Since the incident in Roswell, New Mexico, in 1947 when a flying saucer is said to have crashed, there have been many sightings of unidentified flying objects (UFOs). Many people claim that some of the UFOs are spaceships carrying aliens from distant planets. Many others are skeptical of the explanation that these UFOs are spaceships from alien planets. The skeptic suggest the UFOs are actually weather balloons, undetected airplanes or helicopters; or optical illusions. Which of the criteria of adequacy are the skeptics applying when they reject the alien spaceship explanation?
Group of answer choices
O Simplicity -- The theory of alien spacecrafts visiting the earth is not simple; it is more complicated.
O Fruitfulness - the existence of aliens does not acadequately explain global warming or the rise in violent crime.
O Scope - the existence of aliens is out of the scope of science.
O Testability - No alien has ever permitted itself to be tested as real or imaginary.
O Conservatism -- The existence of visitors from alien planets is inconsistent with other knowledge about life on other planets.