Is there Intelligent Life Out There?
Is there Intelligent Life out there?
Does intelligent life exist beyond Earth? Everybody believes they know what intelligence is. Everybody says if I see it I will know it. But how do you define intelligence?
Only humans have the ability to change the planet Earth.
Other animals have to adjust to the environment. This is what many scientists use as a way to classify intelligence.
A recently published study in the Proceedings of the National Academy of Sciences of the United States of America indicates that the essential building blocks for early life on Earth may have indeed been delivered through extraterrestrial material such as meteorites.
These molecules, known as nucleobases, are key components of DNA and have been found in meteorites several times before. However, until now, scientists could never be certain that these compounds were native to the meteorites or if they were simply contamination from the terrestrial environment in which they landed.
To this end, researchers analyzed eleven different organic-rich meteorites, called carbonaceous chondrites, for the presence of nucleobases and found that three of these molecules are very rare on Earth. Additionally, none of these nucleobases were found in the soil or ice in close proximity to where the meteorites were found.
This led the researchers to conclude that it was likely that these molecules were extraterrestrial in origin which could mean that life on Earth may have originally been seeded by such material. The possibility of finding intelligent life is most likely much lower than the possibility of finding microbial life. The SETI program is one of the best ways to search for intelligent life.
Hawking has indicated that he is almost certain that alien life exists in other parts of the universe and uses a mathematical basis for his assumptions.
"To my mathematical brain, the numbers alone make thinking about aliens perfectly rational.
The real challenge is to work out what aliens might actually be like."
He believes alien life not only certainly exists in planets but perhaps even in other places, like within stars or even floating in outer space.
He also warns that a few of these species might be intelligent and threaten Earth.
What If We Do Make Contact With Aliens?
Contact with an Alien Species
After three years working on a new television series for the Discovery Channel, Stephen Hawking concludes that aliens are "almost certain to exist" and could even be dangerous.
Hawking says that it is rational to assume that intelligent life exists somewhere in the universe, and mathematically unlikely that life is unique to the Earth, given the existence of a hundred billion galaxies, each of them containing hundreds of millions of stars.
Hawking imagines nomadic aliens, having exhausted their home's resources, could attempt to take control of other planets, invading with "massive ships", and draws a comparison with Christopher Columbus discovering America, resulting in similar devastating consequences. With this in mind he advises "intelligent life might develop into something we wouldn't want to meet."
However, he believes that the most likely forms of life would be microbes or simple animals on planets, in the center of stars or drifting through space. His declaration comes in the month of the 20th anniversary of the Hubble Space Telescope's launch into space.
The Drake equation, created in the 1960s, estimates the probability of extraterrestrial civilizations; feeding in modern research gives a high likelihood. The contradiction between this and actual discovery is known as the Fermi paradox. Sir Martin Rees, the Astronomer Royal, supports efforts to search for transmissions that might be artificial in origin.
"Even if we couldn't make much sense of it, we'd have learnt that 'intelligence' wasn't unique to the hardware inside human skulls, and had emerged elsewhere," he said. Into the Universe with Stephen Hawking will begin on May 9 on the Discovery Channel. Stephen Hawking, 68, retired as Lucasian Professor of Mathematics at the University of Cambridge in 2009.
Known for his research into cosmology, quantum gravity and black holes, he became a household name following the publication of his 1988 book A Brief History of Time, which remained on the Sunday Times bestseller list for a record-breaking 237 weeks.
National Geographic Channel: Alien Contact
Michio Kaku is an American theoretical physicist specializing in string field theory, and a futurist.
believe we are on the verge of contacting alien life-forms. Join the
search for extraterrestrials and hear from those convinced that life
exists beyond our planet.
He is a popularizer of science, host of two radio programs and a best-selling author. In 2005 Kaku appeared in the short documentary Obsessed & Scientific.
The film is about the possibility of time travel and the people who dream about it. It screened at the Montreal World Film Festival and a feature film expansion is in development talks.
Kaku also appeared in the ABC documentary UFOs: Seeing Is Believing, in which he suggested that while he believes it is extremely unlikely that extraterrestrials have ever actually visited Earth, we must keep our minds open to the possible existence of civilizations a million years ahead of us in technology, where entirely new avenues of physics open up.
He also discussed the future of interstellar exploration and alien life in the Discovery Channel special Alien Planet as one of the multiple speakers who co-hosted the show, and Einstein's Theory of Relativity on The History Channel.
Carl Sagan on the Drake Equation
Carl Sagan discusses the drake equation. He believes that the drake equation helps put into perspective how many possible planets within our universe may actually contain intelligent life.
In 1961, University of California, Santa Cruz astronomer and astrophysicist Dr. Frank Drake devised the Drake equation.
This controversial equation multiplied estimates of the following terms together:
- The rate of formation of suitable stars.
- The fraction of those stars which are orbited by planets.
- The number of Earth-like worlds per planetary system.
- The fraction of planets where intelligent life develops.
- The fraction of possible communicative planets.
- The "lifetime" of possible communicative civilizations.
Drake used the equation to estimate that there are approximately 10,000 planets in the Milky Way galaxy containing intelligent life with the possible capability of communicating with Earth.
Based on observations from the Hubble Space Telescope, there are at
least 125 billion galaxies in the Universe. It is estimated that at
least ten percent of all sun-like stars have a system of planets, i.e. there are 6.25×1018
stars with planets orbiting them in the Universe.
Even if we assume
that only one out of a billion of these stars have planets supporting
life, there would be some 6.25×109 (billion) life-supporting planetary systems in the Universe.
The Drake equation is closely related to the Fermi paradox in that Drake suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations (the Fermi paradox) suggests that technological civilizations tend to disappear rather quickly.
This theory often stimulates an interest in identifying and publicizing ways in which humanity could destroy itself, and then counters with hopes of avoiding such destruction and eventually becoming a space-faring species.
A similar argument is The Great Filter, which notes that since there are no observed extraterrestrial civilizations, despite the vast number of stars, then some step in the process must be acting as a filter to reduce the final value.
According to this view, either it is very hard for intelligent life to arise, or the lifetime of such civilizations must be relatively short.
Carl Sagan, a great proponent of SETI, quoted the formula often and as a result the formula is sometimes mislabeled as "The Sagan Equation."