living in space

Albert Kalifa wants to find out what the chances are of finding life outside the earth.

Published for the first time on the knowledge site on 19/4/2005

Extraterrestrial life is supposed to develop on Earth's twin planets, which are planets with conditions for the development of life that has the potential to eventually reach intelligence... and the reference is to life similar to what developed on Earth, which is currently the only known life model today. Admittedly, such planets have not yet been discovered, but another vision for the time.

The possibility of extraterrestrial life
The assumption regarding the existence of extraterrestrial life is based on two factors: the first is the belief of the masses (without proof of course), and the second is the hypothesis of scientists (still awaiting proof). In contrast, knowledge (with proof) of the existence of other lives does not yet exist.

From the dawn of history to the present day, human culture has believed in stories and legends about gods and all-powerful beings that exist outside our world and influence our lives. Such beliefs can be found, among others, in:
1- The Sumerians and the Babylonians - who believed in the gods who come in chariots of fire "Harpoon" (an American missile is named after them)
2- The Greeks and Romans - who believed in the gods of Olympus, Uranus and Jupiter, who determined the movements of heaven and earth (mythology)
3- Judaism and Islam - those who believe in God and the reincarnation of souls that eventually reach heaven (heaven or hell)
4- The Bible and the Zohar - which talk about gods coming down from heaven and making us genetically better (Genesis 4, verse XNUMX)

And the last word of these beliefs are the aliens in their flying saucers who visit us en masse since the "Roswell" incident in the USA in 1947 until the very present day, and our small country also 'earned' their visits especially towards the end of 1996, when we too were carried away by this modern 'obsession' .

What all these legends and stories have in common are two things, the first is a strong belief of the majority of the human race in the existence of life outside of our world as mentioned, and the second is the total absence of any evidence of their existence, an evidence that can be seen or felt, neither in the past nor in the present. Furthermore, there is still no proven evidence of an encounter with life outside our world. All evidence of face-to-face encounters with alien life are stories of prophets and legends from the distant past or the testimony of a single person in our time without reliable backup.

But on the other hand there is a hypothesis of scientists about a high probability of the invention of other life in the universe.
This hypothesis is based on several solid facts, among them:

• The number of stars in the universe is infinite.
• All the materials that make up the universe are the same materials that make up the earth.
• All the laws that operate throughout the universe are the same laws that operated and operate on Earth.
• The findings from Earth show that life in all its forms is the result of the evolutionary development of the first living cell (according to Darwin, 'The Origin of Life' - 1859), which was probably created from the evolutionary development of matter (which is possible according to Prof. Lipson - Weizmann Institute).

That is: it is possible that life is not a one-time creation of God, but is a possible development of matter under the special conditions that prevail on Earth and over a very long period of time estimated at no less than 3.8 billion years.
If this hypothesis is correct, then there is no reason why life similar to us should not develop on planets with conditions similar to ours, i.e. "Earth twins". Because there is no reason why nature, which is very fruitful on Earth, should be barren on other planets. And if we want contact or an encounter with such life, we have to look for it in planets with similar conditions to us.
It is true that there are ideas in science fiction about exotic life forms that can develop not on earth twins, but in clouds of cosmic dust, in massive stars, at high temperatures, etc., but for now this is a matter for science fiction only, and for science fiction the sky is not the limit either.

What are the characteristics of planets that allow the development of life?
All the variety of life on earth, starting with bacteria, through plants, animals and up to man, all without exception need, for their development from a cell to intelligence, a planet with three basic conditions, and they are:

water: a substance needed for metabolism inside the living cell. As we know, there is no life without water. Even in the driest desert, the plants and animals must obtain water absorbed from the moisture in the air or under the sand. We do not know of any other substance used for metabolism in the living world besides water.

Two - flowing water: all forms of life require water in a liquid state for free flow through the membranes that surround the entire living cell. Frozen water does not allow metabolism in the cell. And water in a gaseous state evaporates from the cell and it dries. Liquid water is only possible in a certain temperature range, which is between 0-100 degrees Celsius and clean water at sea level. (This range changes at different atmospheric pressures and in solutions of water with salts inside the cell). Such a temperature range requires:

1. A certain distance of the planet from its sun, too close will be hot, too far will be cold.
2. An atmosphere that will wrap the planet like a blanket, otherwise the temperature at night on the planet will drop to values ​​far below zero. (The space temperature is about 270 degrees)
3. A certain size of the planet (ie mass) that can hold a stable atmosphere that will not evaporate into space.
In short, liquid water requires a planet with water and an atmosphere of a certain size and at a certain distance from the sun.

