In the 12th episode of Cosmos that aired on December 14, 1980 host and co-creator Carl Sagan introduced viewers to the Astronomer Frank D. Drake’s famous equation. With it, he estimated the probability of the existence of advanced civilizations in the Milky Way that could contact us through the extraterrestrial equivalent of current radio communication technology. Sagan’s estimates ranged from “a small number” up to billions. “If civilizations don’t disappear after they discover radio astronomy the night sky could be humming softly through the sky with the messages of the stars.” Sagan made his voice heard in his signature style. The hope is that some aliens respond to us and we’ll then make use of the familiar aliens to name them. Also, we can utilize the alien name generators to give them interesting names.
Sagan was skeptical about civilizations’ ability to survive their technological “adolescence”–the moment when the advancement of a civilization’s nuclear power, bioengineering, or any other technology that is powerful could lead to self-defeat. In all other respects, Sagan was optimistic about the future of life in the universe and also about the future of intelligence. However, the scientific basis that backed his theories was doubtful at the very minimum. Sagan along with other scientists thought the presence of life in planets that have moderate climates could have been a necessity of cosmic origin since the evidence of geology indicates that it was born extremely fast on Earth at the rate of over 4 billion years old close to the time when our planet experienced a cooling process that was sufficient from its flaming creation. I like Earth, the existence of planets other than ours developed quickly and became more complex over time, then technology and intelligence could be present in the universe.
In recent years, however, some skeptical astronomers have sought to prove their claims by using an advanced form of analysis known as Bayesian statistics. Their efforts on two main issues that deal with the probability of life being created on planets that resemble Earth due to Abiotic conditions also called Abiogenesis. In turn, the probability of intelligent life evolving. Even with these estimates, Astronomers aren’t certain which of them is saying about existence elsewhere within the Universe. The reason for this could be due to the reality that even the finest Bayesian analysis is capable of doing so much in the case that evidence for life and intelligence from other planets is difficult to find.
The Drake equation, which the astronomer introduced in 1961, calculates the number of civilizations in our galaxy that can transmit–or receive–interstellar messages via radio waves. It is calculated by multiplying the number of elements in each that quantify certain aspects of our knowledge of our planets, our galaxy’s life intelligence, and the galaxy. This is the percentage of stars with extrasolar planets, and another count of the planets that are habitable within the solar system that is not in the sun; fl is the percentage of planets that can be habitable, where life forms exist in addition to others.
“At the time that Drake created the equation down, perhaps even 25 years ago, all of these factors could have been factors that made life very scarce,” states Ed Turner, an astrophysicist at Princeton University. We know today how the stars revolved around planets are widespread and the ones which are like Earth in terms of simplest dimensions of mass, mass, and insolation of stars are frequent. That is it appears that there are lots on the galactic surface that life could take over. However “one of the most significant concerns in the whole set of events is the possibility that you will begin to ever take that leap from life to chemistry in the event of a favorable environment,” Turner declares.
Since there is no evidence of such knowledge scientists have made some extravagant claims. For instance, during the past week, Tom Westby and Christopher Conselice both of The University of Nottingham in England have were the subject of news the news when they concluded that there are at a minimum 36 intelligent species within our galaxy capable of communicating with us. The calculations were founded on the notion that there are intelligent life forms that exist on Earth-like planets that have living environments that are habitable in the range of 4.5 billion to 5.5 billion years after the time of their creation.
“That’s only a very particular and solid hypothesis,” says Astronomer David Kipping from Columbia University. “I haven’t seen any evidence to support that it’s an appropriate option to make.”
The answer to questions about biogenesis as well as the evolution of human intelligence poses a problem since scientists have only one piece of evidence regarding the existence of Earth. “We do not even have only one complete data point,” Kipping declares. “We aren’t sure the date when life first appeared, for instance from the Earth. This is also open to doubt.”
Another issue with making assumptions based on local conditions is called selection bias. Imagine buying lottery tickets and then winning the jackpot after 100 attempts. It is possible to calculate a one percent chance that you will win the jackpot. This is obviously an error in the selection procedure that is caused by polling only the winners, not the winners (that is, the many people that purchased tickets but didn’t take home the prize). In making a decision on the probability of biogenesis “we aren’t able to access all the failed experiments,” Kipping states. “So that’s the reason we’re in a difficult position with regard to this issue.”
After that, you are able to begin Bayesian analysis. The technique is based on Bayes’s Theorem that is named after Thomas Bayes, an 18th-century English statistician, and minister. To determine the probability of a certain phenomenon, for instance, an abiogenesis phenomenon, scientists first assess the probability of the process. It is the most precise estimate if you are able to say it like that. For example, one can assume that abiogenesis is as likely between 100 million to 200 million years after Earth formed as it is between 200 million to 300 million years after that time or any other 100-million-year-chunk of our planet’s history. These assumptions are called Bayesian priors and are clearly declared. They then collect evidence or facts. They combine the evidence and the prior to determine probabilities of the future. If the cause is abiogenesis it is the probability of the existence of life on Earth-like planets in the context of our prior beliefs along with the proof. The posterior isn’t an unambiguous number, but rather an underpinning probability distribution that measures uncertainty. It could show the case that abiogenesis is more or less likely over time, instead of having a uniform probability distribution, as was suggested by the previous.
The year 2012 was the time when Turner and his coworker David Spiegel, then at the Institute for Advanced Study in Princeton, N.J., were the first scientists to apply Bayesian analysis to understand the process of biogenesis. Based on their study, the Earth-like globe around a sun-like star does not form until a certain period of time, known as minutes after the birth of the planet. If life doesn’t emerge before a certain limit of time, the star’s age is reached (and eventually, it ceases to exist) those conditions that exist on Earth cease to be sufficient for abiogenesis. Between the min and the maximum, Turner and Spiegel’s goal was to assess the likelihood of the process of abiogenesis.
Researchers studied a variety of previous distributions of this probability. The researchers also believed in the fact that intelligence requires an exact time to develop following the process of biogenesis.
Based on these theories and the evidence from geophysics and paleontology of the beginnings for life on Earth and the evolutionary theory that suggests the evolution intelligence Turner and Spiegel were capable of calculating various posterior probability distributions of biogenesis. While evidence that suggests life began on Earth might suggest that biogenesis is not difficult to determine the posteriors. It did not place any lower limits on the probabilities. Its equation “doesn’t eliminate the extremely low probability that is a bit of common sense when you’re dealing with the statistics of one kind,” Turner states. Despite the rapid expansion that life has on Earth biogenesis could be an extremely rare event.
Turner and Spiegel’s findings were the “first seriously serious Bayesian attack on this issue,” Kipping states. “I think the thing that I found interesting was that they broke the default uninformed interpretation of the earliest emergence of the universe.” Do you believe there’s a milky way to a nation for aliens? If there is, what’s the name for an alien’s home country? If you’re looking to make your own name for your alien friend’s name then you can use this awesome online tool to country name generator.
