| Electrostatics_equations Main equations and formulas of electrostatics. |
| EMCoS_-_Electromagnetic_Consulting_and_Software The company specializes in consulting on electromagnetic problems and in development of sophisticated software for electromagnetic simulations, as well as in data processing and visualization. Based i |
| EMF_Shielding_in_Buildings Remediation of EMF interference in buildings. Custom designed, quality EMF shielding. |
| High_Field_Magnet_Laboratory_(HFML) Research in the high magnetic field facility in Nijmegen, the Netherlands. |
| How_a_Compass_Works Explanation of how compasses work and how to make your own, from How Stuff Works. |
| How_a_metal_detector_works Interactive Java tutorial explaining the principles of electromagnetic induction. |
| How_an_Electromagnet_Works Explanation of principles and experiments, from How Stuff Works. |
| How_Van_de_Graaff_Generators_Work Description of Van de Graaff generators and static electricity, from How Stuff Works. |
| Is_it_Possible_to_Generate_Electricity_Directly_from_Heat? A brief explanation from How Stuff Works. |
| Magnet_Formulas A small web site devoted to the vanishing art of practical magnet design without FEA, including field formulas for simple conductor configurations, air core solenoids and Helmholtz Coils. |
| Magnet_University Educational information on electromagnetism, permanent magnets, and the application of magnetic materials. The site is maintained by the company Rare-Earth Magnetics. |
| Maxwell\'s_Equations Description of Maxwell's equations. |
| Maxwell\'s_Equations_and_Electromagnetic_Waves An overview of Maxwell's Equations and how they determine the speed of light. |
| Negative_Permittivity_and_Permeability_Material The true "left handed" material is described. In this medium, light waves are expected to exhibit a reverse Doppler effect. |
| Paradoxes_of_Modern_Electrodynamics Provides analysis of some modern electrodynamics concepts including peculiarities and «white spots» in the model of an electromagnetic wave. The site is in English and Russian. |
| PowerLabs___Rail_Gun Electromagnetic capacitor powered 20kJ rail gun research. |
| Science_Ebooks_Ezine This site offers a variety of electronics and physics animations and visual aides for teachers or students. |
| Spin_Science Research conducted at the University of Amsterdam utilizing x-ray magneto-optical techniques for the study of thin film and nanometric magnetic systems. |
| Static_Electricity Website by Jeremy Smallwood on static electricity. Describes the physics phenomena, possible electrostatic damages, materials for electrostatic solutions, and standards. Gives advice on solution of co |
| Static_Electricity_Projects Site devoted to projects utilizing static electricity (motors, generators) which are simple enough and can be relatively easily built. |
| Vacuum_Tube_Diode A demonstration of how a vacuum tube diode works. |
| The_Van_de_Graaff_Generator_Website This site includes information on how Van de Graaff Generators work, typical classroom demonstrations, and instructions for building one. |
| VRML_Gallery_of_Electromagnetism Visualization of the electromagnetic field. |
| Wireless_Lab_at_Nizhny_Novgorod_University Laboratory of Physical Fundamentals and Technologies of Wireless networks at Nizhny Novgorod State University, Russia. |
| Wondermagnet_com Images of magnets and their uses, experiments, a discussion board about magnet-related topics, and an elementary primer on magnetism and magnetic physics. |
| X-ray_Optics_and_Microscopy_at_Stony_Brook Research describing use of coherent soft X-rays for optics experiments, including Fresnel zone plates, to produce the smallest focused spot of electromagnetic waves for studies of biological and mater |
| NSSDC__Venus From NASA's photo gallery. |
| Planet_Venus_-_overview_and_pictures Illustrated guide to Venus. Contains description, facts, statistics and a brief history. |
| Venus From The Nine Planets. |
| Venus NASA's Windows to the Universe. |
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| Venus__Earth\'s_troubled_sister Although it looks a lot like Earth, it's actually dramatically different. |
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| ACalendar_com The calendar has many options with a standard monthly interface, including sunrise, sunset, and Moon phases. |
| Annus_Novus_Decimal_Calendar A proposal for a non-sectarian, culturally neutral calendar system. |
| Astro_Portal_-_CalSKY The worldwide interactive online astronomical/space calendar and calculator - for friends of astronomy, as well as astronomers. |
| Astronomical_Time_Keeping Extensive descriptions of many astronomical time keeping systems, with information on time zones and Julian day numbers. |
Home / EM
If this field is moving at a velocity vector ‘v’ relative to the observer it induces a vector magnetostatic field of induction ‘B’...