Water flows into the world: intelligent life must have liquid water in their world for the entire period of their development, in other words, they must have a stable range of temperatures between 0-100 degrees without a break since the creation of the single cell up to man, which as is known lasted for about 3.8 billion years. Any change in the stability of the temperature above the boiling point or below the freezing point of water, even for a few years, destroys the entire animal world and the game of life's evolution must start all over again, if at all. Such incredible stability of temperature over billions of years requires a planet with one sun and one large moon. Because a system with more than one sun (which is quite common in our galaxy) changes over time the stability of the planet's orbit, i.e. its distance, i.e. its temperature beyond the above range. Even the absence of a moon, or even a (relatively) small moon, will not be able to stabilize the rotation axis of the planet around itself, and as a result, the seasons will not be perpetuated in the various regions of the planet for continuous development for millions of years.

To summarize: Earth twins who have a chance to develop a life from cell to intelligence must be planets with Mzal (acronym for water flowing to the world), because Mzal is the ultimate condition for a planet with intelligence. And in order for a planet to have a star and become a twin Earth like us, it must have water, an atmosphere and a mass above a certain size and have one large moon, and have an appropriate distance from a single sun that was formed more than 3.8 billion years ago.

Where to look for life? :
The universe is made up of countless galaxies, and each galaxy is made up of billions of stars, and the hypothesis is that each star (that is, the sun) holds some kind of system of planets. Therefore, life can be sought in our solar system, in our galaxy or in the millions of other galaxies.

Local tip: As we know, our solar system consists of nine planets, several dozen moons and thousands of asteroids and comets. The asteroids, comets, and all the moons are planets without luck because they are either small and unable to hold an atmosphere, or they are far from the sun and therefore frozen without flowing water (except Europa and Titan, the moons of Jupiter and Saturn).
The four distant planets, Saturn, Uranus, Neptune and Pluto, are also unlucky planets because of the freezing temperature that prevails on them, close to 200 degrees below zero. Luck was also not kind to the small 'hot' planet without an atmosphere and closest to the sun. The temperature on its surface rises to 450 degrees during the day, well beyond the boiling point, and at night it drops to a freezing point of 150 degrees (a difference of 600 degrees between day and night).

The most promising candidate as an 'Earth Twin' was revealed, unfortunately, as a total paradox of the solar system. And of course the reference is to 'Venus', the symbol of the beauty of the sky, as evidenced by its foreign name "Venus". Although it is very similar in size and distance to Israel, and has a rich atmosphere that also contains a little water, but unfortunately it does not have Mzal, because a massive greenhouse effect developed on it that caused the heat on its surface to rise up to 480 degrees, almost constantly, and made it the queen of beauty of heaven to a real and dry hell of the solar system.

Mars was also a natural candidate to be a 'Twin Earth' in terms of size, age, distance, water and atmosphere, but he too had no luck, because the liquid water that previously flowed over its surface did not last 'forever', it evaporated when it was in the past or went down Below the surface, some of them are still in their poles. Therefore, it is possible that primitive life developed on it in the past, but they did not have time, due to lack of running water, to continue to develop to intelligence.
It is possible that the reason for this is the small moons of Mars, Phobos and Demos, one 15 km and the other only 27 km in diameter, which did not manage to stabilize its axis, as our large moon with a diameter of 3480 km did.

One of the places in the solar system that may turn out to be auspicious is the moon Europa, a moon of Jupiter. It is indeed a little smaller than our moon (3135 km in diameter), far from the sun, cold and without an atmosphere, but it has a thick uniform and cracked ice layer, which protects an ocean of liquid water, which is heated by the volcanic activity of the interior of the moon, an activity caused by the very strong gravitational force of justice
There is a hypothesis that in such an environment of 'liquid water for the world' that is under the ice layer, life types can develop like the living organisms discovered in the depths of our oceans, near hydrothermal vents with volcanic material at a temperature of 113 degrees, but it will be difficult for them to reach a high intelligent level inside the water .
To test this hypothesis, a NASA spacecraft is planned to be sent to 'Europe' in 2008.
Another moon with the same chance is Titan, the large moon of Jupiter that also managed to hold a thick nitrogen atmosphere, the Cassini spacecraft will reach it in early July 2004 and a lander will be launched to land on it in early 2005 to carry out initial tests of the aforementioned hypothesis.

