Question

viperousdraco

What does Ed mean when he says: volt meters and amp meters are one sided?

viperousdraco

Again what does he mean by: one half of the electricity escaped their notice

Jehovajah

Briefly: voltmeters and ammeters developed from the Galvonometer. Both Ampere and Volta contributed to its basic use, and early development. In those early days a galvonometer was simply a magnetic or current sheathed wire hung over s current sheathed coil of wire,. The deflection of this wire indicated the presence of electrification and the direction of the connection to the voltaic cell or battery.

The Galvonometer thus did not specifically measure current ( Amps) or voltagr( ohms) . these measurements were defined and named at an intenational conference in Europe, at which the concept of a current flow in a wire was adopted, thus relegating the two fluid idea / hypothesis as obsolete. In so doing the galvonometer now measured the current by its displacement, and a scale was introduced. Old ammeters used to deflect both ways as did the galvonometer and the scale consequently measured both ways.
By carefully choosing the resistance in the ammeter circuit the voltmeter was designed and voltage defined by the displacement of the needle.
Old voltmeters and ammeters were built around a standardised permanent horse shoe magnet, but of course that lost its standard magnetism with time so a problem of accuracy and consistency was addressed in later times.

The definition of a current in a wire immediately loses the 2 fluid concept and replaces it by a single current flow. At the time most pioneers did not have a problem with the 2 flows , but over time the scientists who believed In the electron dominated and insisted that only the electron flowed in the wire. However engineers resisted because they loved the positive sign flowing so for a time the 2 currents were once again visible. But by Eds time no positive charge was allowed to flow. The situation was so bad that Dirac was censured heavily for claiming a positive charge existed! We now call it the positron but it is still ignored in basic electrical theory!

We do not reflect reality by claiming an electric current of electrons flows in a wire. It lead to serious problems with the design and functioning of transmission line cables! The concept of 2 standing vortices that carry the power by phase variation is what transmission line theory is based on! Tesla ensured that part functioned appropriately.

We assume AC current is a currents only by convention. By that convention we learn to ignore the oscillation of the two vortices as they transmit power over vast distances.