EUV

Mauricio M. Ortega

When it comes to Physics, there is definitely a wide array of topics that come to mind. We’ve learned so much this semester and there’s still so much more to learn. I, personally, am interested a lot in radiation; so I set myself to find out how it’s being used in today’s world to better our technology. The answer was lithography. Optical exposure technology has already reached its limit. Extreme Ultraviolet lithography will hopefully take over, becoming the leading contender, establishing the new generation of lithography. One critical problem is to develop a source-emitting radiation with high power and life time at a short wavelength such as 13 to 14 nanometers. The production of EUV radiation includes two possible processes, the laser-produced plasma and the discharge-produced plasma. Oxygen, Lithium, Tin and Xenon were considered for the development of the source, but due to Xenon’s low conversion efficiency we might be able to produce a higher quantity of photons. Laser-Produced Plasma is focused on a Xenon beam which also presents some problems, for example, it is required an exact pulse duration with an exact power output. Additionally the difficulty to control this process is very high. Due to these LPP issues, interest in DPP has increased. But the biggest advantage of DPP it has to be its simplicity to control and its cost-effectiveness. With Z-pinch discharge the magnetic field compresses the plasma to a capillary of 3mm and 5mm diameter, for later production of EUV radiation. Xenon will emit EUV, which will flow through the discharge tubes of 3mm and 5mm. 

The Z-pinch plasma is characterized by measurement of its temporal intensity. The discharge current is detected by a pick-up coil. The energy for this process will be provided by a magnetic pulse compressor exceeding a 90% of energy efficiency. The EUV energy is measured with a monitor that consists of a filters and diode tools. A pinhole camera, filter, a multichannel plate-image intensifier and a digital camera will be used to record time-resolved images of the discharge plasma around the EUV wavelength. The Z-pinch design and circuit pulsed-power excitation parameters will be optimized to achieve the required characteristics for the source-emitting radiation needed in the first place.

In today’s market, between laser-produced plasmas (LPP) and gas discharge-produced plasma (DPP), DPP is currently the most powerful EUV source. Despite its superiority to LPP, DPP still faces problems such as the thermal load on the components. This particular problem causes the degradation of the lifetime of the components, such as the electrodes, the insulator wall, and the light-handling mirrors. This problem was solved by shortening the discharge current pulses, reducing thermal problems and improving conversion efficiency from the discharge energy to the in-band EUV emission power (CE).

As for the monitoring of the DPP, the temporal development of the relative EUV emission intensity is monitored by a fast PIN photodiode (Hamamatsu, 3883, 300MHz) covered with a 150-nm-thick Zr filter Luxel). The intensity of the EUV radiation depends on the Xenon flow rate. These two are directly proportional. However, at a too large flow rate, EUV intensity tends to decrease and maximum emission is delayed. Moreover, the vacuum level in the discharge chamber changes with the xenon gas flow rate which absorbs, partially, the EUV radiation. Now, EUV emissions not only strongly depends upon discharge current (amplitude, duration), but also on the filling-gas pressure or xenon gas flow rate delivered to the discharge chamber. The emission spectrum of the radiation was measured with a reflection grating spectrograph including a flat-field grating and a charge-coupled device detector. For the amplitude of the current and the Xenon flow rate is influenced by the temperature. We find proof for this in several studies on the EUV spectra of DPPs reported that the 4d-4f transition of Xe¬11+ becomes stronger for higher electron temperature.

Lastly, and in general, the EUV emission energy from these pinched plasmas tends to be proportional to the square of the peak current amplitude. On the other hand, the increase in electrical energy input to the discharge causes the ablation of electrodes and insulator wall, which results in the generation of large amount of debris and the impurity contamination in the target plasmas. In order to increase EUV power without increasing energy input, a key issue is to improve the conversion efficiency for the discharge energy to the in-band CE. One is to use tin or lithium plasmas. The other is to optimize the plasma temperature and density for the 13.5 nm emission. The formation process of the high-energy-density plasmas in a DPP scheme is flexible compared with an LPP scheme and is dependent on the current waveform, electrode geometry, and the target gas, gas pressure, and gas initial ionization state.

So what do we make out of all of this? EUV is evidently the way of the future as far as lithography, for the time being. The ability to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate is a priceless for circuits. However, the smaller we can make these patterns, the better, and the more efficient. That’s what EUV is bringing to the table, the ability to do this at an even smaller scale than previous technologies such as photolithography, and allow us to create smaller electronics. Paving the way for nanotechnology.

 

Works Cited 

Zhang, C. H., P. Lv, Y. P. Zhao, Q. Wang, S. Katsuki, T. Namihira, H. Horta, H. Imamura, Y. Kondo, and H. Akiyama. "Xenon Discharge-Produced Plasma Radiation Source for EUV Lithography." IEEE Transactions on Industry Applications 46.4 (2010): 1661-666. Print. 

Electric Forces in Deoxyribonucleic Acid (DNA)

Iliane Miranda Fonseca

The concept of electric force studied in Physics II can be applied to other science fields such as Biology, specifically Molecular Biology. Our body is compound of billions of cells and each one has many molecules that interact with each other to perform a specific function. These interactions occur in water, because this is the main component inside the cell. Water is a polar molecule which has a dipole moment and can interact with other water molecules forming hydrogen bonds, or also can be able to interact with other molecules such as DNA, RNA, and proteins. The electrons in water spend more time around the oxygen atom than around the two hydrogen atoms making the oxygen more negatively charge. 

In the case of the proteins, biochemical compounds consisting of one or more polypeptides, there are six forces or bonds that stabilized its tridimensional structure. These are the following: ionic bond, covalent bond, Van de Walls forces, hydrogen bond, electrostatic forces, and intermolecular forces. One example is the ionic bond which is form when a positive atom (cation) and a negative atom (anion) can hold together under electrostatic attraction because of the opposite charges. As we learned in physics II, “unlike charges attract; like charges repel”. Another example is the intermolecular forces due to molecules with dipolar moment that are attracted with others dipolar molecules electrostatically. 

The DNA contains the hereditary material or genetic information that is passed from one generation to other. This molecule is made up of nucleotides, and each nucleotide is composed of one nitrogenous base, a deoxyribose, and a phosphate group. Adenine (A), guanine (G), cytosine (C), and thymine (T) are the four nitrogenous bases. The DNA consists of 2 strands that are wrapped forming a double helix. The two strands are attracted because of the electrostatic forces between the nitrogenous bases which are positively or negatively charged forming a hydrogen bond. This electrostatic attraction is very important to transmit the genetic information with precision to the other generation. As we can see in the following picture, adenine is always attracted to thymine and guanines to cytosine because this is the most stable form. 

The concept of the Coulomb force acting at a distance can be applied to the DNA using gel electrophoresis. This is a technique in where the DNA fragments or other molecules can be separate based on the mobility of ions in an electric field. Since the DNA is negatively charged when dissolved in water, the electrophoresis will separate the DNA by size. This is because small molecules migrate more easily through the gel matrix while bigger molecules experience a larger resistance. The DNA is placed in a side of the gel and by applying an external electric field it will move to the positive side. The picture at the left is how this technique works and the one at the right is a result of the DNA gel electrophoresis. 

