Alternating current and the electric motor propelled by magnets! Fascinating!

Bell Telephone but so sad now, people are switching to cell phone use

Indoor plumbing with hot water on demand! IMHO.

It's interesting to think about a time when such-and-such a technology didn't exist, and how different people's lives were then. *** Consider cities 2000 years ago. Even Roman cities, which had sewers and aqueducts, generally did not have INDOOR plumbing...and no room for outhouses in cities, where property values were at a premium (and this continued in most cities for most of the next 2,000 years). Chamber pots were the standard of the day, and one you used the pot you dumped it out the window (which, BTW, was covered only by a shutter - no glass, no wire screen). Imagine anywhere from tens of thousands to millions of people in a city doing this several times a day. If you were wealthy enough, you had a chamber maid to deal with chamber pots. In some cities during the last 2,000 years there were laws requiring the pot-tosser to shout a warning before tossing the contents of a chamber pot out the window...but either way, out the window it went. Then remember that practically all transportation in the city was animal-powered...and animals "go" wherever and whenever they want to go. Streets - both near homes and in center - were inundated with urine and manure throughout the day. In some cities, street sweepers would remove this - some, only at night, others, working throughout the day - but still, the streets were inundated with this stuff. Sewers made it easier for the street cleaners...but the streets still needed cleaning. City residents - nearly all of them on foot - went about their business along these same streets. *** Ever wonder why cultures so different as classical Japan and the New Testament period Roman Empire both considered it de rigueur to wash a visitor's feet on entry to a home? And why the upper class considered such a duty to be menial or demeaning? Now you know. *** Consider further the state of the Orkney island people until a very few hundred years ago. Some of the islands were much too small to offer wood or peat for heating in the extremely cold Winters, and they typically lived in one-room hovels...with their farm animals. Once Winter began in earnest, the entire family - with animals - would be shut up inside the home. The inevitable manure was spread out on the floor every day. By the time Spring came the floor was several feet higher than previously. The heat of the decomposing manure is what heated the homes during Winter. One well-meaning Scottish Lord (I believe in the early 1600s, but I might be wrong about the date, it might have been much later), cut to the heart by the squalid conditions in which they lived, ordered their homes razed and new, more modern wooden homes established in their place, free of charge. The next Winter people died in droves. They (of practical necessity) went back to the traditional method for the next several centuries, until finally these tiniest islands were abandoned as the young found jobs in the cities during the Industrial Revolution. *** Of course, 90% or more of the people were farmers in those days, and so outhouses or something of the sort (in the West) or private gardens (in the Orient) were used as places to "do one's business". No wonder the English poets of the pre-indoor-plumbing period idolized life in "the country"!

The light bulb invented by Thomas Edison. He was very bright. Every house needs a light bulb.