What about the wheel, the internal combustion engine, and the plough?
First gut answer is electricity. The industrial revolution is in my mind the great shift from agrarian society to what we start to know of as society today.
After reading the thread I’m waffling toward ag. tech. of domesticated animals.
The lawn mower might be a candidate.
I think whatever it is has to enable concurrent tasks. If I can set some machine to do something, then walk away and not pay attention to it while doing something else, I’ve effectively reduced the work I’m doing on the task to zero.
So while a tractor may save a lot of time, some hypothetical Google Auto-Tractor would save tons of time in aggregate because you can go milk the cows while you’re tilling the field.
I gave it time, but still missed:
The agricultural revolution spawned many - we got thresher and horse collar.
Missed the biggie which tore the USA apart: Cotton Gin.
Getting the fibers out of a ball of cotton is a trick - before the gin (meaning: engine), the process involved two paddles with wire surfaces (thing toothbrush bristles) - combing the cotton. ! slave could produce about 1 lb a day - hardly cost-effective.
The gin could go through tons - now you needed lots of cotton GROWN - a labor-intensive, nasty business. Perfect use for a slave.
Birth control.
Think of every married couple having to feed, clothe, and manage 12 to 18 children. Couple that with vaccines and antibiotics, and now the family isn’t requiring multiple rounds of major home nursing each year. Times are good.
In the last century, Containerization, packing of cargo into standard-sized containers that can go seamlessly from truck to ship to railroad.
There used to be thousands of people in every city solely dedicated to unloading crates from trucks and putting them on ships, or unloading crates from ships and putting them on trucks, or unloading crates from railroads, etc.
Or the lever, the inclined plane, the screw, the pulley or the wedge?
I think the OP and a few others just missed the right answer: engines of all types, from steam through IC. These compact, tireless, harnessable power modules lie behind nearly every other candidate suggested - candidates that would be impossible or have had nowhere near the impact without a self-powered engine to drive them.
Are you suggesting that all families were a dozen before 1900 or so? i suggest the data shows otherwise. Even at the turn of the last century, a family of 8-10-11 was nationally noteworthy.
Women have always been able to limit the number of children they had, at least to some degree. The only thing birth control brought was the ability to enjoy sex more or less separately from procreation.
Technically, wedges, inclined planes, screws, and the other simple machines do not reduce work. They simply allow a smaller force over a longer distance.
Perfect! And it freed up the mind to solve many other problems.
I think, with no data to back it up, that it was probably the steel plough. Surely the OP’s suggestion of a sewing machine must be a long way down the list.
Isn’t that the very definition of less work?
Some really interesting replies. Electricity, engines, birth control–all of these affect a huge variety of jobs.
But they don’t feel right. So I think I want to emphasize something in the OP: we’re looking for something that facilitates a major activity.
Electricity facilitates a tremendous variety of activities, and in aggregate it reduces time spent in some (while increasing time spent in a lot of others). Same thing with birth control.
But what’s enabled us to reduce our time on one major activity the most?
So far, I’m most convinced by something like nitrogen fertilizer. The activity it decreased, presumably, is time spent growing food, to the extent that a person spends on average very little time engaged in this activity compared to someone 500 or even 100 years ago.
Indoor plumbing. When I was a kid, my grandmother used to tell me about how it was, back in the “old country.” Shlepping water from a well or stream for drinking and cooking and bathing and laundry, having to go to an outhouse in all kinds of weather.
Ooh, good one!
If electricity is disqualified for facilitating too many activities instead of just one, why should indoor plumbing not suffer the same fate?
Because even if you focus on just one activity–porting water–it suffices.
No Eli Whitney love? Wasn’t ginning cotton a bitch before Eli? Whatever ginning is, that is.