Visualizing Radio Waves

Visualizing Radio Waves

What is this?

Austin Rings Mystery117 V isolation transformer

Primary

Secondary

Austin Rings Mystery117 V isolation transformer

Primary

Secondary

Primary

Secondary

Primary turns wound around toroidal core


The turns of the secondary are this diameter.

Primary

Secondary



No core in here.

Primary

Secondary



No core in here.

Primary

Secondary

the core for both is this

magnetic flux is within core

(primary turns)

(secondary turns)

(primary turns)

(secondary turns)

If the changing magnetic flux is contained within the core…what in heaven’s name carries the power out to the secondary?


(primary turns)

(secondary turns)


There is nothing you can place in this area which would reveal a field.


How We Were Taught

That a field expands around and collapses around the coil.



It’s not so obvious, but even when close wrapped, the flux does not touch any of the wire.


It’s not so obvious, but even when close wrapped, the flux does not touch any of the wire.

Answer…


Answer…


Answer…a circulating electric field



something rarely taught

It is a special kind of E field, an E-field that doesn’t radiate.



It is a special kind of E field, an E-field that doesn’t radiate. It has curl and no divergence.



Any attempt to measure this kind of electric field with an antennawould fail.

A


A

A


Unless…

A


Unless…

A


Unless…the measurement involves going through the opening.

A



A



A

Efficiency is not affected by the looseness of the wind.



Austin Rings mystery shows how poor our models are.

• Models seem to have as their purpose, an aid to explain the math.• •


• Models seem to have as their purpose, an aid to explain the math.• That the E-field can circulate and few teachers explain when and why.•


• Models seem to have as their purpose, an aid to explain the math.• That the E-field can circulate and few teachers explain when and why.• That the fields do not collapse around a coil, they just get stronger and

weaker


The Fields of a Transformer are not Radiating Fields


A

nothing


nothing

A

The magnetic field isentirely contained in the core


electric field

A

nothingThe magnetic field isentirely contained in the core


electric field

A


nothing


electric field

The electric field is the kind that circulates

A


nothing


electric field

magnetic field


electric field

magnetic field

If there’s no load on the secondary, the primary has high impedance. It becomes a choke.


electric field

magnetic field

If there’s no load on the secondary, the primary has high impedance. It becomes a choke.

air core choke



A

Can now be used to couple with the field

A

And Now: Radiating Fields

A



A

A radiating field sends away power, whether there is a load there or not.



Fraunhofer Region

A



Fraunhofer Region

AFresnel RegionCan now be used to couple with the field

electric field

Fraunhofer RegionFresnel Region

A


Radiating Fields

Radiating Fields

The Most Important Difference:• If there’s no receiver for the EM wave the power is radiated

anyway.•

Radiating Fields


anyway.• Whereas for the transformer, if there’s no load the power

doesn’t come out.

Radiating Fields


anyway.• Whereas for the transformer, if there’s no load the power

doesn’t come out.

Tesla was hoping there was a way to have both.

Fields do not collapse and expand,they just get stronger and weaker.

Radiating Fields


There is nothing that “flows” in spite of the word “flux”.

Radiating Fields

Sound Waves in a Solid



Compression Wave


Shear Wave

There’s any number of orientations the “S”

wave can move.



wave can move.


activity is

but energy goes


wave can move.


measurableintensity


wave can move.


measurableintensity

not


wave can move.


this is polarization


wave can move.


polarization is only possibleif vibrating transversely


polarization is only possibleif vibrating transversely




Sound Waves in a Liquid

Cannot Support Polarization






A liquid cannot support a force called a “shear force.



Cannot Support PolarizationLongitudinal Waves


Longitudinal Waves

Longitudinal Waves

activity is

but energy goes

Transverse Waves Do Support Polarization

the medium has to berigid to support polarization

activity is

but energy goes

it has to be able transmit a shear force









Electric Waves Have PolarizationTherefore they must be:• •


Electric Waves Have PolarizationTherefore they must be:• transverse and•



Electric Waves Have PolarizationTherefore they must be:• transverse and• travel through something rigid



Electric Waves Have PolarizationTherefore they must be:• transverse and• travel through something rigid

energy is not because of motion energy gets stronger and weaker



demo

The Spinning Bargraph Shows What an EM Wave Looks Like Rotationally

Now for a Longitudinal View

The Spinning Bargraph Shows What an EM Wave Looks Like Rotationally

An EM wave is said to be transverse

An EM wave is said to be transverse • this does not mean that something has to move transversely• •

An EM wave is said to be transverse • this does not mean that something has to move transversely• it exists in a dimension that is transverse to its direction•

An EM wave is said to be transverse • this does not mean that something has to move transversely• it exists in a dimension that is transverse to its direction• it gets weaker and stronger


this construct is used because it is so hard to show something that gets weaker and stronger



units are V / cm



The length of the sensing element has nothing to do with the extent of the wave.

units are V / cm


units are V / cm

where this unit has a “direction”


units are V / cm

Fills space with an infinitely fine grain

another way to view it


units are V / cm



this w

ay: n

othing

horiz

ontal


units are V / cm



this w

ay: n

othing

horiz

ontal

units are V / cm


Fills space with an infinitely fine grain array of batteries

horiz

ontal

units are V / cm



units are V / cm


units are V / cm


units are V / cm

To visualize this we need to “strobe” it.


Stroboscope

source

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The Basic Interferometer

source

detector

The Basic Interferometer

source

detector

mirror

partialmirrormoving

mirror

source

path 1

detector

source

path 2detector

source

path 1

path 2detector

source

detector

source

from moving mirror

from fixed mirror

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detector

source

detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

source

detector

(both waves are moving)

source

detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

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detector

source

detector

it doesn’t matter where our detector is

source


detector

source


detector

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detector

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detector

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detector

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detector

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detector

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detector

source

detector

any object

source

detector

improved

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detector

improved

source

detectormore sensitive because no limit on the power

improved

Interferometer

Motion Sensor

end

compels one to believe in an electrically rigid medium.



Electric Waves Have PolarizationTherefore they must be:• transverse and• travel through something rigid• energy is not because of motion

compels one to believe in an aether.



Electric Waves Have PolarizationTherefore they must be:• transverse and• travel through something rigid• energy is not because of motion

Documents

Visualizing Radio Waves