I just read an amusing article that was written by a fundamentalist thinker. He claimed that he could prove that there is no life except on Earth, and just in case nobody read it but me, his proof was Bible verses. He warned that it was evil to believe there was life except on Earth. He claimed it was mendacious (not the word he used - probably sinful) to tell people that there is life throughout the universe because it was being done to cause people to lose their faith.
Carl Sagan believed that it is nearly impossible for other intelligent life not to exist in the universe. Sagan was not saying that aliens had visited earth or that anyone has observed an alien. He was using the Drake equation or an exact method to reach a conclusion about the plausibility of life somewhere else in the Universe.
Carl Sagan solved a mystery about Venus long before any spacecraft went to Venus. The question was "why is Venus such a strong source of microwave radiation?" Sagan theorized that the greenhouse effect was why there was such a strong source of microwave radiation on Venus and life could not exist there, and at that time other scientists did not agree. Many years later the Pioneer Venus spacecraft verified Sagan's explanation as to why Venus was such a strong source of microwave radiation and could not sustain life. Sagan recognized that the study of other planets could provide vital clues for understanding the Earth. Sagan was already concerned in 1963 that increasing carbon dioxide in the Earth's atmosphere would lead to serious global warming.
Astrophysicist Dr. Frank Drake devised The Drake equation in 1960, in an attempt to estimate the number of extraterrestrial civilizations in our galaxy with which we might come in contact. The main purpose of the equation is to allow scientists to quantify the uncertainty of the factors, which determine the number of such extraterrestrial civilizations. The Drake equatio(sometimes called the "Green Bank equation", or the "Green Bank Formula") is a famous result in the fields of exobiology and the search for extraterrestrial
Carl Sagan lectured on the Drake equation, which is a way of estimating the number of technologically advanced civilizations in the galaxy. This presentation of the Drake equation, from the Cosmos series, is the best evidence for the possibility of alien life, and was based only upon the number of stars in our galaxy at that time. This was before the Hubble discovered that there are hundreds of billions of galaxies throughout the universe. The existence of these newly found galaxies pushes back the time when galaxies began to form to before 500-600 million years after the Big Bang. There are astronomers building a much more powerful James Webb Space Telescope (JWST); planned for launch in 2014, which will allow astronomers to study the detailed nature of primordial galaxies and discover many more even farther away.
Statistically, alien life is virtually a guaranteed proposition. The Drake equation incorporates several values, including the rate of star formation, the fraction of stars with planets around them, the fraction likely to have evolved intelligent life etc. The confounding value is L, which stands for the average lifetime of a technologically advanced civilization. If these civilizations are long-lived, then the equation predicts that there are millions of intelligent societies out there, and one might be just a few hundred light years away, which means that radio telescopes would be able to pick up signals from other advanced beings.
Life's basic building blocks comprise a group of chemicals known as nitrogenated aromatics. They form the very foundations of all life on Earth. Astrophysicists study the composition of the universe by analyzing spectra - the unique signatures of light either emitted directly by stars or reflected by non-luminous objects, such as moons, asteroids, comets, dust and gas. Using sensitive instruments called spectrometers; scientists can detect elements and compounds at great distances. Nitrogenated aromatics exist throughout the Milky Way galaxy. The chemistry that underlies life on Earth is abundant throughout the universe.
Carl Sagan's final book was The Demon-Haunted World: Science as a Candle in the Dark (1996), and it puts prayer in the same category as astrology, ESP, spiritualism, and superstition.
In 1986, Sagan briefed the Soviet Central Committee on the subject of nuclear winter. Some of those present later said that his effect was profound.
Gorbachev personally told Sagan that he had studied the nuclear winter research and it bolstered the case for deep cuts in the nuclear arsenals. Some Russian scientific colleagues credit Sagan with having a major influence on ending the cold war.
Carl Sagan said, "extraordinary claims require extraordinary evidence." He believed that the public's ignorance of science would lead to disaster and this is why he tried to inform the public (as much was possible) about science, and how to use critical thinking.
The current interest in space deals with fantasy, groundless science fiction, and horror stories about evil space aliens. When people look into space they do see a demon haunted world, and they wonder about myths and folklore. They don't use their imaginations to wonder about the true mystery of outer space and all of the planets. These kinds of programs have taken the place of programs like Carl Sagan's Cosmos. These programs are a senseless, pointless distraction away from the worthy use of man's imagination. With his series Cosmos Carl Sagan was trying to show the average person how science works, and inform them about the mysteries of space, and why space is so important. Everyone should see the series Cosmos because there really is nothing else like it; even the music is great. I bought the series on DVD, but you can watch it on YouTube.
I read an article a while back about what Buzz Aldrin, the second man on the Moon, thinks about America's place in the space contest. He warned that if America does not invest now in the space agency NASA, we will have to surrender leadership of space exploration to Russia and China.