Anyone feels like repeating Wheatstone's 1834 experiment to disprove Einstein?

[lamare]

As I posted on the Gray tube thread, Wheatstone's 1834 experiment could be pretty easily repeated with modern electronics.

Tuks Unsorted KieknWatTWordt Stuff : Wheatstone Experiments To Measure The Velocity Of Electricity

It is a very interesting experiment. Very cool how he managed to measure the rotation speed of his shaft:

It was a point of essential importance to determine the angular velocity of the axle carrying the mirror. No confidence could be placed in the result obtained by calculating the train of wheels, as in such rapid motion many retarding causes might operate and render the calculation uncertain : it was necessary, therefore, to devise a means independent of these sources of error, and which should immediately indicate the ultimate velocity. Nothing appeared more likely to effect this purpose than to attach a small syren to the instrument, the plate of which should be carried round by the axle of the mirror. [...] The difficulty was at last overcome by employing the arm Q itself to produce the sound. A small slip of paper was held to it ; and as at every revolution a blow was given to the paper, its rapid recurrence gave rise to a sound the pitch of which varied with the velocity of the motion. When the machinery was put in motion with the maximum velocity I employed in my experiments, the sound G#4 was obtained, indicating 800 revolutions of the mirror in a second. I am not aware that anything can have interfered with the accuracy of this result ; the same sound was heard when different pieces of paper or card were used ; and on moderating the velocity, the sound descended through all the degrees of the scale below it, until distinct percussions were perceived.

That is just awesome!

Anyway, I studied this article a while back and there is an important detail: you have to take into account the fact that the current, shockwave or whatever it is, is balanced. You get one pulse traveling from the positive pole of the HV cap/coil, and one from the negative. So, if you would only take two spark gaps at the begining and at the end of the long wire, your gaps would fire simultaneously. Wheatstone already thought of that, too:

But as it is only on the hypothesis of an actual transfer of a fluid from one end of the wire to the other that a difference of time between the two sparks at its opposite extremities might be expected to be observed, in order to render the proposed experiment independent of this theoretical view, I took the necessary precaution of bringing a third spark, formed by disconnecting the middle of the wire, near to and in a line with the extreme sparks. For on the supposition of the transfer of two fluids in opposite directions, the extreme sparks would be simultaneous, but the middle spark later in its occurrence; the same appearances would also accord with the theory of one electricity, if we admit that a disturbance of electric equilibrium is simultaneously propagated from each end, arising in the one case from successive additions to, and in the other from successive subtractions from, the neutral quantity in the conducting wire.

So, I made a drawing of how this experiment could be repeated pretty easily with a decent scope and a handful of standard components.

It's a matter of mounting three spark plugs in light-tight enclosures together with photo transistors and measuring the time it takes for a pulse to propagate along a long wire using a scope:

Some time ago, I thought about re-doing Wheatstone's experiment with modern equipent, which shows you schematically what Wheatstone was doing:

High res: http://www.tuks.nl/img/Wheatstone_reloaded.jpg

The idea is that when using photo transistors, you don't need a rotating mirror. Just three spark gaps with three photo detectors in order to detect the moment of sparking.

You may need pretty fast photo transistors or use photo diodes or something, but OTOH the switch-on times are not critical, as long as the response delays on the three different sensors are (almost) the same, which means the connection from transistor to scope should have the same length for all three transistors.

For insulators, one could use the kind of insulators used by farmers:

In principle I can do it myself, but I only have a 10 MHz scope, so I would need about 600 meters of wire. With a 300 MHz scope, one could do with as little as 20 meters of wire, which is a bit more practical...

If this experiment is pulled off succesfully and achieve the expected result, namely the measurement of a propagation speed of about 1.5 times the speed of light, you would probably get your name in the history books as having performed the single experiment with which Einsteins theory has been proven wrong.

[lamare]

Some more info on Wheatstone's experiment with some better pictures as on my site:

Sir Charles Wheatstone Frs: 1802-1875 - Brian Bowers - Google Boeken

[kunkmiester]

Looking at prices, a 50Mhz is closer to my price range. If my math is right that's 120 meters?

