Fermi Paradox: Where are all the Aliens!??

 

The intriguing idea known as the Fermi Paradox poses the question of why, despite the likelihood that there is extraterrestrial life out there, we have not yet found any proof of these civilizations. The paradox draws attention to the apparent contradiction between the likelihood that extraterrestrial civilizations exist and the paucity of evidence or communication with them. It is named after the Nobel prize-winning physicist Enrico Fermi, who famously raised the question during a discussion about the viability of space travel and the existence of intelligent alien life.

The Fermi Paradox has several proposed solutions and explanations.

The rare earth hypothesis lowers the possibility of the existence of additional intelligent civilizations by suggesting that the conditions required for complex life to arise are exceedingly rare.

The Great Filter Hypothesis postulates that life, whether it be microbiological, complex multicellular, or technological civilizations, may be stuck at some point in its evolutionary process due to an impenetrable barrier.

The theory of technological singularity postulates that sophisticated civilizations will ultimately reach a point at which their technology advances to the point that they are undetectable and uninterested in communicating with other civilizations.

Self-destruction: The theory suggests that civilizations may eventually wipe themselves out through conflict, deterioration of the environment, or other ways before they have an opportunity to colonize other planets or extend into space.

Transcendence: This theory postulates that advanced civilizations may evolve into entities that live outside the realm of human comprehension, such as energy- or digital-based beings, rendering conventional means of communication obsolete.

The Zoo Hypothesis postulates that extraterrestrial civilizations exist and are aware of us, but they have decided not to contact us, either so they may observe us in peace or so they can let us evolve naturally.

Though each of these theories provides a unique viewpoint on why we haven't yet found any evidence of extraterrestrial intelligence, the real reason is still one of the greatest mysteries of science. These days, several studies from various research groups are published annually on the subject of extraterrestrial intelligence. The current exoplanet revolution has bolstered the hypothesis that advanced civilizations might exist outside of Earth.

More instruments are available for researchers to use in this kind of investigation. In April 2018, for instance, NASA's Transiting Exoplanet Survey Satellite (TESS) successfully launched and quickly took over from Kepler, which was retired later that year. Among many other things, the highly anticipated $10 billion James Webb Space Telescope of the agency was launched in December 2021 and is currently searching for possible biosignature chemicals in the atmosphere of neighboring exoplanets. The PLATO (Planetary Transits and Oscillations of Stars) mission of the European Space Agency is scheduled to launch in 2026. Later this decade, three massive ground-based observatories with adequate power to detect exoplanet air are expected to go online: the Extremely Large Telescope, the Giant Magellan Telescope, and the Thirty-Meter Telescope. Furthermore, a very ambitious initiative called Breakthrough Starshot intends to use swarms of small, laser-sailing nanoprobes to conduct up-close studies of Proxima b (The exoplanet Proxima Centauri b, also known as Alpha Centauri Cb, is a member of the larger triple star system Alpha Centauri and is circling the red dwarf star Proxima Centauri, which is the nearest star to the Sun.) and other adjacent worlds. Around 2050, if technology development proceeds as planned, the first of these robotic interplanetary vehicles may take off.

These kinds of missions and tools will aid scientists in expanding their knowledge of astrobiology, which is still in its infancy. For example, we have no idea whether our backyard contains worlds that support life. Since bacteria can endure in harsh conditions, studies conducted on Earth have led to the possibility that microbial life exists on Mars, Europa, Enceladus, and/or Titan, the massive satellite of Saturn. However, none of those planets have been investigated quite well enough for us to be certain.

But the Fermi Paradox is thinking much beyond microorganisms. In order to find a solution, we must ascertain the frequency with which extraterrestrial life emerges as well as the frequency with which it acquires the capacity and inclination to interact with other sentient beings or travel among the stars.

Perhaps the most prevalent life-supporting habitats in the Milky Way galaxy are subterranean waters, like those found on Europa and Enceladus. It appears improbable that organisms evolving in such environments will create spacecraft; in fact, a large number of them might not even be aware that there are other planets to discover. 

Another possibility is alien psychology. Perhaps there are many advanced extraterrestrial civilizations, but the majority don't seem to want to interact with humans or come to Earth. Maybe Earth and its people are just too boring for them to play around with, and they won't until mankind proves intelligent and deserving enough to be accepted into the "galactic club."

Or perhaps the majority of sentient aliens generally remain silent out of fear that communicating with their galactic neighbors will result in their own captivity or destruction. Such possibilities have been mentioned by some researchers, including the late Stephen Hawking, to support their contention that mankind shouldn't actively promote itself.

Then there are the practical challenges associated with the search for sentient aliens. The cosmos is vast and extraordinarily old. Only 200,000 years have passed since the beginning of human history, and only since 1960 have we been searching for potential E.T. radio transmissions. Thus, the likelihood that we coincide with a detectable alien civilization in space and time doesn't appear very high.

Most academics believe that there is most likely no single answer to the Fermi Paradox. The "great silence" that faces us now is probably the result of several circumstances, some of which may have been mentioned above. And it could not be too long until the characteristics of those things become more apparent. 

Prabir Rudra

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Mysterious radio signals from space indicate that we may have contacted the Alien world

 

China's five hundred meter aperture spherical radio telescope (FAST) has recorded some strange signals coming from a faraway galaxy (3 billion light-years from Earth). The cosmic source from which these signals are coming is identified as Fast radio burst (FRB) and the source is named FRB 20201124A. 

This is in fact the second time that such repeated signals have been received after its discovery in 2019. FRBs are intense but brief flashes of radio frequency emissions. They last just a few milliseconds, and so detection of these signals requires high-end instruments and proper knowledge.

Chinese astronomers who have studied these signals say that the signals are coming from a magnetar or neutron star residing in that galaxy, having an extremely high magnetic field. The scientists continuously monitored these signals coming from the same direction for 91 hours. Out of these 91 hours, 1863 signals have been received for 82 hours.

                                     Magnetar

Scientists from China and America are now collaborating in studying these strange signals and trying to derive meaning from them. They say that radio signals of different wavelengths have been received from time to time coming from this same direction. Moreover, the object is said to emit smaller and weaker radio bursts between the fast radio bursts. Observations from FAST, Guizhou, China have been localized by the US National Science Foundation's Karl G. Jansky Very Large Array (VLA). 

                                       Signals

They speculate that there is a hidden code in these signals and probably some alien species is trying to communicate with us via these signals. The trouble is however the decryption of this code and understanding the message hidden in it (if at all there is any).

Fast radio bursts are not new to us, in fact, they have been discovered 15 years ago. These radio bursts are associated with the energy release equal to millions of suns. Generally, most FRBs explode once and the corresponding radio signals are received once during a particular time. But there have been exceptions to this. Many FRBs have been found to emit signals continuously over a period of time which is quite baffling indeed. In 2020 a fast radio burst was discovered inside its galaxy, which is again a very rare and strange incident.

Since then the study of FRB has gained interest and scientists have continuously monitored FRB 20201124A. It has been found that the source is not only sending the signals but also polarizing them simultaneously. More polarization would mean stronger magnetic fields of the source. 

Carefully studying these signals would help us to know more about the atmosphere of the source magnetar. The study has been published in the prestigious journal Nature. These signals are continuously reaching us for the past few years, but we are yet to derive any meaning from them. If we finally do succeed in doing that, probably it will be a new dawn in the scientific prowess of humans.

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Prabir Rudra

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