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THE END OF CERTAINTY

2024-11-29T10:16:48.31-05:00

Analytical Mathematical proof of Newton's second law

2019-04-11T15:01:38.577-04:00

The equations about fluids without solutions for manny years.

2018-03-16T16:07:22.343-04:00

GENDER INFLUENCE ON STUDENTS ENROLLMENT IN PHYSICS IN TERTIARY INSTITUTIONS IN IMO STATE, NIGERIA.

2014-09-10T19:30:42.463-04:00

sound and its characters

2014-07-02T11:25:41.14-04:00

SOUND AND ITS CHARACTERISTICS We are well aware of the property of sound in our routine life, train reaching the platform, ringing bell, blowing whistle etc. are the best examples for sound. Sound is a form of energy produced by vibrating bodies and travels in the form of wave ,while travelling it moves from place to other place by transporting the energy and this makes sensation of hearing to our ears, since the vibrations move from one place to another the particles of the medium move closer to each other and produce compression and at the same time when they move away from each other they produce rarefaction. Therefore compressions are points of high pressure and rarefactions are the points of low pressure. Sound requires a material medium to travel, for example vibrations in the tuning fork can be produced only when external force is applied manually with hand, string in the sonometer will produce vibrations after applying external force. Sound can travel in solids, liquids and gases but it cannot travel in vacuum. We can easily know the motion of sound in solids, for example putting our ears on the rail we can easily observe the sound produced from the coming train, in a similar way sound will be produced in the river water as well as sea water which is a liquid.When we make comparision between light and sound where both are form of waves, light do not require any material medium to travel because energy in the light can move from one place to other by means of oscillating electric and magnetic fields present in them, light can travel anywhere even in space. Sound waves are mechanical waves, we can classify mechanical waves into two types 1. Transverse waves 2. Longitudinal waves Transverse waves:- If the particles of the medium vibrate perpendicular to the direction of propogation of waves, such type of waves are called transverse waves. Light is form of transverse electromagnetic waves which contain electric and magnetic fields which are perpendicular to each other. Longtiudinal waves:- If theparticles of the medium vibrate parallel to the direction of propogration of waves we can call them as longitudinal waves. Sound waves are longitudinal waves. CHARACTERISTICS OF SOUND:- 1. Wave length:- The distance between the crest and trough is a wavelength. Crest is

crystal-its properties

2014-07-01T14:32:26.123-04:00

CRYSTAL – ITS PROPERTIES Matter exists in three forms solid , liquids, gases and finally plasma state. In the case of solids atoms or molecules will be in a fixed position i.e they do not move from one place to other because they are firmly fixed by the nuclear forces of attraction. In the case of liquids and gases atoms or molecules move from one place to other in random motion because they are weakly bounded by the forces of attraction. That is the reason why liquids and do not have definite shape, but solids have definite shape and volume, hence they are rigid in shape and structure. Since crystal belongs to the class of solids where atoms or molecules are arranged in regular, repeated and periodic fashion. They are arranged in regular fashion due to the presence of vectors called crystal translation vectors along x, y, z axes respectively. Crystal being made of transparent material glass it shows optical properties like reflection and refraction and mechanical properties like stress and strain, youngs modulus, bulk modulus, compressability and also used in the detection of methods of ultrasonics like piezoelectricity, magnetostriction method. Depending on whether atoms or molecules are arranged regularly or irregularly crystalline solids can be picturised into two types. 1. Single crystalline solids:- If the periodical arrangement of atoms is extended through a larger distance without any breakage in its structure such type are classified as single crystalline solids (or) if the regular arrangement of atoms or molecules is extended throughout the crystal without any breakage it can be termed as single crystalline solid. 2. Polycrystalline solids:- If the periodical arrangement of atoms is limited through a small regions called crystallites , i.e small pieces of crystal is called as crystallites. These crystallites are in different shape and size, separated by crystallite wall. Even though they are of different symmetries and shapes when considering the entering volume of the crystal the arrangement of atoms will be regular in fashion. Glass and plastic are best examples for polycrystalline solids. Amorphous solids :- The behaviour and arrangement of atoms in

superconducting materials

2014-07-01T12:09:16.077-04:00

SUPERCONDUCIVITY- DISAPPERANCE OF RESISTIVITY In the case of conductors resistance arises due to the thermal vibrations present in the material, these vibrations increases with the increase of temperature.as the temperature of the material decreases resistance also decreases linearly. But there are certain strange materials where the resistance of material abruptly goes down to zero as the temperature is decremented. Because as the temperature decreases thermal vibrations starts to decease and thereby resistance of a material drops down to null value. The temperature at which the resistance drops suddenly to zero is termed as critical temperature and material is said to exist in a state called superconducting state and the phenomenon is called superconductivity. This concept was put forward by a scientist kamerlingh ones while doing experiment on mercury, he could observe the drastic change of resistance at 4.2 K proving the phenomena of superconductivity. The pheonomenon of superconductivity is observed only at low temperature, hence it is also known as low temperature physics. The property of superconductor can be best understood as follows. Consider a core of positive ions present inside a material, let us assume an electron having larger energy is approaching towards the +ve ion core of the material, as it is in the vicinity of +ve ion they undergo distortion with the thermal vibrations present in them due to which the energy of the electron will decrease. Consider another electron having higher energy from the other end is interacting with positive ion core, after sometime the energy of the second electron will try to decrease, thereby the thermal vibrations present in this ion core alone will be acting as a mediator to bound thes two electrons in pair, because a certain repulsive force will exist always between two electrons if there is no mediator between them, hence this interaction is called as electron-lattice-electron interaction. The bound energy of this electrons is very low of the order of 0.024 ev, on application of thermal energy we can easily break this pair of electrons and transform the material to conducting phase. These pair of electrons are called as cooper

electrical properties of semiconductors

2014-07-01T09:55:50.797-04:00

ELECTRICAL PROPERTIES OF SEMICONDUCTORS It is a known fact that electrons revolve round the nucleus in definite circular orbits under the influence of short range attractive forces called nuclear forces. If the potentiality of electron is strong enough to overcome this force of attraction we can designate them as conductors, on the other hand if the energy of electron is least to overcome the nuclear short range forces such materials are called as insulators or in simple words we can say that materials which reveal intermediate behaviour in between conductors and insulators are termed as semiconductors. At Ok semiconductors behave themselves as insulators, because it is general pedagogy that all electrons at Ok will be localised in the valence band. As a result of this electrons cannot jump from valence band to conduction band because they are tightly bounded themselves, even after the application of higher temperatures only few electrons will try to jump to conduction band. So on the whole some of the insulators at OK will behave as a conductor at room temperature. l The band formed by valence electrons is valence band it is always fulfilled but can never be empty, on the other hand band formed by conduction electrons will serve as conduction band. For an electron to behave as an conductor there should be an unfilled electron in its configuration, the conduction band may be partially filled or empty. Since energy band is nothing but the packet of energy levels, they may be degenerative or non degenerative energy levels depending on the nature of atom. If the atom is in isolated form the energy levels are non degenerative and degenerative in the sense if it is unisolated form. The gap between conduction band and valence band is called forbidden band where the electron cannot stay less than a nanosecond of time. The phenomenon of semiconductors can be best understood with the help of quantam mechanics which specifies the motion of microscopic particles electrons by assuming that the electron has got particle nature and wave nature as proposed by debroglie. Semiconductor is nothing but a crystal where constituent particles like atoms or molecules are arrayed in

