WARNING: DO NOT TRY THIS AT HOME. We are dealing with live wires and 120 volts of electricity which can cause fire and/or injuries.
Have you ever wanted to electrify something just to see what would happen? Running electricity of a high voltage through a pickle is definitely dangerous, but also tons of fun! But how is the circuit completed, and why does the pickle glow?
There are two basic types of electricity, static and dynamic. Static electricity is simply a buildup of electrons on a surface whereas dynamic electricity is a steady flow of electrons. Dynamic electricity is what powers things like our home electronics and appliances. There is about 120 volts that can come out of a wall socket, which is exactly what we used to power this experiment.
In order for this experiment to work, we need to be able to complete the circuit. Luckily, pickles are great conductors of electricity due to their high salt content, meaning that electricity can easily flow through them. The salt found in pickles is sodium chloride, NaCl. Electricity at 120 volts is powerful enough to split the NaCl apart into Na+ and Cl-. It then strips the extra electron from the sodium atom producing a photon of yellow-orange light, which is the glow that you see!
If you connect multiple pickles together by a conductive material such as a nail, you will still be able to see the glowing effect. In fact, it is possible to make a long chain of glowing pickles in this manner. However, the more you link the more energy it takes to make it through the circuit and therefore the dimmer the glow will be. How many pickles do you think it would take to no longer see the light?
During a thunderstorm, lightning often appears to flash instantaneously from cloud to ground, but there’s much more going on than meets the eye! Friction between air currents causes a buildup of negative charge in the lower parts of the clouds. Like charges repel each other, so the excess negatives begin developing an escape route. Strong, invisible electric “feelers”, called stepped leaders, branch downwards through the air.
Lightning over Norman, Oklahoma, 1978. Image credit: C. Clark, NOAA
As stepped leaders inch closer to Earth’s surface, they leave a conducting path in their wake. Their electromagnetic field also begins affecting electrical phenomena on the ground. Positive streamers of charge reach up towards the negative stepped leaders. When streamers and stepped leaders meet, an ionized bridge is completed from clouds to ground.
Given an unbroken conducting path to follow, the negative charges built up along the stepped leader flow rapidly into the ground. The lowest charges are the first to dissipate, clearing the way for charges higher up to follow downwards along the same channel. This upward propagation of charge movement emits visible light, as shown in the NOAA gif at left. Stepped leaders emit light, too, but very faintly. Since the whole process happens incredibly quickly, our view is dominated by the brighter return stroke.
Ever been told not to go swimming in a thunderstorm? That’s because water is a great conductor! If lightning struck the water you were swimming in, a massive shock would be efficiently transferred to your body. In this video, the Oudin coil generates a buildup of negative charge (concentrated on the metal tip of the device). When we bring the excess charge near water, artificial lightning arcs both to and through the puddles!
An atom consists of three types of building blocks: protons, neutrons, and electrons. Protons and neutrons stick together in the center, or nucleus, of the atom, while electrons whiz around the outside at breakneck speed. The parts of an atom are incredibly tiny and surprisingly spread out. Let’s consider the simplest element of them all: hydrogen. Its atom contains just one proton and one electron. If the proton were two football fields across, the electron’s orbit would be about the size of the earth! Between the central proton and the faraway, speeding electron? A whole lot of empty space.
Protons are defined as having positive charge and electrons as having negative charge. Neutrons are– you guessed it– neutral. It’s a law of nature that like charges repel each other and opposites attract. Put a lot of negatively charged electrons in one place, and if they’re free to move, they’ll spread out as much as possible. Getting a lot of negatively charged particles in one place and giving them the ability to move is one common way to generate electrical power. Batteries create a surplus of electrons via a chemical reaction.
Large-scale generators get electrons moving using a different trick: electromagnetic induction. Moving magnetic fields spur charged particles into motion, creating electrical activity in wire coils.
Whether the source is a battery or a generator, moving electrons don’t provide useful energy unless they have the right path to follow: a closed loop through a device to be powered, such as a light bulb or motor. This path is called a circuit. Light switches, power buttons, and outlets all provide different ways of closing a circuit so that electrons can flow.
The simplest circuit is a single loop, but in practice, it’s useful to be able to power several devices with just one source. Consider a string of lights. There are two ways to light them all at once: by linking everything together in one long chain, or by connecting the power source across each output element independently. We call the single chain approach a series circuit and the independent connection strategy a parallel circuit. Each method comes with tradeoffs in voltage and current. As you can see in the video, this affects the brightness of our two test bulbs!
These light bulbs are connected in parallel. The voltage through each one is equal to the whole voltage of the attached battery.
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