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).
> designed to be unprovable (multiverse, string theory, and similar)
None of those are "designed" to be unprovable, and many make predictions, they just don't currently make predictions within the measurement capabilities of existing instruments or near-future instruments.
Work on them is specifically oriented towards trying to find achievable measurements that they can uniquely predict the results of. They also don't have more mundane secondary explanations ("it looks like a rock and is a rock") because in most cases there just isn't one.
>None of those are "designed" to be unprovable, and many make predictions, they just don't currently make predictions within the measurement capabilities of existing instruments or near-future instruments.
It's worse than that. The obvious and natural theoretical predictions have already been ruled out by experimental discoveries like a positive cosmological constant, and lack of discovery of super-symmetric particles at the LHC. But those theories tend to be infinitely fine-tunable, so you can always find a way to make them 'fit' whatever you want. Also, I'm not sure if there is ANY experimental guidance that suggests something like string theory is actually worth pursuing as a description of reality ... but I hear the math beautiful.
All physical theories are fine-tuneable to some extent. The Standard Model of physics, our best tested theory, has 25 physical constants that need be put by hand. That doesn't make the theory able to predict "whatever you want". It means that you have to perform at least 25 independent physical experiments to fix those free parameters and then your theory is set and can be used to make predictions.
The reason theoretical physicist pay attention to String Theory is because it's the only consistent theory of Quantum Gravity we know of. That doesn't make it the correct one for our universe, but is the only one that we know. And since physicist have been trying to crack the problem for almost 100 years now, it makes sense that some attention is paid to it, at least in the hopes that we learn how to build other theories of Quantum Gravity.
Like you said, people take the Standard Model seriously not because they like it (in fact, there is a level of embarrassment that physicists seem to have on this because the theory is so ugly), but because it has been experimentally verified within its regime. The fine-tuned constants have been experimentally derived.
So you're right, fine-tuning by itself is not necessarily a problem ... if it's experimentally tested. If you don't have experimental guidance, what else is left? At that point, you're a mathematician working in abstract worlds.
>The reason theoretical physicist pay attention to String Theory is because it's the only consistent theory of Quantum Gravity we know o
Another String Theory wart ... the theory fits more naturally in a universe with a negative cosmological constant - which is not our universe.
To be clear, I'm not making an argument that String Theory should be abandoned. I'm not physicist or a mathematician so I don't have the expertise to make that kind of judgement, although there are credible physicists who do make this argument. But at at least part of the popularity of String Theory entails an interesting socio-cultural phenomena that should be studied and analyzed by philosophers of science.
Disclaimer: I have no horse in this race, I studied Theoretical Physics but left academia for the industry many years ago. My bills won't be paid whatever side of the discussion gets funded.
1. In its canonical formulation we don't know if Loop Quantum Gravity produces the right classical limit (i.e. General Relativity). In its spin-foam formulation we can get the right classical limit but we don't know if the formulation is mathematically consistent.
2. The semi-classical results that LQG obtains, namely Black Hole entropy, is very suspect. The semi-classical result is pretty much cooked in (at least it was years ago when I was studying these things, maybe they have refined the way the calculate it recently) and the logarithmic quantum corrections are wrong (see: https://arxiv.org/pdf/1205.0971.pdf).
3. Furthermore, it's questionable how can you come up with a consistent theory of pure-Quantum Gravity that doesn't include all other forces and matter since gravity interacts with everything (that is its most defining characteristic) and in Quantum Mechanics you must include everything that can happen otherwise the diagrams would need to conspire in very peculiar ways to produce consistent results.
TL;DR: The viability of LQG as theory of Quantum Gravity has always been overstated to the general public. By the classical journalistic trick of giving equal voice to the two sides of the discussion; the reader, with not much else to judge by, has to assume equal plausibility for both sides of the argument.
With a bit more careful inspection you would notice that the number of experts paying attention to one side or the other is radically different. So either the entire High-Energy physics community has fallen in some collective delirium and "big physics" conspires to suppress LQG or maybe LQG doesn't deserve as much attention as the general public has been led to believe.
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.
> 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.
> 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.
Surface conditions is not the geometry: Oumuamua has spent thousands to millions of years nowhere near the heat of a star, in the interstellar medium. So unlike cyclic comets in orbit around Sol, having an unusual surface chemistry would be expected since it's not being evaporated every few hundred years by close encounters.
The point is, pleading about potentially naturally occurring conditions we've never seen before occurring in an object we've never seen before isn't much of an argument when you have no evidence to actually exclude them (and the observation timeline was in a phase where it was already faint).