Magnetic materials-dipole moment

2014-07-01T09:40:39.013-04:00

MAGNETIC MATERIALS – DIPOLE MOMENT Materials which has got the ultimate capacity of attracting pieces of Iron, nickel, cobalt , dyasporium when they are subjected to external field can be noticed as an important property of magnetic materials. Magnetic materials will not exist as a monopole they always exist as a dipole, because even if we break the magnetic material into pieces the tiny pieces of magnet will also behave as a dipole. Actually the dipole in a magnet is formed due to two reasons 1.Orbital Motion 2.Spin motion of electron We know that electron revolves round the nucleus in definite circular orbits and with consistent energy levels. If the path of this electrons is treated as circular current loop it produces some electric force, due to the generation of this electrical force the size of the nucleus in the material gets distorted, as a result of this the shifting of +ve and –ve charges will take place resulting in the formation of dipole. The moment of such dipole is known as orbital magnetic dipole moment. Generally dipole moment can be defined as the product of pole strength and geometrical length of the bar magnet . The unit of pole strength is Ampere-metre. In addition to the electron revolving round the nucleus in definite circular orbits it spins on its own axis, as a result of which the displacement of positive and negative charges takes place, the moment of such dipoles is known as the spin magnetic dipole moment . There is another type of magnetic moment called Nuclear magnetic moment where the absolute moment of nucles and electrons will take place. Depending on the alignment of atoms and their response to the external magnetic field at a given point of time magnetic materials can be broadly classified

ALUMINIUM VERSUS ALUMINUM - Why a difference in spelling

2007-02-13T14:40:33-05:00

The metal was named by the English chemist Sir Humphry Davy, even though he was unable to isolate it: that took another two decades’ work by others. He derived the name from the mineral called alumina, which itself had only been named in English by the chemist Joseph Black in 1790. Black took it from the French, who had based it on alum, a white mineral that had been used since ancient times for dyeing and tanning, among other things. Chemically, this is potassium aluminium sulphate (a name which gives me two further opportunities to parade my British spellings of chemical names). Sir Humphry made a bit of a mess of naming this new element, at first spelling it alumium (this was in 1807) then changing it to aluminum, and finally settling on aluminium in 1812. His classically educated scientific colleagues preferred aluminium right from the start, because it had more of a classical ring, and chimed harmoniously with many other elements whose names ended in –ium, like potassium, sodium, and magnesium, all of which had been named by Davy. The spelling in –um continued in occasional use in Britain for a while, though that in –ium soon predominated. In the USA—perhaps oddly in view of its later history—the standard spelling was aluminium right from the start. This is the only form given in Noah Webster’s Dictionary of 1828, and seems to have been standard among US chemists throughout most of the nineteenth century; it was the preferred version in The Century Dictionary of 1889 and is the only spelling given in the Webster Unabridged Dictionary of 1913. However, there is evidence that the spelling without the final i was used in various trades and professions in the US from the 1830s onwards and that by the 1870s it had become the more common one in American writing generally. Actually, neither version was often encountered early on: up to about 1855 it had only ever been made in pinhead quantities because it was so hard to extract from its ores; a new French process that involved liquid sodium improved on that to the extent that Emperor Napoleon III had some aluminium cutlery made for state banquets, but it still cost much more than gold. When the statue of Eros in Piccadilly Circus in London was cast from aluminium in 1893 it was still an exotic and expensive choice. This changed only when a

An Infinite Universe

2005-04-18T16:42:56-04:00

Now I am not a physics major nor do I claim to be extremely knowledgeable in physics. In fact, this essay (more of an extension to a theory) is only in the Physics category because I did not see any other category it could fit in. So here it is. I am assuming that Albert Einstein is a somewhat familiar name for you. You may even know of some or all of his theories. Such as those on relativity and the possibility that the universe is infinite. The latter is the theory I am extending. What I have come to realize is that, quite simply, IF the universe is infinite, then the possibilities are infinite. I am not speaking of how, if you apply yourself, anything is possible. I mean it in the literal fashion. ANYTHING is possible. Not only that, but if the universe truly is infinite, then EVERYTHING is not only possible but it is all happening. If you can imagine it, it is happening. All at the same time. Another theory about the universe is that there are an infinite number of 'realities.' Where every choice or event, no matter how small, branches the realities like a fork in the road. I do not believe this. What I believe is actually happening is that there is only one reality, but that everything that happens or has ever happened is in this universe... somewhere, and that it is all happening constantly. I am not theorizing that we 'move' from one reality to another. I believe that each reality is a completely separate entity with separate lines of events. There is another planet out there exactly like Earth in every detail except that on the planet, instead of typing 'the' before planet, I typed 'a' instead. Now imagine an infinite number of different worlds like that. Whether they are only minute differences or large ones that defy the laws of physics such as planets that are perfectly square. So even if it isn't possible, it IS happening on an infinite number of worlds. Imagine a planet with a purple atmosphere that is inhabited entirely by giant Bic ballpoint pens. Think it's insane? Sounds like it doesn't it? Think outside of what you have grown up learning and knowing was absolutely true. Now, think about all of the stars in the universe. You