As we can see, Physics is everywhere including our own body. The laws of Physics can apply to almost all other science and engineering fields and for this reason is very important to understand and learn more about Physics. 

References:

1. Deoxyribo Nucleic Acid

http://mrsec.wisc.edu/Edetc/background/DNA/DNAintro.htm (Acceded November 23, 2011)

2. Electric Fields – Coulomb Force at a Distance. http://www.physics.udel.edu/~bcwalker/phys208/lab2.pdf (Acceded November 23, 2011)

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

Are Neutrinos Faster than Light? 


Kevin J Soto Villanueva 

Several days ago, there was a commotion in the Physics world. Scientists of the CERN discovered that a previously known particle called neutrino travels faster than light. But, is this phenomenon possible? According to the special relativity theory that we learned in Physics, which in part states that light is always propagated in empty space with a definite velocity c (one of the fundamental constant of nature), which is independent of the state of motion of the emitting body, it cannot be.

Neutrinos are particles that emerge in nuclear reactions, radioactive decay, nuclear bomb explosions and death of stars exploding in supernova. They are uncharged particle, fermionic type with half a spin. These particles have mass, but very small, and it is very difficult to measure it, which implies that they are not affected by electromagnetic forces, and gravity has little influence on them.

We know that to accelerate a body, you have to apply an energy, bodies with greater mass, the greater the energy that should be applied. As we approach the speed of light (c), the mass of the moving body increases more rapidly, so that to continue accelerating, and as we get closer to "c", the mass of the object gets closer to infinite magnitudes. This would be absurd because it is not possible to apply such energy, as well that is impossible the existence of a body of infinite mass. This is the reason nothing can travel faster than light. In advance, we can deduce that to accelerate a neutrino at speeds approaching that of light is much easier than to accelerate a proton, since it has less than a billionth of the mass of it. However, despite this apparent ease to accelerate it, the theory of relativity demonstrates that even the very small mass of neutrino, in order to accelerate it, will increase the more it approaches "c". Then by the theory, there is no place for the neutrino; if it wants to travel at the speed of light it'll require infinite energy.

What this phenomenon could change is variable. From the size and age of the Universe to the distance of the stars and galaxies. All of them would be miscalculated and would need to be done again. Also one such possibility is to look again at the 'mass' of photons, because they may have it and are beyond the limits of detection, thus traveling at the speed of light does not alter the principles of relativity. Either Einsteinium physics are right and nothing travels faster than the speed light or it is wrong, maybe incomplete and scientists will need to rebuild the theory of relativity from the start up. Neutrinos have been a difficult particle to study, unreactive, illusive and even ghostly. They can pass through the heart of a star and not interact with a single particle of matter. It's more likely that this discovery may finally answer why neutrinos are so hard to detect or interact with. Maybe they are able to burrow in and out to different dimensions. It would allow them to travel faster than light not by exceeding light speed itself, but by taking what we can call “shortcuts”. How they do that though will be an interesting process of discovery.

How do Cameras relate to our Physics Class

Adriana C. Santos-Rodríguez

Have you ever wondered how a camera works? It’s pretty amazing to see what it can do, but how does it do it? This very popular device used in the 21st century, were even cell phones have tiny ones.  The basic principles on how a camera works are learned in our very own Physics class. A digital camera takes light and focuses it via the lens onto a sensor made out of silicon. It produces the photos by converting light particles into electricity. The basic technology that makes all of this possible is not very complicated. A camera is basically made of three basic elements: an optical element, a chemical element and a mechanical element. As you can see the only trick to making a camera is combining these elements to create this wonderful device. In this article, we will restrict our information on the optical element, because it is of more relevance to the class. The optical component of the camera is the lens. Like we studied in class, a lens  is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. At its simplest, a lens is just a curved piece of glass or plastic. Its job is to take the beams of light bouncing off of an object and redirect them so they come together to form a real image, an image that looks like you can see on the lens. The lens slows down the light, as we know light travels at different speeds depending on the medium, in the air it travels faster than when it reaches the glass of the lense, therefore helping us capture the image. The light waves enter the lens at an angle, and slowly the wave will reduce it speed. This angle causes the light to bend in one direction, and it causes it to bend again when exiting the lens. This causes that parts of the light wave enter the air and speed up before other parts. In a double convex lens, the light will bend when it exits as well as when it enters. The convex lens takes the light rays and redirects them to the light source, creating a real image where the light rays converge.  The nature of this real image varies depending on how the light travels through the lens. As we learned in class, and like we proved in the physics lab, the angle of light entry changes depending on how far or how close the object is from the lens. But we need to remember that the lens can only bend the light beam to a certain degree, no matter how it enters. Also, we need to remember that from a closer point a light beam converges at longer distance from the lens. To make more clear, the real image of a close object forms farther away, than the one of an object that is at a longer distance. This is what we cause when we turn to zoom in and out with the lens of our cameras to focus on a specific object. Then to capture the image the camera creates a chemical reaction using the film (old cameras) or by using electricity (digital cameras).

Superconductivity

Kyshalee Vázquez

In most futuristic movies we see objects or transportation devices that hover over the ground, such as trains, cars and even skateboards. This was thought as one of the impossible creations of science fiction; nonetheless this could be made possible through the superconductivity phenomenon. However these are not the only cases in which superconductivity can improve our daily lives. But first let us discuss what superconductivity is. 

Nobel Prize winner, Heike Kamerlingh Onnes in 1911 was first to observe the phenomenon in which the electrical resistance of numerous metals and ceramic materials dramatically drops to cero, when its temperature reaches its critical points. This phenomenon was named superconductivity, most probably for its lack of resistance to electrical conductivity. This happened when Onnes cooled mercury to the temperature of liquid helium, four degrees Kelvin, and its resistance disappeared unexpectedly.  Later in 1933, Walther Meissner along with Robert Ochsenfeld noticed that materials in their superconductive states will repel magnetic fields and thus repelling the magnet.   This effect was named the Meissner effect. Therefore the loss of all electrical resistance is not the only feature that distinguishes the phenomenon, for the Meissner effect also characterizes superconductivity. The Meissner effect happens when a material does not interact or excludes magnetic fields from its interior, behaving like a perfect diamagnet. Because of this effect, if you were to put a magnet on a material in its superconductive state, the magnet would hover over the material without falling until the material is no longer in its superconductive state. This happens because the magnetic field of the magnet is not able to interact with the inside of the material, expulsing it outward and thus making it hover. As a result from this vehicles of transportation can be optimized in ways we thought impossible or too far away from our technology, just by applying this phenomena. 

The problematic part of this wonderful discovery is that the material’s temperature has to reach its critical point, which is usually very low. This is usually achieved by the use of liquid nitrogen, which is quite accessible, but a slight disturbance of the process; clearly because it would be ideally best to reach super conductivity at room temperature.   Some critical points are extremely low temperatures such as less than 1 K and others can be as high as 125 K. Superconductors have been categorized in type I and type II, mostly depending in the critical point’s temperature of the material. Type I superconductors are pure metals characterized by no electrical resistivity, no internal magnetic fields and can be explained by the BCS theory, named after John Bardeen, Leon Cooper and Robert Schrieffer, which describes the act of electron pairs as bosons. On the other hand, type II superconductors are made from alloys, mechanically harder and depict much higher critical magnetic fields.

