41. Planetary Magnetism Now we know that among those planets, only Venus lacks any magnetism. The planetsdiffer greatly in size and properties, and their fields differ too. http://www.phy6.org/earthmag/planetmg.htm

Site Map Planetary Magnetism That was before other planets in the solar system were visited and examined. Now we know that among those planets, only Venus lacks any magnetism. The planets differ greatly in size and properties, and their fields differ too. Yet they all seem to have dynamo fields, or (in the case of Mars and the Moon) have had them in the past. Jupiter Jupiter (bigger version) In early 1955, two young radio-astronomers started working with a cross-shaped antenna array of the Carnegie Institution's Department of Terrestrial Magnetism (DTM). The array could select signals from a narrow range of directions, and Ken Franklin and Bernie Burke calibrated it using a known source, the Crab Nebula, then began surveying the surrounding sky. They found another conspicuous radio source, but unlike the Crab, its position slowly shifted. Could it be Jupiter? Standing next to the array at night, Bernie noted a star overhead and asked Ken "what is that bright thing up there?" It was Jupiter, and that's where the signal came from. In publishing their result, the astronomers speculated "the cause of this radiation is not known but is likely to be due to electrical disturbances in Jupiter's atmosphere." In 1959, after the Earth's radiation belt had been discovered, Frank Drake observed Jupiter and concluded from the relative intensities in a range of wavelengths that the signal was probably emitted by electrons trapped in a strong magnetic field. Then in 1973 the space probe Pioneer 10 passed by Jupiter and found there, sure enough, an enormous planetary magnetic field and a very intense radiation belt.

42. MSN Encarta - Magnetism Powerful magnetic fields are used in nuclear magnetic resonance imaging, an How tocite this article magnetism, Microsoft® Encarta® Online Encyclopedia http://encarta.msn.com/encyclopedia_761552678/Magnetism.html

MSN Home My MSN Hotmail Shopping ... Money Web Search: logoImg('http://sc.msn.com'); Encarta Subscriber Sign In Help Home ... Upgrade to Encarta Premium Search Encarta Tasks Find in this article Print Preview Send us feedback Related Items Electromagnet Electromagnetic Radiation more... Magazines Search the Encarta Magazine Center for magazine and news articles about this topic Further Reading Magnetism News Search MSNBC for news about Magnetism Internet Search Search Encarta about Magnetism Search MSN for Web sites about Magnetism Also on Encarta Editor's picks: Good books about Iraq Compare top online degrees What's so funny? The history of humor Also on MSN Summer shopping: From grills to home decor D-Day remembered on Discovery Switch to MSN in 3 easy steps Our Partners Capella University: Online degrees LearnitToday: Computer courses CollegeBound Network: ReadySetGo Kaplan Test Prep and Admissions Encyclopedia Article from Encarta Advertisement document.write(''); Magnetism Multimedia 5 items Article Outline Introduction History of Study Electromagnetic Theory The Magnetic Field ... Applications I Introduction Print Preview of Section Magnetism , an aspect of electromagnetism, one of the fundamental forces of nature. Magnetic forces are produced by the motion of charged particles such as electrons, indicating the close relationship between

43. Magnetism And Magnetic Fields However, magnetism differs from electricity in one important aspect Unlike electriccharges The strength of magnetic fields is measured in units of Teslas (T http://www.cartage.org.lb/en/themes/Sciences/Physics/Electromagnetism/Magnetosta

Themes Science Physics Electromagnetism ... Magnetic Field Magnetism and magnetic fields An phenomenon apparently unrelated to electricity is magnetism. We are familiar with magnetism through the interaction of compasses with the earth's magnetic field, or through fridge magnets or magnets on children's toys. Magnetic forces are explained in terms very similar to those used for electric forces: There are two types of magnetic poles , conventionally called North and South Like poles repel, and opposite poles attract However, magnetism differs from electricity in one important aspect: Unlike electric charges, magnetic poles always occur in North-South pairs; there are no magnetic monopoles Later on we will see at the atomic level why this is so. As in the case of electric charges, it is convenient to introduce the concept of a magnetic field in describing the action of magnetic forces. Magnetic field lines for a bar magnet are pictured below. Figure 9.5:

44. Magnetism: Magnetic Poles, Forces, And Fields in this article Introduction; Magnetic Poles, Forces, and fields; Magnetic Materials;The Basis of magnetism; Evolution of Electromagnetic Theory; Bibliography. http://www.factmonster.com/ce6/sci/A0859426.html

Encyclopedia magnetism Magnetic Poles, Forces, and Fields Any object that exhibits magnetic properties is called a magnet. Every magnet has two points, or poles, where most of its strength is concentrated; these are designated as a north-seeking pole, or north pole, and a south-seeking pole, or south pole, because a suspended magnet tends to orient itself along a north-south line. Since a magnet has two poles, it is sometimes called a magnetic dipole, being analogous to an electric dipole, composed of two opposite charges. The like poles of different magnets repel each other, and the unlike poles attract each other. One remarkable property of magnets is that whenever a magnet is broken, a north pole will appear at one of the broken faces and a south pole at the other, such that each piece has its own north and south poles. It is impossible to isolate a single magnetic pole, regardless of how many times a magnet is broken or how small the fragments become. (The theoretical question as to the possible existence in any state of a single magnetic pole, called a monopole, is still considered open by physicists; experiments to date have failed to detect one.) From his study of magnetism, C. A. Coulomb in the 18th cent. found that the magnetic forces between two poles followed an inverse-square law of the same form as that describing the forces between electric charges. The law states that the force of attraction or repulsion between two magnetic poles is directly proportional to the product of the strengths of the poles and inversely proportional to the square of the distance between them.

45. Electricity And Magnetism Demonstrations Hysteresis 5G40 Hysteresis loop on scope 5G40.10. Temperature and magnetism 5G50Curie point 5G50.10; Meissner effect 5G50.50. Magnetic fields and forces 5H http://buphy.bu.edu/~duffy/electricity.html

Electricity and Magnetism There are: 99 electricity and magnetism demonstrations 72 of which have brief descriptions and diagrams 15 more have pictures and complete descriptions Last update : 2 September 1997 Main topics: Electrostatics Electric fields and potential Capacitance Resistance ... Electromagnetic radiation Electrostatics Producing static charge Rods, fur, and silk Electrophorus Coulomb's law Rods and pivot Pith balls Electrostatic meters Electroscopes Conductors and Insulators Wire vs. string Acrylic and aluminum bars Induced charge Charging by induction Can attracted to charged rod 2 x 4 Metal rod attraction Deflection of a water stream ... Kelvin water dropper Electrostatic machines Wimshurst machine Van de Graaff generator Electric fields and potential Electric field Hair on end Van de Graaff streamers Confetti Fuzzy fur field tank Gauss' law Faraday ice pail Electroscope in a cage Radio in a cage Electrostatic potential Point and ball with van de Graaff Pinwheel Capacitance Capacitors Sample capacitors Parallel plate capacitor Dielectric Capacitor with dielectrics Dissectible condensor Energy stored in a capacitor Short a capacitor Light a bulb with a capacitor Lifting weight with a capacitor Resistance Resistance characteristics Resistor assortment Resistance model Variable resistor Dependence on length/area Resistivity and temperature Wire coil in liquid nitrogen Conduction in solutions Conduction through electrolytes Conduction in gases Jacob's ladder Electromotive force and current Electrolysis Electrolysis of water Cells and batteries

46. Magnetism and Superconductivity magnetism and Superconductivity. Physics in high magnetic fields-. Pulsed field facility at IFW Dresden 60 Tesla pulse produced http://www.ifw-dresden.de/imw/21/high_magnetic.htm

Magnetism and Superconductivity - Physics in high magnetic fields - Pulsed field facility at IFW Dresden: 60 Tesla pulse produced by a non-destructive solenoid with a 15 mm inner bore. IFW Dresden Helmholtzstr. 20 D-01069 Dresden Germany phone: +49-351-4659-527 fax: +49-351-4659-537 e-mail: IFW Dresden Helmholtzstr. 20 D-01069 Dresden Germany phone: +49-351-4659-531 fax: +49-351-4659-537 e-mail:

47. Magnetic Fields A New Theory had called mass can be accounted for entirely in terms of energy in magnetic fields.The phenomena observed in the study of electricity and magnetism are but http://users.powernet.co.uk/bearsoft/MagF2.html

Bruce Harvey 's Alternative Physics site A new theory of Magnetic Fields Important message A major new paper on the subject will be added soon. Keywords Faraday Faraday's law magnetic flux energy density flux ... magnetic energy density flux The tip of the iceberg When man first discovered that a piece of loadstone hanging on a thread would always point in the same direction; when Oersted discovered that an electric current in wire affected a compass needle; when Faraday discovered that electricity can be generated by moving a magnet inside a wire coil; they perceived only the tip of the iceberg. The phenomena which we observe and have used to construct wonderful technologies are just the by products of the true nature of magnetism. What I will show is that magnetism is as fundamental to the structure of matter as the electric force which binds the negative electrons to their positive nuclei. As we delve into the inner mechanisms of nature, magnetism becomes ever more significant. It is the regulator of processes. The phenomena we observe in the macro world are bye products of the inner workings of matter. Without this insight, Oersted, Ampere, Faraday, Gauss, Biot, Savart and Michelson were working in the dark. The laws they developed are not fundamental laws of nature, but mathematical models designed to mimic the observed phenomena. As a result, they are not wholly self consistent and do not make complete sense. I remember sitting in a lecture trying to follow the mathematics. I am dyslexic and so was unable to take meaningful notes. The other students were writing everything down without understanding. I was more concerned with the way a term of

48. Exploratorium: Science Snacks: Circles Of Magnetism I Electricity and magnetism, an online physics textbook. 1.1 The Quest for the Atomic Force 1.2 Charge, Electricity and magnetism 1.3 Atoms1.4 Quantization of Charge 1.5 The Electron 1.6 The Raisin 5 fields of Force. http://www.exploratorium.edu/snacks/circles_magnetism_I.html

Circles of Magnetism I You can make a magnetic field that's stronger than the earth's! Compass needles are little magnets that are free to rotate. Compasses allow us to observe the direction of a magnetic field. Normally, they respond to the earth's magnetic field, orienting themselves parallel to magnetic field lines. If we create a magnetic field that is stronger than the field of the earth - for example, by using electric currents - a compass needle will orient itself parallel to the new field. A 6- or 12-volt lantern battery. A 1 foot (30 cm) length of heavy wire that is rigid enough to stand by itself. (You can use the wire from a coat hanger.) for building the stand (or another improvised stand). A flat, rigid support surface measuring approximately 6 x 6 inches (15 x 15 cm). (This can be made of posterboard or even a manila file folder.) It should have a hole in the center of it that is large enough for the wire to pass through. 4 or 6 small compasses

49. ScienceMaster - JumpStart - Magnetism Magnetic fields*. Magnetic fields. People not familiar with magnetism often viewit as a somewhat mysterious property of specially treated iron or steel. http://www.sciencemaster.com/jump/physical/magnetic_fields.php

Homework Helper Jumpstart Science Topics Learning Galleries Today is JumpStart - Physical Science Magnetic Fields Magnetic Fields People not familiar with magnetism often view it as a somewhat mysterious property of specially treated iron or steel. Either pole can also attract iron objects such as pins and paper clips. That is because under the influence of a nearby magnet, each pin or paper clip becomes itself a temporary magnet, with its poles arranged in a way appropriate to magnetic attraction. But this property of iron is a very special type of magnetism, almost an accident of nature! It is all related to electricity. In 1821 Hans Christian Oersted in Denmark found, unexpectedly, that such an electric current caused a compass needle to move. An electric current produced a magnetic force! Andre-Marie Ampere in France soon unraveled the meaning. The fundamental nature of magnetism was not associated with magnetic poles or iron magnets, but with electric currents. The magnetic force was basically a force between electric currents (figure below): Here is how this can lead to the notion of magnetic poles. Bend the wires into circles with constant separation (figure below):

