Not only are there terms to know but it is also important to know the artistic licenses related to science that have been taken when making the film and, therefore, we will also talk about it here.
In Ad Astra, human being has colonized a large part of the Moon, which, as in international waters, has its own pirates who seek to profit. In addition, we have come to have a base under the surface of Mars that, according to experts agree, would be the only place we could live.
This film introduces us to astronaut Roy McBride, played by Brad Pitt, who will have to face the consequences of the Lima Project, which is called the ship with scientists that goes beyond the heliosphere, has an objective…
To better capture the possible signals from other civilizations because answering the question of whether we are alone in the universe is one of the questions to which we most want to give an answer and this is also reflected in the cinema.
We also explain the artistic licenses that have been taken when talking about science.
“For each particle forming matter exists other particle that is completely symmetrical, which has exactly the same properties but with opposite loading and quantum numbers sign” explains Hector Socas-Navarro.
We know that atoms are formed by protons, neutrons and electrons, but we have to take into account that “there are also antiprotons, antineutrons and antielectrons and these could form anti-atoms that would work exactly like ours”.
“One of the great mysteries of physics is why the universe seems to be made of matter, while antimatter has disappeared. We can produce it in particle accelerators but the same number of particles as antiparticles are always produced equally, which is also what the theory predicts,” explains the expert.
“However, it seems that at some point the universe generated more matter than antimatter and we don’t understand how that asymmetry could have been produced,” he adds.
“One of the interesting aspects of antimatter, and that is the use that is given in the film, is that when a particle meets its corresponding antiparticle, both are instantly annihilated, releasing an amount of colossal energy. A very small amount of antimatter can be used to store gigantic amounts of energy,” says Socas-Navarro.
It is not the first time that the cinema uses antimatter to imagine “incredibly powerful bombs” created with antimatter, as could be seen in Angels and Demons , “or in interstellar propulsion forms.”
“However, we must bear in mind that “nothing is free”, as the physicist points out.
“To generate that small amount of antimatter it would also be necessary to invest that same enormous amount of energy. So, unless we found a natural source (and probably there is none), antimatter would serve as a system for storing energy and moving it from one place to another, but not as a way to produce energy,” he says.
“The heliosphere is the zone of influence of the Sun,” explains Socas-Navarro. “It is usually defined as the bubble in which the solar wind spreads outward and is stronger than the interstellar medium. As we move away from the Sun, the wind is diluted,” he says.
“There comes a time, about 120 times the distance to Earth, when the solar wind has weakened so much that it already stops when it hits the interstellar medium, forming what is called the heliopause,” he adds.
The heliopause is four times the distance of Neptune, this helps us to get an idea of the great distance that the solar wind reaches.
“Today we know this region quite well because it was crossed by the Voyager 1 and 2 probes in 2012 and 2018, respectively and they have measured their properties.”
“The density of the medium is extremely low, there is less than one electron for every cubic centimeter. So, when we talk about medium or winds we must understand that we are talking about practically empty space,” says the physicist at the IAC.
“As we move away from the Sun, the wind is thinning”
“It is the energy source of the future for humanity,” says Socas-Navarro. “This is the reverse process of nuclear fission we do in our nuclear power plants,” he adds.
“In fusion, light nuclei combine to form larger ones, releasing large amounts of energy,” he adds.
In fact, we know that fusion is possible because “it is the source of energy that makes the Sun and stars shine” and because we have been able to “produce nuclear fusion in experiments but we are not able to sustain it too long,” explains the physicist.
“It is clean, safe, virtually inexhaustible and will be universally accessible,” explains the researcher. Moreover, we have been able to maintain the reaction for more than a minute and this record is “an experiment in Korea”.
“So far it has not been profitable (extracting more energy than is needed to produce it). The ITER consortium is expected to produce the first profitable fusion reactor, designed to extract 10 times more energy than is injected”, comments Socas-Navarro.
But what are cosmic rays? Socas-Navarro gives us the answer: “Cosmic rays are high-energy particles that bombard us daily from the cosmos.”
“They are mostly protons or accelerated helium nuclei at speeds close to that of light. They are particles produced in high-energy phenomena (supernovae, black hole environments, starbursts, etc.) that roam space and, occasionally, they collide with our planet,” explains the expert.
“Since they have an electric charge, the Sun’s magnetic field is capable of shielding the arrival of these particles to Earth to some extent. More cosmic rays are observed during the minimum of solar activity than during the maximum,” he adds.
In the case of the film, the rays would come from Neptune and the Sun would not have the capacity to prevent them from reaching our planet, as is the case in Ad Astra.
Although in general on Earth “we live with the geomagnetic storms induced by coronal mass ejections emitted by the Sun”, in the peculiar case of the film it is about beams of antimatter that come from near Neptune and that the protagonist will have what to investigate.
Socas-Navarro comments that “other origins for this type of storm are theoretically possible, including an arms use”.
“But it would probably require putting into play and channeling such huge amounts of energy that it would not currently be within our reach,” he adds.
In the case of normal solar storms “these are clouds of solar plasma that are expelled in huge eruptions and spread through space at thousands of kilometers per second.”
“When impacting with the Earth, very fast variations of the Earth’s magnetic field occur which, in turn, induce currents in the conductive materials.
This can cause damage to our technology and, in fact, we have historically seen how these phenomena can result in blackouts. , damage to facilities or satellites,” adds the astrophysicist.
We already know that the film has taken some licenses, such as the antimatter or the thunderstorm, but there are others that can attract more attention. For example, we know that Voyager probes are the only ones that, today, have crossed the heliosphere and “took 35 years” to do so.
However, in the movie the times that are handled are shorter. For the current technology we have, it is not possible, but this may have a simple explanation: they have discovered how to travel faster than we do.
In addition, Socas-Navarro points out that there is no reason to send human beings to any place since “if we wanted to have access to signals that do not penetrate the heliosphere, the most logical thing would seem to send a probe capable of leaving, collecting these signals, translating them at higher frequencies that can penetrate and forward them to Earth.”
This logical solution would load the entire plot of the film, which focuses on what happened to the Lima Project, which left the heliosphere with the intention of seeking extraterrestrial life beyond Neptune.
So even if it does not coincide with the science at all, to enjoy the film it is convenient to forget these last three paragraphs.