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Avi Loeb has been making the podcast rounds pushing this idea in different forms. For example, he claims (with what feels is a very high level of certainty) that Oumuamua was an alien probe because it has a bunch of anomalous properties. He follows the Sherlock Holmes motto of: "when you have eliminated the impossible, whatever remains, however improbable, must be the truth" ... except he doesn't know what he doesn't know, so he can't be certain about what is and isn't impossible.
He’s also throwing some fun shade in other interviews towards physicists that are obsessing over theories designed to be unprovable (multiverse, string theory, and similar). But are then utterly against something like his theory, even if it’s left in statistical form (IE: based on our current understanding, this object is x% likely to be unnatural).
(Not in this article though)
This has the same basic problem it always does: from a positivist viewpoint, what changes in what we do if we start assuming artificial origin?
We would do all the same experiments we already did (which included sweeping for transmissions), and have the same lack of data that fails to meaningfully distinguish models.
Worse, disproving a hypothesis is not itself evidence in favour of another one unless they're aggressively mutually exclusive - and even then, this is rarely absolute once measurement error/difficulty becomes a factor.
Particularly when you start adding additional items - i.e. unexplained acceleration, okay sure, but how? Either it's something very similar to outgassing (which is what conventional propellants and ion engines are) or it's a new technology we have never encountered, which puts it on worse footing then the more likely explanation of naturally occurring things being observed in an unusual setting (we've never observed an interstellar object before this, haven't after this, it's reasonable to think that the 99.99%+ of it's life it spent outside of the solar system means it starts with surface conditions unlike what we're used to from comets).
But in both cases, starting from the incredible explanation hasn't contributed a way to distinguish the hypotheses - it proposes no new experiments. In fact, generally presuming alien technology artifact shuts down experimental futures: if we're actually being observed by technology, then likely we need do nothing to observe another one - it would be reasonable to expect that aliens are looking for aliens, and will send more probes now that they've found them. Whereas interstellar rocks will require advances in our rocketry and mission staging so we can hopefully find one we can get on an intercept trajectory with.
> it would be reasonable to expect that aliens are looking for aliens, and will send more probes now that they've found them.
Sure, in about a million years. The speed of light is still the speed limit in the universe from what we can tell.
> In fact, generally presuming alien technology artifact shuts down experimental futures... Whereas interstellar rocks will require advances in our rocketry and mission staging so we can hopefully find one we can get on an intercept trajectory with.
Sorry, but in my mind this is reversed. I think the general sentiment, if you asked a large portion of the populace, would be that something we assume to be of technological origin warrants a much larger investment in time and resources in order to catch up with it and study it thoroughly than something of natural origin. The last thing that comes to my mind when thinking about the possibility of an alien probe having discovered us is to sit around waiting for them to show up.
In either case, we should be a bit ashamed that we're unable to conclusively determine the difference between a rock and a solar sail and we should probably put more effort into developing the capability to do so.
I’m not here to disagree with all of your comments, but I’m pretty sure the proposed mechanism for acceleration is a solar sail.
> we've never observed an interstellar object before this, haven't after this, it's reasonable to think that the 99.99%+ of it's life it spent outside of the solar system means it starts with surface conditions unlike what we're used to from comets
In the Lex Friedman Podcast Loeb said that another interstellar object, named Borisov, had been observed since Oumuamua and it had a typical comet shape.
Counterpoints:
https://www.syfy.com/syfywire/is-oumuamua-an-interstellar-sp...
(More convincing ones, IMHO)
I actually don't find that convincing at all. He dismisses the idea of it being castoff as "special pleading", but what else could it be in the galactic rest frame? Same for the size and tumbling: the most reasonable artificial hypothesis was that it was a cast off chunk of solar sail, essentially litter, and that's still completely consistent with the evidence. His best argument was about the possibility of a natural, normal-shaped object just being a lot brighter on one side, but he barely mentioned that for some reason. I'm a lot more convinced that an artificial origin is reasonable to believe.
Thanks for sharing that - it really helped me wrap my mind around both how weird this object is and also the holes in the argument that it's an alien craft.
Thanks for sharing. This is what I was hoping people here claiming he is wrong would provide.
I would take him more seriously if he didn't want to sell a book.
Yup. A book is not a scientific paper. It can be debunked, but it doesn't really matter because it'll sell anyway.
After reading more of "Harvard astronomer"'s comments, I think "paid us a visit" is a bit pointed and unfair.
Considering the unknown odds and likelihood of life/ intelligent life in the universe, ranging from nil to high, it isn't unreasonable to propose that exceptionally unusual space junk is just that - flotsam or jetsam from others. We're certainly on track to be discarding large amounts of our own across the universe. Compare to the amount of plastic in the ocean - it has to go somewhere.
