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Bad Astronomy has an article about an astronomer who had observational data to suggest he had discovered a planet around another star and published his findings in a peer-reviewed journal. In 1855.
We now know, with further, more accurate observations, that no such planet exists there, and the offsets are the product of uncertainty in the telescopic observations that were, to be fair, done by eye.
But still, despite that, I must tip my hat to Jacob. He did his homework, made the best observations and calculations he could, expressed skepticism in his writing, and came up with what he thought was the best explanation. Mind you, again to be fair, this took a great deal of cleverness to dream up. Perhaps he had been influenced by the recent discovery of Neptune.
If anything, he was guilty of overconfidence in his own measurements. Still, technology eventually caught up with his imagination and we did start to find alien worlds. The field of exoplanet research is now a thriving one, which has moved beyond the simple discovery stage to one where we are beginning to physically categorize and model them.
Not so incidentally, we have since found planets orbiting other stars using the method Jacob pioneered in 1855. He may have been the first person ever to publish this idea, and for that he deserves acknowledgment.
This short video gives some more information and context of the man and his (unfortunately erroneous) discovery. The original paper is also freely available.
(Score: 4, Interesting) by ikanreed on Monday December 12 2016, @04:53PM
The enemy of science everywhere: when you don't know how much experimental error your observations are getting, or how much statistical certainty to identify to require to validate your hypothesis. It continues to undermine a lot of science today, and often results in accidental p-hacking.
That's the big lesson here, nothing to do with astronomy. You've got to know what you don't know or your experiment is going to be fraught with problems.
(Score: 4, Interesting) by AthanasiusKircher on Monday December 12 2016, @05:57PM
That's the big lesson here
I don't know that that's really a "lesson" here, since the science of statistics, including error calculations, was still in its infancy at this time. Astronomers were making do with cruder methods to try to estimate error, and Jacob's work was doing what he could at the time.
It's noteworthy that this whole thing happened within a couple decades after the first clear measurements of stellar parallax, which had been hypothesized since the late 1500s at least, but which took centuries to actually locate and measure, due to both imprecision in equipment and then due to the inadequacy of statistical error measures of the day. Also notably, Friedrich Bessel -- who was one of the first to make a successful measurement of parallax -- was also one of the people to suggest perturbations in Sirius may be caused by a "dark body" before Jacob's work here (and which Jacob explicitly alludes to)... in 1862, the "dark" Sirius companion was shown to be a white dwarf star.
So, with crude statistical methods and the idea of unseen "dark" bodies and stellar companions in the air, Jacob's hypothesis seemed at least a reasonable idea.
(Score: 2) by JoeMerchant on Monday December 12 2016, @08:09PM
There's a philosophical discussion: how can you know what you don't know?
🌻🌻 [google.com]
(Score: 2) by AthanasiusKircher on Monday December 12 2016, @08:18PM
There's a philosophical discussion: how can you know what you don't know?
To quote Donald Rumsfeld [wikipedia.org]:
Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones.
The quantification of scientific error is about the process of trying to put boundaries on the "known unknowns." There is of course always the possibility of "unknown unknowns" though, which can obviously lead people astray in science. But just because one doesn't know something for certain, it doesn't follow that you can't know anything about the parameters of that unknown or that one can't quantify it somewhat based on statistical features of the data.
(Score: 2) by JoeMerchant on Monday December 12 2016, @08:39PM
Last time I heard the "unknown unknowns" bit, it was being applied to early space travel. Known unknowns, like the maximum intensity of solar flares, can at least be characterized and predicted with some level of certainty. Unknown unknowns, like - well - anything you say will sound absurd until it actually happens, those are the most dangerous aspect of true exploration.
True scientific exploration is a journey into the realm of unknown unknowns. "Science" that stays in a comfortable place where most or all of the unknowns are actually known and partly characterized, that's bordering on engineering. Both are well worth pursuing.