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.
It absolutely can be debunked, in just about the same way as a scientific paper. That is, people can write other papers and books tearing it to shreds. What people don’t like is that books tend to reach a broader audience and so that audience may not read the subsequent follow-up work debunking it. I’m torn on this because bringing science to a broader audience is generally a praiseworthy thing. (I would not have entered a scientific career but for some great science books.)
There is a difference between vulgarisation of science, and making money out of sensational unproven claims pretending it’s science. This is my moral compass in that matter.
Scientific papers aren't for money, but they are for faculty positions and tenure. They suffer from much of the same grandstanding and outright fabrication as books do.
We're living in a post-truth era, and it's a problem we need to solve.
Where I'd like to land isn't: "Harvard astronomer gets bullied by peers" or "Harvard astronomer makes millions of dollars from half-baked theory" but "Harvard astronomer presents half-baked theory, we have a serious conversation about it, and we treat it as a potential hypothesis."
I like quirky hypotheses, and I've found I've learned a lot investigating them.
"I'm being bullied!" claims are what everyone immediately says when their ideas aren't picked up by everyone else and then they decide to step right around the peer review process for their field.
I think Loeb's meta-argument is that the peer-review process is tilted towards discounting arguments that include the possibility of extraterrestrial life. You can't really have discussions about how the peer-review process should work within the peer-review process. And moreover, since society at large is providing the resources for our science, they should have some visibility and input into how those resources are spent. I say this as a scientist who generally thinks (at least my field's) peer review works pretty well, so to be clear I'm not saying this to discount expert opinion.
You can feel free to disagree with Loeb's points, but I dislike the characterization that some part of this process is "invalid" (bullying) or that communicating with the public is similarly invalid because it "steps around peer review". Even your comments disagreeing with Loeb's approach are part of the process by which science and society make progress, I just happen to disagree with them in this case.
Except the only reason he wants to have a meta-argument is because otherwise the main argument has no credibility. The only reason it exists is because the ET argument is weak. He has to discuss the peer-review process and call it unfair, because otherwise he'd have the problem that the most qualified people to analyze his arguments are all saying the same thing: that it's unconvincing.
I've read some of the criticisms, and I'm not sure that I disagree with you. But let's be clear what "unconvincing" means: it means that there is a single object and hence very little data, and what data we have isn't impossible to explain with non-ET reasoning. There's definitely some weird and unexplained stuff here, and if the result of convincing society "hey there's an outside chance this is a non-natural object and we should make plans to look for and investigate future such objects" is that society ever-so-incrementally does that, we'll end up with more data than we'd have otherwise.
I think either giving the book away for free (thus removing any profit motive to pump it) or constantly updating the book to cite responses (thus addressing the tendency of book readers not to perform their own literature surveys) would both be fair.
There have been absurdly bad papers published in the "best" journals (https://pubmed.ncbi.nlm.nih.gov/2455231/ - on the memory of water by Benaventiste - the graal of homeopaths) and then quietly retracted. Unfortunately the information is now in the news and it is much more attractive that the debunking.
Then you have the poor quality of peer-review in many journals (the more one moves aways from hard science, the worse it gets). I had the opportunity to review a PhD thesis in a prestigious university in Europe (in biology) and the statistical part was disheartening. It was so bad that I have now concerns about everything biology :)
Finally the publish or die approach to contemporary science does not help to have quality and honesty in papers. There were recent cases in South Korea.
I do not have a solution, though. Probably not linking grants and career to publications would help.
A scientific paper is just a glorified blogpost, in a subculture with peculiar rituals around writing blogposts.
Still, a scientific paper is not something you intend to make heaploads of money off, but a pop-sci book absolutely is - which makes the whole thing suspect.
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.
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.
OTOH, his claims have actually probably made him the most famous Harvard astronomer. I pay little attention to astronomy, and I certainly can't name any other Harvard astronomers.
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)
It’s hard to tell since it’s velocity is very close to the mean of the velocities of systems in our local neighborhood. We do know that it probably passed close to another system (Oort cloud distance) but no exact origin has been identified.
> "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.
You're making a lot of assumptions here and basing it on the limited knowledge of a specifies that has failed to make any significant strides into exploring anything other than its own solar system.
There's an easy answer that coincides with our current understanding of physics. Then there is "Aliens have discovered tech that makes it easier for them to fling a half mile long object vs a satellite sized object across the stars at a relatively slow speed."
Sorry if I take "explosion makes rock go far" as being the more plausible explanation than "Aliens want to wait a million years for a brief glimpse at a distant solar system".
