The concept of electromagnetism is used in high speed maglev trains. They use power full electromagnetic force to provide both magnetic levitation of the train and propulsion. The Maglev Train system consists of tree important components: a large electric power source, metal coils coating the guideway (or track) and a large guidance magnet attached to the underside of the train. The electromagnets which are fixed in the tracks magnetically levitate the train with no support other than magnetic fields and also helps move the train by magnetic force. This is done because the magnetized coil running along the guideway repels the large magnets on the train's undercarriage, allowing the train to levitate between 1 to 10 cm above the guideway. Once the train is levitated, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push the train along the guideway. The electric current supplied to the coils in the guideway walls is constantly alternating to change the polarity of the magnetized coils. This change in polarity causes the magnetic field in front of the train to pull the vehicle forward, while the magnetic field behind the train adds more forward thrust. The magnetic pressure is used to neutralize the forces and effect on gravity. 

 

There are two types of Maglev trains: the German engineered electrodynamics suspension (EMS) and the Japanese engineered electromagnetic suspension (EDS), however both methods are based on the same concept, but differ in the approach as to what type of magnetic elevation used. As the EDS uses the repulsive force between the magnets, in the guideway and beneath the vehicle, makes the train levitate and move. On the other hand, the (EMS) uses the attractive force of magnets, in the guideway and beneath the vehicle, makes the train move. The EMS is faster than the EDS, because EDS train must roll on rubber wheels until they reach a lift-off speed of about 100km/h which causes resistance. However having these wheels is an advantage during a power outage, it allows the train can come to a smooth and safe stop. This fact makes the EDS safer, but also more expensive.

What makes the Maglev train such and innovation and revolutionary train it’s precisely the benefits this train offers in comparison to its more traditional counterparts. Being one of the biggest advantages that the Maglev train system does not use Fossil fuels like a traditional train engine, but instead is totally based on magnetism as the magnetic field created by the electrified coils in the guideway walls and the track combined to propel the train. Therefore, being more environmental friendly and reducing the dependence on fossil fuel. More so, the noise pollution is reduced to a significant level and air pollution is virtually absent. Also, the fact that Maglev train is able to levitate on a cushion of air has the effect of eliminating the negative effect of frictional force, this in combination with is aerodynamic design, increases the trains speed. The train can reach unprecedented ground transportation speeds of more than 310 mph, being twice as fast as the Amtrak’s fasts commuter train. Therefore, such a revolutionary train is a faster alternative to heavy air traffic when traveling. This and many other facts of the maglev train make this new form of terrestrial transportation a revolutionize 21st century transportation.

References:

http://science.howstuffworks.com/transport/engines-equipment/maglev-train1.htm

http://www.essortment.com/maglev-trains-work-40054.html

http://ninpope-physics.comuv.com/maglev/howitworks.php

http://www.buzzle.com/articles/maglev-trains-how-do-they-work.html

http://www.brighthub.com/engineering/electrical/articles/72138.aspx?p=2

http://science.howstuffworks.com/electromagnet.htm

http://www.brighthub.com/engineering/electrical/articles/62105.aspx#ixzz1L0tHLbGE

Another Day, Another Glimpse at Air

Arnaldo Cruz Betancourt

The other day, a thought came to my head.  This thought, for the level of understanding that I had at that time, seemed to have no answer.  But now the thought have been answered and without further ado that was:  “If we know that friction is present when two objects rub each other and friction transforms into heat energy.  Then, does air friction transforms into heat energy?”

Friction is defined as a force that resists the relative motion or tendency to such motion of two bodies or substances in contact.  This opposing force, in theory, “creates” heat no matter what two surfaces are in contact and consequently air friction does transform in heat energy.  For example, have you ever try to put your hand outside of a moving car?  At the instant you put the hand outside you feel a force pushing your hand to the back of the car and between that force and your hand exists friction, friction between the hand and the air that rushes by.  When the hand is outside, you feel the hand is getting colder because of the temperature of the wind but you get your hand inside the vehicle what you feel is this rare feeling of the coldness of the air and at the same time the heat of the friction that this force produced.  Remembering the law of conservation of energy that states that energy is neither created nor destroyed it can only be transformed from one state to another (from kinetic energy to heat energy). 

