“The question of existence of the developed civilizations in other place of the Universe was always saddened by three big uncertainty in Drake’s equation”, Adam Frank, professor of physics and astronomy at University of Rochester says. “We know long ago how many approximately exists stars. We don’t know how many from these stars have planets which, perhaps, have sheltered life as life often could develop and lead to reasonable beings; as there can long be a civilization before dies out”.
We don’t even know whether highly developed technological civilization can exist more than several centuries. However Frank and Woodruff Sullivan’s new work allows scientists to begin to use everything that they know about planets and climate and to model interactions of types, strongly dependent on energy, in their native world.
“Our results show that our biological and cultural evolution wasn’t unique and, perhaps, happened many times before. Other cases can include a set of civilizations, dependent on energy, which try to cope with crisis on the planets in process of growth of civilizations. We can begin to investigate this problem, using modeling to gain an impression about what results in longevity of a civilization and that isn’t present”.
The new research shows that recently opened exoplanets in combination with broader approach to a question allow to define new empirically significant probability of existence of the developed civilizations on the Universe history piece. And it shows that if only chances of emergence of life on the planet aren’t infinitely small, the mankind will be neither the only, nor the first developed technological civilization.
The operation published in Astrobiology log also for the first time shows what means “pessimism” or “optimism” in the context of assessment of probability of existence of developed extraterrestrial life.
“Thanks to researches of the satellite of NASA of Kepler and others, now we know that about one fifth stars have planets in “habitable zones” where temperature allows to exist life known to us. Therefore one of three largest uncertainties can already be restricted”.
Frank says that the third largest question of Drake — as long there could be civilizations — still absolutely unclear. “The fact that people located rudimentary technologies about ten thousand years says nothing about whether other societies also long will potter with them or even longer”, he explains.
In 1961 the astrophysicist Frank Drake developed the equation for assessment of number of the developed civilizations capable to exist in a galaxy the Milky Way. It looks so: N = R * (fp) (ne) (fl) (fi) (fc)L, decryption of each variable is lower. Proceeding from the elementary statistics, it is easy to count that somewhere there can be thousands, even millions of alien civilizations:
R*: speed of formation of stars in our galaxy.
fp: percent of the stars possessing planets.
ne: number of planets of earth type around each star having planets.
fl: percent of planets of earth type which developed life.
fi: percent of planets with life on which intelligent life developed.
fc: percent of reasonable types which reached creation of technologies which can be found by forces of an external civilization like ours. For example, wireless signals.
L: a median number of the years necessary for an advanced civilization to mark detectable signals.
Drake’s equation became a basis for researches, and space technologies deepened knowledge of scientists concerning several variables. But it is almost impossible to learn the possible duration of existence of other developed civilizations — L.
Frank and Sullivan offered the new research addressed to a bit different question. What if some civilizations developed in process of history of the observed Universe? Frank and Sullivan’s equation relies on Drake, but removes need for L.
“Instead of asking how many civilizations can exist today, we ask: whether really we the single technologically developed look?”, Sullivan says. “This offset of focus removes need for a question of duration of existence of a civilization and allows us to deal with a so-called “issue of space archeology” — as often in the history of the Universe life developed to technologically advanced status?”.
Still there are serious uncertainties in calculation of probability of appearance of developed life on habitable planets. And here Frank and Sullivan do a turn. Instead of calculating chances of appearance of developed life, they calculate chances against its appearance that is whether the mankind the single developed civilization in the history of the observed Universe can be.
“Of course, we have no idea, the probability of emergence of a reasonable technological look on separately taken planet is how high”, Frank says. “But using our method, we can precisely tell, the probability that we will be the ONLY civilization in the Universe is how small. We call it line of pessimism. If the probability goes beyond line of pessimism, the technological look and a civilization means appeared before”.
Using this approach, Frank and Sullivan have expected how improbable has to be the developed life if no her uniform example would occur among two hundred billion trillions of stars of the Universe. Or even among one hundred billions of stars of the Milky Way.
What result? Applying new data on exoplanets to the Universe in general, Frank and Sullivan have found out that the civilization will be unique for space, only if chances of emergence of a civilization on the manned planet are less than one to 10 billion trillions, or 1 to 1022.
“One on ten billion trillions is very little”, Frank says. “It is obvious to me that other reasonable technologically developed types, most likely, developed to us. Think of it in the following key. To our results you would be considered the pessimist if you have counted probability of emergence of a civilization on the manned planet, say, in one to one trillion. But even if to assume that one chance of one trillion took place, then the event on Earth happened at least 10 billion times throughout our space story to mankind”.
If to take volumes it is less, then in our own galaxy the Milky Way has appeared other technological look if chances that he won’t appear less than one to 60 billion.
It is good. If these figures give to “optimists” reasons to be glad for existence of extraterrestrial civilizations, Sullivan says that the full equation of Drake — which defines probability of existence of civilizations today — can console pessimists.
“The Universe there is more than 13 billion years”, Sullivan says. “It means that even if thousands of civilizations in our galaxy would exist presently — all these ten thousand years — all of them have already for certain disappeared”. And others haven’t appeared. That we have succeeded in search of other technologically developed civilization, it has to exist on average more, than we exist at the moment.
“Considering huge distances between stars and the fixed velocity of light, we anyway will never be able to contact other civilization, to talk to her”, Frank says. “If they were in 50 000 light years, exchange of messages would take 100 000 years”.
But from the philosophical point of view absolutely not very well whether we can contact other civilization. It is important that she existed. And it already sets thinking deeply.