Benjamin Franklin

2002-11-24T13:00:00-05:00

Franklin was born on January 17, 1706, in Boston. His father, Josiah Franklin, a tallow chandler by trade (someone who trades the hard fat from cattle, sheep, or horses which was used for candles, soaps, and lubricants) had 17 children; Benjamin was the 15th child and the 10th son. His mother, Abiah Folger, was his father's second wife. The Franklin family was Generally, like most New Englanders of the time. After his attendance at grammar school from age 8 to 10, Benjamin was taken into his father's business. Finding the work unpleasant, however, he entered the employ of a cutler (someone who makes cutlery). At age 13 he was apprenticed to his brother James, who had recently returned from England with a new printing press. Benjamin learned the printing trade, devoting his spare time to trying to improve his education. When he acquired a copy of the third volume of the Spectator by the British statesmen and essayists Sir Richard Steele and Joseph Addison, he set himself the goal of mastering its writing style. As a result of disagreements with James, Benjamin left Boston and made his way to Philadelphia, arriving in October 1723. There he worked at his trade and made numerous friends, among whom was Sir William Keith, the local governor of Pennsylvania. He persuaded Franklin to go to London to complete his training as a printer and to purchase the equipment needed to start his own printing establishment in Philadelphia. Young Franklin took this advice, arriving in London in December 1724. Not having received from Keith certain promised letters of introduction and credit, Franklin found himself, at age 18, without means in a strange city. With characteristic resourcefulness, he obtained employment at two of the foremost printing houses in London. Palmer's and Watt's. His appearance, bearing, and accomplishments soon won him the recognition of a number of the most distinguished figures in the literary and publishing world. Franklin engaged in many public projects. In 1731 he founded what was probably the first public library in America, chartered in 1742 as the Philadelphia Library. He first published Poor Richard's Almanack in 1732, under the pen name Richard Saunders. This modest volume quickly gained a wide and appreciative audience, and its homespun, practical wisdom exerted a pervasive influence upon the American character. In 1736 Franklin became clerk of the Pennsylvania General Assembly and the next year was appointed deputy postmaster of

Questions: Reactivity Series

2002-11-24T13:00:00-05:00

2.The ancient Egyptians put gold and silver objects into tombs.

a) Explain why people opening the tombs thousands of years later find the objects still in good condition.

Because gold and silver are nearly at the bottom of the reactivity series meaning they do not react with air. If they had been higher and had reacted with air they would have decomposed over the years.

b) Explain why no iron objects are found in the tombs.

Because iron is higher up than gold or silver on the reactivity series and does react with air

3.a) Which are attacked by acid rain more readily:

(i) Lead gutters or (ii) Iron drain pipes? Explain your answer fully.

Iron drainpipes because iron forms an oxide (rusts) with water and because it is higher up on the reactivity series than lead

b) Food cans are made of iron coated with tin. How does this help them to resist attack by the acids in food?

Tin

Dark Matter

2001-06-25T14:00:00-04:00

There is perhaps no current problem of greater importance to astrophysics and cosmology than that of "dark matter". The controversy, as the name implies, is centered on the notion that there may exist an enormous amount of matter in the Universe that cannot be detected from the light that it emits. The evidence of dark matter is from the motions of astronomical objects, specifically stellar, galactic, and galaxy cluster/supercluster observations. The basic argument is that if we measure velocities in some region, then there has to be enough mass there for gravity to stop all the objects from flying apart. When such velocity measurements are done on large scales, it turns out that the amount of inferred mass is much more than can be explained by the luminous mass. Hence we infer that there is non-luminous matter in the Universe, i.e. there is dark matter. Dark matter has important consequences for the evolution of the Universe. According to standard cosmological theory, the Universe must conform to one of three possible types: open, flat, or closed. A parameter known as the "mass density" - that is, how much matter per unit volume is contained in the Universe - determines which of the three possibilities applies to the Universe. In the case of an open Universe, the mass density (denoted by the Greek letter Omega) is less than unity, and the Universe is predicted to expand forever. If the Universe is closed, Omega is greater than unity, and the Universe will eventually stop its expansion and recollapse back upon itself. For the case where Omega is exactly equal to one, the Universe is delicately balanced between the two states, and is said to be "flat". Dark matter candidates are usually split into two broad categories, with the second category being further sub-divided: baryonic and bon-baryonic. Then, under non-baryonic, hot dark matter (HDM) and cold dark matter (CDM) are its types. Depending on their respective masses and speeds, CDM candidates have relatively large mass and travel at slow speeds (hence "cold"), while HDM candidates include minute-mass, rapidly moving (hence "hot") particles. As leading possible candidates for baryonic dark matter, there are black holes (large and small), brown dwarfs (stars too cold and faint to radiate), sun-size MACHOs, cold gas, dark galaxies and dark clusters, to name only a few. The range of particles that could constitute nonbaryonic dark matter is limited only slightly by

The Present State of Neutrino Masses

2001-06-25T14:00:00-04:00

One of the current questions in physics is whether or not neutrinos have mass and what this mass is. Neutrinos are subatomic particles that have no electrical charge and interact only via the weak nuclear force. They are products of radioactive decay processes, and thus are produced abundantly in our Sun, our atmosphere, and in other astrophysical sources such as supernovae and active galactic nuclei. Millions and millions of them are crossing through the Earth every second, but only very few of them will interact with the Earth. In practice you can say they are invisible. But fortunately we can detect them by building a very large detector and waiting long enough. There are several reasons to search for a possible non-zero neutrino mass. Fermion masses in general are one of the major mysteries/problems of the standard model. Observation or nonobservation of the neutrino masses could introduce a useful new perspective on the subject. Nonzero neutrino masses are predicted in most extensions of the standard model. They therefore constitute a powerful probe of new physics. Also, there may be a hot dark matter component to the universe. If so, neutrinos would be (one of) the most important things in the universe. The observed spectral distortion and deficit of solar neutrinos is most easily accounted for by the oscillations/conversions of a massive neutrino. The largest neutrino detector is the Super-Kamiokande and is located in the Kamioka Mine, about 200 km north of Tokyo. It is water cerenkov detector, which means it is a large (40 meters diameter by 40 meters tall) tank of ultra-pure water viewed by thousands of sensitive phototubes. Super-Kamiokande will address some of the most important open questions in physics today, such as: why does the Sun appear to produce only half as many neutrinos as theory would predict? Do neutrinos have mass? Do protons decay, as predicted by Grand Unification Theory? One source of neutrinos are nuclear reactions. Inside our Sun nuclear reactions are occurring on a gigantic scale. Lots of neutrinos are produced. There are enough of them, that when they reach the Earth they can still be detected. Since physicists can calculate how many of them should be seen, there is a big problem because we see too few, roughly two times too few. This is so called the solar neutrino problem. There can be several solutions to the puzzle. One is that we do not