Another more convincing example is, have you ever wonder why an airplane can’t depart if the outside conditions are icy and the temperature is cold? Well the answer is very simple, it is because the turbines of the airplane are frozen and the runway conditions aren’t appropriate to the plane to depart (icy runway).  But what if we add an additive to the turbines for them to de-froze and add another additive to the runway to eliminate the ice in it, then the plane can depart.  Getting back to the point, when the airplane is flying at a high altitude, the outside air temperature is colder than the temperature at the airport just mentioned and we can’t simply add an additive to the plane when the plane is airborne.  Then, why the plane turbines don’t freeze?  This is attributed to the force of friction present between the fluid of the air and the solid wing.  Although the outside air is cold, the heat transformed from the force of friction counteracts the freezing component of air making the plane and the wings to work on proper work conditions in which the air temperature is offset by the heat caused by the friction. For which this quote can summarize the two examples presented: “A regular commercial airplane, after landing, will feel cool to the touch. But the Concorde jet, which flies at twice the speed of sound, will feel hotter than boiling water.”

In light of these examples, we can conclude that friction is a force in which at a result enables different types of energy, for instance as mentioned before, heat energy.  The nature of friction is the one responsible that an airplane can work properly, the movement of a car and even the less expected, how humans move. For whichever the question is, the answer is there just for the human being to discover.  Sometimes complicated, sometimes simple the answer may be but with the help of the powerful tool of physics, that has the ability to explain everyday phenomenons, by simple, clear explanations and mathematical equations we can explain such phenomenon.

References

http://www.parentcompany.com/creation_explanation/cx2b.htm

http://www.answers.com/topic/friction

http://www.scienceclarified.com/A-Al/Aerodynamics.html

http://www.scienceclarified.com/A-Al/Aerodynamics.html#ixzz1Ky13nFzU

http://www.allstar.fiu.edu/aero/fltmidfly.htm

Giancoli, Douglas C. Physics for Scientists & Engineers with Modern Physics. 4th ed. Vol. 1. Upper Saddle River, N.J: Prentice Hall, 2009. Print.

This isn’t Rocket Science

Anibal X Diaz Ortiz

My dream has always being to work in a career field where the aspect of space and the universe were involved. This has led me to research a lot of companies and the company that supersedes the rest to me is the NASA. I gained interest in this area as a result that I would always hear the famous irritating phrase, “its not rocket science,” to mock me for the supposed easy task I was performing. So if this phrase is a synonym to one of the most rigorous disciplines, then I knew I would dedicate myself to one day become a rocket scientist.

Rockets are not as common as airplanes or helicopters, but they indeed fly. But the question is how does this occur? “The simple answer is that rockets fly by using Newton’s third law, for every action there is an equal and opposite reaction.” So in layman’s term the thrust the rocket expels, pushes the rocket upward to exit the atmosphere. The physics used to calculate the acceleration needed to depart is the conservation of momentum, “That is, for a given system, in our case the rocket-gas system, the total momentum will remain constant even if individual components move around. So if some component of the system (the gas) moves in one direction with a given momentum, some other object (the rocket) will have to move such that the two momentums exactly cancel each other out.” So if I heard the phrase “its not rocket science” so much, what was the deal with understanding this, as the equation needed to figure out the momentum is P=MV, where p equals momentum, m equals mass, and v equals velocity. Even though this equation is certainly true, its too simple to solve a complex problem, such as finding the momentum of this system, as thrust also needs to be incorporated, making it complex. And it becomes complex, because “you now have two masses to deal with, and two momentums to deal with. However, keep in mind that the total momentum of the system remains unchanged. So if we call the change in the velocity of the rocket dV, the mass of the gas emitted dM, and the velocity of the gas emitted relative to a stationary observer U, then the situation becomes Pf=U*dM+(M-dM)(V+dV), since the momentum of the system is equal to the momentum of the gas plus the new momentum of the rocket.” With this I really started to appreciate the work and time dedicated to understand the principles and concepts needed to realize such million dollar experiments.

Momentum isn’t the only physics concept applied when dealing with these complex systems; specific impulse, thermodynamics, and many others are also found. But specific impulse, “the change in momentum per unit mass for rocket fuels, or rather how much more push accumulates as you use that fuel” also needs to be calculated as it’s found by dividing the total impulse by the weight. This is crucial, because according to the NASA, “First, its a quick way to determine the thrust of a rocket. Second, it is an indication of engine efficiency. Third, it simplifies mathematical analysis of rocket thermodynamics. Fourth, its an easy way to "size" an engine during preliminary analysis.” In conclusion both momentum and specific impulse are probably the most important themes in rocket science, because the goal of launching a shuttle is to move the rocket as fast as possible, allowing maximization in cargo capacity, which is done none other than making the thrust faster and stronger.  

