Sunday, June 20, 2010
Here is an article with video you might want to see, if nothing else, just out of curiosity. As the story goes a Mexican farmer, Marao Lopez, handed over a small so-called alien corpse to some university students, what university they are associated with, I know not.
Allegedly, they had DNA testing done on the body. The results are not revealed, at least not yet, and in another development, Lopez was found dead in his car after being burned to death on the side of a road.
Back in the 1970s, the US Government investigated a series of cattle mutilations in the southwestern part of the States. No answer was found. Every once in awhile, this type of incident rears its ugly head. You've probably heard the vivid descriptions of the draining of blood, removal of sexual organs, and cuts so precise they must have been made by a laser.
One might ask, "How does this relate to UFOs?" This always happens when investigators can find no foot traces, or any other evidence that might suggest a cult, individual, or predator influence at the scene. This implies that the attack must have occurred from above.
UFO expert investigating Colo. cow mutilationsALAMOSA, Colo. - Authorities in Colorado's San Luis Valley are trying to solve a series of bizarre, gruesome slaying: cows, mutilated, carved up, left to die in the fields.
Police are stumped. But rancher Mike Duran, who lost two of his cows to mutilation last December, has a theory that is literally out of this world. He says it was aliens.
"It's almost like the animal was taken away, killed, surgically manipulated and brought back," Duran told us.
Some of the wounds on one cow were "like laser cuts," he said. "There was no blood. No tracks. No witnesses at all."
"Some people say it was a cult. But even if it was a cult, we would find tracks or something like that."
In Duran's mind, that leaves only one other option.
"I believe there are aliens. People may laugh at me for thinking that," Duran said. "(The aliens) do what they have to, and then they bring (the cows) back and they drop them back in the field. And that's why there are no tracks."
Duran is not alone.
"The (female cow's) sexual organs were removed, the eyes were removed, a tongue was removed," said Chuck Zukowski, a self-described UFO investigator and reserve El Paso County Sheriff's deputy, who is trying to solve Duran's case.
"The pattern is that of surgical cuts. There are no bite marks. There are no scratch marks. There's no carnage on the ground...It's as if it was under surgery."
Duran says he found a powerful electromagnetic field coming from one of the cow's carved-out head, only adding to his suspicions that aliens are to blame.
"In my opinion, this is probably one of the best cold cases we have," Duran says.
The Colorado Department of Agriculture, however, doesn't buy the extraterrestrial theory.
"Postmortem changes on an animal happen very fast," said Nick Striegel, a veterinarian with the department. "Predators are coming in...they can lick up that blood. Insects and other parts of the decomposing process can digest body fluids."
If not predators, Striegel says it is also possible that people could be involved.
SETI Still Searching
While SETI continues their search for extraterrestrial contact, a large number of researchers believe that this contact was made many years ago, and continues today.
There are so many ancient references to beings not of this world in writings, paintings, cave drawings, and other artifacts, that it is almost stupid to deny that an alien influence on Earth can be seen throughout history.
That being said, it is my objective in the following article to point out some of the cases of alien contact in the modern era of the studies of UFOs and alien contact.
This first part will address cases from the years 1896 through the decade of the 1960s. I am doing research on cases from then until now, which I will present in another article.
The Beginning of Contact
It is generally accepted by most researchers that human contact with alien beings was first reported as part of a crash retrieval in 1941. The Cape Girardeau Crash Retrieval called for a local minister to come to the scene and administer last rites to several dead aliens.
More evidence would be nice in this case, but it appears that we are locked in with what we have at the present time. Most of the information comes from a granddaughter of the minister.
But the Missouri case may not be the first, if one believes the extraordinary account of two men who claimed to encounter two aliens in 1896. See more details of this case at Attempted Abduction at Lodi, California.
Colonel H. G. Shaw and Camille Spooner recounted an encounter with three, tall alien beings who attempted an abduction. But the aliens' light body mass allowed the two humans to fight them off.
There is also the intriguing case of Cordell Hull, who was Secretary of State under Franklin Roosevelt. As the story goes, Lucile Andrew, the daughter of Reverend Turner Hamilton Holt wrote a letter to the Center of UFO Studies in 1999, relating the details of a case of alien bodies and a UFO vehicle.
She claimed that her father was taken by Hull to a sub-basement in the US Capitol building. There they saw four glass jars with alien creatures, and also a crashed UFO.
This case leaves us wanting more. We are not told when the crash occurred or where. We don't even know if Hull knew himself.
The Roswell Era
Of course, we are all aware of the 1947 Roswell Crash and its many subplots and stories. Numerous witnesses have described seeing dead alien bodies either at the scene of the crash, or in various locked rooms or storage buildings.
Another case of alien contact also occurred in 1947, this time about 20 miles south of Malta. Fishermen working their nets were shocked to see a marine vehicle floating on top of the water.
The fishermen were frightened by the sight, and began to leave the area, when they saw the flash of a bright light. This was followed by the scurrying of a number of small creatures on the strange craft.
The entities, described as about the size of ten-year-old boys, soon disappeared below, and the craft submerged, never to be seen again.
The time period between the early 1940s and 1959 are filled with other accounts of alien contact. Some of the best known cases are:
Two cases in 1950, one from Varese, Italy, and another from Caracas, Venezuela.
Two cases in 1952, one from Maryland, the other from Kansas.
Two cases in 1954, one from France, the other from Brazil.
1955 would bring about one of the most bizarre cases of alien contact in UFO history. A family in Kentucky would endure a night of terror from strange, alien creatures. Read the details of this fascinating case at The Kelly, Kentucky, Alien Invasion.
In 1957, according to Antonio Villas Boas, a farmer in Brazil, he saw a UFO land as he was plowing on his tractor. From a purple-lit craft, several humanoid-like creatures emerged and took him into their craft for medical testing.
He was stripped naked, and had a strange liquid poured over his body. He was left alone for quite some time before a beautiful, blonde-haired woman joined him. Boas was immediately attracted to her naked body.
Sexual intercourse followed, and shortly thereafter, they had a second sexual encounter. Later, in an interview, Boas stated:
"Before leaving she turned to me, pointed to her belly, and smilingly pointed to the sky."
Antonio went on to become a successful lawyer and still stands by his story today. There have been many accounts of human-alien sexual encounters, but the Boas case is the most well known.In 1959, one of the very best documented cases of alien contact occurred. Father William Gill, minister of an Anglican church, along with 30+ eyewitnesses in Papua, New Guinea, had several nights of encounters with a UFO. They were able to interact with alien beings.
