For thousands of years humans looked up at the night sky and wondered are we alone

For the longest time it remained nothing more than a philosophical question, but in the 20th century some

researchers thought it was time to finally start looking. One of the big questions was how do you look for something that you don't know exist and if it does you don't know where it is.

Learn more about SETI, the search for extraterrestrial intelligence on this episode of

everything everywhere daily. The idea that there might be other intelligent life forms in the universe is actually a pretty old one.

We have writings from philosophers going back at least 2,000 years who have pondered the idea.

The Greek thinker Democritus in the late 5th century

B.C. pondered the idea of a plurality of worlds.

St Augustine referenced Epicureus in his idea that there may be many worlds,

quote, throughout the boundless immensity of space.

The Islamic scholar Muhammad al-Bakir wrote in the early 8th century, quote,

maybe you see that God created only this single world and that God did not create humans beside you?

Well, I swear by God that God created thousands and thousands of worlds and thousands

and thousands of humankind."

When the telescope was invented it allowed astronomers to see humankind."

When the telescope was invented, it allowed astronomers to see some of the worlds beyond our own, and

it only added credibility to the idea that there might be someone else out there.

Many noted intellectuals of the time considered if not

advocated the idea of worlds beyond our own including Johannes Kepler, Benjamin

Franklin, Jean Locke, and William Herschel. In the 19th century the French astronomer Camille Flammitt in the

French astronomer Camille Flamarian wrote a popular book titled

The Plorality of Habitable Worlds.

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