References:

Benson, Tom. "Specific Impulse." NASA.com NASA Glenn Research Center, 11 July 2008. Web. 29 Apr. 2011. .

"The Physics of Rockets." The Physics Behind The Rocket. Http://www.uaf.edu/. Web. 30 Apr. 2011. .

"What Is Specific Impulse?" Welcome to QRG. Www.qrg.northwestern.edu. Web. 29 Apr. 2011. .

The Physics of Bungee Jumping

Jesmarie Hernández Cruz

Modern bungee jumping has been an extreme activity for those in search of an adrenaline rush and excitement all around the world. This sport consists on jumping off any sort of tall structure, such as bridges or buildings, while being connected to a large elastic cord that falls vertically downward until the elastic bungee cord comes to decent to a stop, before pulling back and afterwards oscillating up and down until the energy is dissipated. The rebounds or oscillations are what give the person the thrill of the sport. Nowadays, bungee jumping has become a popular trend for many amateur jumpers, but what many enthusiasts of this sport don’t understand is the physics behind bungee jumping, and how important it is for the jumper’s safety.

Hooke’s Law of Elasticity states that the force of an elastic object uses to reinstate itself to an original length is relative to, but in the opposite direction, of the length the spring is stretched. Mathematically this law is expressed as F=-kx, where F represents the quantity of force necessary to restore elastic material to its position, k is the spring constant, x is the distance between the stretched cord to the initial position of equilibrium, and the negative sign means opposite direction and not negative value. When this law is applied to bungee jumping it basically tells us how much tension a spring can endure and the maximum length it will reach. 

It must be taken into accounts different aspects; such as potential energy, kinetic energy, elastic energy, the different forces involved (like gravity, and weight of the jumper), distance to fall, etcetera when bungee jumping is involved. Before the jump, the person is at a specific height, in which there is a certain amount of potential energy (m*g*h). Once the person jumps he enters the free falling, in which gravity is the only force acting on the motion of the body, and this is where the energy begins converting into kinetic energy (0.5*m*v2). After the free falling has occurred in a matter of seconds, the jumper now has fallen to a specific length. In this moment which the ropes starts to elongate, the kinetic energy starts to transform into elastic energy (0.5*k*x2), which is stored in the bungee cord. This elastic energy will first come from the gravitational potential energy. Both the elastic and kinetic energy will begin to grow until an equilibrium point is reached. It is then that the force of the bungee cord will begin to outbalance the weight of the jumper, and now he will decelerate. Then the jumper will have fallen at the bottom extremity of the jump, which is the length plus the distance that the bungee cord has stretched to. Additionally the velocity at that moment is equal to zero. Afterwards oscillations will then begin, pulling the jumper up and down until all the energy has dissipated and the cord will return to its original shape. 

The organizations or groups that conduct bungee jumping must take many decisions into account before providing others with this activity. For example: owning the right equipment, knowing the types and maximum lengths of the bungee cords for different falls, and it must also be taken into account the weight of the jumper (because cords do have a specific weight limit). These are all very important because they guarantee the safety of those who practice this sport, and also one way or another are indefinitely related to Physics. To conclude, Physics laws and principles helps us understand many aspects involved in the different activities that we conduct in our lives. For bungee jumping, modern physics explains and simplifies every detail involving how it occurs and why it behaves in the way it does, resulting in a much safer and more enjoyable sport for everyone participating. 

References

Giancolo, Douglas C. Physics for Scientists & Engineers with Modern 

Physics. 4th. Upper Saddle River, N.J: Prentice Hall, 2009. Print.

Taphorn, Amanda. "Bungee Jumping with Elastic Force." Physics247. N.p., n.d.  

Web. 29 Apr 2011. .

Sky Colors

Grecia P. Butler Pérez

Since, I was a little girl, I question myself, why the sky is blue?  I pass a lot of time looking the sky and all the beautiful colors in it.  It has an intense yellow and a shiny orange when the sun comes down and a baby blue and a dark blue when a sunny day is or the rain is coming.  This situation was interesting for me and I decide to investigate to found an answer for my question.  The important part is that the colors of the sky have a physical explanation.  The sky is like a prism; it reflects colors.

