Driving down the road yesterday they were repairing some electrical lines and I guess one of them sparked and it left a trail of blue sparks on the ground. But when I hook up a battery and short it with a wire sparks appear an orangish-yellow color.
Anyone know why?
In: Engineering
Electricity is actually invisible. When it arcs through the air, it ionises the gasses, and since the air is mostly nitrogen, and nitrogen ionises violet, lightning and sparks appear blue.
If the sparks were travelling through a different gas, they would be a different color.
The discharge also forms O3 (ozone) which is why people often claim to smell rain, as distant storms can create enough to be smelled at a distance. St. Elmo’s fire – Walter Lewin has a video on his MIT EM Physics channel. RIP you wonderful genius.
Electricity doesn’t have a color. Light is made of tiny particles called photons, while electricity is made of electrons. When you “see” electricity, you are seeing a side effect of electricity, not the electricity itself. When electricity moves in outer space, where there is nothing for it to interact with, it is invisible!
When you see sparks or lightning on earth, you are seeing ionized air created by electricity. Ionized oxygen and nitrogen glow a blueish color, and together oxygen and nitrogen make up about 99% of the atmosphere. If Earth’s atmosphere was made of a different gas, sparks and lightning would be a different color! For instance a planet with an atmosphere made mostly of Neon would have bright red lightning!
When you see red or yellow “sparks” caused by electricity (such as coming off an electric welder or the explosion of an electric transformer), you aren’t seeing electricity, but tiny pieces of metal heated up to red or yellow hot. Electricity heated these pieces up and caused them to break off and fly away, but the electricity is invisible. You can see similar sparks come from non-electrical causes such as a flint/steel fire lighter, or metal being ground with abrasives.
There is another type of electricity-to-light effect you see every day but might not notice: light bulbs! There are several types of electric lights. In none of them do you “see” electricity, only its side effects.
1. Old fashioned incandescent bulbs – these work by heating up a wire to be very very hot, so that it glows yellow white. There is a protective glass bulb around the wire filled with gas that prevents the wire from burning up.
2. Arc bulbs – these work almost like lightning! Electricity flows through a gas inside the bulb and ionizes the gas, creating light. Different gasses glow different colors. White fluorescent lamps are a special type of arc bulb. Another common type are the yellowish bulbs used in some street lamps, which are filled mostly with sodium gas, which glows yellow when ionized.
3. LED light bulbs are the newest type and are becoming more common. They use a special type of chip like in a computer that converts electrical energy to light energy. The electricity flows through the chip invisibly, the light is emitted by the chip due to complicated physics that are beyond ELI5.
Electricity has no colour. The plasma created by the electric field releases light when it reforms into normal atoms. The colour changes depending on the plasma too. If you do welding and hit a copper object e.g. wiring, you would see the arc to be greenish.
When atoms split into the nucleus and electrons they require a specific amount of energy and when recombined they shoot out the exact same energy in one single packet. So the colour depends solely on how much energy in that packet of light emitted. When light is higher energy the more blue it seems, and thats not even the limit. The light can be ultraviolet. Thats why if you weld without proper equipment, you get sunburns.
As discussed in several comments in this thread, this is due to ionization of the molecules (in particular, nitrogen) in the air whose emission spectra have peaks in the blue or violet.
In other gases, ionization leads to different colored emission – this video shows this perfectly using a Tesla coil.
[Gases near a Tesla Coil](https://www.reddit.com/r/blackmagicfuckery/comments/b0ozcn/gases_near_a_tesla_coil/?utm_source=share&utm_medium=ios_app&utm_name=iossmf)
The blue or purple is superheated air letting of photons because the air cant hold that much energy. The sparks are usually the ends of the wires melting off because of the arc. Superheats the end till it melts and increases in resistance and then they boil off and that’s the spark you see. It’s all happening extremely quickly though.
No, not quite.
Ionization of the air causes the blueish sparking. Orange, yellow or other sparks are from the metal conductors used.
Its the same sort of thing used in fireworks – certain chemicals and compounds give a particular flame.
Its really as straightforward as that.
When you add electrical energy to a gas, it gets excited. Basically the electrons jump up to another energy level. When they come down to their natural resting level, that energy has to go somewhere, so the electrons emit photons. This is known as fluorescence and it’s also how fluorescent lights work.
Depending on what has all that extra energy, you get different colors of light. Excited air (nitrogen, oxygen, etc.) just happens to fluoresce in that iconic electric blue.
What you experience as sparks from electricity in your case has 2 causes. First of all, the sparks that fly off and glow orange are actually burning metal. Not molten. Burning. When metal is sitting at rest, it has a thin oxidation layer. In steel and iron it’s a thin coating of rust. Other metals also have it. When you knock some of that metal off with a decent amount of energy (like enough to ignite it) it immediately reacts with oxygen and burns, glowing bright briefly. In the case of a high tension line transformer or a car battery, there’s a ton of amperage involved. Add enough amperage, and some of that metal is going to fly off from the sudden flow of energy.
Otherwise, the sparks you see from the wire as it arcs to the terminals of the battery are the same as lightning, but they have another component that changes the color of the arc. Some of the wire is actually shooting off the end, over the arc, and onto the terminal. It’s also how arc welding works. The presence of the metal actually changes the composition, and thus the color of the arc.
The electricity itself isn’t blue, per se. It’s the ionization of Nitrogen in the air that makes it look that way. When you burn metals or create a spark, you aren’t ionizing Nitrogen in the air, instead you are burning the material that caused the spark, which is going to burn a different color.
That’s about as ELI5 as I could get lol.
The reason “electricity” is blue is because it ionises the nitrogen in the air, and when the atoms go back to a lower energy state, they shoot photons out.
The reason sparks are orange is because they’re not electricity, they’re just superheated bits of metal.
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