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Humans on Mars could become a new species

Image Credit: NASA

Babies born on Mars may be quite unlike those born on Earth. 

An evolutionary biologist has outlined what is likely to happen when people start living full-time on Mars.

Imagine for a moment that mankind has not only achieved a successful manned landing on the Red Planet, but has also constructed a permanent, self-sufficient colony populated by hundreds of people.

In a recent interview with Inverse, Prof Scott Solomon of Rice University, Texas talked about some of the changes and adaptations that humans living in such a colony may start to undergo.

“Evolution is faster or slower depending on how much of an advantage there is to having a certain mutation,” he said. “If a mutation pops up for people living on Mars, and it gives them a 50-percent survival advantage, that’s a huge advantage, right? And that means that those individuals are going to be passing those genes on at a much higher rate than they otherwise would have.”

Martians could, for instance, develop stronger and denser bones to compensate for the lower gravity. They could also end up with a different skin tone to help protect against harmful radiation.

Living in cramped habitation modules could mean that nearsightedness becomes a more common trait, as could the ability to make more efficient use of the available oxygen.

Cut off from the bacteria and viruses found on Earth, the people of Mars may also end up with a weaker immune system that could make intimate encounters with visitors from Earth very risky.

Eventually, given enough time, Mars colonists may even become a whole new species.

Source: Tech Times

Space

Black holes turned out to be three-dimensional holograms

Image: Gerd Altmann / Pixabay

An international team of scientists has come to the conclusion that black holes can look like holograms, in which all the information they contain can be encoded on a two-dimensional surface. 

This model is consistent with Einstein’s theory of relativity, which describes black holes as three-dimensional, spherical, and smooth objects. An article by researchers is published in the journal Physical Review X.

It is known that black holes, within the framework of Einstein’s theory of relativity, have thermodynamic entropy, which, as discovered by Hawking, is proportional to the area of ​​the event horizon. In other words, the larger the black hole, the more information it carries in itself. Information, in this case, is the number of quantum microstates, as follows from quantum mechanics. However, both descriptions of black holes (quantum-mechanical and thermodynamic), as it turned out, conflict with each other.

To prove the correspondence between the two descriptions, experts applied a 30-year-old idea called the holographic principle of Hooft. It consists in the fact that all information contained in a certain region of a three-dimensional (or n-dimensional) space can be encoded on a two-dimensional boundary (or n-1-dimensional) surrounding this space. This helps to solve some fundamental physical problems, for example, describe the behavior of gravity in the region of the Universe in a system with fewer dimensions. In this case, there are no contradictions between quantum mechanics and Einstein’s theory of relativity, which physicists usually encounter when studying black holes.

The researchers described the properties of a black hole as a two-dimensional system in which gravity is not present explicitly, and accordingly, there is no contradiction generated by it. To do this, they applied a special kind of holographic principle called AdS / CFT matching. It consists in the fact that a certain five-dimensional space with negative curvature (anti-desitter space, AdS) is equivalent to a world-boundary with four dimensions. According to string theory, this boundary, called the brane, contains particles in the form of strings, and the behavior of these particles is similar to the behavior of particles in AdS with gravity.

Scientists came to the conclusion that the entropy of a rotating charged black hole in AdS can really be expressed by the number of microstates in space with fewer dimensions.

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Space

ESPRESSO spectrograph confirms the existence of an earth-like planet near Proxima Centauri

The surface of Proxima b through the eyes of the artist ESO / M. Kornmesser

The ESPRESSO spectrograph confirmed the existence of the earth-like exoplanet Proxima b in the star closest to the Sun. Additional observations made by the tool made it possible to clarify its mass, as well as register a second signal, which theoretically can be explained by the presence of another planet. Accepted for publication at Astronomy & Astrophysics, the preprint is available at arXiv.org.

In 2016, astronomers reported the discovery of the planet at the red dwarf Proxima Centauri, the closest star to Earth, located about 4.2 light-years from Earth. The celestial body revolves around the star with a period of 11.2 days and is in the habitable zone – this means that the conditions on its surface allow the existence of liquid water. 

The discovery of Proxima b was one of the most important milestones in exoplanetary astronomy in recent years, but the limited accuracy of the available measurements of radial velocity and the complexity of the simulation required confirmation of the existence of an earth-like planet.

