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The human lives in the tiny planet, which we call Earth, which revolves around one of the billions of stars that, in turn, revolve around the center of one of the billions of galaxies.

On the cover image, you can see the Thinker, sculpture of a pensive nude male by French artist Auguste Rodin.  Credit: web “”

The human lives in the Earth

The philosopher and mathematician René Descartes said: “I think, therefore I am“, “Cogito, ergo sum”.

The Earth and the Moon seen from 1.4 billion kilometers by the Cassini spacecraft when it flew over Saturn. Credit: NASA (April 12, 2017)

Characteristics of the human brain

The Human brain has 100 billion neurons that link together, forming 1,000 million connections for every cubic centimeter of cerebral cortex.

They are about 1,300 cubic cm that each of us wears on our heads. National Geographic has just made magnificent information about the wonders of the human brain.

David, The human
Face of David by Michelangelo in the Gallery of the Academy of Florence.  Credit: web “”

Everything that is in the body of any human being, was already present from the moment of the Big Bang, in the form of elemental matter.

Over millions of years, these elementary particles were combining to form what we can see and admire today. It is scientifically correct to say that “we are stardust“.

The human lives in a tiny place in the immense universe

Galaxy m81m82
M81 and M82 face-off, a mere 12 million light-years away. Credit: web “”, Author: Ivan Eder

In the image, two galaxies are visible: they are named M81 and M82.

The galaxy we live in is called the Milky Way and is very similar to the galaxies seen in the figure.

Our Sun is one of the estimated 100,000 million stars in the Milky Way.

What is the human made of?

From a material point of view, it seems that an efficient combination of quarks, protons, neutrons and electrons that interact, due to really mysterious forces, and according to pre-existing and unknown laws, have resulted in the HUMAN.

Electrons. The human
Graphic of electrons in orbit in atom.  Credit: web “ “ Author: Mehau Kulik

If the HUMAN is reduced to what is strictly “matter”, it is impossible not to feel astonishment and admiration.

The joy that comes with accepting oneself as something wonderful, originates respect and acceptance towards those who share this miracle of human life.

Love your neighbor as yourself

Teresa of Calcutta symbolizes solidarity with the pain of others, and greatness in the face of their weaknesses. Work for other human beings can and must continue to be done.

Teresa Calcuta. The human
Teresa of Calcutta dedicated her life to the poorest of the por. Credit: web “”

All thinkers agree on the idea of ​​”loving your neighbor as yourself.”

Are there other intelligent beings in the universe?

This HUMAN has developed his faculties to such an extent that, in addition to being aware of his existence, he has begun to discover what lies beyond the planet on which he lives.

With the conviction that it is possible and very probable that there are other intelligent beings on planets of other stars, since the early 1970’s he has been trying to establish some contact with them.

Voyager Badge. The human
Voyager Badge

The top image represents the gold plate attached to the Pioneer X and XI space probes of NASA’s space exploration program. They were released in 1972 and 1973, respectively.

Carl Sagan persuaded NASA to have the probes carry this plate designed by him and Frank Drake.

The plates carry a symbolic message, that would inform a possible extraterrestrial civilization that could intercept the probes, about the human being and his place of origin: the Earth.

In them, they appear: to the right, the image of the probe, with the sole purpose of giving proportion to the two human figures drawn in front, one female and the other, male.

On the left, a bundle of lines starting radially from the same point. That reference point is the Sun, the lines indicate the direction of the most significant pulsars close to our solar system and in each one, in a binary numbering system, the sequence of pulses of each one.

A technically advanced civilization, with knowledge of pulsars, could interpret the plates.

The diagram located in the upper left part of the plate, represents an inversion in the direction of spin of the electron, in a hydrogen atom, the most abundant element in the universe.

At the bottom is a diagram of the solar system, with the planets arranged according to their distance from the Sun and with an indication of the initial path of the Pioneers.

Since when has the human existed on Earth?

Modern genetic procedures have been a fundamental impulse for the investigation of when the human on Earth emerged.

Anatomically, modern man, classified as Homo sapiens-sapiens, appears to be a little over 120,000 years old.

Specimens of “homos”, which lived 195,000 years ago, have been discovered in both East Africa and Asia.

Over tens of thousands of years, the migratory movements of prehistoric peoples spanned almost all continents.

The human began to study the place where he lives.

From what is currently known, around 3,000 years ago there were already men who were interested in finding out the shape and size of the Earth.

1,000 years BC, the Chaldeans constituted an aristocracy, superior to the other peoples of Mesopotamia, at the southern end of the Euphrates and Tigris basins, in an area of ​​present-day Iraq.

Caldeos Babilonia
The Chaldean priests were great astronomers. Credit: web “

The main city of the Chaldeans was Babylon. The Chaldeans were famous for their knowledge of astrology and mathematics.

The science accumulated since the time of the Sumerians, thousands of years ago, was taught in their schools.

About 600 years BC, the ancient Greeks were the first to try to understand how and why stars moved in the sky. They discovered that the light from the Moon is due to the reflection of sunlight that reaches the Earth.

They were interested in knowing the size of the Earth, which they conceived as a circular disk that had a diameter of 8,000 km at most.

Anaxagoras was a friend of the great Athenian leader Pericles. Credit: Wikipedia

Their observations led them to conclude that the Earth moves around the Sun and that it rotates on its own axis.

In the 16th century, Nicolaus Copernicus, after many years of looking and thinking, came to the conclusion that the Earth and the other planets revolve around the Sun, and formulated the theory that the Earth is not the center of the universe.

In those years, in addition to Nicolás Copernicus, Tycho Brahe, Kepler, Galileo, Herschel and Newton, they culminated the astronomical revolution and laid the foundations to arrive at the current knowledge of the place that the human being occupies in the Universe.

Milky Way
Marveling at the beauty of the Milky Way. Credit: web “”