Earlier this month, Avi Loeb, the head of Harvard University's astronomy department, drew widespread criticism and mockery for his paper suggesting the mysterious interstellar object called ‘Oumuamua could be an alien spacecraft. But Loeb isn't backing down, he's doubling down.

Loeb recently sat down for a lengthy interview with science publication Ars Technica, which the website published on Thursday, in which he defended the science behind his conclusions. Loeb turned the issue around, though, going on the offensive by suggesting that his critics were abdicating their responsibility as academics and scientists rather than taking risks and remaining humble.

YouTube screenshot/ Falling Walls Foundation Avi Loeb, Chair of Harvard Astronomy, speaking at the Falling Walls Foundation, November 26, 2018

"I regard being a scientist as a great privilege of maintaining your childhood curiosity, because children ask questions. They are not afraid of being wrong," Loeb told Ars Technica's Rob Reid. "Somehow, when they become adults, adults lose that inner sense. That includes scientists as well. Many of my colleagues are not willing to take risks. Not daring to be wrong, and that's a problem, because sometimes we just don't know in advance what's right and what's wrong. We have to take the risk in order to make discoveries, because what I want to understand is what ‘Oumuamua is. For that purpose, it doesn't really matter how popular is one idea versus the other on Twitter. It is what it is, and we want to find out."

Loeb said he doesn't think humans have progressed much since Galileo's time, when scientists were persecuted for speaking out against established facts about the universe.

"Many people think they know the answer in advance," he said. "People still have a lot of prejudice about what the outcome of science should be, and they want to see that answer."

"One should remain humble," he emphasized.

"The academic community has this concept of tenure, where someone has faculty position for life, [irrespective] of what happens, OK? As long as that person doesn't commit a crime. That is a great privilege. It's a privilege to follow ideas to where they lead you without worrying about what other people think. However, many practitioners in academia do not use that privilege. Once they get to the position of tenure, they worry about their image and about not being wrong. By doing so, they betray the purpose of their profession. The tenure process is aimed at allowing you the freedom of coming up with your own conclusions, and therefore, if people have a problem with this idea, they should come up with a specific alternative interpretation of the extra push that ‘Oumuamua has, rather than calling names or saying things without scientific context."

Loeb said he thought the public would be both interested by, and benefit from, an honest debate about subjects of dispute among scientists. He faulted his fellow scientists for eschewing topics the public is interested in by associating them with simplicity and plebeian attitudes not worth their time to investigate.

"I say, ‘Who cares about what people say? Nature is what nature is.' I try to understand it, and if it happens to be alien civilizations, and people are very excited about it, that's great. If it happens to be the nature of dark matter, and people don't care about it…. I want to understand nature, and I think nature is always beautiful; the only thing that can be ugly is human made," Loeb said.

"One of the reasons to explore space is because you can see nature left on its own. But if you go to the beach, and I like to do that on vacation with my daughters, and you look at seashells that were swept ashore, you see all kinds of seashells that came from different origins; and every now and then, you see a plastic bottle, which came from an artificial origin."

"I think the same approach should be adapted in the context of looking at all the interstellar objects that arrive at our door and examining each and every one of them. Even if ‘Oumuamua is natural in origin."

"First, we learn about the completely different process that makes these weird class of objects with much larger abundance than we ever expected. But in the more interesting case, we might learn about another civilization, and without a prejudice, we are just collecting data about the universe," Loeb said.