Many technological advances and discoveries have been made during the last century, but there is so much more left to uncover. The future of superconductivity lies in the simplification of the application of this phenomenon in our daily lives. To achieve the upmost simplification it would be ideal to find another way to cool the material or a material which can be superconductive without cooling it. If this were to happen, the electrical systems in houses and cities would be even more efficient. Our mediums of transportation could be completely revolutionized, by the decrease of our dependence of petroleum.

Bibliography

"Superconductivity." Hyper physics. Web. 15 November 2011.

"Superconductivity." The teacher’s web. Web. 20 November 2011.

"What is superconductivity?" Howstuffworks. 7 May 2009.Web. 17 November 2011.

How the Aurora Borealis is formed and why it occurs in diurnal period?

Amarillys Avilés Miranda

The aurora borealis is produced by of the oscillations and disturbances of terrestrial magnetism. It is caused by the collision of energetic charge particles with atoms in the high altitude atmosphere (Arctic and Antarctic regions). The sun, which has a lot of particles at 40,000 ⁰C and enormous pressure make the aurora effect. The light makes the particles inside of the sun to move to the surface creating the electrical current charged gas that makes a magnetic field inside. In some places strong magnetic field pushes the wave trough the surface making a band. When the band breaks, causes a solar storm. This storm travels until it arrives to the planet Earth where the aurora effect is created when the particulate collide with terrestrial magnetism. This effect makes a wonderful spectrum of colors in the sky.

Our magnetic field is originated by the liquid metal movement and it extends a lot of miles far away from Earth. It's movement is undulated through the meridian line with South and North dipole like it is shown in the figure in the left. The solar storm tries to enter the surface but the magnetic field of the Earth breaks it. At this breaking point the particles collide with different gases of the atmosphere and create the colors that we observe. The effect is frequently produce at the Earth's poles because the rays of the aurora are oriented along the line of the force of the magnetic field.

A previous study of the cathodic phenomena tries to explain the diurnal period of the aurora borealis. The author thinks that the aurora borealis: is caused by cathodic phenomena produced  in the atmosphere under the action of the Hertzian wave emanating  from  the  sun. This is because the greatest  frequency  of the aurora coincides with the greatest frequency of the sun spots in one decennial period, which seems  to  correspond  with  the  period  of  synodical  rotation  of  the  sun (regions  of maximum  activity  of  the sun). This theory explains that the diurnal period of the  phenomenon that occurs by the maximum production should correspond with the maximum  of  solar  radiation  in  a  given  point. The apparent  maximum of the aurora cannot be observed until the early hours of the evening, in accordance with experimental facts, this is because the brilliancy of daylight at the instant of the real  maximum  will  hide  the  phenomenon.

Rotational Doppler Effect

Angelica M. Cortes Velez

The article “Like a speeding watch” is about the rotation in lights electric field vector, that can alter the lights frequency. It has been spotted in the laboratory, that this rotational is the equivalent of the Doppler effect. The author of the article was, Miles Padgett, his report 

“Physical Review Letter”, with Barreiro and colleagues have measured the broadening of a spectral line caused by an effect analogous to the conventional Doppler Effect.

Talking more about Miles Padgett, him is a Professor of Optics in the Department of Physics and Astronomy in the University of Glasgow. He heads a 15-person team covering a wide spectrum from blue-sky research to applied commercial development, funded by a combination of government charity and industry. In 2009 Padgett was awarded the Institute of Physics, Young Medal "for pioneering work on optical angular momentum".

Padgett has an international reputation for his contribution to the fundamental understanding of light's momentum, including conversion of optical tweezers to optical spanners, observation of a rotational form of the Doppler shift and an angular form of Heisenberg's uncertainty principle.

The Doppler shift or Doppler effect is the change in frequency of a wave for an observer moving relative to the source of the wave. Doppler first proposed the effect in 1842 in his treatise “ On the coloured light of the binary stars and some other stars of the heaven”. The hypothesis was tested for sound waves by Buys Ballot in 1845. The Doppler effect is used in some types of radar, to measure the velocity of detected objects.

The shift in frequency of this case arises from rotation. The effect was observed in terms of Jones polarization matrices, wich describe this effect in a medium with an orientation of the electric field. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding. 

Polarization (also polarisation) is a property of certain types of waves that describes the orientation of their oscillations. Electromagnetic waves, such as light, and gravitational waves exhibit polarization; acoustic waves (sound waves) in a gas or liquid do not have polarization because the direction of vibration and direction of propagation are the same. By convention, the polarization of light is described by specifying the orientation of the wave's electric field at a point in space over one period of the oscillation. When light travels in free space, in most cases it propagates as a transverse wave—the polarization is perpendicular to the wave's direction of travel. In this case, the electric field may be oriented in a single direction (linear polarization), or it may rotate as the wave travels (circular or elliptical polarization). In the latter cases, the oscillations can rotate either towards the right or towards the left in the direction of travel. Depending on which rotation is present in a given wave it is called the wave's chirality or handedness. In general the polarization of an electromagnetic (EM) wave is a complex issue. For instance in a waveguide such as an optical fiber, or for radially polarized beams in free space, the description of the wave's polarization is more complicated, as the fields can have longitudinal as well as transverse components. Such EM waves are either TM or hybrid modes.

In many areas of astronomy, the study of polarized electromagnetic radiation from outer space is of great importance. Although not usually a factor in the thermal radiation of stars, polarization is also present in radiation from coherent astronomical sources (e.g. hydroxyl or methanol masers), and incoherent sources such as the large radio lobes in active galaxies, and pulsar radio radiation (which may, it is speculated, sometimes be coherent), and is also imposed upon starlight by scattering from interstellar dust. Apart from providing information on sources of radiation and scattering, polarization also probes the interstellar magnetic field via Faraday rotation. The polarization of the cosmic microwave background is being used to study the physics of the very early universe. Synchrotron radiation is inherently polarised. It has been suggested that astronomical sources caused the chirality of biological molecules on Earth. The rotational Doppler effect is interesting because here the spin and orbital components are indistinguishable. Instead the total angular momentum of the light beam, that is crucial.

A Life Without Gravity

Alexander Rivera

Do you ever think what could happen if we woke up one day and were no gravity? Before start, we must understand what gravity is. Gravity is an attractive force between any two atoms. The more matter, the more gravity. Things that have a lot of matter such as planets and moons and stars pull more strongly. Mass is how we measure the amount of matter in something. The more massive something is, the more of a gravitational pull it exerts. The perfect example for this is when we walk on the surface of the Earth, it pulls on us, and we pull back. But since the Earth is so much more massive than we are, the pull from us is not strong enough to move the Earth, while the pull from the Earth can make us fall flat on our faces. In addition to depending on the amount of mass, gravity also depends on how far you are from something. This is why we are stuck to the surface of the Earth instead of being pulled off into the Sun, which has many more times the gravity of the Earth.