Even if it acted under its own power, that doesn't mean that "it came here to spy on us", or that it noticed us at all. Even speculating on the purpose and function goes beyond reasonable, and Loeb doesn't.
I agree [1], just nitpicking:
> Even if it acted under its own power,
He doesn't claim it's self powered. He claims that it may have the form of a sheet instead of the form of the cigar. This shape is similar to a solar sail[2], and the shape cause a small acceleration by the solar light.
[1] Every time this is repost, I'd like to repost an angry rant about pushing the "alien" solution for a problem where we clearly have not enough data.
[2] That is casually his research field.
Last week the Spanish side of Vice published a post that literally said in the title "Most famous Harvard astronomer said aliens tried to contact us".
I think that beats everything else I've read so far regarding this issue.
He was on Sean Carroll's podcast and he sounded pretty reasonable to me. He clearly doesn't think "aliens" is the only or necessarily even the best explanation, just one that can't be eliminated and it's worth thinking about.
One thing that I'm curious about. Where and when did it come from?
(A) Assuming sub-light travel, (B) no energy/mass-intensive interstellar major course corrections, (C) planetary origin... shouldn't we be able to work out where and when it was last in the vicinity of a viable source?
And at the distances (and therefore timescales) we're talking about, we might also hit low-metallicity systems... which would make intelligent, space-faring life less likely.
(Not impossible, but getting around convenient chemistry at a civilization-scale seems unlikely)
> "These ideas that came to explain specific properties of 'Oumuamua always involve something that we have never seen before," said Loeb.
"If that's the direction we are taking, then why not contemplate an artificial origin?"
This reasoning seems strange to me. We discover new things in nature all the time. Why would we consider an artificial origin, when we're constantly revising our knowledge of the natural world?
I'm a little tired of articles mentioning "Harvard Astronomer" to add credibility to this ridiculous theory. Nobody else seriously believes this and we all know Avi wants to sell his book. Out of my network of ~200 astronomers/physicists, I haven't heard one person support the idea that this is an alien probe.
And why would it be? It was HUGE. Why on earth would aliens design a probe so large? It would take a ton of energy to make it to our solar system (like, a star exploding... hmmm..).
If aliens have probed us, I DOUBT we would have actually noticed them. Because, likely the probe would be about the size of one of our satellites and maybe even a lot smaller to cut down on the amount of energy needed to get them here.
> Out of my network of ~200 astronomers/physicists, I haven't heard one person support the idea that this is an alien probe.
I've heard little to nothing in any media articles of anyone supporting alternatives.
Is it once a year these are thought to come through, or 100 times a year? Do we get things that are 100 times smaller at 100 times the rate?
If people won't make a public call, then lets run with aliens.
I was a fan of it's not interstellar, just more fake 'life on Venus' science, but reading some journal articles[1], it seems like it is expected. But it's been hard to work that out.
[1] Realistic Detectability of Close Interstellar Comets https://iopscience.iop.org/article/10.3847/0004-637X/825/1/5...
Can it be proven that it is not an alien probe?
We have emitted the Voyager gold plate and a Tesla car more recently.
It could be a message, a test or alien waste, but all the one's dismissing the professor have not explained the acceleration and cha ge of trajectory in a satisfying or convincing manner. People really think the guy is financially desperate to cash in with a kookie book?
> all the one's dismissing the professor have not explained the acceleration and cha ge of trajectory in a satisfying or convincing manner
I find the explanations pretty convincing.
https://www.spaceflightinsider.com/missions/solar-system/inc...
> Davide Farnocchia of the Center for Near-Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, recognized ‘Oumuamua’s increased speed and altered path as consistent with the actions of comets, which eject gas and dust as they approach the Sun. These jets of ejected material increase the comets’ speeds by giving them a slight push.
> People really think the guy is financially desperate to cash in with a kookie book?
"People are often willing to lie for money" seems like a claim with a lot more evidence behind it.
It's difficult to know because I never meet the guy so I have to speculate with the available information[1]. I think he is doing this for the fame, not for the money, but I don't think he is lying on purpose to get fame or money.
<speculation> After year and year of hard work improving details of solar sails in papers that only a bunch of specialist read, he made a paper about 'Oumuamua because it was a hot subject at the time and that is good to get your paper published and citations. His specialty was solar sails, so he added the solar sail hypothesis and some calculations. It got more traction than he expected, so he become famous. Not as famous as Madonna, but much more famous than most astronomers [2]. Fame is a hell of a drug. He is probably convinced that the alien possibility is worth exploring, but it's very easy to self deceive. The paper got in the news for some time, but it was fading away, and a book is a good reason to get coverage again.</speculation>
[1] Perhaps he knows because he is an alien?
[2] Can you name an astronomer that is alive?