An international group of astronomers used the new-generation spectrograph ESPRESSO, which is part of the VLT complex, to measure the radial velocity of a star with an accuracy of 30 centimeters per second. The data obtained were three times more accurate than the data of the HARPS spectrograph, an instrument of the same type, but of the previous generation, with the help of which the discovery was made. Combining ESPRESSO observations with past measurements showed that the mass of Proxima b is not less than 1.17 earth masses, which is less than the previous estimate of 1.27 earth masses.

In addition, scientists recorded an additional signal repeating with a period of 5.5 days, which so far they have not been able to explain. Hypothetically, it can come from the second planet: if the assumption is true, then its minimum mass is less than a third of the earth, and it is located at a distance of 0.03 astronomical units from Proxima Centauri (one astronomical unit is equal to the average distance from the Earth to the Sun).

In the past, researchers suspected the existence of another planet in the system – this time the super-earth, on which the year lasts about five years. It is five and a half times more massive than the Earth and may have rings similar to the rings of Saturn, but this discovery has not yet been confirmed.

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It’s time to worry. Planets switched to retrograde motion

© NASA / Tunc Tezel

In May, Venus, Saturn and Jupiter become retrograde – they change the direction of motion in the celestial sphere. Previously, it was considered a bad omen. In fact, in the solar system there is only one real retrograde – Venus. But the discovery of retrograde exoplanets was a complete surprise.

Copernicus explained everything

Even in ancient times, people noticed that planets moving in the heavens sometimes behave strangely, loop. Most of the year they follow from west to east (if they are farther from the Sun than the Earth) and suddenly turn around, back down. The moment when this happens is called standing.In 1514, Nicolaus Copernicus proved that the Earth is not the center of the universe, but together with other planets revolves around the Sun. 

Each celestial body has its own orbit, and the retrograde movement that is visible to us is the result of their superposition. For example, Mars approaches the Earth every two years as closely as possible and, overtaking it, draws an s-shaped loop in the sky.

© NASA / Tunc Tezel

The path of Mars in the celestial sphere in the period from July 2005 to February 2006. It goes from west to east and at the moment of approaching the Earth makes a loop. For a couple of months his movement seems retrograde to us.

Venus and Uranus versus all

All planets in relation to the Earth for a short time move backward, but this is only an appearance. Real retrogrades do not physically rotate like the rest. In the solar system, it is only Venus. If we were above the north pole of Venus, we would see that it rotates clockwise around its axis. Earth and other planets are against.It is believed that planets form together with a star from one protoplanetary disk. In theory, their orbits should lie in the same plane, and the directions of rotation in the orbit and around the axis should coincide. Why Venus is not like this is not yet clear. 

Although scientists note its strong similarity with the Earth – these planets are even called twins. One of the explanations is that the processes occurring in the bowels and atmosphere have slowed the rotation of Venus so much that it stopped at some point, and then began to spin in another direction.

The distant ice giant Uranus also looks like a retrograde. It lies on its side relative to the plane of its orbit, and pecks down the north pole, which makes Uranus seem to rotate clockwise. But if you put it normally, it will become normal. Scientists believe that billions of years ago, Uranus collided with a large cosmic body and turned over in space. Another hypothesis is that in the past the planet had a massive system of rings that caused resonance, rocked it and deployed.

General rules apply to planetary moons. For example, the Earth rotates counterclockwise, and so does the Moon around the Earth. But one of the 13 moons of Neptune – Triton – is “against the coat.” So, scientists conclude, Triton did not belong to Neptune, was an independent small body, until Neptune captured it from the Kuiper belt. By the way, Pluto, similar in composition to Triton, is also retrograde. In part, this contributed to its transfer to the category of dwarf planets.

© Illustration by RIA Novosti. NASA / JPLRetrograde motion of Triton. This is the only major satellite in the solar system that moves in orbit against the course of its planet.

Anomalies of hot jupiters

This is what our system is completely devoid of – planets that would move in orbits against the rotation of the Sun. For a long time, astronomers believed that this should be everywhere. But in 2009, they discovered the first exoplanet with a retrograde orbit at the star WASP-17 in the constellation Scorpio.WASP-17 b is the largest and least dense exoplanet known. Such gas giants are called hot jupiters.

Its retrograde intrigues scientists. Smadar Naoz from the Center for Interdisciplinary Research in Astrophysics at Northwestern University ( USA ) proposed a possible mechanism: the mutual influence of giant planets during migration closer to a star or a brown dwarf. But its implementation requires the coincidence of too many conditions, and this is unlikely. Nevertheless, the astrophysicist put forward a bold hypothesis that such retrograde jupiters are not uncommon – a quarter among those observed. However, the existence of the hot Jupiters themselves is still waiting for its explanation.

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