Fiber Optics

2001-06-23T14:00:00-04:00

Fiber optics is a cable that is quickly replacing out-dated copper wires. Fiber optics is based on a concept known as total internal reflection. It can transmit video, sound, or data in either analog or digital form . Compared to copper wires it can transmit thousands of times more data (slide 2) . Some of its general uses are telecommunications, computing, and medicine. The very first “fiber” was made in 1870 by the British physicist John Tyndal. In this experiment that he showed to the Royal Society he placed a powerful waterproof lamp inside a tank of water, which had closed pipes coming out the sides. When he opened up the pipes so water could flow, to the amazement of the crowd, the light totally internally reflected inside the beam of water as it fell to the ground. One of the very first forms of optical communication was done Paul Revere in his famous Paul Revere’s ride. Here he used the well-known signal “one if by land, two if by sea.” Although primitive, this was still optical communication and we must give him credit for it. Another contender was Alexander Gram Bell and his photophone (slide 3). With this device, one person would speak into a microphone causing a mirror to vibrate. Then sunlight would reflect off the vibrating mirror and hit another mirror 200 meters away. This mirror would then cause a selenium crystal to vibrate and sound would come out the other end. This seems interesting, but unfortunately this did not work very well at night, in the rain, or when someone simply walked in front of it. In the summer of 1970, scientists at the Corning Glass Works developed a single mode fiber with a loss of 20 dB/km. (Slide 4) This corresponds to over a 99% loss over 1 km, which may seem useless, but at the time it was a spectacular breakthrough. On October 30, 1986, a fiber across the English Channel became operational. In December 1988, the TAT-8, the first transatlantic fiber cable became fully functional. Currently, the standard losses of fiber are within 0.5 – 0.25 dB/km with a data transfer rate of 1 trillion bits per second. The basic setup for a fiber optical system is that first, a transmitter receives an electrical signal, usually from a copper wire. (Slide 5) The transmitter drives a current on a light source and the light

Mass, Volume, and Density Lab

2001-03-29T14:00:00-04:00

Mass, Volume, and Density Lab The purpose of this lab was is to find the mass and volume of an object. Then to find the density of the object using the measurements of the mass and volume. Equipment: scale graduated cylinder Hazards: dropping object into graduated cylinder too fast may cause it to break Procedure: First get out the equipment that will be needed. Make sure to have about 5 objects that can fit inside a graduated cylinder easily, preferably

The Decoherence of Measurement

2000-10-09T14:00:00-04:00

Sam Vaknin's Psychology, Philosophy, Economics and Foreign Affairs Web Sites Arguably the most onerous philosophical question attached to Quantum Mechanics (QM) is that of Measurement. The accepted (a.k.a. Copenhagen) Interpretation of QM says that our very act of conscious, intelligent, observable measurement – determines the outcome of the measurement in the quantum (microcosmic) realm. The wave function (which describes the co-existing, superpositioned, states of the system) collapses following a measurement. It seems that just by knowing the results of a measurement – we determine its outcome, determine the state of the system and, by implication, the state of the Universe as a whole. This notion is so counter-intuitive that it fostered a raging debate which has been on going for more than 7 decades now. But, could we have turned the question (and, inevitably, the answer) on its head? Is it the measurement that brings about the collapse – or, maybe, we are capable of measuring only collapsed results? Maybe our very ability to measure, to design measurement methods and instrumentation, to conceptualize measurement and so on – are thus limited as to yield only the collapse solutions of the wave function? Superpositions are notoriously unstable. Even in the quantum realm they should last but an infinitely split moment of time. Our measurement apparatus is not as refined as to capture a superposition long enough to justify the title of “measurement” or “observation”. By contrast, collapses are sufficiently stable to last, to be observed and measured. This is why we measure collapses. But in which sense (excluding longevity which, anyhow, is a dubious matter in the quantum world) are collapse events measurable, what makes them so? Collapse events are not the most highly probable – some of them are associated with low probabilities and still they occur and are measured. Ex definitio, the more probable states will tend to be measured more (the wave function will collapse more often into high probability states). But this does not exclude the less probable states of the quantum system from materializing upon measurement. The other possibility is that the collapse events are carefully “selected” for some purpose, within a certain pattern and in a certain sequence. What could that purpose be? Probably, the extension and enhancement of order in the Universe. That this is so can be easily substantiated: it is so. Order increases all the time. This is doubly true if we

The Rise of Einsteinian Special Relativity

2000-10-05T14:00:00-04:00

In 1905, Einstein’s Theory of Special Relativity was proposed. The reason that it is so "special" is because it was part of the more complex and extensive Theory of General Relativity, which was published in 1915. His theory reshaped the world of physics when it contradicted all previous laws of motion erected by Galileo and Newton. By mathematically manipulating these previous laws of motion, physicists in the nineteenth century were able to explain such phenomena as the flow of the ocean, the orbits of planets around the sun, the fall of rocks, and the random behavior of molecules in gases. At first, Einstein faced great opposition when he came up with his radical new theory because the previous laws of motion proposed by Galileo and expanded upon by Newton had remained valid for over two hundred years. However, it wouldn’t be long before the "cement" in the foundation of Newtonian and Galilean physics would begin to crumble. Galileo had determined in 1608 that merely addition and subtraction could calculate relative speeds. Suppose that an observer stands on the side of the highway, and they watch two cars approach each other at 30 and 40 miles per hour. If they were to ask the question, "how fast is the 40 mile per hour car moving relative to the 30 mile per hour car?" They could solve the problem easily by adding the two speeds of the cars, which would equal 70 miles per hour. This means that the 40 mile per hour car sees the 30 mile per hour car advance at a speed of 70 miles per hour and vice versa. At the core of Newtonian physics was the fact that space and time were absolute. Newton’s absolute space was the space of everyday experience with its three dimensions: east-west, north-south, and up-down. This space gives us our sense of length, breadth, and height; according to Newton. We all, regardless of our motion, will agree on the length, breadth, and height of an object, so long as we make sufficiently accurate measurements. Newton’s absolute time was the time that flows inexorably forward as we age. It is a time whose flow is experienced in common by all humanity. The maximum speeds of birds in nature are regulated by air. No matter what direction a bird flies, it always has the same maximum speed. Newton had proposed something similar for light, which he

History of Monte Carlo Method

2000-07-20T14:00:00-04:00

It could be argued that current physics research could be divided into three areas - theoretical, experimental and computational. Numerical approach, in which systems are mimicked as accurately as possible using a computer

Magnetic Anisotropy Of Fine Particles

2000-07-20T14:00:00-04:00

"Magnetic Anisotropy Of Fine Particles" In nature, single domain particles are magnetized to saturation, where the magnetization has an easy axis, or several easy axes, along which it prefers to