The beauty of the sky is the result of the interaction between the sun light and the atmosphere.  It’s necessary the damp and the particles of dust to have an impressive fest of colors in the sky.  The most seen color is the blue.  The presence of this color is like when a sun ray passes through a prism.  When we have this situation, the prism refracts the sun ray in five colors: purple, blue, green, yellow and red.  The color rays with less wave length are purple and blue.  The other three rays have long wave length.  The short wave length colors have more deviation.   These two colors with more deviation collide with air particles and it trajectory changes, when this happen the two colors collide with another air particle.  The collisions of the purple and the blue rays with the air particles make it travel all the sky and then reach our eyes.  When the rays reach our eyes we see the blue color in the sky.  This is a cyclic process; it is happening all the time.  This energy diffusion process is called Rayleigh diffusion.  The blue sky color is a result of the diffusion of the wave with short length

The color with less wave length is the purple color.  If we analyze this situation, the sky is supposed to be purple.  The sky isn’t blue for two reasons.  The first one is, the sun rays have more blue than purple and the second one is the human eye is more sensible to blue light.  For these two reasons the color of the sky is the blue.  If the particles are big the Rayleigh diffusion doesn’t work.  In this case the process needed is the Mie diffusion.  For this diffusion the sky isn’t blue.  When the clouds are too thick the sky turns gray.  This is the situation in rainy days.  When we see the sun coming down the sky turns orange and red.  This situation is because the rays of light moves more and the colors with short wave length are capture in the particles.  Only the red rays survive because it travels in rectilinear movement.  If the earth haven’t had atmosphere the sun light would reach our eyes directly without diffusion and we would see the sky black.  The astronauts watch this effect in space.  With this effect they can see the planets, stars and the moon, because there is no atmosphere.

Now I understand the color and appearance of the sky, because it has a physics explanation.  Isn’t a simple act of being blue, it is a relation between particles and light rays.  

Proton therapy

Alejandro N Torres Santos

Physics can be used in all aspects in our life, including saving lives. Proton therapy is an example of that. Was the american physic Robert Wilson the first person to talk about proton therapy in 1941, since then this program refined and expanded these techniques while treating 9,116 patients that suffer of cancer. The first treatments were made by particle accelerator made by physicians in Sweden. Its commonly know that we can cure cancer using radiation with x-rays, but we know that is a painful process with side effects that includes hair loss, radiation nausea and fatigue. Using proton therapy all the side effects are gone and patients can continue normally with their life after their treatment.

Cancer is a known disease that destroys tissue with uncontrolled growth. Society is trying to fight this disease that is killing 8 million people each year, so we have different types of treatments. Proton therapy is one of many treatments but people may not know about it. Tissues are made up of molecules with atoms. In the center of every atom is the nucleus and inside are orbiting negatively charged electrons. The protons pulls electrons out of their orbits.  With their positive charge they attract the negatively charged electrons occurring  the ionization that changes the characteristics of the atom and  the character of the molecule within which the atom resides. In other words protons damage the DNA of cells, causing their death or interfering with their ability to reproduce. The cancerous cells have a high rate of division, their reduced ability to repair damaged DNA is particularly vulnerable to attack on their DNA, so by adjusting the energy of the protons during application of treatment the cell damage due to the proton beam is maximized in the specified cancerous area (tumor).

The important characteristic that defines proton therapy is that doesn’t damage other tissue closer to the tumor because other areas receive less radiation. Contrary to the conventional x-rays that results in most of their energy from a single conventional x-ray beam being deposited in normal tissues near the body's surface, as well as undesirable energy deposition beyond the tumor site. This undesirable pattern of energy placement can result in damage to healthy tissues close to the cancerous area.  Standard x-ray therapy and proton beams work on the principle of selective cell destruction.  The major advantage of proton treatment over conventional radiation is that the energy distribution of protons can be directed and deposited in tissue volumes designated by the physicians-in a three-dimensional pattern. Proton therapy is also best than surgery if the tumor is located in places were surgeries are risky like closer to the brain and other important organs. After the treatment patient experiences a better quality of life and feels nothing during the process. The minimized normal-tissue injury results fewer effects following treatment, such as nausea, vomiting or diarrhea. The problem with proton therapy is that needs a high cost machine which cost is approximately half a million dollar. Also is available only in nine centers in the worlds, making this treatment one of the most expensive and exclusives ones.

Internal Energy of an Atom: Heat as Change of Internal Energy

Emmanuel J. Chamorro Rivera

Energy, the ability to do work, and the concept that keeps every particle in the universe moving, reacting; for us this concept is difficult to understand, but it can be calculated. Kinetic energy and potential energy are two basic types of energy that are particular to the system, but those two are derivatives of an even greater energy, the contact between electrons of an atom. In other words when we touch something, the electrons of the tip of our fingers have contact with the electrons of the object. That is precisely the source of sounds and transference of heat. If that is the case, then the atoms carry an internal energy which makes possible for them to do work, and exert forces to different directions. This means that this energy can be transferred and used, but even more important this energy can describe the elements and the components in matter.