All people, scientists and consumers of scientific output, need to keep in mind that results from true scientific exploration can be reversed just as easily as dogmatic opinion. The comfortable engineering-like science is building up stronger foundations of experience based knowledge, when it's not being overly biased by outside influences.
Just calling something "Science" doesn't make it a better foundation for decision making, you also need to know what kind of science you are dealing with - and that's not always an easy thing to determine.
🌻🌻 [google.com]
(Score: 2) by ikanreed on Monday December 12 2016, @08:27PM
Ah, but even if you don't realize it there's a lot you don't know that you know you don't know.
It wouldn't be hard for you to list trivial facts that are easy to find out that you don't know:
How wide is your left foot? At the ball? At the heel? What's its volume?
How wide is the Nile River? What's the flowrate at the delta? What country owns what share of the water rights?
Who was king when the Collosus of Rhodes was built? How much copper is in it? How much did it cost at the time?
Now, I asked several related questions in each category of unknown, because the last question is one where the answers to the previous questions could establish theoretical boundaries on getting the right answer. Where being able to approximate through existing knowledge could help prevent you from making a mistake in determining the answer to the final question.
That's an essential tool in science. In practice, we often treat those unknowns through a process of experimental control, letting them vary as other independent variables to determine the magnitude of the effect. If you can't identify everything the current best theories suggest might introduce error to your tests, you don't even have a hypothesis.
(Score: -1, Offtopic) by Anonymous Coward on Monday December 12 2016, @04:57PM
https://soylentnews.org/article.pl?sid=16/12/11/1758223 [soylentnews.org]
Free Video Game "ChaosEsque Anthology" Reaches Release 100
Btw: Trump won.
(Score: 2) by FatPhil on Monday December 12 2016, @05:00PM
Does it? Does it really. It looks like noise to me. Yes, it swings from one side of the line to the other, but so does noise. Look at 1850 and 1860 - it's on both sides of the line at almost the same time. If that doesn't say "the noise is |<- this ->| wide", I don't know what does. I'm happy that Phil Plait, who I much admire, is prepared to admit to seeing the pattern, but I don't see it all. I'm not 100% sure where the dots plotted on that graph come from, as there are more datapoints there than in the original paper. In addition, as there's a predicted period, it would have been nice for that prediction to be overlaid on the graph, so that we could double-check that the data visually matches the prediction. I'm guessing it won't.
I don't wish to criticise the enthusiasm of the good captain at all, though, and I am very impressed that he is happy to limit his claim to "highly probably", and then to ask others to verify - which is an implicit request to falsify too.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by Thexalon on Monday December 12 2016, @05:58PM
The interesting thing, to me, is that even if there's a clear pattern in the data, that doesn't mean the conclusion was right if the mechanism for collecting that data isn't any good.
I was taught this back in high school, though: One of the first physics class experiments involved using a ticker-tape mechanism to time how long it took differently massed but similarly shaped objects to fall from the table to the floor. Our data quite conclusively showed that the heavier objects were consistently hitting the floor sooner than the lighter objects. So we had a brief moment of triumph as we announced "Galileo was wrong! Heavier objects do fall faster!", until the teacher asked us to consider what forms of experimental error might be at work. Which we eventually tracked down to the friction within the ticker-tape mechanism, of course.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 2) by vux984 on Monday December 12 2016, @06:15PM
Look at 1850 and 1860 - it's on both sides of the line at almost the same time
He published his paper in 1855; so he wouldn't have had the 1860 data points yet. ;)
And you have to realize also how low quality the data was, and how rudimentary even error was; how young the field of statistics itself was. The word 'median' to divide a set in half had just been coined in 1843. The chi-squared test wasn't 'discovered/invented' for another 45 years...
(Score: 0) by Anonymous Coward on Monday December 12 2016, @09:06PM
I understand your point about the noise, but there is a definite recurring pattern to the shifts which makes it less likely to be just noise in the data.