Knowing the definition of gravity, we may ask what if doesn’t exist? A lot of people when first think if there were no gravity, the first thing in their minds is that everything including us is going to float. That’s true but the thing is that imagine cars, humans, animals, furniture and many others floating, is going to be a mess. But that’s not all, two essentially things in our life are going to disappear: water and air. The air depends of our atmosphere, and the atmosphere depends of gravity, what means that in a life without gravity there was no atmosphere. The air will escape into the space leaving us without oxygen. Like the air, the water of the earth is going to be boiling in the space. We were living in a world without air to breath and no water to hydrate. Without gravity no one can live. If it were possible to adapt ourselves to an environment without gravity it is going to be a boring one. We cannot exercise ourselves, there were no sports, no nothing. Another thing is that we are going to be skinniest. Our muscles and bones will deteriorate, they are going to be useless.

Never can we ask a life without gravity because it can’t be possible and can be dangerous for each living thing on the planet. So when you think that this constant (g= 9.81m/s^2) bothers you because makes you slower and lazy, and sometimes limits you to do such things, think that this constant is essentially in our lives. We cannot live without it, and we can't afford to have it change. Gravity is a very important constant in physics, but it is an essentially true constant of our lives that will be with us for our rest of our lives. No better life than a life with gravity. 

How a Physics Class changed the way I See Things

Victor M. Estremera 

I’ve always been curious to know how things are made or how they work, which is why I decided to study Mechanical Engineering. When I started College, I was looking forward to my Major Courses, but wasn’t too thrilled about Physics I & II because I couldn’t find a relation between Physics and Engineering.

As much as I enjoyed watching TV shows that explain how machines and Manufacturing Plants operate from an Engineering point of view, I couldn’t understand why Physics I & II were so important in my curriculum. It wasn’t until I started taking Major Courses such as Thermodynamics, Electric Circuits and Fluid Mechanics that I understood how Physics is associated with Engineering. Physics is the base to Engineering, regardless of the Engineering Specialization.

For example, Civil Engineers couldn’t design a bridge without understanding Newton’s Laws of Motion from Physics I. The Second Law states that F = ma. The Third Law states that the mutual forces of action and reaction between two bodies are equal and opposite. That’s why in Statics, combining these two laws, the sum of the forces acting on the bridge must be zero in order to stay fixed. Chemical Engineers wouldn’t be able to solve problems of Physical Chemistry and Thermodynamics without understanding topics from Physics I such as the Ideal Gas Law or The Kinetic Theory of Gases. 

Electrical Engineers could never design an integrated circuit without the combination of Ohm’s Law and Kirchhoff’s Voltage and/or Current Laws from Physics II. Kirchhoff’s Current Law states that the algebraic sum of currents in a network of conductors meeting at a point is zero. This is the principle of Conservation of Electric Charge. Kirchhoff’s Voltage Law states that the algebraic sum of voltages in a closed loop is zero. This is the principle of Conservation of Energy. 

Mechanical Engineering is perhaps the widest branch of Engineering and contains endless principles from Physics I. Designing an Internal Combustion Engine wouldn’t be possible without the Laws of Thermodynamics and the Ideal Gas Law. Improving the efficiency of the engine couldn’t be done without the model of the Carnot Cycle.

Designing a submarine wouldn’t be possible without Archimedes’ Principle. This principle states that any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. In other words, the Buoyancy exerted on the submarine = the displacement of the water. And once again, Newton’s Laws of Motion come in to play. When it comes to the Design of a Mechanical System or Machine Component, the Second Law is used to analyze dynamic loading. The list goes on.

We can see that the most basic equations of Physics are responsible for some of the most incredible achievements in Engineering. From this perspective, we could say that Engineering is a branch of Physics or, furthermore, an application of Physics, because Engineering wouldn’t exist without Physics. 

Capillary Action

Angel Lugo Lugo

I would like to discuss something that was not explained in our course but always had my attention. Since I was a kid I had a lot of curiosity about why when I had a straw in a glass with liquid I always observed that the level of the liquid was a little higher inside the straw. Now that I studied physics and as a university student I am able to do research and learn about why of the phenomena I know this is called capillary action. 

The capillary action can be observed first of all in a capillary tube and laboratory glassware forming a meniscus. This is caused by adhesion, which is the attraction between different molecular species, when it pulls the liquid column up until there is a sufficient mass of liquid for gravitational forces to overcome the intermolecular forces. After some research I learned that the capillary action is not only present in tubes, I did learned that this is the way tears comes out when we cry. This is because inside our eyelids we have the lacrimal ducts which are of very tiny diameter, then acting as capillary tubes. This is also observed in paper towels, sponges, fabrics, well in most of the material which are sufficient porous to absorb liquids. This characteristic of the materials is even used for chromatographical separations of liquid and gases in chemistry and physics laboratories.

But then I asked myself: It has to be physical explanations which allow me by some sort of equation describe the capillary action. Well I founded an explanation for my beloved liquid inside the straw and why depending the wide of the straw varies the level of the liquid inside it. The height h of a liquid column is given by: 

where gamma is the liquid-air surface tension (force/unit length), θ is the contact angle, ρ is the density of liquid (mass/volume), g is local gravitational field strength(force/unit mass), and r is radius of tube (length). Another thing I really found as a curious detail when I got in a chemistry laboratory is the upside down meniscus of the mercury. After researching about it I found it was because of the polar surface in contact with.

As for the another applications of capillary action that I mentioned before I founded that there is also a physical description of the volume of liquid absorbed by the porous material.  A porous material absorbs liquid by a rate that decreases over time, in other words as more time passes less liquid will be absorbed due saturation of the media. The volume absorbed is described by the following equation

where S is the sorptivity of the medium, with dimensions m/s1/2 or mm/min1/2 , A is the area of the porous object and V is the cumulative volume. The sorptivity of the material is mainly given by tables. So if you can do some research of the porous material you are using, calculate the area of the piece of material being used you will be able to know how much liquid will by absorbed by it.

I found this topic quite interesting and useful in the today’s industry, and very practical and favorable in laboratories technology.

Through the Wormholes

Jonathan A. Varela Escapa

One night I was seeing a program on T.V. of the wormhole and I became so intrigued of it to learn more about it. The wormhole definition is a theoretical entity allowed by the Einstein’s theory of general relativity in which space time curvature connects two distant locations. 

The Einstein’s theory of general relativity also known as the Einstein-Rosen bridges, described by the formula: 

In which it describes that the wormhole connects in different parts of space in time.

The Einstein-Rosen mathematically wormhole was derived by the study of black holes, in which a black hole is a region of space time from which nothing, not even the light can escape from it. Einstein’s theory for the wormhole was never intended as a tool for space travel, it was theoretically created at some moment of time in which it will open up briefly then it will close, and anything that tries to pass through it will get crushed when it squeezes apart, so therefore this is not a traversable wormhole, and what we are looking is for a traversable wormhole.

