Power lines are transmission lines.
A transmission line is a conductor capable of transmitting energy from one point to another. Some examples of transmission lines include power lines, cabling, and coaxial cable. Depending on the project, there are a number of characteristics that a transmission line must have in order to function effectively. For large-scale products and systems, special products may need to be designed and engineered to meet the specific need.
Various types of energy can be transmitted through a transmission line. Electrical energy is an example familiar to many people, but these lines can also carry acoustic energy and electromagnetic energy, which can include light. Transmission lines can be designed to carry large or small quantities and can operate in a variety of conditions, including extreme temperatures and pressures, along with wet environments. Lines are typically rated to indicate what type of power they can transmit and at what volume, and people select transmission lines that are rated well above their intended use to increase safety.
Power transmission inevitably results in some loss along the way. The longer the transmission line, the more serious the problem. Companies that design and manufacture transmission lines must take this into account in the development of their products and manufacture products with measures aimed at minimizing losses. Interference can also be a problem, and adequate isolation is essential so that interference does not cause problems along the line or at either end.
Some transmission lines are quite large, especially when they are designed to carry large volumes of energy. The size is due in part to the wiring within the line and also to the insulation required for safety and efficiency. For lines designed to be used outdoors, the insulation may include a thick layer of material designed to prevent penetration of the line if struck.
The science behind transmission lines dates back to the 1800s, when various researchers began experimenting with the idea of transmitting power through a conductor. This laid the foundation for the development of things like electricity. Some researchers have argued that the development of affordable electricity was one of the most important events in human history, revolutionizing the approach to everything from the workday to life at home. The role of the transmission line in this was quite critical, as without conductors to move it, electricity is not very useful to humans.