We’re rewarding the question askers & reputations are being recalculated! Read more.
51

The practice in the first half of the 20th century was to wrap wire in cotton cloth, resulting in something like a shoelace from https://www.vycombe-arts.co.uk/onlineshop/prod_3699705-Double-Cotton-Covered-Copper-Wire-Reels.html Alternately, pass your wire through wood resin, which will leave a fine insulating layer over your wire, good enough for low ...


41

The bullet will not go far It depends somewhat on the cross-section of the antimatter bullet. Let's assume that the bullet is slightly under 10mm in diameter, giving it a cross-section of 0.0000762 square metres. Passing through 1000m of air it will encounter head-on 0.0762 cubic metres of air, which conveniently is 3 moles. The molar mass of dry air is ...


36

Beeswax Expensive mind you, anything food related is, and you're cutting into the candle supplies of the wealthy, but beeswax is a good insulator, easy to work, and available in almost any historical period. Not suited for high temperature use. Cloth Also available in almost any period, though harder to work with for these purposes most cloths are ...


32

I have done this. I have an interest in old technology and I recreate crystal radios, telegraphs and mechanical television. When winding the solenoid you can seperate the windings by winding thread of similar diameter alternately with the wire (I used waxed sailmakers' thread). Once you get to the end of the coil former wrap a layer of paper (I used wax ...


18

There's actually a (beyond minuscule) loss of mass when fuel is burned. Your figures aren't much off for gasoline -- the extra mass comes from oxygen in the air. To oversimplify, let's assume gasoline is pure octane, C8H18 (molecular weight 114). To fully combust, it'll need 25 oxygen atoms (two for each carbon, and one for each pair of hydrogen), ...


16

Make the antimatter charged and use a magnetic bottle to keep it contained. It will reach its target without touching matter. On impact, the magnetic bottle mechanism breaks and the antimatter escapes. The bullet may be a little bulky, but some hand waving miniturizations should get it small enough to fire out of a weapon. Depending on the size, you may ...


15

You have copper wire. You need a thin insulating layer so that one winding does not contact the adjacent winding. This is easy. Assuming you can produce the copper wire, you need to oxidize it in an acid solution. This will produce a green oxide layer which is insulating. Wind the green corroded wire with no overlap on each layer. Put a layer of silk ...


14

Lacquer is an alternative. It comes in many thicknesses. It's not too expensive. It can be painted on then heat cured. There are many different types that can stand up to a variety of challenges such as wear, heat, cold, even limited bending.


12

Enamel Thin copper wires--like those used in inductors, transformers, motors, etc.--are enamelled. This is known in the modern world as magnet wire. Surely, you would prefer enamelled wire for your solenoid bobbin. We know that enamelled objects existed as early as the 13th century BCE. A concise history of enamel.


12

Let's say the bullet is a standard .308 Winchester round with a diameter of 7.85mm which means the bullet is encountering: $\pi * 3.925^2 * 1000 = 48,400$ cubic mm of air. The density of air at 20 degrees C is $1.2 KG / m^3$ which means the bullet is encountering around $0.058$ grams of air per meter of its flight path. Via $E=MC^2$, a total of 0.116 ...


8

The bullet will only work as intended if flying through high vacuum. In atmosphere, it would be necessary to evacuate its path, or at least a portion of its path directly in front of the bullet. Surprisingly, this might be possible: If an intense laser is fired in the bullet's path, it will heat and ionize the air; this alone will make it less dense, and ...


6

Think Trees Gutta Percha , Latex , and Amber are reasonable insulators. Wrap the wires in various tree saps, and dry the covering over fire. Don't dry all the way, nor burn it, or it becomes inflexible. When working on the electronics, use dry clean wooden tools to avoid sparks and conduction.


6

Take assorted hydrocarbons from the gasoline. As the name suggests, they consist mostly of carbon and hydrogen, and by weight they are mostly carbon. Burn it, and one $C$ (carbon) atom bonds with two $O$ (oxygen) atoms from the air, forming $CO_2$. Each $O$ atom is about 1.33 times the weight of a $C$ atom, which means each $CO_2$ is only 27% carbon by ...


5

Paper? Paper may not have been invented (or be readily available) yet, but it can be made with available tools and materials. Paper is used as an insulator in our time, so could work for you too - it's a good insulator and it provides physical separation. It does require you keep it dry though - but you could coat your work in wax when finished if moisture ...


5

This article might be of interest. It turns out energy expenditure is as much a factor of air temperature as anything else. Figure three seems to be pertinent to your question. As it becomes a matter of simple mathematics to convert from their units to yours, I leave that to you!


