Deep space radio signals – and a controversial Harvard astrophysicist interview – again wonder if we're alone in the universe or not.
First, a new study published in nature. looked at the rapid radio bursts, an astronomical mystery some of which claim to be artificial by origin. We found the first rapid radio bursts in 2007, but the new technology allowed us to find much more of them, and we confirm that some are repeated. The origin of these repetitive signals is unknown, which makes some scientists speculate that aliens can send them.
A few days later, Professor Harvard and Harvard Astronomy Department President Avi Lob argued in a new interview that the interstellar Oumuamua, which passed through our solar system in 201
Every time we find unexplained phenomena in the deep cosmos, people wonder, is this finally a sign of aliens? There are good reasons to conclude that these phenomena are natural in origin. But some scientists, including the chief of Loeb, insist that we are too fast to reject the possibility of aliens.
A great deal of disagreement seems to be rooted in various previous things about common life in the universe. Scientists who think that space must be filled with extraterrestrial life will find aliens as the most likely explanation for a wide variety of astronomical phenomena; scientists who believe that we are probably alone there will interpret the same data in a different way.
But the debate is more than meaningless, fun speculation. Some insights we can make from the search for aliens have profound implications for our own world. In particular, some people worry that civilizations such as ours will inevitably be wiped out – and wonder if watching the universe can give us a sign of what is ahead of us.
If there is life, it is obscure, distant, and difficult to detect. A super sophisticated, technologically advanced alien civilization is likely to leave more reliable traces. For example, a civilization that enjoys millions of years of technological innovation than humans can build Dyson spheres (a massive structure that encloses a star to use it as a source of energy) and sends far more systematic and recognizable signals and probes by force produce. It's hard to figure out exactly what they would do, but their actions are not likely to leave a trace in the universe. The traces we have observed so far are not close to the evidence that could prove the existence of an extraterrestrial civilization. This means that there may be difficult to predict obstacles that prevent developed galactic civilizations from evolving or destroying such civilizations before they reach that size that they can reach. Or maybe it just means that life itself is a spectacular coincidence.
Quick radio-blasts: natural phenomena or alien signals?
Rapid broadcasting is a sudden pulse of radio waves detected by our telescopes and coming from deep space. Normally, they are about a millisecond in length. The first rapid broadcasting was discovered in 2007. In the 12 years, we took a few more dozens, but not enough to make a convincing theory of what they are.
This can change quickly with a new telescope that has just begun to work in the summer of 2018. The Canadian Hydrogen Mapping Experiment (CHIME), led by the Canadian National Research Agency Dominion Radio Astrophysical Observatory together with the University of British Columbia, McGill University, and Toronto University are designed to study the early universe (it can map the interstellar hydrogen density) and it has been extremely well-equipped to detect the FRB.
The Nature paper, created by the CHIME / FRB collaboration, reports the first FRB results seen in CHIME. The telescope is not yet fully operational and has still seen 13 FRBs in just two months when it started work – a significant addition to our understanding of the phenomenon, since before 2007 we had only about 50 or 60 examples. also monitors the second repeating sequence and the lowest frequencies that are still known.
We still do not know much about what the FRB is causing. More justified speculation among astrophysicists is that they are caused by neutron stars, star fusions or black holes. Until the first recurring signals were discovered, one of the theories was that they were caused by catastrophic events of some sort – such as a star that became supernova. But since the signals are already confirmed that they are sometimes repeated, this can not be.
The theory that has been captured by public imagination is that they are caused by intelligent extraterrestrial life. A study by Avi Loeb and Manasseh Lingham of Harvard University, published in 2017, claims that the models can be the result of transmitters designed to drive the interstellar canvas. The article is theoretical; it does not offer any evidence of the "aliens" hypothesis, it simply claims that so far it would be compatible with the recorded data. They conclude that it would be physically possible to build such a transmitter-at least if you have a solar, water-cooled device twice as big as the Earth .
The hypothesis raises some obvious questions. , FRB come from all the space, not just from a certain region of it. Suppose these aliens are complex enough that they have spread to many galaxies, but there are no signs of them except these energy outbursts? Or that many civilizations have established themselves despite the same strange style of energy outburst?
The document argued about the last possibility: many civilizations have separately built such massive transmitters and sent the FRB. "The latest calculations show that there is a" 10/4 "[10,000] BRP per day," notes the newspaper, suggesting an improbable number of exceptionally busy scattered extraterrestrial civilizations.To resolve this, the report argues that perhaps not all FRBs have an artificial of origin – only a small part of them may correspond to extraterrestrial activity. "But once we recognize that FRB can occur naturally, and we come to the conclusion that at least some of them happen naturally, why do we conclude that any of them
And if a civilization had a bruise technical possibilities for building solar powered planetary transmitters would not make other things that we could find and which were less ambiguous? "
" The possibility of FRB being produced by extragalactic civilizations is more speculative "Oumuamua is an alien object
In 2017 we noticed Oumuamua, an interstellar object on a falling trajectory that took it into our solar system and around the sun. Oumuamua traveled extremely fast – twice as fast as the Voyager 1 probe. He slid past the Sun, briefly crossed the telescope on Earth and disappeared back into space.
