Exploring the universe.. Man's search for intelligent civilizations outside Earth
Science fiction writer Arthur Clarke says: There are two possibilities, either we are alone in the universe, or we are not, and both possibilities are equally terrifying 1 .
That is, if we subject the entire universe in our laboratories, and adapt every possible tool and means to study it, we will eventually find ourselves stuck in a terrible maze, by getting one answer from two possibilities that have no third, either there are intelligent creatures other than us, or we are alone in a space Vast majestic We swim in elliptical spheres to a written stable.
Man is ignorant of more than he knows, and what he is ignorant of is much more than he is ignorant of. Perhaps man’s limited awareness of the environment and marine creatures residing in the oceans on the planet – which does not exceed 20%, as indicated by the “Oceanic Exploration and Research Office” (NOAA) – It is the greatest evidence that what is hidden has always been greater than what appears to us 2 .And if we direct our eyes towards the sky, the area will undoubtedly expand more, and our awareness, knowledge and knowledge of what is around us will collapse like crazy, and in order to realize what extent of madness and helplessness a person may reach in his pursuit of exploration and research, we need to study the size of this huge area, an area Universe.
Calculation of astronomical distances.. from the Greeks to the Renaissance
First of all, calculating astronomical distances was not an easy matter since the first human attempt until today, but thanks to the use of some mathematical rules in trigonometry, some ancient scientists were able to reach highly satisfactory results in measuring the distances between nearby celestial bodies.
In 240 BC, a Greek scientist named Eratosthenes performed a very unique experiment to calculate the circumference of the Earth by assigning a man to measure the distance between the cities of Alexandria and Aswan in Egypt step by step, and then he measured the shadow of a column caused by the sun’s rays in Alexandria at a time when the sun was perpendicular to Aswan on the day of the summer solstice, which falls on June 21.
Eratosthenes found that the angle formed by the shadow in relation to the column is 7.12 degrees, and with prior observation that the Earth is spherical due to the appearance of the Earth's shadow curved on the moon at the moment of the eclipse, which means that the circumference of the Earth is 360 degrees, and by knowing the distance between the two cities Aswan and Alexandria, he was able to find the appropriate mathematical relationship between the variables to obtain the distance of the circumference of the Earth, and he was able to obtain a value for the circumference of the globe. We do not know how accurate it is because it was measured in the stadium unit, but no matter what, the method was an accurate
scientific 3 .
Kepler's second law, which describes the speed of a planet in its orbit around the sun
Renaissance and the search for other beings
Then, a few years later, the Greek mathematician Aristarchus of Samos came to develop several concepts and hypotheses about the universe. He was one of the first to assume that the sun is the center of the universe, and that its diameter is between 6.3 and 7.2 times the diameter of the Earth. In fact, the diameter of the Sun is equal to 109 times the diameter of the Earth - although Aristarchus' attempt seems wrong, but it was based on three geometric concepts:
1. It was also observed during the eclipse that the length of the diameter of the Earth is equal to twice the length of the diameter of the moon.
2. Both the Sun and the Moon have angular diameters equal to half a degree.
3. In a quarter of the lunar month, the sun moves away from the moon by an angular distance of 87 degrees.
By finding a geometric relationship between the above data, he was able to find the diagonals of the Sun and the Moon, and of course all of these concepts were not realized by precise mathematical calculations, but by observation, which explains to us the incorrectness of Aristarchus' numbers, but it was a geometric mathematical method anyway. And if we correct the three data today and then use the same geometric relationship, we will get very satisfactory answers 4 .
And if we go towards a larger scale, towards the planets, we find that the Greeks in the past were aware that the planets move on one plane in the sky, because they appear in the sky through the forms of the constellations, and this is what was easy to determine their path.
In the era of the Scientific Renaissance in Europe, the Polish scientist Nicolaus Copernicus appeared in the sixteenth century to contribute to finding the distance between Earth and Mars, given that the sun is the center and all the planets revolve around it in circular orbits.
