I’m pretty sure I’ve figured out how to make a light bulb without anything more “high tech” than copper wire, bronze fittings, glass / ceramic jars, and maybe a wheel with some metal on it; plus, the Baghdad Battery.
The fist step is to gang together a set of those Baghdad Batteries into a battery of about 10 to 20 Volts. That current is then sent to a switch. This could either be a single switch like in the old points and condenser ignition, or it could be a wheel where there are alternating patches of bronze, and wood, that make contact between two wires, or don’t. This makes a pulsing DC current that is “close enough” to AC for a transformer to work. (Cars work this way, so not a hypothetical)… points or electronic ignition ‘chop’ the Direct Current that goes to the “coil” as 12 V DC (chopped) and comes out about 50,000 Volts of spark…
That kind of “coil” is relatively easy to make. Yes, really good ones need a special kind of iron core, but any old chunk of iron is ‘good enough’ to make an ok coil. We don’t really need to jump things up to 50,000 VDC here, just a few hundred to thousand would be fine. In fact, even air core would be OK… see below on Tesla Coils.
Now, the next step, is to make that wobbling quasi-AC at high voltage into a truely spectacular voltage. One that can ionize air (or CO2 or…) in a bottle over a foot or two distance. To do that, there’s a couple of ways. But first, just so you know what we’re trying to make here, the Egyptian Lightbulb:
The “mainstream” view is some fanciful concoction of lotus blossoms and deities, snakes and Osirus… The “Fringe View” is more mundane:
In contrast to the mainstream interpretation, there is a fringe hypothesis according to which the reliefs depict Ancient Egyptian electrical technology, based on comparison to similar modern devices (such as Geissler tubes, Crookes tubes, and arc lamps). J. N. Lockyer’s passing reference to a colleague’s humorous suggestion that electric lamps would explain the absence of lampblack deposits in the tombs has sometimes been forwarded as an argument supporting this particular interpretation (another argument being made is the use of a system of reflective mirrors). Proponents of this interpretation have also used a text referring to “high poles covered with copper plates” to argue this but Dr. Bolko Stern has written in detail explaining why the copper covered tops of poles (which were lower than the associated pylons) do not relate to electricity or lightning, pointing out that no evidence of anything used to manipulate electricity had been found in Egypt and that this was a magical and not a technical installation.
A technically oriented person might note that copper and bronze are highly valuable and that if there were a secret way to use electricity to make light, killing off the dozen folks who knew it would result in the Idiot Victors having a lump of copper and bronze to melt down to make swords to slay more folks with clue… leaving no evidence to speak of…
If, right now, our society collapsed back to pre-electrical, just how many folks 1000 years from now would know what a computer was, how to program FORTRAN, what made a Raspberry Pi special, or why we spend so much time “worshiping” some Goddess named Lady Gaga?
Metals and paper decay fast. Ceramics not so much. IFF it is not in or on a ceramic, don’t expect any evidence of it in 1000 years. Especially anywhere wet / damp / humid.
So here’s the light bulb:
The problem is that this looks like an “arc discharge” bulb, and that takes very high voltage. It also works best with modest frequency AC, not low volts DC from a crummy battery.
So the question is: HOW to turn the small battery volts into BIG discharge arc volts without a whole lot of technology? I’d like to limit it to copper and bronze wires and fittings, coils and flat plates, and ceramics and glass, if possible. The Egyptians had all of that. Oh, and a wheel as on their chariots to do the “chopping” of DC to AC even if square wave.
So what can make a few hundred or thousands of Volts (chopped DC) into something up in the hundreds of thousands to millions? (Mega Volts, or MeV).
Yes, at this point I’m assuming the Egyptians could figure out how to use a wheel with bumps to cause a periodic switch press, or how to put bands of bronze on a wheel such that sometimes they conducted between two wires / pads and sometimes it was bare wood. I’m also assuming they could send this pulsed DC from their Baghdad Batteries down wires to “something” that could use pulsed DC to make higher volts. A lot higher…
I’m not seeing any of this as “beyond the pale” for the Egyptians. They had wheels. The Baghdad Battery is a known artifact. They had copper and bronze and knew how to make wires and cables. Winding a coil is common (much jewelry has that as a motif) and using a bit of iron as a core for the primary circuit is a “nice to do” that they could do, but not essential.
So I’m willing to postulate they can make pulsed D.C. of a few hundred to thousand Volts through just that kind of system that we invented at the very start of our age of electricity. Then what?