It's not the size/volume that matters, but the mass. Even with our limited science and technology, we have designs for interplanetary ships that drag hundreds of meters of radiator surface with them. It's not hard to imagine - and it has been imagined many times - a ship that consists of a core with a gigawatt-range powerplant, reaction mass, efficient engines, and kilometer-long radiators to dump the powerplant heat into space. If anything, based on our knowledge and assuming no magitech breakthroughs in space propulsion, you should expect interstellar ships to be large but light, maximizing surface area while minimizing mass.
To be fair, there is no need for the probe to have been designed for a mission to our star system. It could be that it was a craft meant for something else entirely that left its star system, like our Voyager probes have, and drifted for eons before happening to pass through our star system and be observed.
Of course, that is still less likely than some unusual rock doing the same thing.
Sure, just a bunch of energy for such a large object. "To see if they can" may very well be a reason, but that doesn't seem likely for a species that advances far enough to be able to accomplish such an achievement.
> Sorry if I take "explosion makes rock go far" as being the more plausible explanation than "Aliens want to wait a million years for a brief glimpse at a distant solar system".
Playing Devil's advocate, a probe that size would likely visit many star systems, the Solar being a random one in the bunch. The brief pass would be necessary to avoid the energy expenditure of braking and reaccelerating.
I don't think this was an alien probe but the size argument is not convincing to me. I would think that if you want to design a probe that can keep going for very long time spans and distances it would have to be big and work more like a factory that can constantly refresh its parts. Devices of the size of our satellites aren't and probably can't be designed to last thousands or millions of years. Something bigger on the other hand can be designed that way.
The object was actually in the rest frame of our local patch of the galaxy, so in essence, we came to it via our motion about the center of the galaxy.
The specific reason he contends it may be an alien artifact is that he believes its characteristics match the profile of a light sail:
1) its shape may actually be more like a pancake than a cigar, a crumpled light sail would match this
2) it showed unexpected acceleration away from the Sun without outgassing.
3) its velocity is very close to the mean motion of our local stellar neighborhood, if you needed to drop a solar sail after deceleration so that it would be hard to work out what system you came from then this would be the velocity to do it at.
> 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.
Can it be proven that there's not a teapot in the asteroid belt?
Extraordinary claims required extraordinary evidence. A massive rock being hurled to by a supernova to our solar system is far more likely than advanced aliens dumping a ton of future tech to get this huge thing into our solar system for a split second.
Why? Because, it would cost a lot of energy, something I doubt an advanced race would spend. Further, an advanced race that wants to probe us wouldn't need such a huge object, it's far easier to observe from a far (think, james webb telescope but better). Sure, hard to know what aliens are thinking, but it just seems incredibly unlikely they are thinking "Let's build this half mile long space probe for a glimpse of a distant solar system and send it off for a million year journey".
A star exploding and sending a bunch of mass our direction is far more likely. Why? because we know that happens relatively frequently.
> it would cost a lot of energy, something I doubt an advanced race would spend.
While I agree with your overall conclusion, I don't see that we have any evidence that as a race progresses technologically, they spend less energy. The opposite seems to be true.
I can't prove it's not an alien probe, no. But I can't prove it's a piece of space debris that just wandered through, either, so why not assume that too?
The problem with "can't disprove" being used as evidence is that you need to consider the full universe of statements that we "can't disprove", but humans tend to think as if "alien probe" is a privileged statement simply because it is cognitively appealing and drives our imagination. If you put it on a list of the things we can't disprove about this particular object, it wouldn't really be the most likely one you'd find.
On the flip side, you also ought to consider the question of all the objects for which we can't disprove they are alien probes. It isn't just this particular object; the solar system is filled with millions of objects we can't disprove are alien space probes, things we've labelled as "asteroids" based on a streak someone took a picture of once. Apply the same standard to all of them that is applied to this object; does it now claim that the solar system is just filled to the brim with alien space probes? Probably not good logic.
Personally, I can't wait until we improve our detection a bit and detect another several dozen things like this object so we can get over this and real science stories can be written about these objects again. Guess this is a taste of what reading about pulsars must have been in the first few years.
My point is, have you read the book and can you specifically point to why his theory is wrong? I'm not saying he is right, but I think if you are going to cut him down, be specific about why he is wrong.
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?
> 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>
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.
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.
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.
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.
I guess if it's true, and happened once in the era of never-before-so-comprehensive astronomical coverage (say O(10 years)), then it may well happen again. If it's some space rubbish from very, very far away, then so what, but if was aliens flying by, they may fly by again.