The only thing that is missing is an equation, only a formula to calculate this energy; but it is not simple as it sounds. To find it, speed, acceleration, and position have to be known, which to find for an atom is extremely hard to find. Also Heisenberg’s uncertainty principle can explains that finding those for an electron is impossible at the same time, so the choice of using electrons to measure it also becomes complicated. Although there is another approach, for example, water vapor in a sealed refrigerator.  We know that water then would eventually turn to liquid, or solid, so if viewed from a chemical point we know that the water vapor is releasing energy, which can be measured. Now must we ask what type of energy is it liberating. Is it only thermal? Well, yes, it is thermal, but also it can be seemed as internal energy. The state is a property of matter which atoms move a different speed. So the thermal energy can be seemed like a conversion from internal energy to thermal energy. Which thermodynamics help to resolve these problems as seen in:

∆E_int=Q=mC_s ∆T ,for changes of temperature in same phase

∆E_int=Q=n∆H,for changes of phases

m=mass

C_s=constant of specific heat

T=temperature

n=moles

H=entalpy associated to the change of phase

But what exactly does internal energy implies, well we can use the knowledge of chemistry to define the term of internal energy. Now let’s remember heating curves, when a compound is solid, it needs to absorb internal energy in order to change phases. Well this may mean that compounds that are gas at room temperature have more internal energy than an abject which is solid at room temperature. For example, we have one gram of ice in a closed system, if we heat it up and have the same amount of water vapor in the same closed system; the vapor exerts more force in terms of pressure than the solid. Ergo the internal energy is larger when a compound is in gaseous state.  Now what may this imply? In chemistry there is a term to describe why does certain elements are in different phases, known as intermolecular forces. The larger the forces, stronger are the bonds between the atoms; the more likely the compound would be solid at certain temperature. Well this can give us a proportion to internal energy:

E_int∝(1/F_(inter ) ),F_inter=intermolecular forces

This proportion may seem easy at first, but the term of intermolecular forces is not yet defined as a number; it is defined as a theoretical term. Finding that number is the key to finding the internal energy of a compound in any time in a specific temperature, and from this then the composition can be known. To find the value of the forces, as well as the dimension, experiments have to be conducted for further analysis.

Internal energy is the fundamental energy of all particles, how it changes can be calculated, but the exact value is a mystery. Atoms contain this energy which allows them to make work. This energy is a property of matter itself. The understanding of this energy may drive us to understand more about atoms and how they react. Needless to say this energy is present at all times of our daily lives. Measuring it like another type of energy should be possible, even if now it seems improbable to do so.  The proportions are theoretically easy to find, but the true values are far from being, found. With the adequate equipment and extensive knowledge of composition of matter, eventually should lead to the value of intermolecular forces, which is key to understanding the energy which exist in every atom in the universe: internal energy.

Physics in the Dance

Marjorie Carrión Rodríguez

In the life the humans have different passions and interests. These interests may vary depending on the possible skills in each person. It is incredible that many of us do not realize that our whole world and everything we do is possible for many factors but one of them is very important.  For example, the Chemical and others things but I believe the most important is Physics. We begin by defining, what is the physics?  Physics is a natural science that studies the properties of space, time, matter and energy and their interactions.  Now we know its meaning and we can think if any activity that we do every day and is very passionate have influence of physics.  For my part one of the things I like very much is the dance.  Since I have use of reason I dance and now I realize that not only we need ability to dance, there many factors that affect it and this factors not depend of me for example the science of physics.

Given that physics studies many aspects of the world, we know that some factors that affect the dance are the laws of gravity, momentum and energy. The same influence on the subtleties of balance, the techniques of leaps and pirouettes, and the impressive lifts and turns executed by the partners and body dimensions in the art of ballet. We begin by gravity which is very important if not the principal and it is responsible to keep the dancers in balance. The gravity effects depend of gravity center. The gravity center is the point where reflects all the forces applied to the body of the dancer. The forces are more than one. The weight combined with the movements and the force exerted by the surface of the floor to the dancer. At the same time the gravity influence  the jumps and spins, controlling the speed to controlling the configuration of the body and rotational inertia, the generation of adequate forces on the ground to initiate movements, controlling the time and height of the jumps.