Light on Mount Pudi:
Inverted Saucer-Shaped Object:
The Size of 5 Full Moons:
Four Human-Like Beings:
25 Observers Witness Event:
Beings Working on Object:
"On the large one, two of the figures seemed to be doing something near the center of the deck. They were occasionally bending over and raising their arms as though adjusting or "setting up" something.
Being Waves Back:
Gill then waved at one of the creatures. "To our surprise the figure did the same. Ananias waved both arms over his head-then the two outside figures did the same. Ananias and myself began waving our arms, and all four seemed to wave back. There seemed no doubt that our movements were answered... "
Object Moves Away:
Analysis of Event:
Veteran UFO expert Dr. J. Allen Hynek thoroughly investigated the Papua events, and concluded that they were genuine. No alternate explanation has been offered to explain what happened, except to say that UFOs and alien beings visited New Guinea in 1957.
Just a Fishing Trip:
Brighter Than a Star:
Rowing for the Bank:
Men Were Not Lying:
Abducted by Aliens:
Star Moved Erratically:
Multicolored Lights, Rows of Windows:
Thirty-Five Miles in Two Minutes:
UFO Confirmed by Radar:
"The UFO was also confirmed by our radar."
Two Hours of Missing Time:
Calling Dr. Benjamin Simon:
Also details were released about the actual procedures performed on the Hills. Both physical and mental experiments were conducted. Samples were taken of their skin, hair, and nails. Betty had gynecological testing, and Barney reluctantly revealed that sperm samples were taken from him.
The Betty and Barney Hill case is still studied and discussed today. It is the alien abduction case to which all others are compared and judged.
Shadows Resembling Human Form:
Two Beings Approach Car:
Inside the UFO:
Aliens and Their Ships
On New Years Day, 1970, a bizarre encounter with a UFO and alien beings occurred at the Cowichan District Hospital in Duncan, Vancouver Island, British Columbia, Canada. Nurse Doreen Kendall, along with Frieda Wilson, were checking patients on the second floor at about 5:00 AM.
Doreen was near a window, and peering out, she saw a startling sight - an unknown flying object hovering about 60 feet above the ground. The object was saucer-shaped with a transparent dome on top.
She could clearly see two humanoid beings standing in front of what must have been a control panel. The being were clad in black uniforms, and apparently one noticed they were being watched.
The object began to move away, but not before Kendall alerted Wilson, who arrived in time to see the UFO. The unknown flying object made a couple of circles, and then sped away.Aliens at the Lighthouse
A strange encounter with alien beings in 1972 was recounted by a Uruguayan Navy Captain, Juan Fuentes Figueroa. He was one of five men to maintain the lighthouse on Isla de Lobos, a small island a few miles from the coast of Uruguay.
About 10:00 PM, Fugueroa was assigned to check the generators, located at the base of the lighthouse. His journey was only about 50 meters, and as he proceeded, he was shocked to see unidentified lights on a terrace, which stood about 6 meters high.
Thinking it might be a car, he returned to the office to get his pistol. As he began to return to the lighthouse, he again saw the strange lights, but this time he could also see a small figure by the object, and another coming down from the object.
Then, a third, taller being began to descend from the object. But, as he did, one of the two smaller beings noticed Figueroa, and it appeared to him that the three began to discuss the situation.
Frightened, he raised him arm to shoot at the three, but he felt he was unable to do so. He felt paralyzed, unable to act. The three beings reentered the craft, and were soon gone. No one believe his story, but he swears it is true.
Four Cases of Abduction
1973 would bring about one of the most researched cases of alien contact and abduction. Occurring in Pascagoula, Mississippi, two fishermen, nineteen-year-old Calvin Parker, and forty-two-year-old Charles Hickson were fishing on the banks of the river.
Soon, their entire world as they knew it would change. A low-flying UFO descended upon them. Strange, hideous creatures appeared, and took them into their craft. See the full account of this incident at the Pascagoula, Mississippi, Abduction.
In 1975 we have two well known cases of alien contact and abduction. The first case of note involved Air Force Sergeant Charles L. Moody, and took place in Alamogordo, New Mexico, on August 13, 1975. According to Moody, he was in the desert to watch a meteor shower, when he saw a glowing, metallic object descending to the ground about 300 feet away.
Moody says that the object wobbled as it made a landing. Moody attempted to flee, but his car would not start. Looking back at the craft, he saw a rectangular window with a being inside. He claimed to be abducted, and after a series of self-hypnosis sessions, he recalled his harrowing experience.
A Bright Light Appears:
"Wow! Venus is Falling." :
Object Drops Into Lake:
Two Small Beings on Craft:
Object Shoots Beam:
Taken Against Their Will:
Regressive Hypnosis Employed:
A Description of the Aliens:
Webb also conducted an investigation outside the boundaries of regressive hypnosis. He was able to find other members of Buff Ledge that had witnessed strange lights over Lake Champlain on the same night as Michael and Janet's abduction. Two other members of the camp also claimed to have been abducted after seeing strange lights, but earlier in the summer. Their names were not released. The events at Buff Ledge camp are certainly proof of an alien abduction.
Object Similar to Airplane:
Under Ships Bow:
Moving at 30 Knots:
Second Case of USO:
What are USOs?
As we search the mysteries of UFOs, an area that is often overlooked is that of UFOs entering and emerging from water. Often tagged "USOs," these objects have the capability of maneuvering in, through, and out of the water into open spaces. The proper term for this phenomena is "Unidentified Submersible Objects."
To really investigate this subject, we must separate UFOs seen flying over or near lakes and oceans with those which have been reported to enter or emerge from water. This is not to say that a UFO reported over water cannot navigate lakes and oceans, but there may be special properties to those which have reportedly entered or exited the lakes and seas of our world.
Another fact that we should consider is that although the Earth's surface is approximately 75% water, these areas are not nearly as closely monitored as our lands, which of course, contain the vast majority of our populace. It is very possible, even probable, that UFOs navigating our oceans and lakes are very rarely witnessed by human eyes.
UFOs and Water
There have been many reports of UFOs over water, and a much smaller amount of reports of UFOs navigating our lakes and oceans. The question must be asked: "Why do UFOs enter our waters?"
This question can only be answered with several other questions. Do alien beings have a personal need of water? Do alien craft have a use for water? Do aliens have underground bases in our oceans?