Rotary spark gap –
These use a spark gap consisting of electrodes around the periphery of a wheel rotated by a motor, which create sparks when they pass by a stationary electrode. Tesla used this type on his big coils, and they are used today on large entertainment coils. The rapid separation speed of the electrodes quenches the spark quickly, allowing “first notch” quenching, making possible higher voltages. The wheel is usually driven by a synchronous motor, so the sparks are synchronized with the AC line frequency, the spark occurring at the same point on the AC waveform on each cycle, so the primary pulses are repeatable.
Nothing, nothing at all, prevents making just such a wheel as the thing that chops the battery current into the first stage of a car-type “flyback” transformer to make hundreds or thousands of volts in a nice fat pulse. Then you send it into a very simple coil set-up and it becomes more than enough to ionize air and make it glow.
So a wheel and flyback wound transformer take the place of that input AC voltage and transformer. The result is the same. At the next point, we have a capacitor (those two horizontal lines with C1 next to them). One of those can be made via a jar (glass or ceramic) with metal inside and outside. Then is the spark gap. Two metal rods in free air. And finally the Tesla Coil itself. That is just a big coil of wire (or two coils) and an optional “top hat” of metal that we can replace with a light bulb discharge tube if desired.
But what I find of particular interest, is the ‘bipolar’ Tesla coil. It looks rather a lot like the ‘base’ of the Egyptian Lightbulb, except that the ‘spark gap’ isn’t two wires in free air, but a couple of metal ends inside a glass envelope.
Compare, in particular, the “support” under the big end of the “light bulb” and the overall look of the Bipolar Tesla Coil… Now adding a ground lead to the far “lotus blossom” end and you have the whole magilla…
Next to that “support” end of the bulb, we have a figure with 2 faces one each way. Denoting A.C. current perhaps? The “wire” comes from the box he is on, so I’d suspect that was a caricature of “the guy who chops battery DC into AC with that wheel thing”…
But I said a couple of ways… Tesla also used a “Magnifier coil” on his basic system to make even higher voltage. But what caught my eye was a related system. Used at the very start of the age of electricity as a “medical device” (of dubious quality… then again, send a few MeV though me and I’m definitely going to feel “energized” ;-)
How it works
Oudin and Tesla coils are spark-excited air-core double-tuned transformer circuits that use resonance to generate very high voltages at low currents. They produce alternating current in the radio frequency (RF) range. The medical coils of the early 20th century produced potentials of 50,000 to nearly a million volts, at frequencies in the range 200 kHz to 5 MHz. The primary circuit of the coil has Leyden jar capacitors (C) (one in the Tesla and two in the Oudin coil) which in combination with the primary winding of the coil (L1) make a tuned circuit. The primary circuit also has a spark gap (SG) to excite oscillations in the primary. The primary circuit is powered by a high voltage transformer or induction coil (T) at a potential of 2 – 15 kV. The transformer repeatedly charges the capacitors, which then discharge through the spark gap and the primary winding. This cycle is repeated many times per second. During each spark, the charge moves rapidly back and forth between the capacitor plates through the primary coil, creating a damped RF oscillating current in the primary tuned circuit which induced the high voltage in the secondary.
In earlier Oudin circuits the two coils were separate, not magnetically coupled, with a small horizontal primary “D’Arsonval” coil of 20-40 turns with a tap connected to a large vertical secondary “Oudin resonator” with many turns of fine wire (400 – 600 in large coils, 100 – 300 in small ones), connected to the high voltage terminal on top. In this circuit the high voltage was generated entirely by resonance in the high Q secondary coil. The addition of the “resonator” coil to the “D’Arsonval” coil was Oudin’s contribution; the rest of the circuit was invented by Jacques D’Arsonval.
In later Oudin circuits the coils were magnetically coupled, forming an autotransformer, so the primary induces an EMF in the secondary by electromagnetic induction. Both coils were usually wound on the same coil form, the primary consisting of relatively few turns of heavy wire at the bottom with an adjustable tap, connected to the secondary winding, made of many turns of fine wire. Oudin found this circuit produced higher voltages due to the large turns ratio of the transformer.
Note that a Leyden Jar really is just a glass or ceramic jar with metal foil or plates on the inside and outside. Trivial for an Egyptian to make.
So a large coils of wire with a ‘tap’ on it for tuning, two jars with foil or metal inside and out to make capacitors, and an input from a wheel / transformer (another coil) and Baghdad Battery. With all that, you get arcs that can make light in free air. All that is left is to make it more ‘tame’ with a “lightbulb” wrapper.
One of THE most efficient and common light bulbs most folks don’t know about is the “metal halide discharge” lamp of the more generic “High Intensity Discharge” lamps. Basically a glass bubble with oxygen free air in it and some metal salts. You can have all sorts of metals used. Things like Mercury, or even Sodium.
