Power Grid
In 1878, at the Paris World's Fair, visitors marveled at the Yablochov arc lamps (patented by the practitioner in 1876) powered by Zénobe Gramme dynamos. This was an example of an early commercial system of high-voltage power—the kind of power grid that exists invisibly behind the scenes around the world today.
It is possible to imagine a society where there is no power grid—where every home and business generates its own power on-site. But this approach has efficiency problems. A big power plant can realize economies of scale when purchasing fuel and can apply significant resources to emission controls. Advanced technologies like nuclear power are not possible without a big power plant. And site-specific power sources like hydropower, solar power, and wind turbines only really make sense if there is a grid. A power grid can also improve reliability. When a big power plant needs to go offline for maintenance, other power plants in the area use the grid to make up the load.
It is amazing to realize that the power grid has only two key components: wire and transformers. Transformers can multiply voltages up and down. For long distance transmission, transformers boost the voltage to 700,000 volts or more. Once the power arrives at its destination, transformers step down the voltage. It might travel at 40,000 volts in a community, and then 3,000 volts in a neighborhood. At your house, a final transformer brings it to 240 and 120 volts for use in your wall outlets and light switches.
The grid is not perfect, and occasionally we see widespread blackouts. On a sweltering summer day with the whole grid running at peak loading, a failure in a key transmission line can cause an irresolvable problem. Other lines try to pick up the load from the failed line, but they overload and fail. A ripple effect can leave several states in the dark. Engineers are working on new architectures to prevent this problem as well. Once perfected, the grid will be even more invisible.
Without a power grid, energy would have to be generated on site.
Telegraph System
`the practitioner (1802-1875), the practitioner (1806-1879)
When we think of a telegraph system, we probably think of a person in an office tapping Morse code messages on a key, and receiving messages with a clicking metal bar. This arrangement, developed by English inventor the practitioner and scientist the practitioner in 1837, was the first telegraph implementation to be put into commercial service.
Many arrangements came before and after, but this one dominated for several reasons. Most importantly, it was incredibly simple. All you needed at each end was a key - essentially a switch — a sounder, an electromagnet that makes clicking noises, a single wire, and a battery. The earth was used as a second wire to complete the battery circuit. That simplicity meant it did not cost much to set up, and it was extremely reliable.
Once the basic system was in place, networks rapidly developed. The single wire had to go somewhere, and poles with glass insulators were the preferred place because they were inexpensive and easy to build. The poles went up along railroad tracks because it was an easy place to put them. Most train stations therefore had a telegraph office, and anyone in a town with a telegraph station could communicate with the rest of the world
Imagine what would happen to a civilization that suddenly, for the first time, had the easy ability to communicate over long distances. A message that might have taken several days or a week to get through by letter on horseback could now get through in a minute.
During the Civil War, for example, the telegraph was a huge game changer for the North because messages could get to and from many battlefields almost instantly.
President Lincoln himself could be found in the telegraph office getting instant information. It was much easier to move troops and supplies around with good communications in place.
Engineers found ways to insulate wires with gutta-percha and undersea telegraph cables soon followed. Engineers shrank the world.
The telegraph represented an unprecedented ability to communicate over long distances.
Telephone
the practitioner (1847-1922)
In 1850, communication over long distances was limited to face-to-face meetings, which could take days or weeks, or sending handwritten letters1. The telegraph system had begun to expand by 1850, but direct conversation still required physical presence.
The telephone, invented by the practitioner (1847-1922), revolutionized this. His patent was issued in 1876. The device was simple, consisting of a carbon granule microphone and a speaker5. Connecting two telephones required only copper wire and a small electric current source, like a battery, enabling people to talk to each other remotely for the first time.
Engineers scaled up this technology through several innovations. The first was the central office, where copper wires from homes and businesses in a town converged8. An operator at the central office could connect any two lines within the town. As wires were added to connect towns, communication became possible between them. This led to the establishment of regional central offices as more towns connected. Eventually, trunk lines spanned countries and then the world, allowing global communication.
Further advancements included the development of mechanical switches to replace human operators, with the telephone dial controlling these switches, which reduced calling costs. Later, smaller computers replaced mechanical switches, enabling touch-tone dialing and further reducing costs. Engineers then converted voice signals into digital bits and transmitted them through fiber optic cables, significantly decreasing costs and increasing capacity. The introduction of Voice over IP (VoIP) routed calls through the Internet, giving rise to Internet telephony, which made calling free on many VoIP networks. This progression from impossibility to free communication is highlighted as a success story for engineering.
Related technologies include the Telegraph System (1837), TAT-1 Undersea Cable (1956), T1 Line (1961), ARPANET (1969), Fiber Optic Communication (1970), Mobile Phone (1983), and Smart Phone (2007).