> If it's some space rubbish from very, very far away, then so what
Technological waste from an advanced civilization might have technology or materials that we can learn from. I would argue that it is vastly more valuable than having a drive-by from beings that have no intention of contacting us.
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.
For each original/exciting/intriguing story, whether it arose from a dream, hallucination, psychological trauma, deliberate invention, misinterpretation of natural (or artificial) phenomena, or whatever, there are hundreds of copycats as people (consciously or not) seek their own moment of fame. Of course they share lots of common aspects.
> They're here, and have been visiting us for hundreds of thousands of years
You can believe that if you like, of course, but I don't see a shred of credible evidence to support it.
This is exactly the problem the Randi Challenge tries to solve. There are reports and papers from time to time about ESP, but as far as we know they are just flukes, p-hacking, bad experiment design or plain lying. Some of them get press coverage, but the press just copy&paste the press release.
So the idea is to make some challenge that where there is a magician team to detect frauds, a statistics team to avoid p-hacking and minimize the chance of flukes, something equivalent to pre-registering and other security measures to ensure the result is legit.
What is the best scientifically documented EPS experiment?
Dean Radin has a fascinating book looking at the evidence for ESP. There is quite a bit since the topic has obvious military applications if it works. There are a number of metaanalyses he looks at which indicate it is not p hacking. The book has some interesting brain impulse graphs which show a clear anticipation of randomly chosen images, when the image is distressing.
As for Randi, who watches the watchers? Is he truly disinterested in his challenge, or are his examinations also biased? Additionally, the research I've seen shows a statistically significant, but faint result, so it may not be easy to reproduce in Randi's setting.
All that being said, I have not personally been able to reproduce the results, even though the claim is that almost everyone has a low level of latent ESP capability, which can be amplified through training. SRI even has an ESP training app if you want to try verifying the claims.
I found this nature article which claims he has inflated the p values, because Radin fails to include hypothetical negative tests in his sample analysis of the file drawer. Seems pretty clear, although I don't understand it yet, so I will need need to think about it further. That being said, I would still have trouble accounting for all the various pieces of evidence in his book. E.g. the anticipation graphs are pretty remarkable.
The first thing I though was a bad synchronization, but the anticipation was 3 seconds, that is big enough.
The second possibility is the filtering process. It's weird and it's a common source of error. The interesting part is in page 21-22:
> Low consistency responders
> Given that there was better evidence for presentiment from the consistent responders, one
wonders how the inconsistent responders performed?
> Examination of the raw data revealed that
in most cases, the inconsistent responders were so labeled because one or two of their calm trials
had exceptionally large within-trial variances (i.e., variance of the physiological measure from the
moment of the stimulus to the end of the cool-down period). Because of this observation, as a
post-hoc test we examined the mean presponse correlation for SCL for each inconsistent
responder, after removing the one calm trial with the most extreme within-trial variance.
> Table 9 shows that the effect of removing this single trial from each of the total of 49 inconsistent
responders (across both experiments), indicated as I* in the Table, dramatically changed the
overall results.7
> All data from all subjects combined resulted in a nonsignificant zpre-r = 0.03,
whereas removing the single highest-variance calm trial from each of the inconsistent subjects
(leaving 98.5% of all data) resulted in a combined significant zpre-r = 2.99 for SCL.
So the problem is that they are filtering the people that made a random move just before seeing a calm image, but they are not filtering the people that did a random involuntary move just before seeing an emotional picture.
Very interesting. It is suspicious, but I also wonder if removing 1.5% of the data is enough to produce a statistically significant effect? In other words, filtering is definitely happening, but is it enough to account for the effect?
Also, he has a number of such studies. Are they all suspect due to filtering, or are some filter free?
If you remove the 1.5% of the data at random, it will almost sure no make a change that is statistically significant. If you cherrypick the 1.5% to remove, it's possible.
To simplify the examples, I'll assume that each person saw the same amount of clam and emotional photos, and also that half of the photos were in each class. (In the paper the number varied from person to person and the ratio was approximately 2 to 1, the conclusion is similar but it's more difficult to write.)
They use an analog sensor, but they are essentiality counting how many times a person reacted before seen an image. It can be a premonition or a sneeze or any other cause.
In the part I posted, they selected the people that reacted exactly once before a calm photo. With this selections it's not clear how many times each person would react before an emotional photo. They compare the data, and the difference was not statistically significant, so they reacted approximately once before an emotional photo.
This is somewhat a coincidence, there is no theoretical reason for this, but if you assume some sensible distribution of the chance to react randomly before a photo and use some hand waving, this is not very surprising because if people have no PSI abilities, they'd react approximately the same number of times before each set.