The typically of wormhole that a scientist writes down in equations and studies is very unstable and will vanish in an incredibly short amount of time, and what we want that it stays open so we can theoretically travel through time, therefore we need something to let it open. For a wormhole to be kept open, it requires something called exotic matter or negative matter, we have never seen negative matter before, and this type of matter will have anti gravitational properties. The possibility of a traversable wormhole was first demonstrated by Kip Thorne and his graduate student Mike Morris in 1988, the type of traversable wormhole that they proposed, was held open by a spherical shell of negative matter, and it is referred as the Morris-Thorne wormhole. There have been other theories such as the Matt Visser and the Gauss-Bonnet theory.

The theory of general relativity predicts that if a traversable wormhole exists, this would allow travel in time and space, because the wormhole connects two points in space-time. A traversable wormhole could be used as a time travel machine, and this could be accomplished by accelerating one end of the wormhole to a high velocity relative to the other, and then sometime later bringing it back, this would cause a relativistic time dilation and would result in the accelerated wormhole mouth aging less than the stationary one, but time connects differently through the wormhole than outside it. Therefore synchronized clocks at each mouth will remain synchronized to someone traveling through the wormhole itself, no matter how the mouths move around. This means that anything entering the accelerated wormhole mouth would exit the stationary wormhole mouth at appoint in time prior to its entry or the same age that the accelerated end had been at the moment before entry.

There is still much speculation on whether it is possible for wormholes to actually exist and, if so, what properties they would actually possess. In conclusion, we can say that the wormhole is a system in which something can travel through time and space; in a very distant future we may really discover the facts about the wormhole, and it may be used as a time travel subway through the universe.

Quantum dots, a New World of Study

Emmanuel J. Chamorro Rivera 

In chemistry there are new discoveries, among them is the existence of quantum dots, they are semiconductor compounds too large to be atomic and too small to be colloids. These compounds are unique in their use, from optical wavelength change to sensitization of stable and high-speed lasers. For many scientists the study of these compounds is vital to discover new possibilities in many field of study. These are capable to change the color that they have when they are shot with an Ultraviolet light, the colors depend on the quantity of the particles in a given solution. As we may know from physics when light passes from one medium to another the characteristic of wavelength and speed change but never does the frequency, but what happens with the quantum dots? Because of their characteristics they can change which type of frequency they absorb, and which they leave untouched; a property that we have seen in the sleet experiments, but in a quantum scale, this causes the solution to change the color, in other words, the frequency, leaving the wavelength intact. This causes the brightness of the color to be the same but the color to be different. 

Now many would think that this is unimportant to fields like physics, but if we were to analyze what it means to be able to chose a wavelength and maintain it through a medium, means that we could break the principle that the frequency may not be changed. As many know the frequency is one of the properties of light that remains constant, but quantum dots can change this. This means being able to build a laser that can emit the wavelength in a stable manner, chosen by the scientist. The only thing to be change is the array of quantum dots used to change the wavelength. Why is this important in physics? This means that if a laser with incredibly high energy, a respective quantum dot can be used to manipulate the levels of energy when changing the wavelength. This small particles act as wavelength manipulators, because it is easy to change the wavelength by only changing the quantity and array of quantum dots. 

The characteristics that make this effect of quantum dots possible have to do with something physics study, charges and electric fields. It is well known that atoms have both positive and negative charges; a quantum dot has an array of two elements bonded into each other. The electrostatic forces between them cause many sub-atomic particles to move, and to cause partial charges from time to time. When more quantum dots are added, they interact because of the partial charges, then the particles arrange themselves in different patterns, these patters change the properties of light entering this medium.

In science discoveries are found every day, these discoveries may change our perspective of how the world works. Quantum dots have created a new field to be studied; many are trying to discover the hidden potential of these particles. Even small particles can create change, and worlds to be discovered.

Magnetic Monopoles, Theory or Truth?

Paul Feliciano Abreu   

We live in a world surrounded by enigmatic phenomena. One of the most present phenomena is the asymmetry that we find it in the magnetism and in the electricity, by that; there are no magnetic charges that can be compare to electric charges. A thing that is always there around us is the electrically charged particles like protons and electrons but nobody talks about an isolated magnetic charge, if something would have this charge will be the magnetic monopole. For this idea we will use a magnetic bar with a north pole and a south pole and cut it by half, next we will have two poles isolated but this thing will never be possible or if its possible is in just a rare occasion because the nature does not create magnetic monopoles, they can just be imagine and related to some idea like comparison, but this would not be a thing to stop studying or investigate them, because I think this could be found sooner or later. 

Picture of how should be form the magnetic monopoles

By other hand, we have electric monopoles that are electric charge particles very abundant in matter because every piece of it has a big number of electrons and protons that are authentic monopoles. But in the magnetism we cannot see this phenomenon because there do not exist nothing similar to electric monopoles but it should be interesting to find a case. The electromagnetic theory unifies the electric force and the magnetic force, because the electric charges work for both forces, in the electric force they generate the force and in the magnetic with the movement of the particles the magnetic force arises. An example of what could be a magnetic monopole is if we took a magnet bar really thin and about 1 kilometer of distance with a magnetic field at each end of the bar, because the ends are really separated and the bar is so thin that the lines of the magnetic field don’t surround the end of the magnet the unify in the bar creating a way back to the other end or creating a cord with a radial field (Dirac’s cord) or something like it. Going to Dirac’s theory he just wanted to explain the behavior of the relativistically moving electron, and so to allow the atom to be treated in a manner consistent with relativity. And for this theory he apply the next equation:

where

m is the rest mass of the electron,

c is the speed of light,

p is the momentum, understood to be an operator in the sense of the Schrödinger theory,

x and t are the space and time coordinates,

ħ is the reduced Planck constant, h divided by 2π.

Dirac strings or cords

After Dirac’s theory was proposed, physics accept the possible existance of magnetic monopoles. If these magnetic monopoles exist they will be producing a magnetic force, and also by their movements they could gain electric force. As a matter of fact these monopoles could be a great help to the universe density.

News of magnetic monopoles detected in a real magnet:

From: Science Daily webpage in Sep 03 2009 http://www.sciencedaily.com/releases/2009/09/090903163725.htm

Usefulness of Magnets

Arnaldo López Rivera

When I was younger I was intrigued by magnets, even though I never understood how they worked in a deeper level. All I knew was that magnets attract each other based on their polarities, in that opposites attract while same polarities repel. After reading and taking a few physics and engineering courses I have found many diverse uses for magnets, besides hanging up papers in the refrigerator. You may wonder. What are magnets useful for? The answer is magnets are useful in a wide variety of areas, such as medical equipment, electronics, and transportation.

For starters in the medicine field, most magnets are used for the diagnosis of medical problems, such as physical and organ function. Some of the equipment that use magnets are MRI, hearing aids, x-rays, and VCD. In MRI (Magnetic Resonance Imaging), uses superconducting magnets to form images of the inside of a human body. While hearing aids use magnetic fields to increase the ears ability to hear. And finally there’s a VCD which uses a magnetic rotor, in order to pump blood and aid those with failing hearts who cannot afford a heart transplant.