(Note that the symbol ‘x’ refers to the vector cross-product, so (X x v) is the vector X’s cross-product term with v, vectors all being in a bold typeface.)
This induced magnetostatic field has an energy density ‘dEM/dS’ of...
The cross-product ‘(X x v)’ is zero where the vectors ‘X’ and ‘v’ are parallel to
each other, and a maximum where they are orthogonal. At this maximum...
...so the ratio of the induced magnetostatic field energy density to the primary electrostatic field energy density is simply v2/c2 at this maximum.
If the orientation between the electrostatic field and the velocity vector is other than the optimum of 90 degrees, the ratio of induced magnetic energy to the rest electrostatic energy is v2.cos2/c2. The “cos” term refers to the cosine of the
angle between the velocity vector and the orientation of the primary electrostatic field lines.
Electrostatic inertia - problem in Relativity!Click here to skip the heavy stuff!
Can we apply the maths to the electron on the assumption that the electron is a pure radial electric field?
Because of its spherical symmetry the electron can be dealt with by three orthogonal vectors - one along the direction of motion, and the other two normal
to the direction of motion, with the rest energy of the electric equally distributed between them. The 1/3rd along the direction of motion induces no magnetic
energy, while the other two vector directions induce 1/3rd of v2/c2 each, so the total induced energy is 2/3rd of v2/c2.
Now the actual kinetic energy of an electron at Newtonian speeds is one half of v2/c2, so this result is 4/3rd of what we might expect. This is famous as the
“4/3 Problem”. In 1922 Enrico Fermi, in the paper “Il Nuovo Cimento”, derived this result relativistically (the maths here is the Classical solution), but showed
nothing new - after all the relativistic approach must reduce to the Classical approach at sub-relativistic speeds. Feynman’s “Lectures on Physics” showed
how this 4/3 result violated relativity. The conclusion often made is that the electron could not be purely electromagnetic. However the calculation was made
for a radial electrostatic field (albeit on the working assumption that the electron could be modelled by this) and hence the proper conclusion is that a radial
electrostatic field violates relativity. By geometrical inference all electrostatic field structures violate relativity. We cannot suspect the laws of induction, which
are well-proven - electric motors work because induced fields containing energy, nor can we suspect the laws of relativity, which are again well proven, but there
is little doubt the two are in conflict. There is no mechanism for an electrostatic field to propagate like an electromagnetic wave yet it has an effect at a distance.
Either the electrostatic field must convert to an electromagnetic wave and then magically convert back when it sees another electrostatic field it can interact
with, or else no energy is involved in its propagation implying that the speed of propagation of an electrostatic wave is either zero or infinite - the only possible solutions for this condition for any propagating field. The former is obviously
disallowed by experiment, but no-one has ever worked out the speed of propagation of an elctrostatic wave from first principles as has been done for
eletromagnetic waves to check the latter. Bear in mind that electromagnetic waves propagate by a falling magnetic field creating a rising electric field, and
vice-versa, while moving electrostatic fields simply generate magnetic fields in situ. A electric dipole generates electrostatic and electromagnetic fields; near the
dipole the electrostatic fields dominate, but the field falls off at 1/r3 while the electromagnetic fields fall off only as 1/r2, so more then a wavelength or more
away from the aerial the electromagnetic waves dominate.
There is an conflict between the scientists who work with relativistic particles and photons, and those who work with motion-induced induction, and neither group is interested in resolving it.
Magnetostatic inertia
For completeness it is worth looking at the induction of a moving magnetostatic field.
If a point in space has a magnetostatic field of induction ‘B’, energy density...
which is moving at a velocity ‘v’ relative to the observer, it induces an electrostatic vector field of strength ‘X’...
X = (B x v)
...with an energy density...
The induced field is zero when ‘B’ and ‘v’ are parallel, and reaches its maximum when they are orthogonal to each other. At this maximum...
...so again the ratio of the induced electrostatic field energy density to the primary magnetostatic field energy density is simply v2/c2 at this maximum.
If the orientation between the magnetostatic field and the velocity vector is other than the optimum of 90 degrees, the ratio of induced electrostatic energy to the rest magnetostatic energy is v2.cos2/c2. The “cos” term refers to the
cosine of the angle between the velocity vector and the orientation of the primary magnetostatic field lines.