The Gem Of Magnetic Fluids

2000-07-18T14:00:00-04:00

1.1 PRELUDE: The phenomenon of ferromagnetism is associated only with the solid state of matter; like iron, nickel, cobalt and some rare earth metals and their alloys. Thus, up to now, there is no intrinsic homogeneous fluid having ferromagnetic properties; although, theories admit the possibility of ferromagnetism in the liquid state, and suggest that there is no inherent reason why they should not exist [1-3,5]. Ferromagnetism occurs when paramagnetic ions in a solid lock together in such a way that their spins all point (on the average) in the same direction . At a certain temperature this locking breaks down and ferromagnetic materials become paramagnetic. This transition temperature is called the Curie point (TC), which is invariably well below the melting point of the corresponding material [1,8,12]. 1.2 MAGNETIC FLUIDS: Magnetic fluids ( MF ) are stable colloidal suspensions of ultrafine ferro- or ferri- magnetic particles ( D100Ao ), coated with a surfactant like oleic acid, in a suitable liquid carriers such as Isopar-M, kerosene, decalin, etc., [1,2]. The idea of MF was put forward independently and almost simultaneously by several investigators. The first prepared MF was developed by Stephen Papell of the National Aeronautics and Space Administration (NASA) in the early 1960s. After that, Ronald E. Rosensweig and his colleagues succeeded in formulating MFs that were 10 times as strong magnetically as Papell`s original MF [1]. The special feature of magnetic fluids is given by the fact, that they combine normal liquid behavior with superparamagnetic properties, as will be discussed later. The possibility of magnetic fluid control gave rise to the development of many technical applications in our everyday life [1-3]. Mixtures are classified into three kinds: colloidal suspensions, suspensions, and solutions, and one of the principal features that differentiate one kind of mixture from another is the size of the particles [6]. Colloidal suspensions (also called colloids) are mixtures that are intermediate between solutions and suspensions. Typically the radius of the particle is of the order 100Ao. Since this is much smaller than the size of a single magnetic domain in bulk solids, which is about , the magnetization of the individual particle is saturated, but the direction of the magnetic moment is subject to thermal agitation [1,2,5]. The particles used are commonly Fe3O4, Fe, Co and Ni. MF is a two-phase system with three components, which combines magnetic properties, carried by the solid magnetic fine particles, with fluidity of the carrier liquid. The

Air Resistance, Tyres and Friction

2000-05-25T14:00:00-04:00

Dragsters use a combination of large wide tyres or the rear and small narrow tyres on the front this combination is used for the following reasons: The front wheels: The front wheels are very narrow. This is so a minimum of air resistance or drag affects the dragster with lower drag better acceleration an in turn a better top speed can be achieved all leading to a better pass (race time). Now lets try to understand the concept of air resistance and drag. A basic example is placing your hand out the window with your palm facing forwards as you are driving your car along at about sixty kilometres per hour. You will feel a strong force of the wind (air resistance) pushing back at your hand. Now turn your hand side or so that your little finger is facing the front and your thumb is facing the rear at the same speed. The force of air resistance exerted on your hand is greatly reduced. This force is similar as to that exerted on the front wheels of the dragster. Now dragsters reach speeds of up to five hundred kilometres per hour, imagine the force needed to hold your hand against the wind if your palm was facing the front. It would be much easier to hold your hand side on. The same as it would be much easier for the dragsters engine to push the narrow front wheels compared to large ones. Air resistance is a form of friction (namely fluid friction) a friction from the air, as we know friction is defined as a force that opposes movement. The formula used to determine aerodynamic drag is as follows: Drag = 0.5 * rho * Cd * v2 * S Aerodynamic drag is a function of the following:

rho is the air density, which we cannot change.

v2 is velocity squared which is endeavoured to be maximized for the best time and/or pass.

S is the frontal or cross sectional area which we want to minimize. I.e. less frontal area means that a less significant amount of air resistance impedes the top speed and acceleration.

Cd is the coefficient of drag, which we want to minimize. So the two things with which can be worked with or changed, the frontal area and coefficient of drag, both of which need to be to minimized for the best results. Having very narrow front wheels minimizes the

Seatbelts

2000-05-25T14:00:00-04:00

When travelling at slow speeds in your car the wearing of a seatbelt has little effect of your body when you brake. So why is it important to wear your seat belt? A driver or passenger travelling in a car is moving at the same speed as the car. If the car suddenly stops, the body of the rider inside will keep moving forward at the same speed. This demonstrates inertia. The tendency of a moving object to keep moving, or of a stationary object to remain at rest. Basically Newtons first law; that a body stationary or moving with constant velocity will want to continue to do so, unless acted on by a force. Lets understand what is happening here. First drive along in your car at 60 km/h on a backstreet with no traffic, then brake gently and slowly. You will notice that the seat belt doesn’t really do much to hold your body. Now do the same again but this time break as quickly and sharply as you can. Your body will be thrown forwards with great force, and your seatbelt will be literally holding you in place. Now your body was what is commonly referred to as being "thrown forwards", however this is not the case. Your body was actually not slowing down much at all and your velocity relative to the car initially was much greater. The car began to slow down due to breaking and your body in accordance with Newtons First law wanted to continue to move at the original constant velocity. Now if your seat belt was not there to provide an opposing force, to your momentum and inertia, by holding you from going forwards, you very likely would have been thrown into the dash or steering wheel. Lets look at this mathematically. m= your mass in kilograms for this purposes 70kg V= final velocity 0 m/s U= initial velocity 60 km/h or 16.6 m/s straight line S= distance taken to stop 42 m t= 3.8 a= -4.368 m/s/s Now your momentum at 60km/h is P=MU So P= 70kg*16.6m/s P=1162 Kg m/s Impulse I=MU/t I=70*16.6/3.8 I=305N So your body will weigh about 610kg when you are breaking hard, a force it is difficult for any person to withstand. Now in the context of a head on accident at around 60km/hr the force exerted on your body is greatly increased. In the event of such an accident it will take the car approximately 0.4 seconds to stop. This

Angular Momentum

1999-11-18T13:00:00-05:00

Angular momentum and its properties were devised over time by many of the great minds in physics. Newton and Kepler were probably the two biggest factors in the evolution of angular momentum. Angular momentum is the force which a moving body, following a curved path, has because of its mass and motion. Angular momentum is possessed by rotating objects. Understanding torque is the first step to understanding angular momentum. Torque is the angular "version" of force. The units for torque are in Newton-meters. Torque is observed when a force is exerted on a rigid object pivoted about an axis and. This results in the object rotating around that axis. "The torque ? due to a force F about an origin is an inertial frame defined to be ? ? r x F"1 where r is the vector position of the affected object and F is the force applied to the object. To understand angular momentum easier it is wise to compare it to the less complex linear momentum because they are similar in many ways. "Linear momentum is the product of an object's mass and its instantaneous velocity. The angular momentum of a rotating object is given by the product of its angular velocity and its moment of inertia. Just as a moving object's inertial mass is a measure of its resistance to linear acceleration, a rotating object's moment of inertia is a measure of its resistance to angular acceleration."2 Factors which effect a rotating object's moment of inertia are its mass and on the distribution of the objects mass about the axis of rotation. A small object with a mass concentrated very close to its axis of rotation will have a small moment of inertia and it will be fairly easy to spin it with a certain angular velocity. However if an object of equal mass, with its mass more spread out from the axis of rotation, will have a greater moment of inertia and will be harder to accelerate to the same angular velocity.3 To calculate the moment of inertia of an object one can imagine that the object is divided into many small volume elements, each of mass ?m. "Using the definition (which is taken from a formula in rotational energy) I=?ri2?mi and take the sum as ?m?0 (where I is the moment of inertia and ri is the perpendicular distance of the infinitely small mass' distance from the axis