A piece of plywood from the home improvement store is four feet by eight. You could get a meter across, but you'd have .8 inches between the wire. Is that enough to avoid inductance? Most of the criticism I've read says that his experiment likely showed a faster time because the wires were inducting the current across the array of wire, and so it was taking a shortcut so to speak.

[kunkmiester]

New thought. Would an LED work fast enough to use a lower voltage/current? That could reduce your inductance, or detect the inducted peak before the sparking current gets to the gap showing that the inducted current is not causing a false result.

[Ernst]

Why not use even more modern stuff such as in attached diagram.
The response time of a 74HC86 is 9 ns. Its output will be pulled low if the inputs are equal, otherwise it will 'float' (open collector). So for as long as the inputs differ pulses can go to the counter. Counting these pulses will give you an indication of the time that the inputs were different.

Just a thought...

Ernst.

[lamare]

Why not use even more modern stuff such as in attached diagram.
The response time of a 74HC86 is 9 ns. Its output will be pulled low if the inputs are equal, otherwise it will 'float' (open collector). So for as long as the inputs differ pulses can go to the counter. Counting these pulses will give you an indication of the time that the inputs were different.

Just a thought...

Ernst.

I don't know if that will work.

The idea is that two separate energy flows exist:

1) The normal electric current, which involves the movements of charged particles such as electrons drifting trough a wire;

2) a mass-less "current" involving movements of the aether itself.

This mass-less "aether current" is the force which actually causes the normal electron-based current to flow. It is this aether current which gives rise to the pressure variations in the aether which we measure as the electric field E. And this aether current appears to propagate as a longitudinal shockwave with a speed of sqrt(3) times c.

So, a normal electron based current won't propagate that fast. It may be possible to work with capacitive coupling and detect a pulse, since Eric Dollard used capacitive coupling with his experiments with longitudinal waves along a coax cable, as stated in NASA's Advanced Energetics for Aeronautical Applications: Volume II:

http://www.tuks.nl/pdf/Reference_Mat...20VOL%20II.pdf

page 61:

The BSRF researchers claimed that they have demonstrated that the wave propagation velocities of transverse waves and longitudinal waves are significantly different, even when they are produced by the same signal source.

The wave velocity of transverse waves was determined by measuring the frequency for which low-power radio waves directly coupled to the end of a conductor of known length produced a resonance condition that resulted in a maximum voltage measured at the "far" (nonsource) end of the conductor. Wave velocity was calculated as (resonant) frequency times wave length, which was equal to frequency times conductor length times four. (The factor of four is included because reflected energy and input energy result in a maximum output when the conductor length is one-quarter of the full [electric] wave length.) The wave velocity of longitudinal waves was determined in a very similar manner; however, the radio waves were capacitively (i.e., not directly) coupled to one end of a conductor equal in length to the conductor used for the transverse wave velocity measurement. As was done for transverse waves, wave velocity was calculated as (resonant) frequency times conductor length times four.

The results of these determinations were as follows:
– transverse wave velocity = 2.44 x 108 m/s = 0.81 x c; and
– longitudinal wave velocity = 3.74 x 108 m/s = 1.25 x c.

The velocity of transverse waves in "free space" (i.e., not confined to a conductor or other physical material) has been measured to be 3.00 x 108 m/s, and this value is commonly referred to as "the velocity of light, c" (Ref. 25).

This refers to this video:

Transverse & Longitudinal Electric Waves - Eric Dollard And Thomas Joseph Brown on Vimeo


However, when I watch the video (from about 11:24), I see inductive coupling into the coil and capacitive coupling at the detection side, whereby the windings are pretty close to one another, which does suggest inductive coupling between the windings and thus the taking of a "shortcut".


All in all, a signal with a fast rising edge capacitively coupled into a long wire and detected at the other end with a high impedance detection circuit (i.e. an opamp), also capacitively coupled, might work. Any low impedance detection circuit (requiring considerable current) will most likely not work.

In order to prevent inductive coupling, the core of a coax cable might work. IF a longitudinal shockwave propagates trough a coax cable with a propagation factor of about 0.8, one would expect a propagation speed of about 0.8*1.72 = 1.376 times c, which would be more than sufficient for demonstrating faster than light signal transmission.