Is There Intelligent Life on Earth? - Carl Sagan on Environmentalism

Carl Sagan ponders what theoretical planet observers might think while orbiting and watching the Earth.

This excerpt was taken from 'Chapter 5: Is There Intelligent Life on Earth?' from the audiobook "Pale Blue Dot: A Vision of the Human Future in Space", written in 1994.

Carl was able to narrate some of the audio book before passing away, but unfortunately not all of it. Luckily, some of the most moving passages (namely "You are Here") were near the beginning of the book.

Category:

Education

Tags:

• carl sagan the pale blue dot
• planetary observers
• global warming
• environmentalism
• holocene extinction
• deforestation

[StephennAlbert]

@hydrolito Yeah, maybe for the causes of fires - but changes in the chemical composition of the atmosphere can actually be measured spectroscopically, since different substances absorb and emit very unique and specific wavelengths of radiation. This can be done over astronomical distances, which is why we know so much about the chemistry of the universe.

[hydrolito]

@StephennAlbert Obviously in deep space it's likely radiowaves would be notice first, so would have to get closer to observe fires and there causes, and ozone layer and if and why it was depleted or not and some of the stuff he was talking about. So by then might also observe sound of whales, dams of beavers, etc.

[hydrolito]

In his speech he talks about beings who would observe the earth and know about fires, etc. Fires are caused by lightning not always by people. Ozone layer is affected by volcanoes again not necesarily humans. If they were observing from far in space they wouldn't necesarily assume these things were caused by man. So he's pushing his conclusions.Think he's suggesting man isn't so intelligent which again could be his conclusion.

[StephennAlbert]

@hydrolito Because these manifestations of intelligence that you speak of are not detectable from space. Remember that this thought experiment involves observing Earth from orbit, so beehives, underground tunnels and even sonic communication are undetectable. Humans are the exception because we produce complex radio signals which leak out into space, providing a clear demonstration of "intelligence".

[hydrolito]

First of all humans aren't the only intelliegent life on earth, ants know how to build underground tunnels, bees complex hives, and gather nectar from flowers (so people copied getting sap from trees?)spiders build webs (lines (bungly cords?)and nets (Before fishermen?) and adhesives (Before Elmer), wasps nests lead to the invention of paper, Beavers build dams, etc. Whales and dolphins use sound to communicate long distances. So why would they only notice people?

[twocementshoes]

@SaganAppreciationSoc thank you sir (or ma'am). checking your page as we speak.

[SaganAppreciationSoc]

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