- Phil Plait on the history of planetary discovery, since 1992;
- Flossing and the quest for scientific certainty;
- How placebos sometimes work;
- Peter Gabriel’s “Mercy Street”.
Good summary of the past thirty years’ discoveries of new planets.
Phil Plait, Scientific American, 6 Oct 2023: The Sky Is Full of Stars—and Exoplanets, Too, subtitled “Of the thousands of stars visible to the eye, only a few hundred are known to have planets. But that number may be far higher in reality”
I remember quite clearly when we only knew of nine planets in the entire universe.
That was the case on the first day of 1992, but scarcely a week later, everything changed. On January 9 of that year astronomers announced the discovery of the very first exoplanets—worlds orbiting stars other than our own. These new planets are so weird that it was difficult to grasp how profoundly they changed our cosmic context: they orbit a pulsar, a rapidly spinning, ultradense, city-sized stellar remnant left behind after a massive star exploded as a supernova. Although that’s extremely interesting, it’s not entirely satisfying. A pulsar is the least sunlike kind of star out there, and we, as irredeemably self-centered human beings, prefer to find places more like home—planets around stars more like our own.
Then, in 1995, astronomers announced they’d found one: 51 Pegasi b, a Jupiter-class planet circling a star that very much resembled our sun in size, mass and age.
Plait goes on with later findings, and references the NASA Exoplanet Archive (which now lists 5,523 confirmed planets), where a search on its database for planets orbiting naked-eye stars yields a count of 183. Then he explains why some naked-eye stars apparently don’t have planets, e.g. Aldebaran, and Sirius, and geometrical reasons why their planets simply might be undetectable by us. And ends:
But as this chancy viewing geometry suggests, most planets will never transit as seen from Earth, which renders them effectively invisible to this workhorse detection technique. So from a statistical standpoint, our searches to date have missed a large fraction of existing planets. Present estimates are such that the actual number of planets out there could be at least 10 times higher. The meaningful takeaway of all this is that most stars in the galaxy probably host planets. We just haven’t seen them yet—at least not with the transit method or any of the various other methods that have added smaller numbers of worlds to our galactic tally.
Think on that the next time you’re outside at night under a clear sky. It may well be that nearly every star you see has planets. The odds are that trillions of them exist in the Milky Way alone. From being able to count all the known planets on two hands to cataloging thousands to positing the existence of trillions, we’ve made incredible progress in our census of worlds in the past 30 years.
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NY Times, guest essay by Adam Mastroianni, 8 Oct 2023: The Quest for Scientific Certainty Is Futile (the homepage headline was “We’re Teaching Science All Wrong”)
The writer discusses flossing his teeth, and discovering a study that indicated the benefits of flossing “were uncertain and barely significant statistically.” Nevertheless, his dentist tells him to floss. This leads him down an epistemological rabbit hole. What is true? What is certain? Very little.
I thought I was born into the age of science and reason. But what my trip down the flossing rabbit hole taught me is that this is nowhere nearly as true as I hoped it to be. It wouldn’t matter much if it was just dentistry, which has long been the Wild West of medicine. But the more I learn about science, the more I discover basic mysteries that I assumed were solved long ago. Perhaps we’ve exited the Dark Ages, but our own age still seems rather dim.
How do you make sense of a world where the scientific sands are always shifting and where so much remains unknown? It’s taken me a long time, but I’ve made my peace with it by learning to hold everything loosely, to remain ever humble about what we do know and ever optimistic about what we will.
He makes some good points, but he’s teetering on cynicism. Science is never about absolute certainty, and this is why many people, those who prefer to live in a black-and-white of certainty even when it’s built on mythological sources, cannot deal with it.
Unfortunately he cites that misunderstood meta-analysis about the inefficacy of masks, from earlier this year. And even more unfortunately, that study was by Cochrane, who also produced the study he saw that questioned flossing. (I posted an item about why the Cochrane meta-study on masks was misunderstood back on March 10th, first item; and two takes on that study on February 25th.)
(The writer does reference this Atlantic article from May 2019: The Truth About Dentistry, subtitled “It’s much less scientific—and more prone to gratuitous procedures—than you may think.”)
The writer concludes,
My dentists could have been matter-of-fact with me about flossing: “Look, nobody’s ever run a good study on this, but it makes theoretical sense why flossing would work, and in my experience it helps patients, so I encourage you to do it.” That would have made me feel respected and even curious — maybe I would have aspired to be the person who runs the conclusive flossing study. At the very least, I might have picked up some floss. For now, I remain skeptical that scraping the sides of my teeth with a piece of nylon is a good use of my time, but I also remain hopeful that someday we’ll know for sure.
They could have, but they won’t. The vast majority of people are comfortable with clear recommendations by their doctors and dentists, without analytical discussions of the strength of those recommendations.
And in any case, part of science, and advice from doctors and dentists, comes from a broad understanding of how the world works, not simply the results of a bunch of individual studies, about masks or flossing. The world is consistent. How could wearing masks *not* help? Why would surgeons and dental technicians wear masks if all they did was prevent oxygen flow (which they don’t) rather than block floating pathogens? Why would flossing *not* help? Or is it more beneficial to leave tiny, decaying particles of food in between your teeth all day?
I’ll confess: I very rarely floss anymore. But I do use a water-pick, maybe three times a week, which is just as good getting out those small particles of food.
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And this dovetails with an item about placebos.
NY Times, guest essay by Ted J. Kaptchuk, 10 Oct 2023: No Better Than a Placebo
An advisory committee for the Food and Drug Administration recently concluded that a popular oral decongestant sold over the counter was no better than a placebo. The agency now faces the question of whether to pull medications that use the ingredient, phenylephrine, off store shelves.
The news spurred shock and anger over how long ineffective medicines have been for sale. But amid the criticism, there were also some who lamented the possibility that their favorite cold medicine would be taken from them. In their view, it may not work, but it still does something for them.
I’m a researcher who studies the placebo effect, and in some situations, it’s powerful. That said, oral phenylephrine sold over the counter should be removed from the market; despite some people’s love of phenylephrine cold medicines, there’s no evidence that the drug even provides placebo benefits. In clinical trials reviewed by the F.D.A. committee, phenylephrine and a placebo affected patients’ perceptions of nasal congestion equally, but the existing trials do not tell us to what extent people felt better because of placebo effects or because their colds simply resolved on their own.
This controversy highlights the perplexing messages that imprison placebos in general. In research settings, placebo responses are powerful but a nuisance, as they make detecting a drug’s superiority over a placebo difficult. And in clinical practice they are powerful, but they often require deception, making them unethical. But can placebos ever come out of the shadows and become a legitimate component of health care? My research suggests so.
The ironic observation of modern medicine is that placebos often *work.* Some patients get better using them. There is something psychological going on here; belief in a cure sometimes translates into a cure. Thus physical conditions are mediated through the mind. It’s been observed (I lost the reference) that virtually all “medicine” before the modern era relied on placebo effects — all the witch doctors, the rain dancers, the bloodletters — survived for centuries, because sometimes people got better anyway, or it rained anyway, and so the belief in that treatment survived, via cognitive dissonance. What else was there?
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Moving on with Peter Gabriel. Here is my favorite song from his breakout album So, from 1986, which also included hits “In Your Eyes,” “Sledgehammer,” and “Red Rain.” This is a song about the poet Anne Sexton: “Mercy Street”. Wikipedia. Lyrics.
“She pictures a soul with no leaks at the seam.”
Final lines:
Anne, with her father
Is out in the boat
Riding the water
Riding the waves on the sea