From the preponderance of reports, all three of these questions can be answered with a big "Yes." There have been multiple reports of aliens either asking for water for either themselves or for their craft. And reports of UFOs staying underwater for several days without emerging must indicate that they have somewhere to anchor their craft beneath the surface, or have bases under the sea.
These theories bring us to the gist of this article, where I shall bring to light some of the most notable, best documented cases of these UFO underwater events.
South of Malta - 1947
In 1947, about 20 miles south of Malta, fishermen were at work raising and lowering their nets in hope of a big catch. Suddenly they saw an unusual object not too far from their boat. Frightened by the strange object, the fishermen quickly yanked their nets from the sea, fired up their boat, and put distance between themselves and the unknown craft.
Suddenly, a bright light lit up the area around the craft. Small beings could be seen running across the deck of the object. Visible to the fishermen was some type of apparatus around the waist of the beings.
Later after initial reports of the incident were revealed, one of the witnesses claimed that the beings were about the size of a 10-year-old boy. He could see them enter the craft, which soon submerged, never to be seen again.
Golfo Nuevo - Argentina - 1960
In a report released through the History Channel, in 1960, the Argentinean Navy encountered two unknown submerged objects in the "New Gulf," or Golfo Nuevo. This event occurred about 650 miles south of Buenos Aires, Argentina.
It was initially thought that the objects were submarines, but this theory was soon dismissed, as the objects appeared to break into smaller pieces, and fly out of the ocean. According to reports by Philip Mantle, these pieces disappeared as they left the water.
Of course, skeptics believe that all that was seen were submarines firing torpedoes, but it was revealed that in 1960, the firing of six or more torpedoes at one time was not possible.
Seattle, Washington - 1966
In 1966, the USS Tiru SS-416 left Pearl Harbor bound for Seattle, Washington, during the Rose Festival. The submarine was set at a pier near downtown Seattle, and toured by thousands of curious individuals.
Unknown at this time was that the sub's trip to Seattle had been far from routine. While cruising on the water's surface one late afternoon, the port lookout reported a strange object at a range of 2 miles bearing 315 degrees relative. The port lookout referred his contact to the starboard and OOD (Object Oriented Design) lookouts.
The three lookouts, using binoculars, were shocked to see a metallic craft, larger than a football field, drop from the clouds into the ocean. It was reported to tumble end over end, hit the water, and disappear among the water geysers and ocean.
When starboard and OOD lookouts confirmed what they had seen, the port lookout related that initially he had seen the object go from the water up into the clouds.
All three lookouts would soon see the object leave the ocean and join the clouds. During the same time period, radar reported a contact at the same range and bearing. Sonar was picking up strange echoes. The Captain was called to the bridge.
The Captain, along with the chief Quartermaster, arrived within minutes. Almost immediately, the unknown object fell from the clouds into the ocean once again. Soon, however, the Tiru moved out of visual contact with the object. The Captain issued an order to all present: Never discuss what they had seen under any circumstances.
The Captain went below and sent a radio message. The witnesses had seen a metallic craft, decked out with machined parts. There appeared to be windows around its circumference. No noise was heard. The object was shaped like a saucer with a bowl inverted in the saucer and it was huge.
Shag Harbor, Nova Scotia - 1967
One of the most well known UFO cases is that of the Shag Harbor Crash of 1967, although it is most difficult to determine if the UFO navigated into the water purposedly, or crashed into the waters.
However, if later eyewitness testimony can be believed, a second craft entered the waters to aid the first craft. It has been reported that the US Navy monitored the objects for quiet some time. This would certainly indicate to me that the first object, possibly in trouble, had used the waters to avoid detection, awaiting aid from the second ship.
For a time, the small fishing village of Shag Harbor, Nova Scotia, Canada was actually not on the map. But, something very extraordinary happened there in 1967 that would change their status in their geographical area. The harbor, located at the southern most part of Nova Scotia, would be the location of a well-documented and investigated case of a UFO Crash. Reports of UFO crashes in or near water are extremely rare.
Object Floats on Water:
Four Lights on One Craft:
Coast Guard Investigates:
Russian Submarine Present:
MUFON Joins Investigation:
Finally, the two underwater UFOs made a break for it. Outracing the Naval ships to the Gulf of Maine, they broke the seas, and sped away into the skies. These details were corroborated by many witnesses, civilian and military, making the mystery of Shag Harbor a mainstay of Ufology, and one of the best documented crash cases of all time.
Psychologist Carl Jung, in his book “Flying Saucers”, stated “something is being seen, but it isn’t known what.... This formulation leaves the question of ‘seeing’ open. Something material could be seen, or something psychic could be seen. Both are realities, but different kinds”.
Albert Einstein said, “as far as the laws of mathematics refer to reality, they are not certain; and so far as they are certain, they do not refer to reality”.
Timothy Mcveigh, recently executed for the Oklahoma bombing, blamed an implant in his brain for his actions and described several UFO encounters to police investigators.
Between 80 and 90 percent of (UFO) reports are misperceptions of fairly conventional, natural or man-made phenomena, hoaxes.
Theories about UFO and aliens are numerous but can be divided into four categories:
Intelligence from another planet with advanced technology
In the thirties, Mars and the Moon were the most popular candidates for hosting aliens but it seems that we have to go beyond the solar system to find the first planet with similar living conditions than the Earth. Though scientists last century thought the planet Mars might be a good candidate, and some even thought they detected a huge canal system stretching across the planet, recent probes sent to Mars have failed to detect even bacteria-like creatures, let alone a civilization capable of producing a flying saucer. With the rest of the planets in our solar system seemingly too hot or cold, the best hope for intelligent life seems to be across the void of interstellar space in other parts of our galaxy. If we do assume there is intelligent life in places other than Earth, where might they be? In an attempt to detect intelligent life beyond our solar system researchers have conducted a number of SETI programs trying to use radio waves to detect the existence of other civilizations. So far no SETI program has been successful in finding intelligent life, but there are millions of stars in our galaxy alone that might have planets that could harbor life and carefully looking at each one of them will take a long time.