History Of Physics

1999-10-10T14:00:00-04:00

Early Physics Physics began when man first started to study his surroundings. Early applications of physics include the invention of the wheel and of primitive weapons. The people who built Stone Henge had a knowledge of physical mechanics in order to move the rocks and place them on top of each other. It was not until during the period of Greek culture that the first systematic treatment of physics started with the use of mechanics. Thales of Miletus (636BC. - 546BC.) Thales is often said to have been the first scientist, and the first Greek philosopher. He was an astronomer, merchant and mathematician, and after visiting Egypt he is said to have originated the science of deductive geometry. He also discovered theorems of elementary geometry and is said to have correctly predicted an eclipse of the sun. Many of his studies were in astronomy but he also observed static electricity. Phythogoras (582BC. - 497BC.) Phythogoras was a Greek philosopher. He discovered simple numerical ratios relating the musical tones of major consonances, to the length of the strings used in sounding them. The Pythagorean theorem was named after him, although this fundamental statements of deductive geometry was most likely first an idea from Egyptian methods of measurements. With the help of his followers he discovered that the earth was a sphere, but he did not believe it revolved around the su Democritus (470BC. - 380BC.) Democritus was the leader of a group called Atomists. Although they were unable to prove that matter was made up of small particles, they were the first to come up with the idea. Democritus believed that atoms differed in size, shape, and movement but were all made of the same substances. Aristotle (384BC. - 332BC.) Aristotle was the most important scientific philosopher in Greece. He believed that all matter on earth consisted of four pure substances or elements, which were earth, air, fire, and water. He also believed that the earth was the centre of the universe, and that anything beyond the earth consisted of a fifth pure substance called quintessence. Archimedes (287-212B.C.) Archimedes was an inventor and mathematician, who discovered several basic scientific principles and developed a number of measuring techniques. Ptolemy (100AD.) Ptolemy was an Egyptian astronomer. He developed a model for predicting the positions of the sun, moon, stars, and planets. Like Aristotle, he believed that the earth was the centre of the universe. The Middle Ages Between 400 AD.

Optics

1999-10-09T14:00:00-04:00

Aim: To examine characteristics of a converging lens and the images they create. Also to examine the focal length and how the focus point may be found and developing rules for locating an image via ray drawings and the intersection of rays. Chromatic aberration will also be explored and why it happens. Theory: Both lenses and mirrors have a principle axis, yet a lens has two focal points as opposed to a mirror that has only one. When considering converging lenses, the primary focal point (PF) can be found on the opposite side of the lens in regards to the light. The secondary focal point (SF) being on the same side as the light source. Focus points on thin double convex lenses are located at either side of the lens, measured from the middle of the lens itself (see below). Chromatic aberration is a problem of converging lenses that will also be explored in this experiment. A description of each image produced will also be given (attitude, type, magnification and location). Apparatus: The main tools (apparatus) used in the experiment consist of a ray box containing cards which allow one, two, three or four rays onto a sheet of paper at a time so that rays path from the box to the mirror will be able to be traced. Also two (2) different types of converging lenses, one being cylindrical while the other being spherical, the difference being that the spherical one is used for viewing, the cylindrical one for use with the ray box. These lenses are one of many different sorts of lenses in the "lens box". The use of a ruler would also be helpful so that accurate measurements may be taken. Method: 1. A cylindrical lens was placed on paper and traced around, a principal axis was drawn making sure that it's at rights angles to the lens. The ray box was switched on (exposing only one ray) and lined up parallel to the principle axis, a mark where the ray leaves the box was made as well as where it hits the lens (on both sides) and where the ray bisects the principle axis. After this, the ray box was removed and using a ruler, rays were accurately drawn. The focus point (f) was measured to be of length 7.3cm (7.25). 2. The lens was replaced back on a sheet of paper with ray box emitting three rays, the

Physics Research Assignment - Solonoids

1999-10-09T14:00:00-04:00

Summary of Investigation An investigation was carried out to find out the relationship between the force created in a wire (or solenoid) when current flowed through it and the force from gravity. This was investigated by connecting a solenoid up to a variable power pack and then placing a light ring of either copper or aluminum around the solenoid. When the current flows through the solenoid, a magnetic force created from the solenoid should make the ring 'jump' up or levitate. When carrying out the experiment, the assumption was made that there will be some movement from the ring when current starts flowing through the solenoid and thus a magnetic field will be present. However, the results of the experiment did not back up this assumption in any way. No magnetic force was observed in any of the experiments carried out. Introduction Electromagnetism is the study of the relationships between magnetism, and electricity. It was found by Hans Oersted, that when an electric current flows in a wire, the current creates a magnetic force around this wire. It is also known that a solenoid produces a considerably large amount of magnetic force when a current flows through it (diagram 1.1 ). By using a solenoid and some small, light rings of copper and aluminum, it is said that the ring when placed over the solenoid when current is flowing will 'jump' up and sometimes levitate if the force of the magnetic field equals that of the earth's gravitational force. Aim The main objective of this experiment is to investigate the relationship between gravitational energy and electric and magnetic energy. This will be achieved by attempting to suspend a light ring of copper and/or aluminum around a solenoid with a current passing through it. The only presumption is that if the ring is unable to be levitated (due to lack of power), there will still be movement and the ring will jump up from the base of the solenoid. Method The circuit used first (see diagram 2.1) was made up of a small solenoid. The solenoid was constructed using a small pencil, bound with electrical tape and copper wire wound around it to a length of 13cm. Zinc plated washers were first used in the circuit using a DC voltage. Because DC voltage was being used, the ring was expected to 'jump' only when the circuit was switched on and off. All voltages on the power supply were