So now you have a bunch of people that reacted exactly once before a calm photo and approximately once before an emotional photo. We all agree that this is obviously not a proof that they have some premonition.
Then they remove the 1.5% of the reactions before a calm photo and keep all the reactions before the emotional photos.
And now you have a bunch of people that never reacted before a calm photo and reacted approximately once before an emotional photo. So there is a clear difference in the reactions before the photos and they misinterpret this as a proof of premonition.
They actually use an analog sensor, so there is more noise involved and makes everything more fuzzy. If the noise level were too high it could have overshadow the bad cut they made in the data, but the noise was not so high.
> Also, he has a number of such studies. Are they all suspect due to filtering, or are some filter free?
I don't have time to read every study he published, but if you link one (with full text) I'll try to see if I can find an error.
This would naively seem to be a yes to psi. Bem got a strong signal and Scott doesn't believe in psi so he thinks science in general is deeply flawed as it currently works.
What is your takeaway? Scott at the end says he doesn't believe is psi despite the results because Coyne says psi is crap. That doesn't sound like checking your priors at the door.
At any rate contra your original claim it appears a psi effect has been extensively scientifically documented.
Should we "check our priors at the door", though? When neutrinos were "observed" to travel faster than light, the most appropriate conclusion wasn't "well I guess we were fundamentally wrong about just about everything we've found in the last century", but was probably something like "okay, but can I take a closer look at your data". With priors left aside, the foundations of physics are questioned. I think the same holds for psi: if you abandon your priors and just make conclusions from which way some data swings, there is something very different about the universe than what has previously been attested to.
I think Scott's analysis of "my priors against this are so strong that evidence in support of it looks more like evidence against the validity of the methodology" broadly matches with mine.
Yes, that is my takeaway. Psi is heavily evidenced by the scientific literature, and is dismissed because it goes against the priors of the scientific establishment. Not dismissed because there is anything inherently faulty with the research, at least compared to the standard scientific milieu.
Section V is where he explains why he doesn't believe the results.
"I looked through his list of ninety studies for all the ones that were both exact replications and had been peer-reviewed (with one caveat to be mentioned later). I found only seven...Three find large positive effects, two find approximate zero effects, and two find large negative effects. Without doing any calculatin’, this seems pretty darned close to chance for me.
...
That is my best guess at what happened here – a bunch of poor-quality, peer-unreviewed studies that weren’t as exact replications as we would like to believe, all subject to mysterious experimenter effects."
Why would an even proportion of positive to negative be considered chance? If half the entrants won the powerball and half did not, I would not consider that chance.
Because "large" here is still "very tiny". Large with respect to "p-values" isn't the same as "actually large". Equating the "positive results" to "winning the powerball" is not a fair comparison. If there were Powerball-level results here we wouldn't need further studies to confirm the effect exists.
He isn’t saying it’s a probe. He says that it kind of looks like and acts like a discarded light sail. The probe it belonged to could be in a different part of the galaxy having dropped the sail long ago and we just ran into it or if it was aimed at us then the probe could still be decelerating and about to enter the solar system at a velocity that would allow it to be captured by the Sun’s gravity.
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.
There's plenty. You're just not looking for it, because you're not interested. That's ok. Just don't say that there's no evidence, say that you don't care.
You and I are evidence. We are part of an advanced (or at least, spacefaring) technological civilization, and we are alien to everything else in the universe. Therefore, we know other alien civilizations are possible. One is much greater than zero in this case.
It’s a simple probabilistic argument: P(other alien civilizations exist | we exist) > P(other alien civilizations exist | we do not exist). Our existence is statistical evidence in favor of other civilizations existing elsewhere.
Similarly, the fact that we observed planets in our solar system should have increased our belief that other planets exist elsewhere. Then again, Giordano Bruno (https://en.m.wikipedia.org/wiki/Giordano_Bruno) was burned at the stake for pointing this out.
To be honest, the dominant source of nonsense around here is sneering comments that contribute absolutely nothing to thoughtful conversation.
The question is not about whether alien civilizations exist (very likely yes) but whether they can meet. Other civilizations existing is necessary but not remotely sufficient to prove that meetings are possible, let alone probable. That's where you equivocated, and I believe that calling out and naming fallacies is a worthwhile contribution.
Ed: but I guess you weren't doing it on purpose. I retract the "cute".
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.
https://news.ycombinator.com/item?id=25956720
https://news.ycombinator.com/item?id=21948804
https://news.ycombinator.com/item?id=18923591
Others?