Other universes

2010/03/01 Roa Zubia, Guillermo - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Fisika
• Astrofisika

Universes without stars

The divulgators Martin Rees and John Gribbin explain in the book Cosmis Coincidences the fusion of stars. When, by joining two atoms of hydrogen, an atom of helium is formed, mass is lost in the process. The new helium atom does not weigh the sum of the weights of the two hydrogens. 0.7% lower. The lost percentage has become energy, which is the light and heat of the stars.

Both authors affirm that fusion is a consequence of strong nuclear force, with an efficiency of 0.7. But in another universe the efficiency could be 0.0006 or 0.0008. In the first case, it would not suffice to maintain the nuclei of atoms together. There would be no atoms. In the second, the fusion of hydrogen would be too fast, after the Big Bang there would be only helium. In both cases there would be no star in the universe.

Lost in dimensions

One cannot imagine a universe of more than three dimensions. But you can imagine a two-dimensional. This was done by the English writer Edwin Abbott Abbott in his book Flatland, in 1884. It is a story about a two-dimensional world. The inhabitants are flat polygons; the more differences, the higher they are in the society of Flatland.

In the novel, the protagonist visits the third dimension and thus sees the world from a perspective that he cannot understand. "The idea is developed with a lot of imagination, with satirical touches, and the book is very entertaining, more than this criticism suggests," they wrote in the journal The Academy, on November 8, 1884. XIX. It is a 20th century writing, but it "helps the reader understand the expansion towards greater dimensions," says American critic Katharine Osborne. In the twentieth century.

Acronyms Acronyms Acronyms

How would the world have been if Hitler had won the Second World War? Some cosmologists say this has happened in many other universes. In fiction this idea has been used a lot, alternative history is called "Ukraine".

Philip K is one of the most prestigious novels based on a Ukraine. The Man in the High Castle is the novel by writer Dick. Lost during World War II, the United States is largely in the hands of Germans and Japanese. A character in the novel is a writer and is writing a Ukraine to analyze how the world would be if Hitler had not won the war. One Ukraine within another.

According to critic Emmanuel Toledo, "the novel raises the same question as other books by Dick: What is the real thing? ". With more than one universe, everything is possible.

Continuous energy source

The Gods Themselves, by Isaac Asimov, is an example, a reference in science fiction. Communication between a parallel universe and our universe makes the aliens of another universe want to use ours as a source of permanent energy.

"Among the sci-fi stories, it prevails by the description of the cosmos it makes," say critics of New Dimensi n. The physical key to the novel is violent nuclear energy. The force that unites protons and neutrons in the alien universe is different. In our universe the unstable isotopes are stable. It is a fertile example of a different universe of physics.

Continuous energy source

The Gods Themselves, by Isaac Asimov, is an example, a reference in science fiction. Communication between a parallel universe and our universe makes the aliens of another universe want to use ours as a source of permanent energy.

"Among the sci-fi stories, it prevails by the description of the cosmos it makes," say critics of New Dimensi n. The physical key to the novel is violent nuclear energy. The force that unites protons and neutrons in the alien universe is different. In our universe the unstable isotopes are stable. It is a fertile example of a different universe of physics.

Travel in time

Einstein's general theory of relativity allows trips in time. In theory, you can make a time machine. However, it is not possible to travel in time after the time the machine was made. That is why there are no future travelers in our world because the time machine has not yet been built. But in another universe with a different theory of relativity, it could be possible to go back in time.

Thus, communicating universes could go back in a parallel universe and return to our universe to overcome the limits of relativity. Thus, if a person kills his grandfather causes a paradox: the death of his grandfather prevents the same person from existing.

But the idea of the multiverse unravels that paradox: when grandfather died, that person would enter another universe. It exists in one universe and in another no. But there is no paradox.