50. MaNEP - Switzerland. Magnetic Fields, Superconductivity And Medical Imaging. Since matter is composed of atoms, all materials are sensitive in some way to magneticfields. Without going into detail, the source of magnetism lies in the http://www.manep.ch/en/technological-challenges/emfields.html

Introduction Video Scanning Probe Microscopy Muons as microscopic probes ... Site map Magnetic fields, superconductivity and medical imaging History of magnetism Magnets are very common in our everyday environment and their existence has been known for centuries. The ancient Greeks (originally those near the city of Magnesia) and also the early Chinese had discovered strange and rare stones which had the power to attract iron. Around 1000, the Chinese even found that a steel needle could become magnetic when put into contact with one of these stones known as lodestone (magnetic iron ore). Furthermore, when freely suspended such a needle appeared to point north-south: in this way they invented the compass! The magnetic compass then spread to western Europe and C. Colombus (1451 - 1506) was one of the first to make use of it while crossing the Atlantic in 1492. He even noticed that the needle was deviating from the north (as indicated from the stars) during the trip. Later, around 1600, W. Gilbert (1544-1603), physician under Queen Elizabeth I of England, published De Magnete ("On the Magnet") which rapidly became a standard reference document on electrical and magnetic phenomena. For example, he was the first to make a clear distinction between magnetism and the amber effect (or static electricity as we call it today). Moreover, he linked the polarity of the magnet to the polarity of the Earth and built an entire magnetic philosophy on this analogy. According to Gilbert, magnetism was the soul of the Earth; a perfectly spherical lodestone would spin on its axis when aligned with the Earth's poles, just as the Earth spins on its axis in 24 hours... Although he didn’t express an opinion to whether this rotating Earth was at the centre of the universe or in orbit around the Sun, he was after N. Copernicus (1473-1543) one of those who inspired other famous scientists like J. Kepler (1571-1630) and later G. Galileo (1564-1642).

51. NYU-STEM: Exploring Magnets And Magnetism inquirybased exploration of magnets and magnetism. The primary goal will be toshow how students can discover the properties of magnets and magnetic fields. http://www.nyu.edu/projects/mstep/lessons/magnets.html

EXPLORING MAGNETS AND MAGNETISM Primary Target Audience: Elementary school teachers, grades 1-5 Secondary Target Audience: Elementary school students, grades 1-5 Workshop Objectives This workshop will introduce the teacher to the an inquiry-based exploration of magnets and magnetism. The primary goal will be to show how students can discover the properties of magnets and magnetic fields. This activity will allow participants to use the science process skills of observation, data collection and recording. Through inference, they will make generalizations based upon their results. At the conclusion of the workshop, participants will be able to: understand that some materials are magnetic and some are not; identify natural magnets and manufactured magnets; test a sample to determine if it is magnetic; understand that magnets contain two opposite poles; understand the concept of the magnetic forces of attraction and repulsion; understand magnetic fields; make a temporary magnet; record data; and infer the magnetic properties of a material. Learning Styles Accommodated by the Workshop Visual: Visual learners will be stimulated by observation of the testing of materials and the magnetic field patterns.

52. Electricity And Magnetism Name Date _. MAGNETICFIELDS. Background. A magnetic field is the area around a magnet http://www.galaxy.net/~k12/electric/fields.shtml

MAGNETIC FIELDS Background A magnetic field is the area around a magnet where its magnetic force can be felt. Materials Needed 1 bar magnet 1 compass Procedure 1. Place the magnet in the center of the next page. 2. Put the compass near one end of the magnet. Let the needle stop moving. Note the direction of the needle. Lift the compass and draw an arrow where the compass was. The arrow should point in the same direction as the painted end of the compass needle. 3. Move the compass toward the middle of the magnet. When the needle settles, note its direction and draw an arrow as before. 4. Repeat this as you move the compass to the other end of the magnet. 5. Now start again from a different place near the end of the magnet. Go from end to end at least 3 times. Explore both above and below the magnet. 6. When you're done, your arrows show you where the magnetic field is. Go To Table of Contents Last Update: July 20, 1997

