Eternal Gardens Journal

Living stories shaped by conversations with our personas

Tesla Notes 19: Wardenclyffe and the World System (1901 to 1917)

Morgan's money, Stanford White's laboratory, a tower crowned with a sphere sixty-eight feet across, and the arithmetic of how much charge it could hold.

Tesla's Wardenclyffe tower: why the terminal was huge and smooth (E = V/r, C = 4πε₀r), Marconi in 1901, and an honest verdict on wireless power.

Tesla Notes 18: The Stationary Waves of July 3 (Colorado Springs, 1899)

A storm walks east across the plains, my relay counts its nodes, and I spend five years deciding what was holding the waves still.

Tesla's night of 3 July 1899: the receding storm, his stationary waves, the 6 Hz of patent 787,412, and why Schumann's 7.83 Hz is a near-miss.

Tesla Notes 17: The Magnifying Transmitter (Colorado Springs, 1899)

A barn on a plateau, a coil fifteen metres across, a free coil standing on a driven one, and the long work of finding its pitch.

Tesla's 1899 Colorado Springs notebook: the extra coil as a quarter wave, why a ball on top lowers its pitch, and three ways he measured capacity.

Tesla Notes 13: Light Without Wires (Columbia College, 1891)

A tube lit in empty air between two hanging sheets, and the arithmetic that says why frequency makes the impossible lamp easy.

Tesla's 1891 Columbia lecture: how an alternating electric field lights an exhausted tube, why only the field along it counts, and why frequency matters.

Tesla Notes 12: The Oscillation Transformer, or the Coil (1891)

Why the induction coil fails at high frequency, and how a condenser, a spark and two tuned circuits without iron became the Tesla coil of patent 454,622.

Tesla tunes two coils without iron, derives their two frequencies and the voltage gain √(L₂/L₁), and files patent 454,622 for the coil.

Tesla Notes 11: The High-Frequency Alternator (1890)

Tesla builds a dynamo with 384 poles to reach ten thousand alternations a second, silences the arc lamp, and finds the current hiding in the skin of the copper.

Tesla works out how many poles make 10,000 alternations a second, why the iron must be wire, and why copper carries current only in its skin.

Tesla Notes 10: Hertz's Waves and Maxwell's Equations

From the Paris Exposition of 1889 to a laboratory in Bonn in 1892: Tesla works through Maxwell's wave equation, measures waves on a wire, and argues with Hertz.

Tesla derives the speed of Maxwell's waves from the ratio of the units, estimates Hertz's wavelength, and takes his objections to Bonn.

Tesla Notes 09: The Oscillating Spark and Lord Kelvin's Formula

A jar of glass and a loop of copper swing a million times a second of their own accord. I derive why, count the swings in a turning mirror, and weigh the thief in the spark.

Tesla derives f = 1/(2π√(LC)) and the damping of a Leyden-jar discharge, counts the swings in a turning mirror, and finds the spark's loss.

Tesla Notes 08: The Mathematics of the Alternating Wave

A sine is the shadow of a turning radius. With that one picture I could see every alternating circuit whole before a turn was wound.

RMS by integration, impedance, phase lag, power factor and series resonance, derived step by step from Tesla's geometric method of turning radii (proto-phasors).

Tesla Notes 07: Pittsburgh and the Question of Sixty Cycles

Westinghouse's alternators gave 133 periods a second and my motor wanted far fewer. I spent a year between two numbers.

Why 60 Hz? Tesla's Pittsburgh year worked out: motor speed n = 120f/p, split-phase motors, lamp flicker and filament heat, and transformer iron versus frequency.

Tesla Notes 06: A New System of Alternate Current Motors (1888)

Five years after the sand in Budapest, the field turned in iron at 89 Liberty Street, and I had to say exactly what I had seen.

Tesla's 1887 to 1888 polyphase patents and AIEE lecture: the rotating field's circle proof, synchronous versus induction motors, and why three-phase saves copper.

Tesla Notes 05: The Transformer and the Ratio of Turns (1885 to 1888)

A converter has no moving part and turns a thousand volts into fifty as quietly as a sum is carried in the head. I wanted to know exactly why.

Why a transformer needs alternating current: the ratio of turns, V = 4.44 f N Φ, magnetising current, eddy losses and laminations, worked in Tesla's voice.

Tesla Notes 03: Arago's Disc and the First Induction Motor (1883)

Paris and Strasbourg, 1882 to 1884: a copper disc chases a field made of timing, and I learn why it must always fall a little behind.

Tesla's Strasbourg notebook: Arago's disc, eddy currents and Lenz's law, the torque-slip law T = 2xm/(x² + m²), and his first induction motor.

Tesla Notes 02: The Rotating Magnetic Field (Budapest, 1882)

Budapest, 1882: two currents a quarter period apart, drawn with a stick in the sand, make a field that turns while nothing turns it.

Tesla's Budapest notebook: how two or three phase-shifted currents make a field that turns, the (3/2)B cos(θ − ωt) proof, and why one phase cannot.

Tesla Notes 01: The Gramme Dynamo and the Professor's Verdict

Graz, 1877: a Gramme machine sparks at its brushes, my professor calls a motor without them perpetual motion, and I set out to prove him wrong.

Tesla's Graz notebook: the emf of a turning coil, why a commutator gives 2/π of the peak, why brushes spark, and Poeschl's verdict.