Physics Prac - Mesuring Wavelengths of Light

1999-10-09T14:00:00-04:00

Aim: To determine the approximate value of l for red light using a diffraction kit. Theory: Diffraction of light is one explanation of the wave theory of light. Francesco Grimaldi first observed this type of behvaiour from light. However, Thomas Young was the scientist that was able to derive a mathematical formula where l can be calculated. The original experiment involved sending white light into a screen with two small holes to serve as point sources. The light from these sources was then projected onto a screen and light and dark bands were observed. The mathematical formula could then be used after taking certain measurements. Equipment: Light source (Ray box), Red cellophane, Double-slit slide, and Measuring rod (can be already attached to Ray box. Method: 1. Set up the ray box and place red cellophane in clip so that it is over the bulb. 2. Switch on ray box and stand approximately two meters away from the ray box, hold the slide up to your eye and look through one of the double slit patterns into the light. Observe disturbance pattern. 3. While looking through the slide, have someone move the white marker along the slide rule until its edge is approximately halfway inside a dark or light band. 4. Take measurement down and then repeat step 3 and gain measurement for other dark or light bands. Results: The results gained from the experiment were conclusive and accurate when compared to the original value for l for red light. Below is a table of the measurements recorded and calculations to gain l. Calculation (con't): The value d was calculated by placing the slide in a projector and then on the whiteboard (acting as a screen), marks were made. The slide had a measurement of 1cm and from this the ratio 35:1 was established. Measurements were then made and the slides actual measurements were determined. For this particular experiment, the slide marking D was used. L was measured also using simple trigonometry. The person viewing through the slide sat at a table and then looked down at the ray box on an angle. From measurements taken, L was able to be calculated quite accuratly. Conclusion and Discussion 1. The l for red light is approximately 662nm (averaging out three results gained). This is within the acceptable range being 650nm à 700nm. 2. Difficulties were experianced when trying to take measurements for x. It was hard to define the edge of the white marker and also count the number

Beta Particles

1999-03-16T13:00:00-04:00

Aim: I will investigate how the field strength varies the deflection of Beta Particles. Preliminary Work I started my preliminary work because, when I started my measurements using 2 coils used in experiments to deflect electrons from and electron gun. While testing for the deflection of beta particles, I found that beta radiation was scattered in a very large cone, I can not get any readings with amount of beta radiation scattering. So I would have to construct some type of shielding for this investigation, this is so I can measure the deflection more easily. The angle at which the beta particles are being scattered is 48o. Deciding on the Type of Shielding I will test for the best shielding. The best properties of the shield will be; it can be malleable to form different shapes and can be punctured, can stop radiation at a small thickness. Equipment

Strontium 90 beta source

GM tube + counter

Different thickness of different metals

Clamps, bosses and clamp stand to hold the source and the material being tested. Method 1. Set-up equipment as in the diagram 2. Record the thickness and the material being used. 3. Record 5 readings of the radiation count, and record them in a table 4. Replace material being tested with different material or a different sized material. 5. Repeat steps 2 to 4 as required. Results The background radiation reading is 2, 4, 6, 4, 5, 2. The average count is 3.8 (1dp). Conclusion This shows that aluminium stops radiation at 3.5 mm, this would be difficult to use because, this thickness of Aluminium is not malleable and the aluminium is not soft enough to puncture. Lead can stop radiation at very thin thickness', also lead is very malleable and is soft enough to puncture. I will use Lead shield at 0.6mm thick, since it is the most abundant thickness' available and it is the easiest to form to any shape I want. Deciding how the shielding can be used. I want to have a tight beam of beta particles in this investigation, so I will use my knowledge on what would be the best way to shield the source. An unshielded source The source is unshielded and has beta particles spreading out. Angle Theta is the angle which the beta particles are scattered through. The path of the beta particles is not a straight line, but a curve because the beta particle are deflected by the moles in the air. The points A B are the furthest points where beta ration is

Black Holes

1999-02-26T13:00:00-05:00

Everyday we look out upon the night sky, wondering and dreaming of what lies beyond our planet. The universe that we live in is so diverse and unique, and it interests us to learn about all the variance that lies beyond our grasp. Within this marvel of wonders our universe holds a mystery that is very difficult to understand because of the complications that arise when trying to examine and explore the principles of space. That mystery happens to be that of the ever clandestine, black hole. This essay will hopefully give you the knowledge and understanding of the concepts, properties, and processes involved with the space phenomenon of the black hole. It will describe how a black hole is generally formed, how it functions, and the effects it has on the universe. In order to understand what exactly a black hole is, we must first take a look at the basis for the cause of a black hole. All black holes are formed from the gravitational collapse of a star, usually having a great, massive, core. A star is created when huge, gigantic, gas clouds bind together due to attractive forces and form a hot core, combined from all the energy of the two gas clouds. This energy produced is so great when it first collides, that a nuclear reaction occurs and the gases within the star start to burn continuously. The Hydrogen gas is usually the first type of gas consumed in a star and then other gas elements such as Carbon, Oxygen, and Helium are consumed. This chain reaction fuels the star for millions or billions of years depending upon the amount of gases there are. The star manages to avoid collapsing at this point because of the equilibrium achieved by itself. The gravitational pull from the core of the star is equal to the gravitational pull of the gases forming a type of orbit, however when this equality is broken the star can go into several different stages. Usually if the star is small in mass, most of the gases will be consumed while some of it escapes. This occurs because there is not a tremendous gravitational pull upon those gases and therefore the star weakens and becomes smaller. It is then referred to as a White Dwarf. If the star was to have a larger mass however, then it may possibly Supernova, meaning that the nuclear fusion within the star

Newton's Three Laws of Motion

1999-01-22T13:00:00-05:00

Isaac Newton was born on Christmas day in 1642, in Lincolnshire, England. Newton attended Trinity College in 1661 and had both his Bachelor of Arts and his Master of Arts by 1669. That same year he became the associate of the French Academy of Sciences. He was elected to Parilment, then appointed a warden, and finally, President of the Royal Society. Newton was a master of science and mathematics. He discovered calculus, before Leibniz' became popular.

Your Bones in Space

1999-01-22T13:00:00-05:00

Osteoporosis: a condition characterized by an absolute decrease in the amount of bone present to a level below which it is capable of maintaining the structural integrity of the skeleton. To state the obvious, Human beings have evolved under Earth's gravity "1G". Our musculoskeleton system have developed to help us navigate in this gravitational field, endowed with ability to adapt as needed under various stress, strains and available energy requirement. The system consists of Bone a highly specialized and dynamic supporting tissue which provides the vertebrates its rigid infrastructure. It consists of specialized connective tissue cells called osteocytes and a matrix consisting of organic fibers held together by an organic cement which gives bone its tenacity, elasticity and its resilience. It also has an inorganic component located in the cement between the fibers consisting of calcium phosphate [85%]; Calcium carbonate [10%] ; others [5%] which give it the hardness and rigidity. Other than providing the rigid infrastructure, it protects vital organs like the brain], serves as a complex lever system, acts as a storage area for calcium which is vital for human metabolism, houses the bone marrow within its mid cavity and to top it all it is capable of changing its architecture and mass in response to outside and inner stress. It is this dynamic remodeling of bone which is of primary interest in microgravity. To feel the impact of this dynamicity it should be noted that a bone remodeling unit [a coupled phenomena of bone reabsorption and bone formation] is initiated and another finished about every ten seconds in a healthy adult. This dynamic system responds to mechanical stress or lack of it by increasing the bone mass/density or decreasing it as per the demand on the system. -eg; a person dealing with increased mechanical stress will respond with increased mass / density of the bone and a person who leads a sedentary life will have decreased mass/density of bone but the right amount to support his structure against the mechanical stresses she/she exists in. Hormones also play a major role as seen in postmenopausal females osteoporosis (lack of estrogens) in which the rate of bone reformation is usually normal with the rate of bone re-absorption increased. In Skeletal system whose mass represent a dynamic homeostasis in 1g weight-bearing,when placed in microgravity for any extended period of time requiring practically no weight bearing, the regulatory system of bone/calcium reacts by