53. ThinkQuest : Library : Project Physics: Myth, Legend, Science Quintessential Concepts. magnetism, like electric fields produce both attractiveand repulsive forces. When an object is magnetized, two poles are created. http://library.thinkquest.org/23718/magnetism.html

Index Physical Science Project Physics: Myth, Legend, Science Vectors, dimensions, laws of motion, sound, light, circuits, and other mysteries of physics are explained at this site. Illustrated with many Java demonstrations and animations which break up the otherwise dense text, this site is a virtual textbook of formulas and facts. If you find yourself strangely attracted to this site, be sure to check the section on Magnetism. Visit Site 1998 ThinkQuest Internet Challenge Languages English Students Lisa Stuyvesant High School, New York, NY, United States Gavin North Arlington High School, North Arlington, NJ, United States Coaches Paul Want to build a ThinkQuest site? The ThinkQuest site above is one of thousands of educational web sites built by students from around the world. Click here to learn how you can build a ThinkQuest site. Privacy Policy

54. Magnetismofplanets magnetism of the Planets. The Earth. All planets with strong magnetic fields rotaterapidly (at least once every few earth days) and also contain an electrically http://www.exo.net/~pauld/activities/magnetism/magnetismofplanets.html

Magnetism of the Planets The Earth The Earth has a magnetic field. Compasses line up with the magnetic field of the earth. The magnetic field has a north and a south pole. It is called a dipole field. The north magnetic pole is located just off the coast of Antarctica (yes, the north magnetic pole is located near the south geographic pole.) Here is a space photo of the Northern and Southern Auroras of the earth superimposed on a model of earth. The magnetic field of the earth interacts with charged particles from the sun to create auroras circling the polar regions The magnetic field of the earth is made by a billion ampere electric current which circulates within the liquid metal of the outer core of the earth. (The liquid metal outer core stretches from the solid metal inner core about a quarter of the radius of the earth to the rocky mantle which begins 1/2 way from the core to the surface.) When molten rocks which contain iron, cool in the presence of a magnetic field they record the magnetic field direction. We can look at the magnetic field recorded in the rocks and find out about the magnetic field of the earth in the past, the paleomagnetic field. The paleomagnetic field shows that the magnetic field of the earth has flipped its direction many times. The flipping of the poles occurs after times of hundreds of thousands of years. It does not reverse on a regular basis but reverses chaotically.

55. BBC NEWS | Science/Nature | Ghostly Magnetism Explained Ghostly magnetism explained. By Arran Frood. The research also threw up evidencesuggesting a link between magnetic fields and ghostly sightings. http://news.bbc.co.uk/1/hi/sci/tech/3046179.stm

Home TV Radio Talk ... Programmes Last Updated: Wednesday, 21 May, 2003, 09:28 GMT 10:28 UK Email this to a friend Printable version Ghostly magnetism explained By Arran Frood British psychologists have published research findings which they believe go some way towards explaining why people think they see or feel ghosts. Hampton Court: A link between haunted rooms and field variation The study - in which hundreds of volunteers were taken around two allegedly haunted locations - found that people reported having more unusual experiences in the specific places at each location which are considered most haunted. The researchers think this can be explained by the way people react to environmental cues, such as subtle drafts, and in particular visual factors, like low lighting. The research also threw up evidence suggesting a link between magnetic fields and ghostly sightings. At both Hampton Court Palace, in Surrey, and the South Bridge Vaults in Edinburgh, the variance in local magnetic fields was highest in the areas thought to be most haunted, and lowest in areas where people typically did not record experiencing ghostly phenomena. The variations in magnetic fields were incredibly small - about 100 times less than you get from sitting about a metre away from your TV - but the researchers think the findings are significant.