4

Your villain is just going to commit a very elaborate and probably expensive suicide, and his target will be dead as a collateral effect. A magnetic field is effective at keeping away only moving charges. Most of the matter we have at sea level is in neutral state, including air, hands of whoever is loading that gun, the gun itself and the building where ...


4

Not mentioned yet, but leather is also a good insulator. So there are plenty of options, most likely you'd want a combination of them for optimal effect of course, and to reduce the mess (resin gets sticky, so wrap the resin coated cable in cloth and wrap that in leather because the cloth is vulnerable to mechanical damage for example).


4

Let's start the estimation with the drag: $$ F_D = \frac{1}{2}\rho v^2 C_D A $$ Where $C_D A$ is going to be your form factor, depends on your drone design. Here are some example $C_D$ values $\rho$ is the air density. Here are some values, depending on temperature. If you increase the pressure to say 2x, the density also increases 2x. v is the velocity If ...


3

Mentioned before leather. Intestines (small-large) best leather for a wire coating. Already a tube just pull it tight and let it dry. Smaller animals smaller tube.


3

Pitch and cloth or paper. the first widely used insulated wire was insulated with asphalt (pitch) soaked cloth. both materials are available in a medieval setting. pitch is widely used by shipbuilders and a dozen other trades and cloth is a bit expensive but not prohibitively so especially for how little you need. Cotton cloth is expensive but nearly and ...


3

With the large amount of CO2 generated by the burning gas, there could be a multitude of uses. 1.A) Terraforming, specifically on planets with little/no atmosphere, could use the quick greenhouse gases(though not practical) 1.B) The military could use it to gas-out areas that are crucial to capture or to kill/capture the opposing forces.


2

Wax boil/VPI that solenoid Suppose you have a V volt solenoid with N coil windings laid out in L layers. In solenoid windings, you only have very low voltage between adjacent windings - just V/N. Thus, a simple varnish will suffice for wires in one layer. Between each layer, you have 2*V/L voltage, and you can use wax-impregnated cloth between the ...


2

In addition to the great answers so far, wax in general is usually an insulator, so a nearby candle or rendered animal fat might do the trick. If you don't want to kill an animal, or can't find a candle, then you can use wool. Really any type of fur or silk would do, but wool is a decent insulator, and would almost certainly be available in medieval Europe....


2

If the beam is supposed to be ionising radiation (gamma / neutrons) you could have a critical mass of your chosen element contained in a strong and heatproof container (probably ceramic rather than starlite as it needs strength) configured like a sphere but with a channel for a control rod down the middle. With the control rod inserted the beam is off; with ...


2

Firstly, you would need to define 'circulation cells'. If you're talking about, say, low pressure surface systems, these are considered 'synoptic scale', and tend to be on the order of 1000km+ of horizontal distance. These surface lows circle Antarctica, for instance, riding the upper atmospheric river of air known as the jet stream. As wind exits troughs ...


2

I think you could use grape juice thickened with flour. Both materials should be available in a medieval context (and long before that). It dries to a rubbery texture and you could run the wire through a trough of it a few times to ensure full coverage. To get an idea of the finished appearance, consider Georgian Churchkhela. You would want it thinner, of ...


2

Dredging through long-ago memories of my time in a laser lab... One critical reason for pulsed beams for cutting or weaponry lasers is to allow literal physical detritus to exit the beampath - there's a nontrivial outpuffing of small particles, splinters and fragments, and vapour of the target material at the beam impact point as the surface reaches a boil-...


2

If you remember televisions before they were flat, those had electron beams which created your picture. The secret to making the beam hit an extremely precise target on the screen was by shooting the beam in a vacuum. In any atmosphere, you won’t get a charged particle to go anywhere you want it to. It’s going to find it’s way to the nearest oppositely ...


2

For a star of that mass, you are looking at a G0V to F9V main sequence star. It's luminosity, depending on age, is probably around 1.2 sol, from which you can calculate the bounds of the habitable zone. The inner edge of the zone is around 1.04 AU. The comfortable outer limit is around 1.5 AU. The maximum outer limit is around 1.86 AU. Your planet's moon,...


2

Since you want your world to be a habitable giant moon of a gas giant planet in another star system, an exomoon, you should look up some of the many previous questions about moons of gas giant planets on this site. for example, the most recent such question that I answered was this one: If Earth Were a Gas Giant's Moon1 And you should look up this ...


Only top voted, non community-wiki answers of a minimum length are eligible