In the dance the kinetic energy is important to study the movement of the dancers. The dancers make work to do their movement.  That movement can be done with coordination and perfection that also needs to develop a specific acceleration starting from rest and integrating the couple that is an additional source of force that combined with the gravity and soil. 

Something that calls my attention was an engineer that use pieces of bricks and for physical process caused an explosion called The Physics of Dance. This engineer make possible that the pieces of bricks dance a beautiful song. For me the fact of know that the physics can do things that a lot of us thought are impossible to do is something incredible and surprising. Personally the dance is one of the things that make me happy and comfortable, I love the dance and today I understand that physics is very important in the developing dance. 

LIGHT PASSES THROUGH OPAQUE MATTER

Omar A Piazza Hernandez

It has long been believed that rays of light bend around objects and, of course, pass through them if they are clear, but new research has proven that when it comes to opaque surfaces, light can indeed pass through. Most people learned this in high school and assumed that that was the main difference between clear and opaque surfaces, but now that notion is starting to get heavy scrutiny.

When light passes through an opaque object, most of the energy usually bounces around the surface of the object or is scattered back to the source, while very few light particles actually make their way through. It is kind of like putting grains of rice through a strainer, where few grains make it to the other side and most of them get stuck in the strainer. Using special filters in a new experiment carried out in the Netherlands by two scientists named Ivo Vellekoop and Allard Mosk, most of the radiation actually passed through a layer of milk, illuminating the other side.

Scientists used cow’s milk for example because it had been thought that when light strikes an opaque substance like milk, it scatters around instead of penetrating it completely. In new studies, that has not been the case. The filters they used make the light particles behave differently, whereas in a normal, controlled scenario light would strike opaque matter in an orderly fashion, these new filters actually disorganize the ray of light and distribute it unevenly across the surface. The randomly distributed particles then propagate through the object at a higher rate than orderly rays, although some still bounce back to the source. This new technique, although very rarely seen in nature, questions the modern definition of opaque substances.

The experiment had been years in the making, but now these remarkable conclusions have been confirmed. Although further optical experiments are underway for theorists to find a catalyst for these studies, the base work is mostly done. Scientists believe that they could apply these new findings to technology. Whether it is sunglasses or paint primer, the immediate benefits of such every day applications is obvious. Imagine a greenhouse built with opaque panels, something like wood or concrete, but as you open the door you find plants growing in its seemingly dark interior.

I found this story interesting because it directly challenged my knowledge of light as I know it. In high school, “clear” meant “transparent”, which would allow light to easily penetrate it, and “opaque” meant “not transparent”, which obviously would have the opposite effect. I find it amazing that such a theory had not been developed before. I would also love to find out if there is one true opaque substance, which would be 100% impenetrable to light even under the toughest experiments. Such a material could really have its uses in technology, although none pop into my mind at the moment. Still, this news attracted my attention because of how simple it sound, yet how significant the discovery is.

The Dead Sea Vs. Fresh Water

Daniel Maldonado Sanchez

Throughout my life, I always wondered why I floated much better in the beach than the pool. Since I always was fascinated with documentaries on bodies of water such as the Dead Sea and the Great Salt Lake, I decided that something in these bodies had something unique that allowed great buoyancy. Because of my interest in this question, I turned to the concept of buoyancy. Buoyancy is nothing other than “the tendency of a body to float or to rise when submerged in a fluid.” But in order for this to happen, the fluid has to exert an upward force on the body in order to maintain the body above the surface of the body. 

From common sense, I knew that the salt had something to do with this phenomenon, but that was all I knew before I understood that physics principles apply in order for this to take place. The principle that significantly applies to this is Archimedes’ Principle, which states “if the weight of the water displaced is less than the weight of the object, the object will sink, otherwise the object will float, with the weight of the water displaced equal to the weight of the object.” So if the displaced water weighs less than an object that is trying to float, then it will sink. But if the displaced water is equal to the object trying to float, then the object will indeed float. This cleared many doubts in my mind, because when I spread my body as uniformly as possible, I tended to float evenly, compared to when I stood up in the water.

The salt that I knew that had something to do with this absolutely did, as “the Dead Sea has a density of 1.24 kg/L, making swimming difficult, but providing a relaxing floating experience.” And because “the density of fresh water is 1.0kg/L and that of a human body is of 950g/L, therefore an individual can float with ease over the water.” If we put the numbers into perspective, then one can conclude that if one has the capacity to float with not much trouble in fresh water of 1kg/L, then it will be way easier to float on denser saltier water of 1.24kg/L.  I finally understood that the beach water was denser than the pool water from which I swam regularly, as a result of all the salts and minerals the beach has in its recipe.