However, this was not really correct, and the arithmetic records did not correspond to the shape of the circular orbits of the planets, and this is what called the German scientist "Johannes Kepler" (Johannes Kepler), who lived in the same time period, to correct Copernicus' claim, as he said that the orbits of the planets It is rather elliptical rather than circular. Then he laid down his three famous laws well-established in astronomy:
1. The planets revolve in elliptical orbits around the sun.
2. The speed of the planet changes with the change in its positions around the sun. The closer it is, the faster it is, and vice versa.
3. The square of a planet's orbital period is proportional to the cube of half the length of its greatest orbit around the Sun.
With these three laws, it became easy to know all the characteristics of the motion of the planets and the cosmic distances between the nearby celestial bodies in our solar system using only mathematics.
Astronomers are still searching for the capacity of this universe, but they have not yet reached a tenth of what they are aiming for
"Cosmic microwave background radiation"... Measuring the age of the universe
As we move away from Earth, we find that the universe is expanding more and more, and that the store of classical mathematics and geometry that we possess is hardly sufficient for us in calculating the long distances between Earth and between stars and galaxies, let alone calculating the size of the universe.
But with the development of science and technology, astronomers have very effective weapons to answer many questions, although the exact answer about the size of the universe seems far from being achieved due to the difficulty of verifying this with complete certainty.
In 2013, the European Space Agency's Planck telescope announced the "cosmic microwave background CMB" image, which is the most accurate and oldest possible image of the universe, as the age of the universe in the image is 380,000 years, and radio telescopes were used instead of optical telescopes To capture the electromagnetic waves scattered between stars and galaxies in the picture, and also shows the distribution of these radiations, which indicate the variation in temperature from one place to another, and it appears that the average temperature of the universe is 2.73 Kelvin, which is equivalent to 270.42 degrees below zero.
If we imagine that the universe represents an 80-year-old man, then this image will show that man as a newborn child less than one day old 5 .
The importance of this wonderful scientific masterpiece is that it gives scientists the ability to estimate the age of the universe, which is 13.8 billion years, by studying the "baryonic acoustic oscillations" that fill the picture (baryons are the material of which the universe and stars are made). Those invisible rays as they appear in the picture have traveled this many years to reach us in this way, and using the relationship between distance and light "electromagnetic rays", we will find that wherever we direct our eyes in all directions around us, we see a distance equivalent to 13.8 billion light years.
It is as if we are stationed in the middle of a spherical universe with a radius equal to that distance, and its full diameter is equal to 28 billion light-years, which is what is called the observed universe. There is something more amazing and miraculous.
Astronomers are aware that the universe has been expanding since its creation, and according to their estimates, the correct figures for the length of the radius of the universe are about 46 billion light-years, and the length of its diameter is about 92 billion light-years, and this is what is called the "visible universe" and not the observed, because The light has reached these astronomical regions during the expansion of the universe, but we have not yet reached their light 6
Finally, if we are looking for something greater than that, scientists estimate the actual size of the universe, which has not yet reached the light, far exceeding the size of the visible universe. Scientists estimate, based on some calculations, that the entire universe is at least 250 times the size of the visible universe. They are undoubtedly staggering numbers, and this gives us the opportunity to ask and wonder if there are really other creatures in this universe on the surfaces of some planets in this huge cosmic expanse.
The message, designed by astronomer Frank Drake at the request of Carl Sagan, to be sent on board the two Pioneer spacecraft
“Only one ear of wheat in a large field” .. a dialectic since the time of the Greeks
Talking about the possibility of extraterrestrial beings is not the talk of this hour and not the talk of this century, but rather just fantasies, perceptions and debates that spanned for centuries, as evidenced in the ancient records, as the Greek philosopher Metrodorus says in his book “On Nature” 400 BC: It is unnatural to have only one ear of wheat in a large field, and also to have only one world that has life in an endless universe 7 .
It is his belief that this universe must have a cause, and that the Creator would not have created anything in vain, and the conflict continued and its climax appeared at the beginning of the seventeenth century when the Italian philosopher and monk Giordano Bruno was executed by burning by the Italian authorities, after he The Inquisition launched a campaign against him, describing him as a stubborn heretic, for his insistence on violating the beliefs of the Roman Church by saying that this universe is large and has no end, and that there is life there other than that on earth 8 .
