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

[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.

[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?

[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]

@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.

[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.

[SaganAppreciationSoc]

Liked and favorited.

[twocementshoes]

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