Saturday, November 30, 2013

UFO & Alien Visitation 'Trace Cases'

The show examines evidence of what ufology calls "trace cases", where physical material from a strange encounter is analyzed to determine if it is evidence of an alien contact.

An extraterrestrial civilization may choose to communicate with humanity by means of artifacts or probes rather than by radio, for various reasons. While probes may take a long time to reach the Solar System, once there they would be able to hold a sustained dialogue that would be impossible using radio from hundreds or thousands of light-years away. Radio would be completely unsuitable for surveillance and continued monitoring of a civilization, and should an extraterrestrial civilization wish to perform these activities on humanity, artifacts may be the only option other than to send large, crewed spacecraft to the Solar System.

Although faster-than-light travel is being seriously considered by physicists including Miguel Alcubierre and Michio Kaku, Tough speculates that the enormous amount of energy required to achieve such speeds under currently proposed mechanisms means that robotic probes traveling at conventional speeds will still have an advantage for various applications. 2013 research at NASA's Johnson Space Center, however, shows that faster-than-light travel with the Alcubierre drive requires dramatically less energy than previously thought, needing only about 1 metric ton of mass-energy to move a spacecraft at 10 times the speed of light, in contrast to previous estimates that stated that only a Jupiter-mass object would contain sufficient energy to power a faster-than-light spacecraft.[note 1]

According to Tough, an extraterrestrial civilization might want to send various types of information to humanity by means of artifacts, such as an Encyclopædia Galactica, containing the wisdom of countless extraterrestrial cultures, or perhaps an invitation to engage in diplomacy with them. A civilization that sees itself on the brink of decline might use the abilities it still possesses to send probes throughout the galaxy, with its cultures, values, religions, sciences, technologies, and laws, so that they may not die along with their civilization.

Freitas finds numerous reasons why interstellar probes may be a preferred method of communication among extraterrestrial civilizations wishing to make contact with Earth. A civilization aiming to learn more about the distribution of life within the galaxy might, he speculates, send probes to a large number of star systems, rather than using radio, as one cannot ensure a response by radio but can (he says) ensure that probes will return to their sender with data on the star systems they survey. Furthermore, probes would enable the surveying of non-intelligent populations, or those not yet capable of space navigation (like humans before the 20th century), as well as intelligent populations that might not wish to provide information about themselves and their planets to extraterrestrial civilizations. In addition, the greater energy required to send living beings rather than a robotic probe would, according to Michaud, be only used for purposes such as a one-way migration.

Freitas points out that probes, unlike the interstellar radio waves commonly targeted by SETI searches, could store information for long, perhaps geological, timescales, and could emit strong radio signals unambiguously recognizable as being of intelligent origin, rather than being dismissed as a UFO or a natural phenomenon. Probes could also modify any signal they send to suit the system they were in, which would be impossible for a radio transmission originating from outside the target star system. Moreover, the use of small robotic probes with widely distributed beacons in individual systems, rather than a small number of powerful, centralized beacons, would provide a security advantage to the civilization using them. Rather than revealing the location of a radio beacon powerful enough to signal the whole galaxy and risk such a powerful device being compromised, decentralized beacons installed on robotic probes need not reveal any information that an extraterrestrial civilization prefers others not to have.

Given the age of the Milky Way galaxy, an ancient extraterrestrial civilization may have existed and sent probes to the Solar System millions or even billions of years before the evolution of Homo sapiens. Thus, a probe sent may have been nonfunctional for millions of years before humans learn of its existence. Such a "dead" probe would not pose an imminent threat to humanity, but would prove that interstellar flight is possible. However, if an active probe were to be discovered, humans would react much more strongly than they would to the discovery of a probe that has long since ceased to function.