However the are where magnets truly shine is in electronics. First, without them televisions would not work. The reason for this is because there are magnets inside the cathode ray tubes, which deflect electrons towards any region  allowing us to see the images on the screen. Secondly without them all of our media carrying devices would have nowhere to store the information, such as IPODS, PS3, XBOX, PSP, computers, etc. The reason for this is because hard drives use magnetic fields in order to read and/or write data (which is also known as magnetic reading). It is possible to see the effects of magnets on electronics, for example if you put a magnet against an old computer, the screen would crash or if you’d put it against a floppy disk, all the information would be erased.

And lastly magnets can be used in the transportation industry. For example in cars magnets can be found throughout the whole car, such as in the motors, the electric window motors, are in the alternator. The alternator uses a magnetic field in order to convert the mechanical energy put into the motor into electrical energy. Another example of transportation, is in roller coasters, magnets are used to cause a propulsion at the start of a ride usually; and they’re also used to gradually slow down a roller coaster, making them a cost effective method for brakes.

Magnets have a wide variety of uses, ranging from a refrigerator magnet to a motor, and a media storage device. They are of high importance in today’s society, which relies heavily on technology. Without magnets we would not have a means for transportation, since most motors, if not all use magnets. We would also not have many of the electronics we use in our home every day, such as computers, and gaming devices, because we would have no way to store all the programs in order to make the device work efficiently. In retrospect today’s society has come a long way thanks to the usefulness of magnets.

Neutrino: Faster Than Light?

Rubén D. García Avilés 

When I heard the news that there was a particle that runs faster than light and that Einstein may be wrong I was shocked. A group of physicists were doing some measurement with neutrinos and developed then using a particle accelerator at CERN. 

This has been widely reported as being the end of relativity, but this is not the case at all. Neutrinos are interesting little neutral particles according to literature that have almost a mass of zero. Knowing their nature, they can go through matter without being absorbed, going faster. The time of traveling of the neutrinos was measured with extreme precision and caution using GPS timing signals and a cesium atomic clock. 

The speed of neutrinos was measured and compared to the speed of light by simply subtracting the expected time of light to travel with the distance from the time that the neutrinos need to travel the same distance. The expected was zero for traveling at speed of light and a negative value for any below speed of light, but it presented a positive value of 60.7 nanoseconds causing some intrigue in the science world. The final paragraph of the report shows:

This is very important because the physicists established that no conclusion could be drawn without more experimentation. The shocking part is that the measurements were using some of the most amazing and precise instruments and techniques ever created. No matter what is found to be the actual cause of this 60.7 nanoseconds variation, the conclusion that you can draw is that it’s an amazing time in history were such measurements can be made, and an exciting time to be a practitioner or admirer of science. 

As discussed in class Einstein is one of the greatest minds in history. He developed the equation E=mc2 and established that nothing could travel faster than light which has a speed of 3.00 x 108 m/s. All of this was established around 1904, Would be true that 107 years later in our world history recent scientists demonstrated that the Einstein, Newton, Volta and others were wrong on their postulates? The answer is No, because these great people established their thoughts with the knowledge of the era, they developed theories that transformed human history, having in mind that it’s not for the little error that some men believe but maybe they forgot to create an equation able to classify everything. Our world is a world of changes that will be responsible of transforming the laws of some of the world’s greatest men in history. 

The future generations of young scientists who are sitting on a classroom with many ideas running through their minds and the interesting’s findings that they will had to contribute and make a world better. “Einstein wouldn’t be disappointed by these findings; he would be intrigued and proud to see the legacy of great science continuing forward’’ leading a group of scientist to appreciate his findings make a revolution in world.

Bibliography:

¿Puede un neutrino acelerado refutar a Einstein? - WSJ.com. (n.d.). Retrieved November 27, 2011,from http://online.wsj.com/article/SB10001424052970204831304576596823787257198.html

Neutrinos and the Speed of Light — A Primer on the CERN Study | GeekDad | Wired.com. (n.d.). Retrieved November 24, 2011, from http://www.wired.com/geekdad/2011/09/neutrinos-and-the-speed-of-light-a-primer-on-the-cern-study/

Physics shocker! Neutrinos clocked faster than light | Deep Tech - CNET News. (n.d.). Retrieved November 24, 2011, from http://news.cnet.com/8301-30685_3-20110594-264/physics-shocker-neutrinos-clocked-faster-than-light/

What’s a Neutrino? (n.d.). Retrieved November 24, 2011, from http://www.ps.uci.edu/~superk/neutrino.html

An Introduction to Antimatter

Benedict D Newball Diez

In my article I would like to talk about a subject that has not been discussed in our course of FISI 3172. I would like to talk about antimatter, some of its potential uses and give some opinion as to how it could be used and why we are not using it right now. 

I should start by giving a brief description of what antimatter really is. We could start by remembering solving a quadratic equation you always would get two answers a negative and a positive. Well antimatter is precisely the exact opposite of matter. A funny way to look at it would be taking matter and multiplying it by negative one. What this means is that the anti-proton would have a charge of –e and the anti-neutron has a charge of e. Everything with the same mass. There is very little antimatter in the universe; this is known because when it comes into contact with regular matter they annihilate each other, releasing a lot of energy sometimes in the form of gamma rays that would be detectable. Because of this the formation of antimatter requires vast amounts of energy. 

Antimatter is made where there are high-energy particle collisions. Artificially these can also be produced with highly advanced equipment that requires a vast amount of energy and even more funding. One of the most important creations related to antimatter would have to be the anti-hydrogen atom which was created in an experiment using a Low Energy Anti-Proton Ring (LEAR). This was an experiment designed to decelerate and store the precious antimatter, study the properties of it and create antihydrogen atoms. This experiment was made in 1982 and in1996 was converted into the Low Energy Ion Ring (LEIR). 

Antimatter has the potential to be the primarily energy source in the world. One of the most extraordinary uses would have to be its ability to provide fuel for interplanetary travel for space ships. It would be called antimatter catalyzed nuclear pulse propulsion. This type of energy would be a lot more useful than regular energy. Studies have shown that antimatter has ten times the energy per unit mass that the conventional chemical energy that is typically used is space travel. Another amazing fact about antimatter energy is that it is not only more efficient than chemical energy but it has been calculated that the use of this energy source has about 3 times more energy per unit mass than the energy that would be produced by a nuclear fission and 2 times as much energy as a nuclear fusion! 

As a mechanical engineer major I must admit I get blown away by all the potential this type of energy has. It is said that a very small amount of antimatter could power a city for a very long time and that a gram of it could run your car for 100,000 years! This has the potential to grant us victory over the long fought light-speed battle we faced when traveling in space. It is obvious to say that this type of energy represents the future and in my opinion should be dealt a lot more importance in the research and development programs. 

On the down side with our technology as it is we might be very far away from achieving this utopian idea. The cost of development alone has put a stomp on the research and development of this energy. Another pessimist way to look at this situation is the corruption of man-kind and the fear of this energy being used for bad and not peaceful porpoises. Exactly what happened with nuclear technology. 