A century later - that is, in 1698 - the famous Dutch physicist Christian Huygens published his book "Cosmotheoros", in which he alluded to the possibility of the existence of other living beings far from Earth, and indicated to the Church to accept this idea because it is not It contradicts religious concepts. On the contrary, there must be a divine motive for everything.
It was just conflicting ideas based on philosophical beliefs and other manifestations that do not go beyond seeing the eye, until the German mathematician "Carl Friedrich Gauss" (Carl Friedrich Gauss), to whom the first practical proposal to communicate with aliens appeared at the beginning of the nineteenth century. Gauss suggested that human communication should be based on a visual mechanism, by designing a huge forest of trees in the form of geometric shapes represented by a right-angled triangle as a reference to the famous Pythagorean theorem, and a square limiting each of the three sides of the triangle, which would be a strong hint for any guest lurking Us that intelligent creatures inhabit the earth 9 
.
.Gauss's proposal was not implemented due to its high cost, but scientists became increasingly enamored with the existence of extraterrestrial life, especially when the Italian astronomer Giovanni Schiaparelli claimed the discovery of artificial water channels on the surface of Mars in 1877 to explode them to the public. There are intelligent creatures that are similar to us and that they live on the surface of the red planet, and this would have caused uproar in the scientific community, but later investigations proved that what was on the surface of Mars was nothing but natural terrain features and that there is no evidence of the existence of living creatures.
All of the above was just a fuse about to ignite, and with the advent of radio-ray technology, the planet Earth moved from one stage to another in the ability to discover and communicate invisible across the universe.
Every moment, millions of radio messages are sent out from Earth
? into space, so does anyone pick them up there
Modern day technology..invisible communication with other civilizations
At the beginning of the twentieth century, with the advent of the wireless telegraph by the prestigious American inventor Nikola Tesla, communication between two places separated by a long distance seemed very possible using electrical signals to send radio waves between these two points. the radio.
The fever of communicating with extraterrestrials was creeping into the heart of Tesla, and this was evident by giving him promises that we would communicate with the inhabitants of Mars one day, thinking that someone was trying to communicate with us through the newly discovered radio technology 10 .
Radio has evolved over time, but it has not practically volunteered to serve the search for life outside the blue planet because of the countries’ preoccupation with fierce wars for half a century, and after the pace of direct military conflicts subsided, the conflict between the leading countries moved to another arena in technology.
On the nineteenth of September 1959, a research paper, the first of its kind, was published in the monthly scientific journal “Nature” in its issue of that date, and it was titled “The Search for Communication with Beyond the Earth” under the supervision of the two scientists “Giuseppe.” GIUSEPPE COCCONI and PHILIP MORRISON. Their research did not go beyond the two papers, but it did include some mathematical equations and frequency band estimates for the received signal to distinguish between a natural signal that came from nature and a modified signal that was cleverly made to transmit.
Then followed the emergence of the famous equation "Drake Equation" developed by the American astronomer "Frank Drake" in 1961, and it was a simplified answer to the expected number of intelligent civilizations in our galaxy the Milky Way. This equation is the cornerstone in this regard, and its importance is equivalent to the value of the famous Einstein equation: energy is equal to mass multiplied by the square of the speed of light (E = mc^2).
The Drake equation included seven variables as follows:
N: The number of civilizations in the Milky Way that can be detected by an intelligent radio message.
R*: The number of stars born each year.
fp: the ratio of the number of stars around which planets revolve.
ne: the average number of life-sustaining planets in each solar system.
fl: the proportion of planets inhabited by life.
fi: the proportion of planets inhabited by intelligent civilizations.
fc: The percentage of intelligent civilizations that have developed technology and are able to emit electromagnetic waves into the universe.
L: the time distance between the transmitted signals and the intelligent civilization 11 .
The Drake equation for rational civilizations in the Milky Way
SETI.. Exploring creatures that communicate with Earth
The Drake equation led to impressive results, as it predicted the existence of intelligent civilizations exceeding ten million civilizations in the Milky Way alone. Using a radio telescope with a diameter of 26 meters in the heights of West Virginia and pointing it at the star Tau Ceti to study the possibility of the existence of intelligent aliens.