The chupacabra, or aliens that we are seeing would be humans of the future.... our own children.... travelling through time in order to prevent the chemical crisis that caused them to evolve into "chupacabras". This would explain the "time-line" of sightings and the secrecy of the U.S. government regarding their findings. Our future-humans arrive at times when chemical progress is at a peak - in order to either warn us or attempt to prevent the progress of the technology that will go awry and cause physical mutations. What might cause such a leap in evolution, to create the unusual appearance of chupacabra? Is it a large-scale chemical war? Instant, single-generation mutation? Or a slow, gradual "morphing" of physical structure in order to adapt to our habitat - which we created through ignorance? Is it a positive change, or a negative change? Certainly, chupacabra is not attractive to us, pre-historic man.
Aliens are only the results of hallucinations caused by numerous alterations of the mind of witnesses. This argument is used in most cases of paranormal apparitions wether it is a ghost, a Bigfoot or an alien.
Hidden earthly intelligence
According to this theory, what we call aliens would be pre-flood civilizations that have found a refuge in the depths of the sea or underground.
In August 1977, a sky survey conducted with Ohio State University's "Big Ear" radio telescope found what has become known as the 'Wow' signal. Registering an enormous signal strength (60 Janskys in a 10 KHz channel, which is more than 50 thousand times more incoming energy than the minimum signal that would register as a hit for today's Project Phoenix.). The shape of the signal had the characteristic rise and fall expected for its short 72 second lifetime. But a hitch remains: the signal has not been retrieved from other sky surveys, making it more anomaly than confirmable cosmic source. This odd, one-beam behavior could be caused by an alien transmission that simply went off the air during the 3 minutes between beams.
If the putative aliens permanently shut down their transmitter, then there's no chance of ever hearing the Wow signal again. Like a single sighting of the Loch Ness monster, we would never be able to prove what it was. But if the signal is periodic - if, for example, the aliens are using a rotating radio beacon that sweeps the star-studded strata of the Milky Way once every five minutes or every five hours - then we could hope to find it by just looking again.
For the moment, despite the use of the Harvard META SETI system, the Very Large Array (VLA) and the new 26-meter radio telescope in Hobart, Tasmania, Wow has not been detected again.
Extrasolar planets were discovered during the 1990s as a result of improved telescope technology, such as CCD and computer-based image processing along with the Hubble Space Telescope. Such advances allowed for more accurate measurements of stellar motion, allowing astronomers to detect planets, not visually (the luminosity of a planet being too low for such detection), but by measuring gravitational influences upon stars (see astrometrics). In addition, extrasolar planets can be detected by measuring the variance in a star's apparent luminosity, as a planet passes in front of it.
Besides the detection of at least 80 planets (mostly gas giants), many observations point to the existence of millions of comets also in extrasolar systems.
The Polish astronomer Aleksander Wolszczan claimed to have found the first extrasolar planets in 1993, orbiting the pulsar PSR 1257+12. Subsequent investigation has determined that these objects are not "true" planets in that they are technically "sub-brown dwarf masses orbiting an object that is or once was a star"; it is believed that they are unusual remnants of the supernova that produced the pulsar, and did not form as conventional planets do.
The first "true" extrasolar planet was announced on October 6, 1995 by Michael Mayor and Didier Queloz; the primary star was 51 Pegasi. Since then dozens of planets have been detected, many by a team led by Geoffrey Marcy at the University of California's Lick and Keck Observatories. The first system to have more than one planet detected was Upsilon Andromedae. The majority of the detected planets have highly elliptical orbits.
There are two main methods of detecting extrasolar planets, which are too faint to be detected by present conventional optical means. The first involves measuring the displacement in the parent star's spectral lines due to the Doppler effect induced by the planet orbiting the star and moving it through mutual gravitation. The second involves catching the planet as it passes in front of the star's tiny disk which will cause the light of the star to "dip" in a distinctive way, and do so periodically as the planet completes multiple orbits. The second method is theoretically more sensitive, but is newer and has scored fewer successes. It also depends on the plane of the planet's orbit being aligned with the line of sight between the star and the Earth. As a result, any number of stars with planets that are not so aligned will be missed.
Most of the planets found are of relatively high mass (at least 40 times that of the Earth); however, a couple seem to be approximately the size of the Earth. This reflects the current telescope technology, which is not able to detect smaller planets. The mass distribution should not be taken as a reference for a general estimate, since it is likely that many more planets with smaller mass, even in nearby solar systems, are still undetected.
One question raised by the detection of extrasolar planets is why so many of the detected planets are gas giants which, in comparison to Earth's solar system, are unexpectedly close to the orbited star. For example, Tau Boötis has a planet 4.1 times Jupiter's mass, which is less than a quarter of an astronomical unit (AU) from the orbited star; HD 114762 has a planet 11 times Jupiter's mass, which is less than half an AU from the orbited star. One possible answer to these unexpected planetary orbits is that since astrometrics detects the extrasolar planets due to their gravitational influences and partially-ecliptic interference, perhaps current technology only permits the detection of systems where a large planet is close to the orbited star, rather than such systems being the norm.
On November 27, 2001, astronomers using the Hubble Space Telescope announced that they had detected the atmosphere of the planet orbiting HD 209458, from its absorption of light when passing in front of its star. Also during that year, a star was located which had the remnants of one or more planets within the stellar atmosphere - apparently the planet was mostly vaporized.
In 2002 a group of Polish astronomers (Professors Andrzej Udalski and Marcin Kubiak and Dr. Michal Szymanski from Warsaw, and Polish-American Professor Bogdan Paczynski from Princeton) during project OGLE (the Optical Gravitational Lensing Experiment) worked out a method of easily finding extrasolar planets, based on a photometrical method. During one month they claimed to find 46 objects, many of which could be planets.
On July 10, 2003, using information obtained from the Hubble Space Telescope, scientists discovered the oldest extrasolar planet yet. Dubbed Methuselah after the biblical figure, the planet is about 5,600 light years from Earth, has a mass twice that of Jupiter, and is estimated to be 13 billion years old. It is located in the globular star cluster M4, approximately 7200 light years from Earth in the constellation Scorpius.
The Kepler Space Mission will be launched in the next few years. It is a space-based telescope designed specifically to search large numbers of stars for earth-sized terrestrial planets.
The frequency of extrasolar planets is one of the parameters in the Drake equation, which attempts to estimate the probability of communications with extraterrestrial intelligence.