Floating is summed up in a couple of concepts and principles; density, buoyancy, and the principle formed by Archimedes himself. Understanding these concepts and principles, will guide one into realizing that floating has many interesting physics principles applied, if one tries to question why one is floating in the first place. Once one floats, the upward pressure on the body on the water is equal to the weight of the fluid displaced by the object. Displace the weight of an object and the object floats, making the person enjoy his or her time in the body of water when trying to perform this motion.

References:

"Archimedes' Principle." Physics. Web. 28 Apr. 2011. .

"Buoyancy - Definition and More from the Free Merriam-Webster Dictionary." Dictionary and Thesaurus - Merriam-Webster Online. Web. 28 Apr. 2011. .

"Dead Sea." Wikipedia, the Free Encyclopedia. Web. 28 Apr. 2011. .

Hernandez, Antonio J. "LA FLOTACIÓN." Enseñanza / Metodología. I-natacion.com. Web. 28 Apr. 2011. .

‘Potato Earth' Reveals Gravity's Uneven Pull

José J. Fontán Pagán

The shape of the Earth has historically been a point of debate among people since centuries ago. First it was flat, then round, but now scientists have uncovered that it might more closely resemble a potato (in terms of gravitational pull, at least). Scientists developed a graphic that shows how gravity affects both sides of the planet at any given time, and the results show a ‘potato’ planet that looks more like the well know tuber rather than an orange.

This new data will have big implications in terms of climate study as far as how they are approached. In light of this new info, we can explain how various natural disasters came to be, such as tornadoes, hurricanes, earthquakes, tsunamis, and even landslides. The satellite that captured the images is called Goce, a digital imaging satellite used by the European Union. 

Theoretically, we can assume that the gravitational pull in France, for example, is stronger than that in America, although that hardly explains the gap in height between the two nations. It does go a long way at explaining natural phenomena in those areas with differentiating gravitational pull, and why some natural disasters, as I said before, happen in certain regions and not in others. These new images may one day save countless lives, and in fact, in the most recent images after the Japan earthquake we can actually see that the country moved at least three feet and the area’s gravitational force slightly fluctuated during the tremors before settling down once again.

Ten years ago, this finding might have all seemed like science fiction, but years of hard work and research finally uncovered the true shape of the earth, without the spherical atmosphere surrounding it. The discovery is hailed a result of the congregation of Europe’s best minds and efforts. Thanks to this new achievement, maybe we will revive some of the age old arguments of round versus square and replace them with round versus “slightly potato shaped”.

All jokes aside, I found this article mind boggling when I first saw it on BBC. When you actually see the picture, you can barely tell it is the planet Earth. It looks more like a slowly deflating basketball than a planet, but I guess this where technology has led to. There are colors on the images that depict blue for low gravitational pull and red for high gravitational pull, which makes me question why Americans are not generally taller than the French, since they get hit harder by gravity. I noticed that most of continental Europe is inside the high gravity zone, while most of the Pacific and the Americas are not. Both poles also get a high amount of gravity, although their effect probably is not witnessed as much as other, more densely populated areas. Still, it is a nice little footnote to have nearby next time somebody wants to boast about new discoveries, as surely someone would challenge the notion that the planet is a potato.

SUPERCONDUCTORS

Josue A. Quinones Crespo

A team of Japanese physicists recently discovered a conductor to end all conductors: one that still works well even after 50 Kelvin. Superconductivity is an electrical resistance of exactly zero which occurs in certain materials below a characteristic temperature. Normally, superconductors are used to transport energy and usually they lose very little in the process, but most of the time they are copper based and extremely brittle after a certain heat threshold. Silver based superconductors are being used as well for their relative durability, but the cost of making them has made copper the current favorite, in spite of its obvious deficiencies.

The new superconductors are made from a fluorine enhanced iron arsenic material that can work at very high temperatures provided it is cooled constantly. They never burn out because the iron arsenic compound used to make the wire has an unequaled tolerance for low temperatures as well as high ones, sometimes exceeding tens of Kelvins. The capabilities of the powerful superconductors would make it last for hours on end pumping out high levels of electrical currents, something that the current ones cannot say. The materials used to manufacture this new type of superconductor are often cheaper than their silver and copper counterparts and offer the same type of production.