Galactic search: the galaxy we are a part of has over a hundred thousand million stars (ie suns). They are scattered in space in the form of a disc with a diameter of one hundred thousand light years and a width of thirty thousand light years.
A light year (SA) is the distance that light travels in a year, equal to 9.5 million million km. As we know, the speed of light is 300.000 km per second and light is able to circle the earth seven times in one second.
Despite the hypothesis that most stars have planets, since 1995 until today only signs of the presence of about 120 planets around the stars of the galaxy have been discovered. And only one planet was photographed (with the help of the 'Hubble' telescope), and this is because of the vast distances that separate us, and it is important to note that none of the discovered planets is a twin of Earth.
The closest sun to us is the star Alpha B 'Centauri' whose distance is 4.3 AU. Therefore, the journey to it at the speed of today's spaceships (maximum 30 km per second) will take 43 thousand years. Only in spaceships that are a thousand times faster (that is, 30.000 km per second) can the journey be shortened to 43 years (for one lifetime). Such a speed, which is one tenth of the speed of light, may be theoretically achievable, but not with today's technologies and certainly not a few hundred years from now. And so the frustrating fact is that the human race has no chance, in the foreseeable future, to browse, travel and explore life on other planets, not even the closest ones. Because here the numbers speak, and they speak loudly!
The only hope left is: to discover earth twins on which life developed and reached intelligence and the ability to transmit and travel fast in space. Then either we will discover their transmissions or they will discover our star, if they haven't already.

Universal search: there is no point in looking for life in galaxies beyond our 'Milky Way' galaxy, and the reason is again the distance. The closest galaxy to us, 'Andromeda', is 2 million light years away from us, so the journey to it, even at the speed of light, will take no less than 2 million years (because there is no speed greater than the speed of light in the universe).
Any smart broadcast received from 'Andromeda' or any salutation such as "How are you people of the country?" They necessarily left there 2 million years ago.
And our every answer, like: "We heard you, how are you, sons of Andromeda?" "You will reach them only in another 2 million years, if they still exist. Therefore planets with life should only be looked for in our 'Milky Way' galaxy.

How to search for life?
It is not possible to see planets in the galaxy, not even with the most sophisticated telescopes, because they are far away, do not shine, engulfed in the strong light of their suns.
There is also no possibility these days to reach them by spacecraft because of the enormous speeds required for such a journey, therefore, the only way today to discover Earth twins is to receive from them a smart transmission of intelligent life such as electromagnetic transmission of radio, television, communication, radar, laser, etc. . In order to receive such a smart transmission, we must direct a radio telescope to each of the hundred thousand million stars in the galaxy, which is long, exhausting, and completely unnecessary. The alternative is to aim a radio telescope only at 'promising' stars, i.e. those that have a reasonable chance of finding planets around them with: Mazel.

Such 'promising' stars must be:
 Not large: because large stars burn out quickly before the 3.8 billion years necessary for the development of intelligence have passed.
 Not small: because small stars do not have enough light for photosynthesis for plants (which are the food for animals).
 Not old: because old stars are the first generation whose planets do not have heavy elements like iron.
 Not young: because young stars do not yet have planets with an age over 3.8 billion years that are necessary to reach intelligence.
 Not double: because double stars attract or throw their planets above them.
 Not far away: because only with nearby stars, like up to 100 light years, can we maintain contact in our generation or in the next century.

Indeed, on 10.12.92 (exactly 500 years since the discovery of America by Columbus) NASA in the USA launched the SETI program. to search for foreign intelligence. As part of this program, NASA selected 773 'promising' stars out of more than 5000 stars located up to 100 light years away from us. She aimed radio telescopes at all of the above-mentioned 773 stars, recorded for a limited time the noises from each of these stars and all the millions of frequencies of the electromagnetic spectrum. And in the recorded material she looked for any sign of a logical transmission of intelligent life from the chosen stars.
NASA spent four years of intensive research analyzing the recordings, and according to various parameters, but without results, until the American Congress stopped the budget for the SETI program in 1996 due to the claim of one of the delegates that: "For four years you have been trying in vain to search for intelligence in space, show me intelligence here first in Congress".
But the program continues to exist, due to its importance, with the help of university budgets, donations from Silicon Valley and the international sharing of personal computers to analyze the recorded data, and this with the help of the SETI AT HOME software, which every computer owner in the world can participate in.

A 'pathetic' attempt to contact intelligent life that may have developed in our galaxy was made by NASA with the sending of the Pioneer-10 spacecraft in 1973, which is today outside the solar system on its way to the stars of the galaxy. It carries with it a picture of a naked Adam and Eve, and the exact location of the Earth in our galaxy includes the time of the spacecraft itself.
Another such attempt was made with the sending of the Voyager-2 spacecraft in 1977. She went out in 1989 outside the solar system with a golden 30 cm CD, upon opening which 100 images of animals, people and landscapes from the earth will be projected and the word 'peace' will be heard in 60 languages ​​from the mouth of President Jimmy Carter (also in Hebrew) and all this in the background of classical, Chinese and pop music, literally 'opera' for foreigners.
These two attempts were probably made under the assumption "Send your bread across space because in most thousands of years you might find us."

