We have found over 2000 exoplanets. In our galaxy there must be billions of them. Where we find the aliens?
The Drake equation helps
First of all, we need to know how many exoplanets in our milky way, the same conditions of life (earth-like, habitable Zone, not bound Rotation) as our earth. With the findings of the past years can be roughly calculated, namely, N = 2∙10∙f.
where f is the factor that determines the above-mentioned proportion. According to today’s Knowledge, he is about f ” 10. Thus, there is in our milky way is about 100,000 planets, on which higher life could arise. The crucial question is, how many could, in principle, occur, but what is the probability that there is higher life is and how many planets exist with such Aliens in our milky way. The famous Drake equation tells how to calculate the theoretical, namely,
N = f∙R∙R∙L
Here, R is the star formation rate in the milky way, we know quite well, namely, R = 20/year, and L is the lifetime of a civilization. The product 2∙10∙R∙L is the fraction of all civilizations that exist today to those that arise in the milky way. f is the probability that out of inorganic matter or the simplest of organic molecules, first primitive life, and this higher life is. About the experts
former Astronaut Ulrich Walter, since March 2003, the chair of space technology at the Technical University of Munich and teaches and conducts research in the area of space technology and systems engineering. His main focus is on real-time robotics in space, inter-satellite communications are explorations of technologies and technologies for planetary.
Where are the problems?
The Nice thing about formulas is that you can see immediately where the problems are. Obviously, we now have two problems. First of all, we know not how large f is. Our own existence only States “It can happen”, but not with what probability. Secondly, we do not have the slightest idea of how long, on average, a civilization exists.
One after the other. The determination of f is a tough nut to crack, he is giving the scientists the life. It is a question of the evolution is to biologists, what is the probability of a single cell, resulting in, say, wire-haired Dachshund, and it eventually intelligent life arises that can operate inter-stellar communication, because that’s the way intelligence is defined today, Astro-biologically. So we are only since the 16th century. November 1974, intelligent, as mankind, with the largest radio telescope in the world, the Arecibo telescope on Puerto Rico, the so-called Arecibo message to alien in the direction of the great globular cluster Hercules, Messier 13, sent. Whether that was actually intelligent is a whole other question.
/iStockphoto radio telescope in Arecibo, Puerto Rico
Critical steps in the development
What my biologist evolution? The shrug their shoulders and think: “This happens pretty rarely!” Why rare? Because, allegedly, the first step from inorganic matter to the first cell is extremely complex. It is a cell envelope must exist, in the random way certain complex proteins (Ribosomes) are in the works, which, in turn, of an extremely complex genome (mRNA), such as other cellular proteins that produce, degrade, transform (enzymes) to name just a few of the components of cellular life. How can this orchestrated an extremely complex Interplay out of Nothing? These so-called first critical step in the evolution the evolutionary biologists, until now, not understood. You just have to say, it was extremely rare.
That from a first single-cell and more cells are formed and thereafter, two or more cells join to form a more complex multicellular organisms, in turn, is not so unlikely. Only, there are in nature no further, targeted development, in the context of the Darwinian selection purely by chance. There is a selection process by the wire-haired Dachshund to the people? Not really, say biologists, the evolution, because a large brain with many neurons is initially a disadvantage. It consumes only two per cent of body mass, about 20 percent of the organism’s available energy. The brain of children at the age of 4-5 years, consumed as much as 43 percent of the total energy. If a primitive person in case of emergency, must escape from a Predator, they can be 20% essential. Larger brain mass, and thus higher long-term intelligence pays off only in the long term. Can’t know a short-term selection principle. Therefore, this development step is for evolutionary biologists to a higher intelligence is also critical, that is to say extremely unlikely.
The evolutionary biologists believe that there is a total of about 5-20, more or less critical steps in its Evolution, including humans. But what does this mean in Numbers, concretely, for f? Since you can not define, but only approximate limits, namely f = 10 – 10. Socorro, New Mexico: With telescopes will exist, the universe examined
How long civilizations?
And then there’s the second Problem: How long a civilization exists after it is created once? This is a question for sociologists, who deal with extraterrestrial civilizations. But there is no. The only thing we can do under these circumstances, from our experiences on other civilizations. There are some who say that if a civilization nuclear bombs are bombs of life, while others say that Really intelligent beings to prevent this knowledge, and therefore exist forever, as soon as they arise. Since our milky way is about 10 billion years old, is somewhere the life, therefore, between L = 100 – 10 years.
By skeptics and optimists
When we use these limits for R and L in our above equation, we get
N = R∙f∙f∙L = 10 – 10
for the number of other civilizations in our milky way. This is all what we can say today, statistically. Everything therefore depends on two questions: How likely intelligent life from simple organic molecules and how long do civilizations exist? According to the skeptics, what Ward and Brownlee with their Rare earth hypothesis, then the answer is “are We alone in our milky way”. Optimists, Some will say: tens of thousands of. But even with so many Aliens, the average distance between civilizations in our vast milky way is almost exactly 1000 light years. But a message to radiate signal in all possible directions in space, a civilization, the whole of our humanity available electrical energy. And that’s not for a few minutes, but permanently over millions of years. That would hardly make a civilization, and this is, in my opinion, the reason why we have after 50 years of painstaking searching (SETI), there is no Signal from aliens is received. It seems to be really so: In our milky way there are not more than about 10,000 civilizations. I personally don’t believe that anymore than a handful, maybe we are even alone.
we Are alone in the universe?
things are different when you have to wonder how many Aliens there are in the universe. Alone in our observable universe there are about 100 billion galaxies, each about as big as our. We apply this number to the Drake equation, we get N = 10 – 10. So, one can say, in the galaxies we can see with our telescopes, in principle, there is bound to be alien. But our universe is much more than what we can see. We know today, we live in a virtually infinitely large universe. In order for the presumption to a certainty, we are not alone in the universe.
But what’s the use? In the gigantic intervals of many tens of millions of light-years between galaxies, we will never (I repeat never!) get in touch with you, because technically, we are prisoners of our own milky way.
Copyright: the rights to The article are with Ulrich Walter.
PR book review Of Ulrich Walter appeared: hell of a ride through space and time (2017)
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