Theories of The Origin of the Moon

1999-01-22T13:00:00-05:00

The Moon is the only natural satellite of Earth. The distance from Earth is about 384,400km with a diameter of 3476km and a mass of 7.35*1022kg. Through history it has had many names: Called Luna by the Romans, Selene and Artemis by the Greeks. And of course, has been known through prehistoric times. It is the second brightest object in the sky after the Sun. Due to its size and composition, the Moon is sometimes classified as a terrestrial "planet" along with Mercury, Venus, Earth and Mars. Origin of the Moon Before the modern age of space exploration, scientists had three major theories for the origin of the moon: fission from the earth; formation inearth orbit; and formation far from earth. Then, in 1975, having studied moonrocks and close-up pictures of the moon, scientists proposed what has come to be regarded as the most probable of the theories of formation, planetesimalimpact or giant impact theory. Formation by Fission from the Earth The modern version of this theory proposes that the moon was spun off from the earth when the earth was young and rotating rapidly on its axis. This idea gained support partly because the density of the moon is the same as that of the rocks just below the crust, or upper mantle, of the earth. A major difficulty with this theory is that the angular momentum of the earth, in order to achieve rotational instability, would have to have been much greater than the angular momentum of the present earth-moon system. Formation in Orbit Near the Earth This theory proposes that the earth and moon, and all other bodies of the solar system, condensed independently out of the huge cloud of cold gases and solid particles that constituted the primordial solar nebula. Much of this material finally collected at the center to form the sun. Formation Far from Earth According to this theory, independent formation of the earth and moon, as in the above theory, is assumed; but the moon is supposed to have formed at a different place in the solar system, far from earth. The orbits of the earth and moon then, it is surmised, carried them near each other so that the moon was pulled into permanent orbit about the earth. Planetesimal Impact First published in 1975, this theory proposes that early in the earth's history, well over 4 billion years ago, the earth was struck by a large body called a planetesimal, about the

Geosynchronous Orbits

1999-01-22T13:00:00-05:00

Geosynchronous Orbits + Geostationary Orbits Webster's Dictionary defines a Geostationary orbit as of, relating to, or being a satellite that travels above Earth's equator from west to east at an altitude of approximately 35,900 kilometers (22,300 miles) and at a speed matching that of Earth's rotation, thus remaining stationary in relation to Earth. 2. Of, relating to, or being the

Black Holes

1999-01-22T13:00:00-05:00

Within our galaxy alone, there are millions upon millions of stars. Within our universe, there are millions upon millions of galaxies. Humans have known the existance of stars since they have had eyes. Although interpretations may have differed on what they were, they were always thought of as white glowing specks in the sky, but the mystery does not lie within what we can see, but what we can not see. There are billions of stars lighting the darkness of our universe, but the question lies in what happens when one of these enormous lamps burns out. Upon many speculations, one of the most facinating is the black hole theory. Not any star can become a Black Hole. For instance, the possibility of our sun becoming a black hole is highly unlikely, simply because it is too small. Only a very large star has the potential to become a black hole. The definitions of black boles are somewhat sceptical. Generally, a black hole is an area of super-concentrated mass. So concentrated, that no object can escape its gravitational pull. In other words, once you get caught by it's graviational pull, you aren't getting out again. The velocity you need to break away from a graviational pull is called the "escape velocity". Roughly, earth's escape velocity is about 25,000 M.P.H. (11.2 kilometers/second). Earth's mass is nothing compared to the mass of a star that has the potential to become a black hole. A black hole has so much mass in such a small area, that its escape velocity is greater than the speed of light. So if were all living on earth, and earth was a black hole, we would need to go at the speed of light in order to get to the moon (and not to mention a lot of milk so our bones could support 800 million ton human beings). Even though a black hole's gravitational pull is enormous, it does have its boundry. This boundry is called the "event horizon". This event horizon is the point where the black hole's gravitational pull begins. Once you cross the event horizon, there is no turning back. As stated before, the escape velocity of a black hole exceeds the speed of light, and since going faster than the speed of light is impossible, so is escaping a black hole's gravitational pull. This explains why all the black holes do not swallow everything

Werner Heisenberg and the Heisenberg Uncertainty Principle

1999-01-22T13:00:00-05:00

Werner Heisenberg, born in the dawn of the twentieth century became one of its greatest physicists; he is also among its most controversial. While still in his early twenties, he was among the handful of bright, young men who created quantum mechanics, the basic physics of the atom, and he became a leader of nuclear physics and elementary particle research. He is best known for his uncertainty principle, a component of the so-called Copenhagen interpretation of the meaning, and uses of quantum mechanics. Through his successful life, he lived through two lost World Wars, Soviet Revolution, military occupation, two republics, political unrest, and Hitler's Third Reich. He was not a Nazi, and like most scientists of his day he tried not to become involved in politics. He played a prominent role in German nuclear testing during the World War II era. At age twenty-five he received a full professorship and won the Nobel Prize in Physics in 1932 at the age of thirty-two. He climbed quickly to the top of his field beginning at the University of Munich when his interest in theoretical physics was sparked Heisenberg was born the son of August Heisenberg in Würzburg, Germany on December 5, 1901. August Heisenberg was a professor of Greek at the University of Munich. His grandfather was a middle-class craftsman who's hard work paid enough to afford a good education for August Heisenberg. The successfulness of August Heisenberg allowed him to support his family well. The professorship at the University of Munich put them in the upper middle-class elite, and was paid three times the salary of skilled workers. Through his life Werner Heisenberg was pestered with health problems. At the age of five, he nearly died with a lung infection which helped him get a little preferential treatment from his parents. During his early years, Werner was in constant competition with his brother Erwin which caused friction. The Heisenberg family were accomplished musicians. Every evening they would sit and practice together. August was on the piano, Erwin played the violin, and Werner played the cello. Their mother insisted that she had no musical talent as an excuse to not be involved in the male competition. Later Werner also learned the piano and used his musical talents as a social vehicle during the course of his life. This manly competition carried out in many other activities in the house. Sometimes August Heisenberg would