Electricity is the transfer of energy through the movement of charged particles. The term was coined in 1600 from the Greek word for amber—elektron—which had been observed to produce static electricity when rubbed against certain substances as early as 600 BCE. Through the 19th century, scientists formulated a unified theory of electromagnetism, enabling humanity to understand, generate, and harness electrical power.
> Simulate the buildup and discharge of static electricity with "John Travoltage." (More)
> Watch a timeline of the history of electricity up until Edison and Tesla's War of the Currents. (More)
Just as fluids move due to a difference in pressure, the flow of charged particles—electric current—is driven by a difference in electric potential between two locations. This electric potential difference, or voltage, can be created through various methods, such as chemical reactions (as in batteries), shifting electrons (as in photovoltaic cells), or a changing magnetic field (as in generators).
> Marie Curie's husband and brother-in-law discovered you can generate electricity by striking crystals. (More)
> How do animals like the electric eel generate electricity? (More)
Once a voltage is established in a circuit, electrons move through a conducting pathway at less than one millimeter per second. However, this movement shifts the electrons' electric fields, producing magnetic fields. The resulting electromagnetic fields, which compose light, transmit energy outside the pathway to devices at near-light speed.
> The speed of electrons through a conductor is called the drift velocity. (More)
> Within a circular superconductor, electrons can travel unimpeded indefinitely. (More)
Electricity is delivered by currents that move in one direction (direct current) or that change direction periodically (alternating current), with both systems relying on circuit components to manage current and voltage.
> Watch a visualization of how rotating magnets generate alternating current. (More)
> ... and how transformers change the current and voltage across wires. (More)
Discover more:
> On average, the human body produces 100 watts of electricity, but it can produce up to 2,000 watts in short bursts. (More)
> Thunder is the result of electricity heating and pressurizing air into producing shock waves. (More)
> When a person dies of electrocution, what killed them: current or voltage? (More)
Keep learning by exploring all our findings on Electricity here.