56. Magnet understand the nature of this attractive or repulsive force of magnetism and we migration,when placed in a large room screened from magnetic fields they fly http://www.newi.ac.uk/buckleyc/magnet.htm

MAGNETISM Author: David Harrison School of Education and Humanities Athrofa Addysg Uwch Gogledd Ddwyrain Cymru North East Wales Institute of Higher Education Wrexham, NORTH WALES Updated: These notes have been written to support your learning. They are not a susbtitute for attending the lectures. At the lectures you will see demonstrations, carry out simple experiments, discuss the underlying physical process in greater depth and obtain lecture diagrams not included in these notes, in order to complete your learning experience. There is a story that a Cretan shepherd by the name of Magnés , whilst tending sheep on the slopes of Mount Ida, found that his iron tipped crook and the nails of his boots were attracted to the ground. To find the source of the attraction he dug up the ground to find stones that we now refer to as lodestones (also spelled loadstone; lode means to lead or to attract) which contain magnetite , a natural magnetic material Fe O . The story may be apocryphal but the earliest discovery of the properties of lodestone was either by the Greeks or Chinese. Pliny the Elder (23-79 AD Roman) wrote of a hill near the river Indus that was made entirely of a stone that attracted iron.

57. Earth Magnetism: Guide Tour Through Magnetic Fields Earth magnetism Guide Tour through Magnetic fields A Guided Tour through Magneticfields Wallace H. Campbell , National Oceanic Atmospheric Administration http://www.harcourt-international.com/catalogue/title.cfm?ISBN=0121581640

58. CONVECTION ZONE What are magnetic fields? Simply speaking a attracting iron. Scientistsuse magnetic field lines to represent these magnetic fields. The http://www.colorado-research.com/~werne/eos/text/magnetism.html

What are magnetic fields? Simply speaking a magnetic field is the region around a magnet. Magnets are made out of mineral called magnetide (or lodestone) which has the property of attracting iron. Scientists use magnetic field lines to represent these magnetic fields. The magnetic field lines of a simple magnet are shown in the picture below.They point from the north pole to the south pole. However, the magnetic field lines do not just end at the tip of the magnet. They go right through it, so that inside the magnet the magnetic field points from the south pole to the north pole. Thus the magnetic field lines form a closed loop and do not have any ends. Therefore the magnetic field in this case does not have any ends either. This is actually always true. Magnetic fields, no matter how complicated they are, do not have any ends. These magnetic fields are very important since they exert an influence on other objects. As we said before, magnets always attract objects made out of iron. In order to see this, put a magnet near a nail (made out of iron) and watch as the magnet pulls the nail toward it? Notice that as you move the magnet closer to the nail the attraction between the nail and the magnet becomes stronger. If you move the magnet further away from the nail the attraction becomes weaker until the moment when the nail stops to be attracted altogether. That's because at some point the nail entered the magnetic field of the magnet and was attracted toward the magnet by the

59. Subtle Magnetism, Torsion Fields And Spin Subtle magnetism Subtle magnetism, Torsion fields, Spin Research ArticlesExperiments and History How to build a spin detector by Dr Payne. http://www.buryl.com/spin/

60. Physics Demonstrations - Magnetism However, magnetism is very closely related to electricity. of a magnetic levitationapparatus is difficult because large magnetic fields are required over a http://sprott.physics.wisc.edu/demobook/chapter5.htm

MAGNETISM Magnetism brings to mind horseshoe magnets and iron filings. However, magnetism is very closely related to electricity. In 1819 the Danish physicist and chemist, Hans Christian Oersted (1777-1851), during a lecture demonstration, observed that an electric current can affect a magnetic compass needle and thus united what until then had been viewed as two distinct subjects[1]. The electric motor is the modern implementation of this phenomenon. In the 1820's Michael Faraday (1791-1867) in England and Joseph Henry (1797-1878) in the United States independently demonstrated that a time-varying magnetic field can produce an electric current. Electric generators and eventually a world dominated by electronics was the result. The same discovery was previously made in 1802 by an Italian jurist, Gian Dominico Romognosi, but was overlooked because it was published in a newspaper, Gazetta de Trentino , rather than in a scholarly journal. REFERENCE 1. J. Nelson, Am. Journ. Phys. Levitated Ball Contributed by Professor Donald W. Kerst

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