       I for one choose to stay on the optimist side of the situation hoping for one day in which I will be dealing myself with this type of technology. Because with modern advances these days you’ll never know what will happen tomorrow.  That is my take on antimatter I hope that you have enjoyed it. 

Superconductivity 

Juan G Perez Narvaez

Not so much ago I saw a video of quantum levitation. The video was very interesting and I wanted to know how that was possible. When I looked this was possible by a phenomenon known as superconductivity. Superconductivity is a quantum mechanical phenomenon in which there is exactly zero electrical resistance. This was discovered by Heike Kamerlingh Onnes. 

What happens is that when a superconductor is cooled below its critical temperature is resistance drops to zero. This means that if we put an electric current in a loop of superconductive wire in a temperature lower than its critical temperature the current will continue flowing indefinitely with no power source. For normal conductor even when the temperature is near absolute zero there exists some resistance in them. In superconductor there is none at all. But the part that I want understand is why do the material levitate and stay locked in an specific point in space. And for that we look at one of the things that characterize superconductivity, and that is the Meissner effect.

The Meissner effect is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state. In a superconductor above its critical temperature the magnetic field goes completely through them, but in a superconductor below its critical temperature the magnetic field does not go through it. It surrounds it and locks it in space.

  

In the pictures above we can see how the magnetic field distributes when the superconductor is above or below its critical temperature. We see that the field won’t let the superconductor move from where it is, unless we apply a force greater than the one generated by the field.

But what would be some uses for this discovery? In the field of levitation the superconductors are very useful. For example in transportation like trains extremely powerful conductors may be used to make train practically float and therefore eliminate friction between the wheels and the track. In medicine they use superconductors in MRI (Magnetic Resonance Imaging) for example. In Korea they have developed the Superconducting QUantum Interference Device that is capable of sensing a change in a magneticfield overa a million time weaker than in a needle in a compass. That is as little as e-14T. This means that people would not have to be exposed to strong magnetic fields.   Also superconductor a can be used in generators instead of using copper wire and other materials. This way the efficiency of the generator would be 99% more than the generator of copper wire, etc. In the military one of the uses of superconductor are in the deployment of “E-Bombs”. These bombs use superconductor to create a high intensity electromagnetic pulse to destroy enemy electrical equipment. These is better known as an EMP.

There are a lot of other uses for superconductors and with time there will be development of the uses of a superconductor. At first I only knew that the superconductor only where user to levitate, but know I know that there are a lot of uses for this phenomenon. And the uses help a lot the entire humanity. 

Our Big Problems, Solved by Small Atomic Structures

Alexander Millet Ayala

We currently have a worldwide problem with our energy usage making the earth taking more contaminants in the atmosphere, contributing to what we call global warming. We depend on power plants to power our houses and household appliances to make our lives simplified. Power plants may be a thing of the past with recent inventions in nanotechnology. Solving the problem requires different types of materials with different uses. Let’s start with the carbon nanotube polymer, which acts like a polarizer when the person needs it. The material is done by vaporizing graphite, turning it into a mesh nanotube and then adding it into a flexible plastic that can be normally seen through, and the light will pass through. The special thing about this material, is that with a minimal electrical charge (2 volts), it will turn colored, and reflect the light trying to cross over the material. Some applications for this is the difference of sun intake on different seasons, turning it on to make the room colder on summer, off when you need the room warmer on winter, and it would also work as a privacy filter. This would save energy in winters by efficiently changing the light and heat into the room, and not the thermostat.

An illustration of the mesh nanotube that would be used.

But what about the energy, how can we get clean and easy energy? The answer is also in nanotechnology, by combining two different kinds of nanomaterials, a detector and imager that turns infrared waves at day, or night, and turns into electrons, which can be stored or used at the moment. Electrons, as discussed in class, are the elemental particle which makes electricity possible when it flows through a medium. This makes obtaining energy in a continuous way, even at regions with low sunlight. The great thing about this material is that it is also a transparent material that can be used with the carbon nanotube polarizer. Combining these two materials can make any window be an efficient energy generator, and energy saver. So, now what is missing is a battery to hold the electrons, which are now being built and tested with various nanomaterials in the University of Texas. These batteries are the last component to the plan, because what’s the use of energy if you cannot store it for when it is needed? These are needed to hold those electrons obtained by the nanomaterials, and release them when needed in the most efficient manner, while occupying a relatively small space. 

A sheet of the nanomaterials in a flexible plastic polymer.

This can change everything and eliminate our dependence on fossil fuels. We could power cars, planes, houses, buildings, etc. with the stored energy in the batteries. This also solves problems in third world countries that need electricity, and clean water. Animals also could benefit too, since the other clean renewable methods of energy have the problem that it could destroy their ecosystems.  Examples with this are natural gas, which can poison water or even explode in the event of a leak, and eolic energy windmills that could destroy bird nests. With free energy, the next generations could have the opportunity to have better human conditions and a cleaner world.

References:

“The Future of Nano-Electric Power Generation”. Sunlitepower.org. Web.  November 11, 2011. November 24, 2011.

Additional resources:

http://www.ted.com/talks/justin_hall_tipping_freeing_energy_from_the_grid.html

Magnetic Monopoles: A feat yet to be reached

Jan K Huertas de la Cruz

Magnets are one of the earths most studied phenomena. Why? Is one of those natural marvels that make our twentieth first century what it is today, a marvelous age in the advancement of technology. And even more, it is an occurrence that helps the earth to be habitable, it produces a magnetic field which without it we couldn’t live on earth and just for us to enjoy it is thanks to it that the beautiful Aurora happens. But why from a most studied phenomenon, the magnets, can’t we get monopoles?  This question has baffled the minds of geniuses for centuries and it is the main argument in this essay.

According to different researchers and scientists a magnetic monopole is “a hypothetical physics particle with only one magnetic pole.” In other words, when we have a magnet we normally have two "charges", a north pole and a south pole, which means that overall, the magnetic charge of the magnet cancels out. To better understand the magnetic charges of a magnet we can use the magnetic field as an example and here is a diagram.

 

In the pictures above we can see a magnet bar with both its north and south poles, and the diagram of the magnetic field it produces.

Everyone knows that the north and south poles are attracted, but why is the question many people have in their minds. When the magnetic force exits from the north pole it begins to weaken, so naturally when it starts weakening it feels attracted and controlled by a stronger force which is the south pole, so eventually this force starts to deviate from its straight course and starts moving to the south pole. This is what we can see in the picture in the right.

But the question we want to answer is why we can’t have magnetic monopoles. There are many theories as to why, and what I’m going to do is explain the why as I understood it. Let’s begin the explanation by making an analogy. Let’s say that the bar magnet is a water hose and that the water is the magnetic field it produces. Looking at the picture, and knowing how a water hose works, we can say that the water enters from the south pole and exits the north pole. But what would happen if we cut a hose in half, one of those halves is going to stop throwing water since by basics physics we know that for water to exit the hose first water must enter the hose. One can’t just cut the hose in half and expect it to keep throwing water from the 2 halves.

