What are 10 things that have had the most positive impact on humanity?

Humans are the first species that can "outsource" mass destruction. We were able to do this with fire. With one stick we can set a whole forest on fire. And yet fire creates warmth and cooks our food. Fire allows us to outsource our digestion.

Without air conditioning, cities would not exist. We would not need concentrated urban areas to work because there would be no skyskrapers. It would be too hot at the top of a tall building. 200 years ago we had cities but we didn't really have a lot of population so these "vertical cities" were not necessary.

Igor Semmelweiss was trying to figure out why many women at the hospital he worked at in the mid 1800s were dying shortly after childbirth.

Finally he figured it out. The doctors were killing them. The same doctors that worked in the morgue were then delivering the babies. They didn't wash their hands because they didn't know that humans carry germs. They didn't know germs existed.

Semmelweiss figured it out but because he was basically accusing his fellow doctors of murder they called him crazy. I think he died in obscurity.

Money allows us to specialize. One person can specialize in making shoes. Another can specialize in making books. And everything is exchangeable for money. Direct barter would be too complicated because you would have to figure out the exchange rate between every item / service and every other item and service.

Pre-farming, humans could get fruits and meat and vegetables. Most of farming has to do with the cultivation of wheat. For all the "no carbs" people out there, farming has turned out to be a disaster.

Yes, I have to incude it. For the first time in history, we can outsource all facts, information, and memories. This seems horrible at first but it allows our brains to run free and be more creative than ever. Since the development of the Web, think of all the industries that have started to blossom from nothing: genomics, alternative energy, automation, AI, etc. The pace of information is increasing very fast because we no longer have to remember where the shoulders of the greats are that we are now climbing on. Those shoulders are stored in Google.

Around the time of the Babylonian Empire, you'd have to do 60 hours of labor to afford just 88 minutes of light (via oil burning lanterns).

In the Roman Empire, 60 hours of labor would get you 10 hours of light (with the invention of the candle).

In the 1800s, 60 hours of labor would get you 16 hours of gas burning light.

1888, Thomas Edison's incadescent light bulbs: 60 hours of labor would allow you to afford an amazing 72 hours of light.

1950, with the invention of fluroescent lights, 60 hours of labor would allow you buy 28,723 hours of light.

By 1994, the compact fluorescent light was made. 60 hour of labor would get you 51 years of light.

"So the darkness shall be the light," as T.S. Eliot wrote, "and the stillness the dancing."

Up until the mid 1850s, soldiers getting surgery in the battlefield (or getting a tooth pulled) had to use a combination of alcohol, biting a bullet, and screaming to survive surger.

On October 16, 1846, a dentist from Boston named William Morton used sulfuric ether to knock a patient out for the first time while performing a dental procedure. This was the beginning of anaesthesia.

After water, oil is the second most plentiful liquid on Earth.

Here are some of the products we can make because of oil. Can you survive without these?

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Almost too obvious. But the mass printing of books (instead of monks painstakingly etching out each page over and over again) created the Rennaissance and all that followed.