Tag Archives: Calculating

Calculating the Likelihood of Intelligent Life in the Universe and Beyond: A New Theoretical Model

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In 1961, American astrophysicist and astrobiologist Dr. Frank Drake multiplied several factors to estimate the number of intelligent civilizations in the Milky Way that could make their presence known to humans. I devised an equation. More than 60 years later, astrophysicists have created a different model that focuses instead on conditions created by the accelerating expansion of the universe and the amount of stars forming. This expansion is thought to be caused by dark energy, which makes up more than two-thirds of the universe.

Artistic impression of the multiverse. Image credit: Jaime Salcido / EAGLE collaboration.

“Understanding dark energy and its impact on our universe is one of the biggest challenges in cosmology and fundamental physics,” said Dr. Daniele Solini, a researcher at Durham University’s Institute for Computational Cosmology. .

“The parameters that govern our universe, such as the density of dark energy, may explain our own existence.”

Because stars are a prerequisite for the emergence of life as we know it, the team’s new model predicts the probability of intelligent life arising in our universe, and in a hypothetical multiverse scenario of different universes. could be used to estimate the

The new study does not attempt to calculate the absolute number of observers (i.e. intelligent life) in the universe, but instead calculates the relative probability that a randomly chosen observer will inhabit a universe with certain properties. will be considered.

It concludes that a typical observer would expect to experience significantly greater densities of dark energy than seen in our Universe. This suggests that its ingredients make it a rare and unusual case in the multiverse.

The approach presented in this paper involves calculating the rate at which ordinary matter is converted into stars for different dark energy densities throughout the history of the universe.

Models predict that this proportion would be about 27% in a universe where star formation is most efficient, compared to 23% in our universe.

This means that we do not live in a hypothetical universe where intelligent life has the highest probability of forming.

In other words, according to the model, the values ​​of dark energy density that we observe in the Universe do not maximize the potential for life.

“Surprisingly, we found that even fairly high dark energy densities can still coexist with life. This suggests that we may not be living in the most likely universe. ,” Dr. Solini said.

The model could help scientists understand how different densities of dark energy affect the structure of the universe and the conditions for life to develop there.

Dark energy causes the universe to expand faster, balancing the pull of gravity and creating a universe that is capable of both expansion and structure formation.

But for life to develop, there needs to be areas where matter can aggregate to form stars and planets, and conditions need to remain stable for billions of years to allow life to evolve.

Importantly, this study shows that the astrophysics of star formation and the evolution of the large-scale structure of the universe combine in subtle ways to determine the optimal value of dark energy density required for the generation of intelligent life. It suggests that.

“We will use this model to investigate the emergence of life across different universes and reinterpret some fundamental questions we ask ourselves about our own universe,” said Lucas Lombreiser, professor at the University of Geneva. It will be interesting to see if there is a need.”

of study Published in Royal Astronomical Society Monthly Notices.

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Daniele Solini others. 2024. Influence of the cosmological constant on past and future star formation. MNRAS 535 (2): 1449-1474;doi: 10.1093/mnras/stae2236

Source: www.sci.news

Study finds that astronauts possess extraordinary skills in orienting themselves and calculating distances while in space

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New research has implications for crew safety in space and could give clues about how aging affects the balance systems of people on Earth.

horges other. We addressed the question of whether body posture influences humans' perception of self-motion and distance. They found that the same amount of optical flow can elicit the sensation of traveling farther when lying on one's back and when sitting upright; that is, optical flow We found evidence that it is more effective in eliciting the sensation of movement. This constitutes evidence that visual and nonvisual cues are at least partially integrated, even when self-movement is presented only visually. However, we found no significant differences in performance in microgravity on Earth and on the ISS, suggesting that vestibular stimulation is not important, if any, in estimating visually presented self-motion.

The study's lead author, Professor Lawrence Harris from the University of York, said: “The perception of gravity has been repeatedly shown to influence perceptual abilities.”

“The most profound way to study the effects of gravity is to remove it. That's why we brought our research into space.”

“We have had a steady presence in space for nearly a quarter of a century, but our efforts in space are ever-increasing as we plan to return to the moon and beyond, ensuring health and safety. It is becoming increasingly important to answer questions about

“Based on our findings, it appears that humans are surprisingly able to use vision to adequately compensate for the lack of Earth's normal environment.

For the study, Professor Harris and his colleagues surveyed more than a dozen astronauts aboard the International Space Station (ISS), which orbits about 400 kilometers above the Earth's surface.

“Here, Earth's gravity is almost canceled out by the centrifugal force generated by the station's orbit. In the resulting microgravity, the movement of people becomes close to flight,” Professor Harris said.

“People had previously reported anecdotally that they felt like they were traveling faster or farther than they were actually in space, so this actually motivated us to record this.”

The authors compared the performance of 12 astronauts (six men and six women) before, during, and after a year-long mission to the space station and found out how far they traveled. I discovered that my sense of what I had done was almost intact.

Space missions were hectic endeavors, and it took several days for researchers to make contact with the astronauts after arriving at the space station.

“Our study may not have captured early adaptations that may have occurred during the first few days. Because whatever adaptations occur, they occur very quickly. This remains a good news message,” Professor Harris said.

Space missions are not without risks. Because the ISS orbits around the Earth, small objects can occasionally collide with it and enter the ship, where astronauts must move to safety.

“During the experiment, the ISS had to take many evasive maneuvers,” Professor Harris said.

“Astronauts need to be able to get to safety or escape through a hatch on the ISS in an emergency. So to see that they were actually able to do this with great precision was very exciting. I felt relieved.”

“Our research shows that exposure to microgravity mimics the aging process primarily at a physiological level, including bone and muscle wasting, changes in hormonal function, and increased susceptibility to infections. However, this paper found that self-movement was largely unaffected, suggesting a balance problem.''The problem, which often comes from old age, may have nothing to do with the vestibular system. ”

“This suggests that the mechanisms of movement perception in older people should be relatively unaffected, and that the problems associated with falls are probably more to do with this than in terms of perception of distance traveled. How can they translate that into a balance reflex? ”

of study Published in npj magazine microgravity.

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B. Horges other. 2024. Effects of long-term exposure to microgravity and body orientation relative to gravity on perceived distance traveled. NPJ microgravity 10, 28; doi: 10.1038/s41526-024-00376-6

Source: www.sci.news