Confirmed extrasolar planets
The following is a list of main sequence stars with confirmed extrasolar planets. Note that the masses of the planets are lower bounds only. If a planet is detected by the spectral line displacement method referred to above, no information is gained about the inclination of the planet's plane of orbit around its star, and a value for this is needed to calculate the mass. It has become customary to arbitrarily assume that the plane is exactly lined up with the line of sight from Earth (this produces the lowest possible mass consistent with the spectral line measurements). The planets are listed with indications of their approximate masses as multiples of Jupiter's mass (MJ), and some also have approximate distances in astronomical units (AU) from their parent stars.
·HD 83443 - .35 MJ and .16 MJ
·HD 16141 - .215 MJ.
·HD 168746 - .24 MJ
·HD 46375 - .249 MJ
·HD 108147 - .34 MJ
·HD 75289 - .42 MJ
·51 Pegasi - .47 MJ (0.25-AU)
·BD -10 3166 - .48 MJ
·HD 6434 - .48 MJ
·HD 187123 - .52 MJ
·HD 209458 - .69 MJ
·Upsilon Andromedae - .71 MJ (0.06AU) , 2.11 MJ (0.83AU), and 4.61 MJ (2.5AU)
·HD 192263 - .76 MJ
·Epsilon Eridani - .86 MJ
·HD 38529 - .81 MJ
·HD 179949 - .84 MJ
·55 Cancri - .84 MJ (0.25-AU) and >5? MJ
·HD 82943 - .88 MJ and 1.63 MJ
·HD 121504 - .89 MJ
·HD 37124 - 1.04 MJ
·HD 130322 - 1.08 MJ
·Rho Coronae Borealis - 1.1 MJ (0.5-AU)
·HD 52265 - 1.05 MJ
·HD 177830 - 1.28 MJ
·HD 217107 - 1.282 MJ
·HD 210277 - 1.24 MJ
·HD 27442 - 1.43 MJ
·16 Cygni B - 1.5 MJ (1.5+AU)
·HD 74156 - 1.56 MJand >7.5 MJ
·HD 134987 - 1.58 MJ
·HD 160691 - 1.97 MJ
·HD 19994 - 2.0 MJ
·GJ 876 - 1.98 MJ and .56 MJ
·HD 92788 - 3.8 MJ
·HD 8574 - 2.23 MJ
·HR 810 - 2.24 MJ
·47 Ursae Majoris - 2.54 MJ (2+AU) and .76 MJ
·HD 12661 - 2.83 MJ
·HD 169830 - 2.94 MJ
·14 Herculis - 3.3 MJ
·GJ 3021 - 3.37 MJ
·HD 80606 - 3.90 MJ
·HD 195019 - 3.43 MJ
·HD 213240 - 3.7 MJ
·GJ 86 - 4 MJ
·Tau Boötis - 3.87 MJ (0.25-AU)
·HD 50554 - 4.9 MJ
·HD 190228 - 4.99 MJ
·HD 168443 - 7.2 and 17.1 MJ
·HD 222582 - 5.4 MJ
·HD 28185 - 5.6 MJ
·HD 178911 B - 6.47 MJ
·HD 10697 - 6.59 MJ
·70 Virginis - 6.6 MJ (0.5AU)
·HD 106252 - 6.81 MJ
·HD 89744 - 7.2 MJ
·HD 141937 - 9.7 MJ
·HD 114762 - 11 MJ (0.5-AU)
Solutions to the Fermi Paradox can be grouped in three categories:
They Are Here
Those who attribute UFOs to alien spacecraft have a ready answer to the paradox. However, there is little mainstream support for this view.
They Exist But Have Not Communicated With Us
Another possibility is that advanced civilizations either deliberately or accidentally hide evidence of their existence from humanity. They might do so out of ethical concerns for primitive beings or a desire to encourage cultural diversity. This has the Uniformity of Motive flaw common to other Fermi solutions: assuming that all alien civilizations throughout time will behave in the same way.
Civilizations might be deliberately hiding themselves in order to avoid destruction from more advanced civilizations. It has also been proposed that a fundamental information theoretical axiom might be behind the lack of recognized signals. Information theory states that a message which is compressed maximally, is indistiguishable from white noise. The counterargument to this would be that even though as bandwidth becomes a bottleneck to communication, there ought still be some niche technologies which would not or could not strive to maximal data compression. Science fiction authors have proposed another possible explanation -- that someone, or something, is destroying intelligent life in the universe as fast as it is created. This theme can be found in novels such as Frederik Pohl's Heechee novels, Fred Saberhagen's Berserker novels and Greg Bear's The Forge of God. Technological civilizations may usually or invariably destroy themselves via nuclear war, biological warfare, grey goo or destroying their planet's ecosphere) before or shortly after developing radio or spaceflight technology (a very real possibility).
Another possible explanation is that advanced civilizations would construct multiple concentric Dyson Spheres around their stars, each one radiating less energy than the next smallest one, with the outermost sphere radiating energy at close to the background radiation. These would be essentially unobservable from any distance.
Yet another is that all intelligent life inevitably evolves towards a technological singularity and quickly becomes unrecognizable to humanity in our present state.
They Do Not Exist
Others argue that the conditions for life, or at least complex life, are rare. For instance, some hypotheses say that complex life required the stimulation of tides from Earth's moon to evolve, and the Moon is the result of freak
occurrence, a body of a certain mass striking Earth at just the right angle to
carve off the material and put it in a stable orbit.
Another possibilty is that ice ages, comet or meteor impacts, supernovae, gamma ray bursters or other catastrophic planetary or galactic events are so common that life rarely has the time to evolve. Alternately, these events may not be frequent enough on other planets and evolution is slowed because there aren't enough mass extinctions to encourage diversity.
Even if the conditions for life are common, the evolution of human-like intelligence, the invention of radio technology or interest in the exploration of outer space may be vanishingly rare.
A common concept used in the scientific method to test the validity of certain ideas is Occam's Razor. To paraphrase, Occam's Razor states that the explanation for a given phenomenon that has the fewest assumptions should be preferred over more complicated ones.
All this draws us to a few possible conclusions, say adherents of the Fermi Principle: that as a technologically advanced species, we are alone in our part
of the Cosmos. The simplest explanation, say adherents to the premise behind the Fermi Paradox, is the last one.
The commonly held belief that the universe has many technologically advanced civilizations combined with our observations that suggest otherwise, appears to be paradoxical, suggesting that either our understanding or our observations are flawed or incomplete. The Femi paradox, after Enrico Fermi who first publicised the subject, suggests that our understanding of what is a "conservative" value for some of the parameters may be overly optimistic or that some other factor is involved to eradicate the development of intelligent space-faring life.