A metal-halide lamp is an electric lamp that produces light by an electric arc through a gaseous mixture of vaporized mercury and metal halides (compounds of metals with bromine or iodine). It is a type of high-intensity discharge (HID) gas discharge lamp. Developed in the 1960s, they are similar to mercury vapor lamps, but contain additional metal halide compounds in the quartz arc tube, which improve the efficiency and color rendition of the light. The most common metal halide compound used is sodium iodide. Once the arc tube reaches its running temperature, the sodium dissociates from the iodine, adding orange and reds to the lamp’s spectrum from the sodium D line as the metal ionizes. As a result, metal-halide lamps have high luminous efficiency of around 75 – 100 lumens per watt, which is about twice that of mercury vapor lights and 3 to 5 times that of incandescent lights and produce an intense white light. Lamp life is 6,000 to 15,000 hours. As one of the most efficient sources of high CRI white light, metal halides as of 2005 were the fastest growing segment of the lighting industry. They are used for wide area overhead lighting of commercial, industrial, and public spaces, such as parking lots, sports arenas, factories, and retail stores, as well as residential security lighting and automotive headlamps (xenon headlights).
Now I’m not going to assert that they invented the Metal Halide Discharge lamp as we know it. I’m just pointing out that the use of a very high voltage current limited discharge can act a lot like a ballast (limits the current / Wattage) and that a glass bowl full of relatively inert gas (like CO2 from a fire) with some salt on the elctrodes would make a dandy light. (FWIW, I’ve put salt on wires from my 18 kV neon sign transformer and it makes a dandy Egg Yolk Yellow light… Other salts give other colors).
So take your Oudin coil or Tesla coil output (from your interrupted current from your Baghdad batteries) and apply it to metal ‘arms’ coated with your typical desert salts. Put the thing inside a glass bowl, and burn a bit of something inside to clear out the oxygen. Viola, electric light with 1700s era tech and none of it beyond the Ancient Egyptians to make.
Gas-discharge lamps are a family of artificial light sources that generate light by sending an electrical discharge through an ionized gas, a plasma. Typically, such lamps use a noble gas; (argon, neon, krypton, and xenon) or a mixture of these gases. Some include additional substances, like mercury, sodium, and metal halides, which are vaporized during startup to become part of the gas mixture. In operation the gas is ionized, and free electrons, accelerated by the electric field in the tube, collide with gas atoms.
The history of gas-discharge lamps began in 1675 when French astronomer Jean-Felix Picard observed that the empty space in his mercury barometer glowed as the mercury jiggled while he was carrying the barometer. Investigators, including Francis Hauksbee, tried to determine the cause of the phenomenon. Hauksbee first demonstrated a gas-discharge lamp in 1705. He showed that an evacuated or partially evacuated glass globe, in which he placed a small amount of mercury, while charged by static electricity could produce a light bright enough to read by.
The father of the low-pressure gas discharge tube was German glassblower Heinrich Geissler, who beginning in 1857 constructed colorful artistic cold cathode tubes with different gases in them which glowed with many different colors, called Geissler tubes. It was found that inert gases like the noble gases neon, argon, krypton or xenon, as well as carbon dioxide worked well in tubes. This technology was commercialized by French engineer Georges Claude in 1910 and became neon lighting, used in neon signs.
So there you have it. Using not much more than a Baghdad Battery, copper wire and coils, a jar with metal foil inside and out, a wheel and ‘chopper’ switch, and a glass bowl with CO2 in it via a candle or such, and maybe a bit of salt on the electrodes, you, too, can invent very effective electric lighting with (your choice) 1600s A.D. or 2000’s B.C. technology.
Somehow I think they could have made it work. In the 1600s, we had not yet figured out how to make Roman Cement again, nor how to do many other things done by Romans, Greeks, and ancient Egyptians in prior eras… Who’s to say the light bulb was not one of them? I find it harder to believe that in 4000 years of playing around with metals, wires, salts, and such they NEVER made coils, made a Baghdad Battery as their neighbors did, never once made a switch in a wire, etc. etc. Besides Ramesses II was a Red Head and we know how those folks can be ;-)
Microscopic inspection of the roots of Ramesses II’s hair proved that the king’s hair was originally red, which suggests that he came from a family of redheads. This has more than just cosmetic significance: in ancient Egypt people with red hair were associated with the god Seth, the slayer of Osiris, and the name of Ramesses II’s father, Seti I, means “follower of Seth.”
So when your Dad was a follower of a God Slayer and you are “associated with the God Seth”, well, what’s a little thing like making electric lights…