# What is electromagnetic radiation

#### Noji

On your web page titled "What is electromagnetic radiation?" your article stated that Maxwell reduced his 20 equations to four, which is not correct. It was Oliver Heaviside that reduced it to the four we have today.

#### Hartmann352

Noji -

Let me apologize if you've been mislead.

For mathematicians, Heaviside’s greatest contribution was in discovering how to simplify 12 of James Clerk Maxwell’s 20 field equations with complex calculus expressions, into a much simpler algebraic formulation involving a mere four equations:

ε E = ρ
∇ × E = − μ ∂ H/ ∂t
∇ · μ H = 0
∇ × H = k E + ε ∂ E/ ∂t

Where E represents the electric field, H represents the magnetic field, ε is the permittivity, μ is the permeability, ρ is the charge density, and k is the conductivity.

Heaviside proposed a number of arcane electrical terms, some a little fanciful, that we use to describe electrical parameters:

Admittance, the inverse of impedance.

Electret, a dielectric material that has and retains an electrostatic charge. It is analogous to the permanent magnet.

Impedance, the opposition in a load or conductor to the flow of current. It is made up of resistance and, added vectorially, inductive or capacitive reactance. Like resistance, it is measured in ohms.

Inductance, the property whereby change in current in a conductor induces a counter voltage in itself or in a nearby conductor. (There is self-inductance and mutual inductance.) The unit of inductance is the henry.

Permeability, the amount a material can be magnetized in the presence of an electric field. All materials including a pure vacuum are permeable to some extent. Soft iron, often used in a magnetic core, is highly permeable.

Permittance or susceptance, as it was later known, the reciprocal of magnetic reluctance. It is analogous to conductance in an electrical circuit.

Reluctance, in magnetic circuits, parallels resistance in electrical circuits. Reluctance opposes magnetic flux just as resistance limits electrical current. But the big difference is that resistance causes electrical energy to be lost forever, dissipated in the form of heat, while reluctance causes magnetic energy to be stored in a magnetic field so that when the field collapses, the magnetic energy returns to the magnetic circuit.

While we're at it, we might as well mention the Heaviside Layer, which is mentioned in Ian Fleming's 'Dr. No' from Crab Key, who discussed "toppling" at length, or the knocking space vehicles out of their intended trajectories by means of radio waves:

There is a million dollars’ worth of equipment up above us in the rock galleries, Mister Bond, sending fingers up into the Heavyside Layer, waiting for the signals, jamming them, countering beams with other beams.
DR. NO, Chapter 16
Doctor No is continuing to brag to James Bond about his installation on Crab Key, having just named a bunch of armed missiles that he has interfered with on behalf of the Russians.

Fleming tosses in a reference to the 'Heavyside Layer', referring to the Heaviside layer, sometimes called the Kennelly–Heaviside layer. This is a region of the Earth’s ionosphere, between roughly 90 and 150 km above the ground.

This region was predicted separately and at almost the same time by Arthur E. Kennelly and Oliver Heaviside. At the time the use of radio waves was in its infancy, and scientists didn’t understand why radio waves followed the curve of the earth rather than shooting directly out into space.

Heaviside, a self-taught British engineer, hypothesized in 1902 that there was a layer in the Earth’s atmosphere that forced radio waves to skim around the planet.

This led to great advances in radio technology so that by the time of Doctor No in 1962, it was possible not only to guide missiles by radio but also to intercept them or to topple them.

The term (with the correct spelling) also appears in Chapter 2 in Ian Fleming's 'Moonraker' in a description of MI6 headquarters building.

Variations in received signal strength are ascribed partly to the existence of a "Heaviside cloud" layer consisting of masses of ionized gas at considerable heights. A partial bibliography of the subject is given. The theory of interference caused by a spherical reflector is given, and results of receiving experiments due to Mr. Leonard Fuller, are studied in the light of the derived theory. It is shown that the Heaviside layer is probably quite irregular, and that refraction of the traveling waves is probably existent.

See: https://www.testandmeasurementtips.com/oliver-heaviside-and-maxwells-equations/

See: https://flemingsbond.com/heavyside-layer/

See: https://ieeexplore.ieee.org/abstract/document/1646012

Oliver Heaviside’s life, spanning the years 1850 to 1925, began and ended in squalor. He was never entirely free of the dark melancholy that characterized his private as well as his public persona.

Beyond a little primary schooling, Heaviside was self-educated. His reading of James Clerk Maxwell’s Treatise On Electricity And Magnetism was a revelation to him. He mastered the mathematics and went on from there. His insights into the behavior of electricity, inside and outside of circuits, were incisive and he knew how to communicate these insights to an eager audience of electrical engineers and theoreticians.

Heaviside gave us coaxial cable and the small coils placed in series with every telephone line, counter-intuitively improving clarity by providing inductive loading. But his great gifts to twentieth-century electrical engineering consisted of concepts, while some were alterations to existing theory.