Many people believe that extraterrestrial life exists and that there are many planets in our own galaxy that harbor life. The idea that life is common everywhere and propelled from star to star by the pressure of starlight was proposed by Svante Arrhenius, who called it "panspermia," but this theory is now in disfavor.
Some believe that our current knowledge of both chemistry and of biology strongly indicates that life is an exceptionally improbable thing to arise spontaneously. "Strong life" proponents counter that because life arose on Earth as soon as the crust cooled, life itself must be intrinsically linked with
terrestrial planet formation. Current data on this issue seems to support this
second view or a related hypothesis that life originated elsewhere within the
solar system and was transported to the Earth by a meteorite.
The fact that signs of life on Earth seem to be present almost as soon as it cooled enough to support it, that life has been found in a variety of environments once thought incapable of supporting it, that planet formation seems to be fairly common, and that conditions to support bacterial life seem to exist elsewhere in our own solar system all support the position that life should be fairly common. A statistical analysis that treats the question of life arising on a planet like winning a lottery—and generalizing from the special case that, on the only terrestrial world we have seen, the lottery was won—some astrobiologists have concluded that there seems to be at least a one-in-eight chance per billion years of "appropriate" conditions that life will form.
As for the Earthly origin of life, it now seems fairly certain that it began within our solar system. The hard radiation of interstellar space coupled with
the extremely low probability that any extra-solar rocks capable of protecting
life in the harsh inter-stellar environment have ever struck the Earth seem to
indicate that, if terrestrial life originated elsewhere, it would almost certainly have to have been carried here on purpose. It is possible that life was brought here, but, if so, it becomes difficult to explain why the first forms of life were simple, single-celled life instead of further up the evolutionary chain.
A widely-accepted view is that terrestrial life originated on the Earth itself.
Lately, there has been increasingly more support for an idea first mentioned by Lord Kelvin— that life first came about on Mars and was transported to Earth by a meteorite. This latter position is defended on the basis that conditions which might support Earth-compatible life existed within a relatively short distance hundreds of millions of years before the Earth cooled. The more improbable that one deems life beginning spontaneously, the more likely it becomes that life arose first on Mars.
The issue of whether intelligent life develops as readily as simpler forms is
still an open question.
The Rare Earth Hypothesis
An emerging line of thought even argues that multicellular life may be exceedingly rare in the universe because of a probable rarity of Earth-like planets. This line of reasoning has been dubbed the Rare Earth hypothesis and relies on that fact that many improbable coincidences converged to make complex life on Earth possible.
Spiral arms have many novas, and the radiation from them is believed inimical to higher life. The solar system is in a very special orbit within the galaxy. It is a nearly perfect circular orbit, at a distance in which the solar system moves at the same speed as the shock waves forming the spiral arms. The Earth has been between spiral arms for hundreds of millions of years, more than thirty galactic orbits, almost all of the time there has been higher life on Earth.
Another crucial item is the moon. Many scientists believe it was formed by a rare collision between the young Earth and a Mars-sized body 4,450 million years ago. The collision had to occur at an exact angle; too direct and Earth would have been obliterated, too shallow and the Mars-sized body would have been deflected. This giant impact sent much of the felsic rich mantle of Earth into orbit. The removal of light-rock types (felsic rock) allowed for the formation of the first ocean basins (which are heavier (mafic) rock). The impact spun the Earth. Lunar tides stabilize the Earth's axis. The axis of rotation of a sphere is unstable, and if the Earth's axis varied, the weather would vary dramatically over periods too short for animals to evolve. Lunar tides also have helped heat the mantle. The molten mantle generates the magnetic field of the Earth. The magnetic field shields the Earth's air from the solar wind, which would otherwise acclerate light molecules away, sapping the air and water over a period of a few million years.
Furthermore, the presence of different crustal rock types allows for the existence of plate tectonics, which recycles limestone into biologically-active carbon dioxide. This is just part of the Rare Earth hypothesis.
Our solar system if seen from a radio telescope within a few tens of light years away would seem unusual for the huge amount of radio waves being emitted from what appears to be an otherwise unremarkable main sequence star. One can presume that a similar solar system civilization nearby would be immediately characterized as unusual by us.
Radio and observational data have for several decades been collected and analyzed by such projects as Project Ozma, the Search for Extraterrestrial Intelligence (SETI), and the various projects searching for extrasolar planets.
So far the SETI data seem to indicate that we are the only radio-transmitting
species in at least that portion of our part of the Galaxy that has been surveyed; there are no known main sequence stars with unusually bright radio emissions. In addition, to date, the majority of the extrasolar planetary
systems that have been found appear to be harsh environments for advanced life-forms.
Some people contend that these results probably have a significant amount of sampling error: that we are searching the wrong radio frequencies in SETI and that we can more easily find planetary systems with planetary orbits and
configurations that are less stable than our own. Still other people contend that we are probably the only spacefaring species in at least our galaxy; otherwise we would be awash in their radio transmissions, and have already been overrun by early colonization efforts.
The Argument Over the Premise Behind the Fermi Paradox
Some of those who subscribe to the Fermi principle state that given enough time to develop, the radio transmissions of any sufficiently advanced civilization will begin to outshine their parent star in the radio part of the spectrum.
Further, the mediocrity principle states that physical laws are the same throughout the Universe and the development of anything within the Universe has to follow these laws. Since the use of the electromagnetic spectrum for information transmission is relatively cheap and easy, one would expect any technological civilization to take advantage of at least a part of this spectrum during their development. We have been actively searching for extraterrestrial signals for almost 30 years with projects such as SETI and have been passively listening to radio static for nearly 100. During this entire period we have yet to hear any confirmed alien broadcasts nor have we observed any main sequence stars with unusual electromagnetic radio signatures that might indicate a technological civilization.
Those that believe the galaxy has many technologically advanced civilizations
counter that the extraterrestrials may simply be using a medium other than radio or they eventually choose to hide their transmissions for some unknown reason.
This could very well be so, proponents of the Fermi Principle say, but only if there are very few such civilizations in both space and time and they very quickly abandon radio as a means of data transmission. Either way, they say, if there were very many of these civilizations their transmissions would make a large impact on at least some part of the electromagnetic spectrum for at least some part of their development. They further state, that if there are as many advanced extraterrestrial civilizations as Drake and Sagan have estimated, then their presence would be made obvious by their transmissions.