> all the one's dismissing the professor have not explained the acceleration and change of trajectory
This is the "God of the gaps" argument[0] - "Alien of the gaps".
"Aliens" is also in need of explanation, more-so than an unexplained acceleration.
> People really think the guy is financially desperate to cash in with a kookie book?
“We don't see things as they are, we see them as we are.”
— Anaïs Nin
I think two things: one, that it is indeed a hypothesis that fits the data, and in a way a very exciting prospect. As Sherlock Holmes said, once you eliminate the impossible, whatever is left must be the answer.
The other is, there must be possible explanations we haven't thought of (even if not actually correct). Furthermore, I'm in no doubt prof Loeb is a great scientist, but as for this being a key justification for the findings, there was a host of great minds holding crazy and unsubstantiated beliefs only vaguely linked to their core expertise. Some of these crazy ideas turned out to be true, but not all.
All I'm saying, this is cool and I'll follow that, but I'm not kitting out the anti-alien survival shelter just yet.
I don't know the question that preceded it, but this kind of presumption of fallacy is not helpful and is akin to trolling:
"Thinking that we are unique and special and privileged is arrogant [...] The correct approach is to be modest"
Maybe his opponents are not being arrogant, but simply didn't come to the same conclusion as him, based on honest assessment of the facts.
Nonetheless I must admit that I find Oumuamua very compelling as a candidate for alien technology; maybe I 30% believe it. Can't we just tone it down a bit? Yet another overly-polarised argument.
I wish people would stop submitting this same story. Its been chewed over a few times here.
https://www.google.com/search?q=harvard+astronomer+site%3Ane...
Interesting that such a big part of the population believe god (one kind or another) exists but when someone thinks aliens exist, then they must be crazy.
If we are to be consistent, then a big part of the population must also be crazy.
If we are to be rational, we tread carefully, and don't call them so.
Alien believers are like "cult" members: small enough in number that's its safe to point out their craziness.
I’m kind of over this topic. He’s got a point and I agree with it in the main. I wish we had satellites we could pivot around circling all of our planets and major asteroids, for that matter. I think this situation highlights how little we’re doing to be aware of our solar system.
But this topic has come up enough on HN.
It's a neat idea and an interesting puzzle, and sure this is one conceivable interpretation, but then the question is so what? It's only one plausible interpretation. Unless we come across one of these again and the speculation gets confirmed we will never know. It's in the curiosity category, but in a complex universe we've got to expect to see things we don't understand from time to time. It's not actionable.
So it's not so much the speculation that's crazy, it's the "and therefore peace, love and uniting humanity in a common, blah, blah" that's straying into the fruitcake zone. He'll find his audience, for sure, but with the uniting humanity stuff it's clear what audience he's aiming for.
Who knows, perhaps an alien threw out a cosmic cigarette butt and its discovery by us completely brings us into disarray, like the villagers in the movie 'The Gods must be crazy'.
There's a lot of parallels between this Harvard dude's theory, and some risk management material I've been studying lately.
It goes something like this... yes, anything is possible. It's possible an alien launched a giant dildo-esque probe from 20 billion light years away as a means of wooing the citizens of Earth.
But it's likely improbable to the point that it's near meaningless to even consider it.
So what is the meaningful math behind this that provides a reasonable level of confidence behind the alien probe theory?
The number of stories of alien encounters is so huge, and share so many common aspects between them, that at the minimum one must be open to the possibility. I mean, there's even official docs released by CIA and etc. The problem is, for each true story, there are 100 fake ones.
For me personally I don't even speculate about it. They're here, and have been visiting us for hundreds of thousands of years.
If it is a probe, how does it send back data?
The data would arrive, when the civilization, sending it away is probably gone..
Doesn't make sense.
assuming that aliens do exist and that they are advanced enough to have invented interstellar space travel, the following possibilities must be true:
a) they can fly between stars but have not yet discovered earth or:
b) they have discovered earth but for some reason have decided not to make themselves known to us.
if a) is true, then we must sit and wait until we are discovered, it seems pointless to try and initiate contact on on our own.
if b) is true then aliens are indeed aware of our existence. who knows why they are still hiding themselves from us... anything is possible. obviously we are powerless to force them to reveal themselves.
and anyway, science has never been based on pointless speculation which is what prof. loebs theory amounts to.
Je n'ai pas besoin de cette hypothèse-là.
is there a term for when someone invokes galileo to support whatever theory they're pushing?
OOoooooo "Harvard"
As far as I know, there’s a Tezla Roadster out there.
Enough advertising this guy's new book already
There is no evidence of alien life, articles' like this are just entertainment.
It is an exciting idea but please lets not get ahead of ourselves.
In other news, the Loch Ness Monster must be an alien too. Because it's hard to explain. Likewise Stonehenge was made by aliens, and the Utah Monolith.