How many planets with intelligent life can there be?:
The American astronomer 'Donald Drake', a pioneer in the search for intelligence in space since 1960 until today, developed a formula for probabilistic calculation of the number of Earth twins with intelligence living in our galaxy today (*N). The formula is a multiple of values, some of which are known and some of which are estimated as a logical probability. The formula looks like this: L N* = NPELIC (the details of its components can be seen in the table at the beginning of the article)

From the calculation of the above formula, an amazing result is obtained, that about 50 million Earth compatibles developed intelligent life at some point in the past, and about 20 of them are living in our time today (if they managed to survive 1000 years on average).
But we must not forget that any evaluation different from the above can change the result from end to end. For example, if the value I or the value L will be zero then the whole result will be zero.
The above formula is a brilliant intelligent exercise, there is no better one today in relation to the probability of other life in the galaxy.

where are they ? :
Based on this logical analysis, it is reasonable to assume that intelligent life has developed in hundreds of twin Earths over the past tens of thousands of years. And their broadcasts were bound to overwhelm us and reach us now from all sides, even if life there had long since died out. And the difficult question asked is the question of the Italian atomic scientist 'Enrico Fermi' that resonates throughout the galaxy: "Where are they?! "
Why don't we have any finds from them in the past and not a single generation in the present? . Why don't they come to the UN Security Council, for example, or to Chaim Yavyan with a glance in the evening and declare: "We have arrived - let's make recognition".
Why aren't they here?
The answer to this paradox, called the Fermi paradox, can be one of three:

One - there is no intelligent life other than us. Maybe there is simple life, maybe there are even dinosaurs, but there is no other intelligent life. Otherwise they would already be here…. and for a long time. Our planet reached reason only thanks to special conditions, chief among them a relatively large moon, conditions that enabled it to be lucky (water flowing into the world) and helped it reach reason, and such luck did not fall to the lot of any other planet in the galaxy.
This conclusion is indeed possible, but it is too "presumptuous".

Two - there is still intelligent life - but they haven't discovered us yet. The truth is that it is difficult to discover us among the billions of stars in the galaxy, even if we assume that today there are 20 intelligent earth twins scattered in it. Because the average distance between them must then be at least 5000 light years in a galaxy that is 100.000 light years in diameter, even if they stand in a back row. And we only started 'tweeting' 70 years ago, when we broadcast TV and media broadcasts for the first time, and today our 'tweet' reached a maximum of stars 70 light-years away, and not stars thousands of light-years away from us.
The journey to us of one of these 20 Earth twins must also take tens of thousands of years, even at a speed of one tenth of the speed of light. (and as we know there is no mass that can approach the speed of light)
Therefore, it is very possible that there is other intelligent life in the galaxy, but they have not yet discovered us, and the Pioneer 10 and Voyager 2 spacecraft that were sent in the seventies, were in the possession of 'Egret' intended for them.

Third - there is still intelligent life - and they did come to us. They came to us in the distant past, and identified a chance for the development of intelligence in the primitive apes, but for lack of reason to make frequent visits to us, which involve journeys of thousands of years of flight in space, or for lack of a 'budget' to send plates Flying news for the mornings, they preferred to leave on the moon or on one of the asteroids some automatic robots that watch us, and transmit to them once in a while (let's say every hundred years) the rate of our development such as: broadcasting capabilities, atomic explosions, building roads, ships in the oceans, etc.
This means that we are under covert and close surveillance by lives much more developed than us. Something that was done only for the sake of 'enriching' their knowledge. Because we have nothing to contribute to them and we are also unable to endanger them. The opposite is true, in meeting you, we may have many opportunities, but we may also face many risks, and it is enough to be clever with a hint.

Absolute knowledge of the existence of other intelligent life in the universe, or their evident non-existence, is of crucial importance in both cases, for the development of human society nowadays.
In the first case, if it is proven that we are not a 'one-time episode as a result of a capricious accident of chemistry', and we are also not a single creation of God, but a natural phenomenon that also exists on other planets, then in this case, the foundations of all religions in the world will be shaken, because then it will become clear that on the sixth day more were created 'in his image and likeness'... and in addition, the whole of humanity, as a united international government, will have to begin adapting its development to the encounter with this life scientifically, culturally, economically, and perhaps also militarily.
In the second case, if it is proven that we are a unique and one-time phenomenon in the universe, and there is no other life besides us, then a cosmic responsibility will fall upon our conscience to preserve this wonderful and unique spark of life on earth, and we must quickly come to the realization that we must stop killing each other, and understand that as the pinnacle of creation of nature we are all in the end: "in one boat... and alone..."
Please direct questions, comments or inquiries to the author of the article. VN70423@INTER.NET.IL

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