Speculation about this began seriously when scientists noticed that she had sent the sun faster than it should be possible. The most likely explanation is that, like a comet, she loses mass as she travels around the Sun, increasing her speed. We were surprised by the trajectories of the objects in space before, without any aliens. Sometimes our calculations are slightly off.
But the researchers studying Oumuamua – including Loeb's disputes – attracted the attention of the fascinating media when they mentioned in their report that Oumuamua could be artificial in origin and may even be a sunblind.
What is a solar canvas? My colleague, Brian Resnick, covers this in a piece for Oumuamua:
You can think of a light sail like a kite, but instead of being pushed out of the air in our atmosphere, the sunlight moves him forward. People have designed these light sails (there is a pretty gong plan in the work called Breakthrough Starshot to develop laser-powered solar lanes to send small spacecraft to the Alfa Centauri star.) As Verge notes, Loeb is the chairman of the Advisory Board for So you might think, "Well, an advanced alien might be able to do these things too."
In an interview with Haaretz published Monday, Loeb doubled his opinion that the "extraterrestrial" of Oumuamua is plausible. Many scientists agree with him, he argues, and are too nervous about their reputation to say this: "The article I published was written partly based on conversations I had with colleagues I respect scientifically. High-level scholars said this was a special subject, but feared that their thoughts would be public. "
Of course many other scientists disagree with it. "You can put [Oumuamua’s movement] with a clear comet-like object," said Michele Bannister, an astronomer who studies Oumoumoua at the University of the Queen in Belfast. An article from nature last fall made the case that Oumuamua was completely explainable as a comet. Comets are much more common than alien solar lanes, making them the most likely explanation.
Indeed, while Loeb claims there are more allies in private relations, most of the articles with titles pointing to scientists who say they may be intelligent aliens are articles in which Leeb is the scientist in question – which he can leave readers have the impression that there are more scientists from the "extraterrestrial" sides of the argument than they actually existed.
This does not mean that Leeb is unskilled or is in the field of his field: he is Professor of Astrophysics at Harvard, the founder of the Harvard Initiative "Black Duke" and director of the Board of Physics and Astronomy Board of the National Academies. But for aliens, its position is hardly a consensus.
A wider debate on extraterrestrial life
As it is clear from the case of Oumoumou, scientists do not agree with how to interpret these phenomena to a great extent because they disagree with the possibility of a strange life. on first place. In statistical terms, they have different priorities, which means that the background assumptions they use to interpret new evidence are different. we did here. Sometimes life will become intelligent. We expect such a universe to have many thriving civilizations – as well as many extinct.
This is the obvious expectation that motivates Avi Loeb. "As soon as we leave the solar system, I believe we will see huge traffic there," he said in an interview with Haaretz. "We'll probably get a message saying," Welcome to the interstellar club. Or we will find many dead civilizations – that is, we will find their remains. "
Obviously, if you think the space is filled with aliens, it is not so much a part of the interpretation of astronomical phenomena as the remnants of these aliens
But if you look at the same data with the expectation that we are alone in the universe, it is more likely to conclude that there is a natural explanation for the rapid radio outbursts and Oumuamua
It is strange, given that the universe is so vast that we seem to be alone in it Physicist Enrico Fermi is the first, who explains this dilemma and is baptized on it: the paradox of Fermi the adox is that with some reasonable assumptions about how often life originates and reaches technological sophistication, we must be able to detect signs of thousands or millions of other civilizations, yet we are not. "Recent studies show that the paradox can have a simple resolution – For more accurate assumptions about how life originates, we are very plausible, and it is quite common, first, if advanced civilizations are common, then why can not we see them? We may have to conclude that they are quite short-lived. This is what Leeb says: "The technological window of opportunity may be very small," he told Haaretz. "The winds are like these, but they no longer have anyone to radiate them back.
This claim will have some consequences for us. If there is any danger to us that destroys any technological civilization that enters it, we can expect to live in a "vulnerable world" where future technological advances will also destroy us.
Thus, the disagreements of aliens have great consequences. But that's probably not the reason everyone cares about them. As Resnick noticed for Vox, speculation about aliens tends to get significantly more coverage than anything else in astronomy. Whether we are alone in the universe feel like a deeply important question about its consequences for human civilization, but also for our own sake. The lack of evidence suggesting that these phenomena are foreign by origin will not suffice to prevent people from wondering.
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