(Score: 5, Informative) by AthanasiusKircher on Monday December 12 2016, @05:43PM
It's not just this Jacob fellow who was confused by this star system, which received huge amounts of attention in the 1800s. Binary stars were of great interest in the early 1800s as the science of stellar dynamics was being developed, and this star system was particularly close. (The video link calls out Jacob for his apparently odd alternative hypothesis that Newton's law of universal gravitation may not be valid everywhere in the universe, but that's precisely why binary stars were of such interest at this time -- astronomers were trying to sort out how gravity manifested itself in multiple star systems.)
Anyhow, others also came to similar conclusions about this system -- as Thomas Jefferson Jackson See wrote in his 1896 article [google.com], "Researches on the Orbit of F. 70 Ophiuchi, and on a Periodic Perturbation in the Motion of the System Arising from the Action of an Unseen Body":
More orbits have been computed for this binary than for any other in the northern sky, but, in spite of the immense labor which astronomers have bestowed upon this star, the motion has proved to be so refractory and so anomalous that the companion has departed from every orbit heretofore obtained. It follows from the phenomena disclosed in this paper that the system contains a dark body, and that no satisfactory orbit can be obtained until this disturbing cause is taken into account.
See goes on to note toward the end of the article that Jacob had previously made this suggestion (among others), and that Herschel himself (the discoverer of the binary star in 1779) "suspected" a "disturbing body" in the binary system.
So, not to take anything away from Captain Jacob, but this was a sort of "puzzle" apparently posed when Herschel discovered the binary star. Presumably Herschel (and most other astronomers) just suspected a third star that hadn't yet been observed, so Jacob's contribution was mostly the supposition that this may be an unseen "dark body."
Moreover, Jacob himself notes that he wasn't the originator of this idea of "dark bodies." In his paper, he explicitly states:
The existence of such dark bodies has been already surmised, though not fully demonstrated in the cases of certain apparently single stars, such as Sirius and Procyon.
And I think it's a bit unfair as in the summary to accuse Jacob of being "guilty of overconfidence." Jacob explicitly hedges:
There is, then, some positive evidence in favour of the existence of a planetary body in connexion with this system, enough for us to pronounce it highly probable, and certainly good ground for watching the pair closely, to procure, if possible, still stronger evidence.
So, he calls for confirmation from more observations, which apparently came with various attempts to search for this unseen body in the 1880s, ultimately resulting in the 1896 article quoted above. And though that latter article was criticized for producing an unstable system, you still had folks even in 1943 [harvard.edu] making this hypothesis.
Anyhow, a better reporting of this whole thing to me would be: (1) Herschel apparently suggested a third body in this system when he discovered it, leading to more intense scrutiny in observations, (2) some other folks (which Jacob alludes to) had suggested the possibility of "dark bodies" to explain anomalous measurements in single stars, so (3) Jacob applies this "dark body" hypothesis in an attempt to explain what's going on in a well-known (and confusing) binary star system, where Herschel had already admitted might contain a third member of some sort, and then (4) generations of astronomers afterward actually follow in his conclusions and think they've seen the same thing (which makes it hard to accuse Jacob of "overconfidence in his own measurements" -- there just wasn't the necessary combination of precision and statistical methods at the time to deal with something like this).
Again, this doesn't take away from Jacob's imagination or work, but he apparently wasn't a lone scientist posing the idea of "dark bodies" outside the solar system, nor was his idea an isolated explanation of this system.
(Score: 2) by hubie on Monday December 12 2016, @07:18PM
A very excellent, interesting and informative post. Thank you.
(Score: 0) by Anonymous Coward on Tuesday December 13 2016, @12:35AM
It does look like a cyclic deviation to me:
http://mnras.oxfordjournals.org/content/15/9/228 [oxfordjournals.org]
The explanation offered in tfa does not satisfy me at all, in fact it seems like a huge vague handwave:
So how did they end up looking so cyclical? From that paper you can tell this is what everyone was wondering back then. Why does he not provide a real explanation?