Introduction There are many theories and ideas which people put forward to try and disprove the existence of intelligent life on another planet. Some of these come from individual philosophers and scientists, while some are widely believed and accredited as true by the scientific community and the general public.
The Drake Equation The Drake equation is a mathematical equation used to estimate the number of detectable extraterrestrial civilizations in the Milky Way galaxy. The equation that bears Frank Drake's name arose out of his preparations for a meeting regarding a search for signs of alien life.
If we use the lowest estimated values of each parameter in Drake’s equation, we get: R* = 7/year, fp = 0.4, ne*fl = 10-11, fi = 10-9, fc = 0.1, and L = 304 years. Resulting in: N = 7 × 0.4 × 10-11 × 10-9 × 0.1 × 304 = 8 x 10-20 (not only are we probably alone in the galaxy, but maybe in the whole universe)
The Fermi Paradox The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations. According to this line of thinking, the Earth should have already been colonized, or at least visited. But no convincing evidence of this exists. Furthermore, no confirmed signs of intelligence elsewhere have been spotted, either in our galaxy or the more than 80 billion other galaxies of the observable universe. Hence Fermi's question "Where is everybody?” A graphical representation of the Arecibo message – Humanity's first attempt to use radio waves to actively communicate its existence to alien civilizations.
Rare Earth Hypothesis In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the emergence of complex multicellular life on Earth required an improbable combination of astrophysical and geological events and circumstances. The term "Rare Earth" comes from Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist. If the conditions for life so rarely occur, then it could be possible that extraterrestrial life will NEVER occur. Are planets that support life, such as the Earth, rare?
Life on Mars: Liquid (water) is thought to have existed on Mars in the past. By July 2008, tests aboard NASA's Phoenix Mars Lander had identified water in a soil sample. Photographs from the Mars Global Surveyor from 2006 showed evidence of recent (within 10 years) of liquid on Mars's surface. There is evidence that Mars had a warmer and wetter past: dried-up river beds, polar ice caps, volcanoes and minerals that form in the presence of water have all been found. Present conditions on Mars may support life such as lichens. http://en.wikipedia.org/wiki/Extraterrestrial_life Europa Jupiter's moon Europa is thought to have liquid water beneath an ice layer, the ice is capable of supporting mircoorgaisms. It is also possible that Europa could support aerobic macrofauna in its ice. The life on Europa was improved in 2011 when it was discovered that lakes exist within Europa’s icy shell. http://en.wikipedia.org/wiki/Extraterrestrial_life http://en.wikipedia.org/wiki/Extraterrestrial_life
The Roswell UFO Incident, was a report of an object that crashed near Roswell, New Mexico, in June or July 1947, allegedly an extra-terrestrial spacecraft and its alien occupants. The United States Armed Forces maintains that what was recovered was debris from an experimental high-altitude surveillance balloon. UFO proponents maintain that an alien craft was found and its occupants were captured, and that the military then engaged in a cover-up. Area 51 is a military base, and a remote detachment of Edwards Air Force Base. The base's primary purpose is undetermined; however, based on historical evidence, it appears to support development and testing of experimental aircraft and weapons systems. It is rumoured that area 51 is the location of the alien’s corpse and UFO. http://en.wikipedia.org/wiki/Roswell_UFO_incident
A crop circle is a sizable pattern created by the flattening of a crop such as wheat, barley, rye, maize, or rapeseed. The documented cases have substantially increased from the 1970s to current times. In 1991, two hoaxers confessed and claimed authorship of circles throughout England. Many of the formations appearing in that area are positioned near ancient monuments, such as Stonehenge. According to one study, nearly half of all circles found in the UK in 2003 were located within a 15 km (9.3 miles) radius of Avebury.
Meng claimed he encountered a 10 feet (3.0 m) female alien with six fingers and braided leg fur. Other than that, she looked human. He maintains that for 40 minutes he had sexual intercourse with the alien while floating above his sleeping wife and daughter. The alien left Meng with a 5 cm scar on his thigh. He asked to see the female alien again, but was told that it wasn't possible. He states they told him that on a distant planet his child, will be born in 60 years. In September 2003, Meng was given a medical exam and a lie detector test and placed under hypnosis. Meng's results indicated that he told the truth. A doctor had checked Meng's scar, they concluded that the scar "could not possibly have been caused by common injuries or surgery." 1994 – Meng Zhaoguo Incident
Quiz 1. What does the Drake Equation try to find an answer to?
2. What shapes have aliens allegedly made in crop fields?
3. Do scientists believe that liquid water existed on Mars?
4. Allegedly, what is the name of the Area __ where an alien’s corpse and a UFO lie?
5. Do YOU believe that intelligent extraterrestrial life forms exist?