Heaviside remains as an unsung hero in describing electricity's behavior and his invention of items like the ubiquitous coaxial cable, familiar to everyone of who subscribes to cable television or who relies on the transmission of effective signals between a transmitter and the antenna and from the antenna to the receiver.
Hartmann352

Noji

#### Noji

Yes, and don't forget gravity waves, the Poynting vector, and something akin to Laplace transforms!

#### Hartmann352

Yes, and don't forget your Hamiltonians, Riemann and the Dirac equation.

Dirac’s equation is a relativistic wave equation that explains that for all the half-spin electrons and quarks parity inversion (sign inversion of spatial coordinates) is symmetrical. The Dirac equation was first explained by P. A. M. Dirac in the year 1928. This equation of Dirac was used to predict the existence of antiparticles and it also supports a solution for free moving electrons. The Dirac equation means - It is a relativistic wave equation that describes the electron and similar kind of particle, It is also used to predict the existence of antiparticles.

Dirac Equation Formula (Dirac Formula)

(βmc2+c∫3n=1αnpn)ψ(x,t)=ih∂ψ(x,t)∂t
Where,
• 𝜓 = 𝜓(x, t) is the electron wave function
• M is the electron mass at rest
• X, t is the spacetime coordinates
• p1, p2, p3 are the momentum components
• c is the speed of light
• ℏ is the Planck constant
Alas, there is so much to explain and so little time to grasp it all!
Hartmann352

Noji

#### Noji

Seems like you and I agree that Max well wasn't the person who reduced his twenty to the four we have today. So, could you please publish the correction? Thanks!

#### Hayseed

It's easy to verify Maxwell's EM equations, isn't it? After all, if we measure the electrical response to an EM emission, with a detector or absorber, we will measure a sine wave response. And if we measure the feed point of an antenna, will see a sine wave feeding it. So we assume a sine wave is going into the antenna, being propagated from it, and then received by the detector. It all makes sense.

And after all, we can duplicate this same dynamic with a speaker and sounds waves, at the lower velocity and frequency........so we can see the dynamic accurately with our
instruments. And we see the same dynamics. We feed a sine wave into the speaker, the propagation occurs, and the detector will give you that same sine wave. We see that a sine wave is propagated.

So EM rad, appears to be a wave dynamic, just like sound. But that assumption has mislead science for over one hundred years. We have to give a separate, and different time, to every object in the universe, in order to explain this wave dynamic. This is because they believe that light, like sound, is a continuous stream of alternations, and being a continuous stream, the waves can pile up, or stretch out, with the velocity of the emitter. Just like sound waves do. And the ONLY way to mathematically justify this constant velocity, is the change the time scale at the receiver. In order to justify, the constant c, between moving frames, we have to change time, or change length.........at the receiver. This is the only way, the math will work.

Were you aware of this? For light to have a constant V, The length of length, or the rate of time, has to be different between the emitter and receiver. And for some reason, all educated people believe and accept this dynamic. And modern science, bases all other science on this dynamic. The concept of light is our base........for all physical understanding. And all our terms, and all our units. ALL of science reinforces this theory.

And I believe it's all a farce. A speaker takes 1 period of motion to emit a wave. The emitted wave has a 1 period duration as it flies by. And when absorbed, it has one period of absorption. 1 period to emit, 1 period fly by time, and 1 period for absorption. And it is a continuous stream.

But light is totally different. When I use the word light, that means any and all EM rad.

Light has a zero emission time. It emits, in an instant. AN instant dynamic. The propagation fly by time, is 1/2 period. And the absorption duration is 1 full period.

Light is an intermittent strobe. With a duty cycle, not a frequency. The "frequency" comes from the absorption. The 1st half of the absorption is the EM propagation, inducting the absorber, the second half is from the reaction, or resetting(inertia) of the absorber, giving an APPARENT full period sine. But the propagation itself has a 1/2 period duration.

The hardest part to understand is the instant emission dynamic. Don't use the speaker dynamic. Instead, use the ignition coil dynamic. When the ignition coil M flux is turned off, the field collapses back into the coil. This collapse takes time, because of the counter EMF of coil built up during the collapse, AND the impedance of the coil. It takes a few milliseconds for this collapse, and during this time a spark is generated across the plug.

A dipole antenna is like a coil, only it uses electrostatic collapse, instead of M collapse. When the E field collapses, it does not collapse back into the antenna, it collapses out....into space. And space has no counter EMF and space has no impedance. The collapse into space is an instant event. This collapse happens at the end of every half sine, put into feed point. Most call this the cross over point of the input signal.

This true dynamic of light, agrees with all of our measurements........using absolute length and absolute time. And proves that light, just like all other velocities......does have a relative velocity that can be measured.

In my opinion, Maxwell's equations only described absorption, not emission or propagation. And because of that, we had to invent space time to verify Maxwell.

I believe I can show you this, if you have a radio background and some instruments.

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