The Anthropic Principle
Those that believe the Fermi Principle also state that from the Anthropic Principle one can see as a logical fallacy the following statement: "With billions of galaxies and countless trillions of planets in the Universe, intelligent life must exist somewhere besides Earth. After all intelligent life happened here, so why not on many of the trillions of other worlds? It is illogical to think that we are the only one." With the Anthropic Principle, Fermi Principle adherents say, one can quickly point out that if a particular planet is the only planet out of the trillions that has intelligent life on it, it would be certain that the people there would assume that they couldn't be the only planet with intelligent life. They would think that, given the sheer numbers of other worlds, there must be others like themselves in the Universe. However, the Anthropic Principle makes it necessary to gather additional information before such an assumption could be made.
Freeman Dyson's Contribution
Popularized by Dr. Freeman Dyson, a Dyson Sphere is an opaque shell around a star. Such a shell would be created by advanced alien civilizations that wished to harness as much of the radiant energy of their sun as possible. The exact design of the Dyson sphere was not specified; it could consist of billions of independent solar collectors and space habitats or be a single unified structure, but in any case it would be made of solid matter and would intercept most of the star's emitted light to re-radiate as waste heat. A star surrounded by a Dyson sphere would thus emit a distinctive black body spectrum without the strong emission lines that incandescent stellar plasma exhibits, probably with its peak unusually far into the infrared for a star of its size. With this speculation, he advised astronomers to search the night sky for unusually colored stars, which, he postulated, could only signify highly advanced and intelligent life. No such stars have yet been found.
Some adherents to the Fermi Principle state that it is highly unlikely that all advanced civilizations would not eventually take full advantage of the power source of their home star, and in doing so changing the electromagnetic signature of their sun.
Dr. Dyson also proposed a type of invention which he deemed likely to appear within the life-span of an intelligent civilization, the absence of which tends to support the Fermi Principle. He said that he thought that it would soon be possible for us to create an explorer-device which drew power from its surroundings to propel itself through the universe in search of intelligent life forms. Moreover, it would be possible to create versions of this device which could create and launch vast numbers of copies of itself by the process of machine reproduction. Even allowing for the realities of vast distances between stars and the relativistic speed-limit, if intelligent life were common, stars in our own galaxy much older than our own would be within a range to have built and launched fleets of these automated exploration devices.
Adherents to the Fermi Principle furthermore argue that, from what we know about life's ability to overcome scarcity and colonize new habitats on our own planet, we can reasonably assume that life elsewhere will follow similar principles. Given this, Fermi Principle adherents state that any advanced civilization will almost certainly try to seek out new resources and colonize first their solar system, and then surrounding solar systems. Several writers have tried to estimate the amount of time it would take for such a civilization to colonize the entire galaxy. What they have determined is that it would take 5 to 50 million years to accomplish this feat  - which is a tiny amount of time on even a geologic scale (not to mention a Galactic one).
Saturday, June 19, 2010
Panspermia is a theory that suggests that the seeds of life are prevalent throughout the universe and life on Earth began by such seeds landing on Earth and propagating.
The theory has origins in the ideas of Anaxagoras, a Greek philosopher and was developed later by British astronomer Sir Fred Hoyle.
There is some evidence to suggest that bacteria may be able to survive for very long periods of time even in deep space (and may therefore be the underlying mechanism behind Panspermia). Recent studies out of India have found bacteria at heights greater than 40 km in Earth's atmosphere where mixing from the lower atmosphere is unexpected, while Streptococcus mitus bacteria that had accidentally been taken to the moon on the Surveyor 3 spacecraft in 1967, could easily be revived after being taken back to earth three years later.
However, a consequence of panspermia is that life throughout the universe would have a surprisingly similar biochemistry, being derived from the same ancestral stock. So the high-altitude bacteria might be expected, whether of earth or extra-terrestrial origin, to have a biochemistry similar to terrestrial forms. This is not resolvable until life on another planet can have its chemistry analysed. Of material definitely known to originate off-earth, analysis of the rock sample known as ALH84001, generally regarded as originating on Mars, suggests it contains artifacts that may have been caused by life forms. This is the only indication of extraterrestrial life to date and is still widely disputed.
This theory has been explored in a number of works of science fiction, notably Jack Finney's Invasion of the Bodysnatchers (twice made into a film) and the Dragonrider books of Anne McCaffrey. In John Wyndham's book, The Day of the Triffids, the first person narrator, writing in historical mode, takes care to reject the theory of panspermia in favour of the conclusion that the eponymous carnivorous plants are a product of Soviet biotechnology.
Some works of science fiction advance a derivative of the theory as a
rationalisation for the improbable tendency of fictional extra-terrestrials to
be strongly humanoid in form.
From Wikipedia, the free encyclopedia.
From Wikipedia, the free encyclopedia.
The scientific study of extraterrestrial life or life beyond planet Earth is called xenobiology (or exobiology or astrobiology).
Panspermia holds that extraterrestrial life is prevalent through space in a
form analogous to spores. Extraterrestrial life forms, especially intelligent ones, are often referred to as aliens.
Scientists are searching for extraterrestrial life in two very different ways.
Firstly, they are searching for evidence of unicellular life within the solar
system: searching Mars and meteors which have fallen to Earth, and a proposed mission to Europa, one of Jupiter's moons with a liquid water layer under its surface, which may contain life.
There is some evidence for the existence of microbial life on Mars. An
experiment on the Viking Mars lander reported gas emissions from heated Martian soil that some argue are consistent with the presence of microbes, though the lack of corroborating evidence from other experiments on the Viking indicates that a non-biological reaction is a more likely hypothesis. Indepedently, in 1996 structures resembling bacteria were discovered in a meteorite known to be formed of rock ejected from Mars. Again, this evidence is vigorously disputed.
Secondly, it is theorised that any technological society will be transmitting
information: man-made electromagnetic radiation is already detectable within an eighty light-year radius of Earth, and is constantly spreading. SETI, the Search for Extraterrestrial Intelligence, takes the data gathered by the world's largest radiotelescopes and analyses it for artificial patterns using
supercomputers and one of the largest distributed computing projects in the
Some scientists believe that some UFOs are the spacecraft of intelligent
extraterrestrials; however since these scientists are currently very much in the minority, work such as SETI continues in the hopes that a signal will be
Astronomers also search for extrasolar planets that would be conducive to life. Current radiodetection methods have been inadequate for such a search, as the resolution afforded by recent technology is inadequate for detailed study of extrasolar planetary objects. Future telescopes should be able to image planets around nearby stars, which may reveal the presence of life (either directly or through spectrography revealing, for instance, the presence of free oxygen in a planet's atmosphere).