The only flaws that have been predicted with the iron arsenic superconductors are the amount of capital need to cool them down and the relative difficulty it takes to turn the compound into miles long strands of wire. These have generally been concerns regarding superconductors, but the benefits outweigh the flaws in various high electrical current applications. For example, MRI machines usually require massive amounts of electricity to operate for long periods of time. These new superconductors may be appealing to MRI machine manufacturers because it necessarily lowers the cost of materials and exceeds the shelf life of their current products. The experiment, led by scientist Hideo Hosono, looks at making superconductors more efficient in operation and more easily maintained, therefore making them widely available for heavy duty use. 

I found this story entertaining because I thought superconductors were a technology that was abundantly used in our modern world. I have heard the word tossed around a few times before, so I instantly assumed it was a commonly used technology. I am glad to see some research being done to progress our knowledge of superconductors because I believe it has much more potential than our current batch of superconductors. It is sad to see that so much heavy duty equipment is still operating with obsolete technology when we are just steps away from creating the new generation of conductivity. It is similar to having the technology to build the world’s fastest computer, but then saying it is too expensive or to inefficient to maintain instead of figuring out a way to make it cheaper and more efficient. Hosoma not only basically did just that, he paved the way for mass production of these new superconductors and hopefully they will be in use sometime in the near future.

Flying: The feat we thought impossible

Jan K. Huertas de la Cruz

The most beautiful thing of physics is that no matter how complex or simple things may look, the reason of their happening can always be explained with physics. That is why the field of physics is always around us, making cars run all by themselves, explaining why when you take a shower the water goes straight down towards you instead of just floating away, why when we throw a ball it has to stop at some time, to put it in the simplest most understandable way, physics is everywhere.  But there is one thing that in older times was thought to be impossible, but in our era is one of the most important and safest ways to travel, flying.

The physics and engineering principles involved in making airplanes fly are very complex and hard to explain without using mathematics to understand it, but the idea to how airplanes fly can be explain in a nutshell. For any airplane to fly there must be four essential aerodynamic forces that must act on the plane, these are: lift, thrust, weight and drag. To better understand these forces we can draw a free body diagram to see how these act on the plane.

In this free body diagram A is the lift force, B is the thrust force, C is the weight force and last but not least D is the drag.

Now, if we want the airplane to fly straight, leveled and in a constant speed, the thrust force must be equal to the drag force and the lift force must be equal to the weight force. But everyone knows that first we need to take off the ground and then we need to land, so these equalities won’t match always. 

In the aerodynamic forces the weight force is the simplest to understand, so let’s start there. Since all objects have mass, every mass have a weight, and this weight produces a downward force. The thrust force is an aerodynamic force that the plane must create in order to overcome the drag force (which I will explain later), this thrust force will make the plane go forward, it will make the airplane accelerate, and each airplane has a different method to produce thrust, some of these methods are propellers, jet engine and even rockets. Now, the drag force is the equivalent to the normal force in one dimensional motion, it just has some different aspects. The drag force is the force which resist the motion of an object that moves in a fluid (air and water are both fluids); to better understand it we can use a simple example. When someone sticks their arm outside the window of a moving car they must have noticed that the air pushes their hand in the opposite direction the car is moving, that is drag, the more mass and weight the airplane has the more drag it produces.

Lastly we have the lift force, unfortunately this is the trickiest and most debated force of the four dynamic forces. There are different explanations to how the lift force acts on the plane, but I will use the simplest one, the “Longest Path Explanation”. This theory states that the top surface of a wing is more curved than the lower part of the wing, and when air approaches the wing the air that goes over the wing and under the wing takes the same time to cross it, and since the top surface is curved it must travel more distance and in order for both winds to cross the wing at the same time the wind at the top moves faster than the wind at the bottom. Here is a little diagram to better explain it.

Now, since the air that goes over the wing moves faster this causes the pressure to decrease according to Bernoulli's equation, and since the lower wind goes slower this causes a more normal pressure. This difference in pressures makes the wing to move up, in other words the low pressure at the top of the wing acts as a vacuum, making the wing move upward.

These are the four essential aerodynamic forces that must act on the plane in order to fly. The physicists and engineers that have put a lot of work and time in the research of this extraordinary phenomenon are the reason for this achievement of our modern era. I hope that for our future our generation can develop better ideas that can amaze everyone’s eyes. 

References:

• Giancoli, Douglas C. Physics for Scientists & Engineers with Modern Physics. 4th ed. Vol. 1. Upper Saddle River, N.J: Prentice Hall, 2009. Print.

• "Aeronautics - What Makes An Airplane Fly - Level 1." Aeronautics Learning Laboratory for Science Technology, and Research (ALLSTAR)Network. Web. 27 Apr. 2011