Then another project followed in 1957 for the same purpose, which was adopted by Ohio State University using a flat radio telescope equipped with a parabolic reflector. The cost of the project was approximately $71 thousand. This project recorded perhaps the greatest discovery in the way of searching for intelligent creatures in space, as the telescope was able on the fifteenth of August 1977 to capture a very exciting signal coming from space.
The signal coming from space drew the attention of those in charge of the project, to the extent that one of them was so surprised when he saw the analysis of the wave data that he did not believe what his eyes saw, so he put a red circle around the signal and then wrote “Wow” next to it as an expression of his surprise and enthusiasm, and since then this incident has been known With the sign "Wow", it is the most prominent evidence of the attempt of some creatures to communicate with humans 12 .
This was the impetus for the emergence of the Search for Extraterrestrial Intelligence in 1984, led by prominent astronomers such as Carl Sagan, who gave the institution an additional dimension to occupy a prestigious rank among the basements of scientific centers in the country This enabled her to use the latest telescopes and radio observatories.
And its tireless work continues to this moment, but without mentioning any concrete evidence of the existence of extraterrestrial life, and this somewhat reinforces the pessimistic theory of physicist Enrico Fermi in this regard.
The Wow signal was discovered by astronomer Jerry Ehman in 1977 while working on the Ohio University project
The Fermi Paradox: "The truth is that we don't see anyone, so where has everyone gone?"
In the fifties of the last century, the Italian scientist “Fermi” appeared confused in his matter and did not find a way without disclosing it. He saw that the data of the universe were clearly manifested in front of us, but there was a dilemma in his way, which called him to call it “Fermi Paradox” ) which says: As long as the universe is very wide and full of galaxies, stars and planets similar to Earth, in addition to its age of more than 13 billion years, it is assumed that the universe is full of different forms of life, and it is expected at the very least that we will see a trace of one of those intelligent civilizations in the universe, But the truth is that we don't see anyone, so where did everyone go 13 ?
Perhaps at first glance it seems a real dilemma, but the scientist "Carl Sagan" - who was presenting the famous TV program "Cosmos" in the mid-eighties of the last century - answered at the time about that paradox and the question "Where did everyone go?" By saying: The absence of evidence for something is not evidence for the absence of that thing.
That is, we may still be at the beginning of the road yet, and it is too early to talk about the inevitability of something without evidence, which is impossible to obtain easily in this vast and majestic universe.
Sources:
[1] Kaku, Micho (1999). Visions: How Science Will Revolutionize the Twenty-first Century. Oxford, Oxford Paperbacks. p 378
[2] Petsco, Emily (2020). Why do so many oceans remain unexplored and unprotected? Retrieved from: www.oceana.org
[3] Brown, Cynthia. Eratosthenes of Cyrene: Calculation of the Earth's Circumference. Retrieved from: www.khanacademy.org
[4] Evans, James. Aristarchus of Samos. Retrieved from: www.britannica.com
[5] Howell, Elizabeth (2018). The Universe's Micro Background: Remnants of the Big Bang. Retrieved from: www.space.com
[6] Reed, Nola (2017). What is the size of the universe? Retrieved from: www.space.com
[7] Delay, Michael (2020). If we found life on Mars, what would it be? Retrieved from: www.astronomy.com
[8] Mason, Michael (2018). Burning for his faith in science. Retrieved from: www.discovermagazine.com
[9] Oberhanus, Daniel (2019). The endless possibilities for life in the universe. Retrieved from: www.supercluster.com
[10] Editors of the site. Nikola Tesla promises communion with Mars. Retrieved from: www.teslauniverse.com
[11] Sharif, Yaman (2019). Arecibo's message...from man to aliens. Retrieved from: www.doc.aljazeera.net
[12] Breitman, Daniela (2017). wow! Was the sign known after 40 years? Retrieved from: www.earthsky.org
[13] Howell, Elizabeth (2018). The Fermi Paradox: Where are the aliens?. Retrieved from: www.space.com
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