Hello, SFIA audio listeners. In this month's Nebula exclusive, big alien theory,

we're asking the reason alien civilizations might be rare is because most aliens are huge.

To hear it and every episode early and ad-free, plus hours of bonus content,

check out go.nebola.tv slash Isaac Arthur and use my code, Isaac Arthur.

By 2050, most of the world's population will be living in cities, but not everyone will choose this lifestyle. So, how might those wishing to go

off the grid be able to do so, while enjoying the comforts of modern technology.

In 1878, Thomas Edison installed a private electric system in his residence,

and by the end of the century, the DC versus AC, direct current versus alternating current, debate was resolved,

and residential electricity began to appear. About 5% of U.S. homes had electricity

by 1900, and by the 1920s, most homes were connected. In 1936, the Rural Electrification Act

aimed to make it universal, though near-universal electrification was not achieved until 1960.

Getting power to rural homes was challenging, but using the same pulse for power and telephone

lines helped a lot, as cell towers weren't even on the radar then.

In fact, radar itself wasn't invented until 1935.

Before phones, alternatives would have required large radio towers and either brought in electricity or an on-site generator.

Generators at the time were costly in terms of purchase, maintenance, and expertise.

Many rural homes had them, but they weren't practical for every household, compared

to connecting to a standard 60-am-2-30-volt fuse panel, typical for rural homes and barns.

The advantage of an on-site generator is reduced transmission loss, whereas rural homes

lose significant energy running down miles of wire. Central power generation,

however, requires little user skill or maintenance beyond occasional visits from electrician

to install or maintain it. A single large generator is generally more cost-effective than numerous

...