Some state that by making what they feel are reasonable assumptions and arguments we can ascertain that if life is possible at all, then the universe is so vast that it should not only be possible, but almost certain that there are large numbers of extraterrestrial civilisations in the Universe. In the early 1960’s Frank Drake sought a way to calculate the probability of finding other intelligent races. He came up with an equation to calculate the possibility of extra terrestrial civilizations; which became known as the ‘Drake Equation’. Drake writes, 'The basic premise behind the equation is that what happened here will happen with a large fraction of the stars as they are created, one after another, in the Milky Way galaxy and other galaxies. People unfamiliar with the accepted pictures of cosmic and biological evolution might think the equation is highly speculative; in fact, it is just the opposite, since the phenomena it assumes to take place in the Universe are only those we are sure have taken place at least once' ('The Drake Equation: A Reappraisal', pp. 115-18, First Contact).
Here is the equation also known as the Green Bank equation:
N = the number of technological civilizations in our galaxy
R* = The rate of formation of suitable stars
F(p) = the fraction of stars having planets.
N(e) = the number of suitable planets per planetary system.
F(l) = the fraction of planets on which life develops
F(i) = the fraction of life that evolves to intelligence beings.
F(c) = the fraction of intelligent species to develop the means of communication.
L = The length of time such civilizations release detectable signals into space.
Drake and other early extraterrestrial-life enthusiasts, including Carl Sagan, arrived at a value for N between 100,000 and 1,000,000--still only about one technological civilization per million stars in the Milky Way, which astronomers believe contains some 200 billion stars.
Drake equation parameters
Considerable disagreement on the values of most of these parameters exists, but the values used by Drake and his colleagues in 1961 are: R* = 10/year, fp = 0.5, ne = 2, fl = 1, fi = fc = 0.01, and L = 10 years.
The value of R* is the least disputed. fp is more uncertain, but is still much firmer than the values following. Confidence in ne was once higher, but the discovery of numerous gas giants in close orbit with their stars has introduced doubt that life-supporting planets commonly survive the creation of their stellar systems. In addition, most stars in our galaxy are red dwarfs, which have little of the ultraviolet radiation that has contributed to the evolution of life on Earth. Instead they flare violently, mostly in X-rays - a property not conducive to life as we know it (simulations also suggest that these bursts erode planetary atmospheres). The possibility of life on moons of gas giants such as Europa adds further uncertainty to this figure.
What evidence is currently visible to humanity suggests that fl is very high; life on Earth appears to have begun almost immediately after conditions arrived in which it was possible, suggesting that abiogenesis is relatively "easy" once conditions are right. But this evidence is limited in scope, and so this term remains in considerable dispute. One piece of data which would have major impact on this term is the controversy over whether there is evidence of life on Mars. The conclusion that life on Mars developed independently from life on Earth would argue for a high value for this term. In 2002, Charles H. Lineweaver and Tamara M. Davis (at the University of New South Wales and the Australian Centre for Astrobiology) estimated fl as > 0.33 using a statistical argument based on the length of time life took to evolve on Earth.
fi, fc, and L are obviously little more than guesses. fi has been impacted by discoveries that the solar system's orbit is circular in the galaxy, at such a distance that it remains out of the spiral arms for hundreds of millions of years (evading radiation from novae). Also, Earth's very large, unusual moon appears to aid retention of hydrogen by breaking up the crust, inducing a magnetosphere by tidal heating and stirring, and stabilizing the planet's axis of rotation. In addition while it appears that life developed soon after the formation of Earth, the Cambrian explosion in which a large variety of multicellular life forms came into being occurred considerable amounts of time after the formation of Earth, which suggests the possibility that special conditions were necessary for this to occur.
The well-known astronomer Carl Sagan speculated that all of the terms except for the lifetime of a civilization are relatively high, and the determining factor in whether there are large or small numbers of civilizations in the universe is the civilization lifetime, or in other words the ability of technological civilizations to avoid self-destruction. In Sagan's case, the Drake equation has been a strong motivating factor for his interest in environmental issues and his efforts to warn against the dangers of nuclear warfare. A lower bound on L can be estimated from the lifetime of our current civilization from the advent of radio astronomy in 1938 (dated from Grote Reber's parabolic dish radio telescope) to the current date. In 2004, this gives a lower bound on L of 66 years.
In an article in Scientific American, Michael Shermer estimated L as 420 years, based on compiling the durations of sixty historical civilizations. Using twenty-eight civilizations more recent than the Roman Empire he calculates a figure of 304 years for "modern" civilizations. Note, however, that the fall of most of these civilizations did not destroy their technology, and they were succeeded by later civilizations which carried on those technologies, so Shermer's estimates should be regarded as pessimistic.
Some computations of the Drake equation, given different assumptions:
R* = 10/year, fp = 0.5, ne = 2, fl = 1, fi = fc = 0.01, and L = 50 years N = 10 × 0.5 × 2 × 1 × 0.01 × 0.01 × 50 = 0.05
Alternatively, making some more optimistic assumptions, and assuming that 10% of civilisations become willing and able to communicate, and then spread through their local star systems for 100,000 years (a very short period in geologic time):
R* = 20/year, fp = 0.1, ne = 0.5, fl = 1, fi = 0.5, fc = 0.1, and L = 100,000 years N = 20 × 0.1 × 0.5 × 1 × 0.5 × 0.1 × 100000 = 5000
The remarkable thing about the Drake equation is that by plugging in apparently fairly plausible values for each of the parameters above, the resultant expectant value of N is generally often >> 1. However, this conflicts with the currently observed value of N = 1, namely ourselves. This conflict is often called the Fermi paradox. However those people who adhere to the premise of the Fermi Paradox believe that, due to a lack of evidence to the contrary, in all probability, humans (as a technologically advanced species) are effectively alone in at least our part of the Milky Way Galaxy. They further say that since we cannot yet determine the variables of the Drake Equation with any real confidence, we cannot determine the numbers of extraterrestrial civilizations based solely on this equation. We must therefore, they argue, rely on data collection - which is only now beginning to be collected in a significant manner. Only then can we even begin to presume what the values of each of the variables in the Drake equation are, they say.