Harvard’s top astronomer to ‘Post’: Alien life could exist
Lightsail technology could allow humanity to achieve interstellar travel • Modern “Noah’s Ark” could help save, reconstruct life on Earth.
By AARON REICHThe planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to our Solar System, is seen in an undated artist's impression released by the European Southern Observatory August 24, 2016.(photo credit: ESO/M. KORNMESSER/HANDOUT VIA REUTERS)
If humanity is truly not alone in the universe, how would we go about finding extraterrestrial life – and would they be as advanced or perhaps even more so than we are?These are the questions that Prof. Avi Loeb seeks to answer, and according to his newest book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, which is set to come out January 26, the clues might already be there.Loeb, an Israeli-born scientist who has been the longest ever serving chair of Harvard University’s Astronomy Department, has long been one of the most vocal advocates for the possible existence of alien life.Harvard University's Astronomy Department chair Prof. Avi Loeb. (Photo credit: Lotem Loeb)To this end, he has served for years on the advisory board for the Breakthrough Initiative, one of the largest scientific efforts at finding alien life, funded by Israel-Russian billionaire entrepreneur and philanthropist Yuri Milner. In this capacity, he is helping direct efforts to coordinate the launch of interstellar probes called StarChips, which would allow humanity to explore the stars.Supporting this hypothesis, as well as the idea of civilized alien life existing in the universe, is ‘Oumuamua, the first ever interstellar object detected entering our solar system.Found by a Hawaiian observatory in 2017 – 'Oumuamua is Hawaiian for "scout" or "first distant messenger" – the object displayed numerous quirks that made it defy classification. And for Loeb, who discusses the object extensively in his book, there is considerable evidence that the object was nothing like we had ever seen before, such as a comet or asteroid.Rather, while he hesitates to say anything definitive, it could potentially be evidence of intelligent life in outer space.Speaking with The Jerusalem Post, Loeb explained his theories. What gave you the impression that ‘Oumuamua could give credence to the possible existence of extraterrestrial life?
“First of all, I should say it’s not an impression but part of my work. In astronomy, we don’t always have all the evidence we need. For instance, we know most of the universe is dark matter, but we don’t know what exactly that is. Science is a work in progress, and we try to find as much evidence as possible. I worked for many years on dark matter, the nature of the universe, black holes and other subjects, and I approached this in the same way.“When it was discovered on October 19, 2017, we saw that it was the first interstellar object ever discovered, and we thought it must be similar to other things in the solar system. People mainly thought it was a comet.But there was a lot of evidence against this. Its brightness changed by a factor of ten, meaning the area around it changes by a factor of ten because the light we get is reflected sunlight. That implies it has a very extreme geometry; this implies a flattened object.“‘Oumuamua also exhibited a gentle push away from the sun, just as comets do. But it wasn’t clear what was giving it this push since there was no comet trail. So it was definitely not a comet. So what gave this flattened, small and round object the extra push? All of this evidence points to the likelihood that it’s unusual and unlike anything we have ever seen before.” What did you think it could have been?“I had the idea that the push could be from the sunlight itself. If we had seen it sooner, we could have possibly gotten a clearer picture, but we only saw it as it was on its way out. We’d have to wait for something similar to make a further conclusion.This, Loeb explains in his book, is similar to the property of a light sail (also called a solar sail), which is a means of using radiation pressure from sunlight to propel a sail-like device similar to wind in a sail.“The idea of a light sail is something we are actually making,” Loeb explained.Unlike wind, which has air particles, light lacks mass. However, Loeb explained that this will not be an issue.“Light doesn’t have mass, but we know from Einstein that light is energy and energy is mass and can be converted as such, which we know from nuclear explosions,” he told the Post.“The point is that when light bounces off a surface, it carries momentum due to the energy. You can think of light as made of particles, photons, and it can bounce off a light sail just like wind bounces off a regular sail. So if you shine a massive laser and it’s 100 gigawatts or so, you can achieve a fraction of the speed of light in principle – as long as you have the right sail and laser.“This is technology we’re working on – and if there are more advanced civilizations, they probably mastered this.”And rather than just being a hypothesis, Loeb has proof that this could work.In September, an object classified as 2020 SO was discovered. When scientists tracked it, they were able to identify it as the Centaur upper rocket stage, which had helped propel a NASA lunar probe to the moon in 1966.“It was pushed by sunlight, and it was a small, narrow object,” Loeb explained. “An object was pushed by sunlight, and we know it’s possible, because this was made by us.” In your book, you mention the possibility of ‘Oumuamua being interstellar garbage. Do you think this is the case?“Maybe it was intended to do something; maybe it’s one out of a group of objects for communication relay stations. Or it could be a means of navigating through interstellar space. Who knows?” he answered.However, if this were garbage, it would make sense, as detecting an advanced alien civilization would be exceedingly difficult – especially if they don’t want to be found.“An advanced civilization with the capacity for space travel would be difficult to detect, as they would move far too fast, and we might just mistake it for rays,” Loeb explained.He also proposed that if a civilization didn’t want to be found, they wouldn’t be sending communications or probes, and might even have ways of hiding themselves – something Loeb dubbed “social distancing on a cosmic scale.”But what they will still likely have, Loeb explained, is garbage.And it is this approach that differs for what has been the predominant means of studying the possible existence of alien life, which has been either radio communications or potentially finding primitive life through the detection of oxygen and water.“In a textbook I co-authored, which should come out in June 2021, I discuss the search for advanced and primitive extraterrestrial life. The search for primitive life is often in the center, while intelligent life is often cast to the periphery of scientific study,” Loeb told the Post.“This makes no sense, since finding oxygen could have a natural cause, while compounds like those made by coolants are conclusive, and I don’t see how they could be seen as anything else. There are so many other planets with Earth’s conditions, but finding these compounds would be proof of intelligent life. And we have all the technology to do so.” Why do you think it doesn’t have mainstream appeal in the scientific community?“I think it’s a psychological barrier. And it’s a crime, given how interested the public is in it – and the scientific community has the technology to find out. I’m trying to change this perception.”Loeb’s theories on the existence of extraterrestrial life and how humanity would find evidence of its existence differs heavily with claims made in December by former Israeli space security chief Haim Eshed, who had claimed in an interview with Yediot Aharonot that the United States and Israel had both been in contact with a Galactic Federation who felt humanity wasn’t ready to be aware of its existence.Eshed had at the time claimed that academic views on his claims was changing, and cited Loeb’s research into ‘Oumuamua as an example.But Loeb strongly disagrees.“When notable people say crazy things, the public assumes that this is evidence. It takes away the reputation of science. Everything I said is based on evidence and is rooted in evidence; Eshed had no evidence.”It should be noted, though, that since ‘Oumuamua was spotted, so was another interstellar object, 2I/Borisov. Unlike ‘Oumuamua, however, all evidence points to it being a comet.“People tried convincing me that this could mean ‘Oumuamua is also one,” Loeb said. “To which I say, when I met my wife, she looked special and unique to me, and I’ve met many women since who don’t change how special and unique my wife is.”But regardless of what ‘Oumuamua is, it lends further support to the viability of light sails. And for Loeb, this could be the hope humanity needs, since it has already “spent a considerable amount of money into destroying the planet.”“It’s like Noah’s ark to save life on Earth,” he told the Post.“It doesn’t need to be a big spacecraft, it just needs to have an artificial intelligence, a large enough computer with the DNA of every living creature and a 3D printer. We will know hopefully in the next few decades how to reconstruct synthetic life, and with a 3D printer we could possibly do it," Loeb said. "With a computer, 3D printer and AI we could reconstruct everything.”