Well, this basic understanding can also be applied to magnets, if we cut a magnet in half, the “force” must exit from one side and enter from the other one. One can’t just cut it in half and expect a constant force to keep acting by its own, like the water hose. Many scientists have conducted many experiments and researches such as the string theory trying to explain the possible existence of magnetic monopoles, but we are yet to see such thing.

This is a basic explanation as to why magnetic monopoles can’t be produce nowadays. Even though we have many theorists claiming that they can be manufactured we are yet to see this happening. But as for now let’s keep in mind that magnets are here for a reason, and the main reason I can think of as to why they exist, is that without them we wouldn’t be able to live on earth, so as for now let’s just keep enjoying their benefits. 

References:

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

• "Magnetic Principles” Magnetic Research and Development. (Physics)Network. Web. 22 Nov. 2011

Life without Electric Current

Natalie J. Aponte Méndez

Today our lives are based in technology, electric devices, internet and others sources that simplify and gives to the human race the ability to control and adapt to their natural environments. The global economy depends of technology and countries around the world use spaceships and some other technological devices to investigate new alternatives and to discover new physics laws. Think about how much we all depend on technological products and the times you use technology each day. In the past Newton discover important laws and in the 1800 Alessandro Volta invented the first electric battery and produced the electric current without technology. How we can reduce this terrible dependence of technology?, What happened if we reduce the amount of electric current consumption? Thomas Alva Edison in 1879 invented the light bulb a historical important device that uses electric current to maintain our houses illuminate in the night.  The light bulb is an electric lamp in which a filament is heated to incandescence by an electric current. It is possible to create a light bulb without electric current passing through it? 

We learn about circuits to complete the charge flow and the different forms to connect a light bulb or any other device. But it is time to create a new alternative to illuminate our world, a new light bulb that reduce or eliminate the current consumption, light bulb created by WATER. Water covers 70.9% of the Earth’s surface and is a natural source.  This is why a group of students from the Massachusetts Institute of Technology installed 10,000 light bulbs made form water in Philippines. This light bulb is composed of nothing more than one-liter plastic bottle, water, and bleach. The installation process is easy and can be installed in less than an hour. They have never needed to be replaced. They are maintenance free. To turn them off on the day time, they can be covered by a solid bucket. The light bulb lasts for five years, and is equivalent to a 60-watt bulb. The principal inventor was the mechanic Mr. Alfredo Moser and now the solar bottle bulb is illuminating poor settlements across the Philippines. 

Figure 1: Water light bulbs installed in Philippines houses

This new creation gives us an idea of the power of water. Water can be used for everything and now is used to replace electric current. This water bulb works simply because the water diffracts the light, letting it spread throughout the house instead of focusing on one point and the bleach function is to keeps the water clear and microbe free. If this new invention reduces the consumption of normal light bulbs what happened if we try to reduce the overall consumption of electricity? Is a new alternative an is possible with some other experimentations, we want to grow and to invent technology but sometimes the simplicity and the natural resources like water give us more energetic and viable possibilities to create the new future. Is life without electric current possible? We don’t know but if we continue with experimentations like this we can create a different life style and a better future free of technology dependence.

References:

Reach Michael J. Coren,  The World’s Cheapest Light bulb Is Made Of Just a Plastic Bottle. November 10, 2011.

Water Light Bulbs. Sustainable Times. October 8, 2008, November 10, 2011.

Additional resources:

http://www.boreme.com/posting.php?id=28861

Verónica Marie Cruz González: Applying physics to my everyday life: Human eye and corrective lens

In the course FISI 3172 we have studied many different topics, but there was one that caught my attention. I could apply this topic to my life and I could finally understand how things work using physics. The topic I am talking about is Lenses and Optical Instruments. I’ve used eyeglasses since I was six months old because I have multiple eye defects. I never understood the prescription or which types of lenses I use, but now that we have studied this topic in class I can understand a little better how my prescription and glasses work. 

The development of optical devices using lenses dates to the sixteenth and seventeenth centuries, although the earliest record of eyeglasses dates from the late thirteenth century. To be a little more specific, history records state that the first spectacles were made between 1268 and 1289.[1]  Around 1284 in Italy, Salvino D'Armate is credited with inventing the first wearable eye glasses.[2]  

There are two types of lenses; converging and diverging lenses. The converging lens is thicker in the center than in the edges and makes parallel rays converge to a point. On the other hand, the diverging lens is thinner in the center than at the edges and makes parallel light diverge. These lenses are used for many purposes but are very useful as corrective lenses for humans with eye defects. 

Some of the eye defects discussed in class were; myopia, hyperopia, presbyopia, and astigmatism. Myopia, also known as nearsightedness, is when the eye can focus only on nearby objects. It is usually caused by an eyeball that is too long or that the curvature of the cornea is too great. In either case, the images of distant objects are focused in front of the retina (Figure 1 a.). The lens used to correct this defect is a divergent lens because it allows the rays to be focused at the retina (Figure 1 b.).

Figure 1: Nearsighted eye (a) Image is focused in front of the retina; (b) image is located on the retina with the use of a divergent lens

Hyperopia, also known as farsightedness, is when the eye cannot focus on nearby objects because the near point is greater than the “normal” (25 cm). It is usually caused by an eyeball that is too short or by a cornea that is not sufficiently cureved (Figure 2 a.). The lens used to correct this defect is a converging lens. Presbyopia is similar to farsightedness. It refers to the lessening ability of the eye to accommodate as a person ages, and the near point mores out. It is also corrected by a converging lens (for older people, bifocals are used. 

Figure 2: Farsighted eye (a) Image is focused behind the retina; (b) image is located on the retina with the use of a convergent lens

Finally we have astigmatism which is usually caused by an out-of round- cornea or lens so that the objects are focused as short lines, which blurs the image. An astigmatic eye may focus on rays in one plane. Astigmatism is corrected with the use of a compensating cylindrical lens. Lenses for eyes that are nearsighted or farsighted as well as astigmatic are ground with superimposed spherical and cylindrical surfaces, so that the radius of curvature of the correcting lens is different in different planes. 

Like I mentioned before, my eyes have multiple defects. These are; myopia, hyperopia, presbyopia, astigmatism, strabismus, and nystagmus. As you can see, I have all the defects discussed in class. But, how can one person be near and farsighted at the same time? Easy, I am nearsighted on the right side and farsighted on the left side. I always got these confused and never knew which one was which, but with the description in class and the book I was able to determine this. So with this we can conclude that I use a divergent lens on the right side and a convergent lens on the left side with superimposed spherical or cylindrical surfaces on each because I also have astigmatism. 

Now, when I read my prescription I know what things mean. The plus sign (+) is for my left side because that is the convergent lens that corrects my hyperopia. The minus sign (-) is for my right side because that corrects my myopia. Even though this topic was only one section on the book, I now understand how to read my prescription and what types of lenses correct each defect. 

[1] What man devised that he might see; Drewry R.D. Accessed on November 12, 2011.

[2] The History of Eye Glasses or Spectacles; Bellis, B. Accessed on November 12, 2011

Other Resources: Giancoli D. (2008); Physics for Scientists & Engineers Fourth Edition p. 882-884