Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Tuesday, September 14, 2021

Unknown unknowns

One of my college physics professors made a statement to his class that was mind-boggling in its inaccuracy.  We'd been learning about the subatomic particles, and he was telling us about the smallest pieces of matter known: quarks.  Physicists had given the different types of quarks fanciful names -- up, down, top, bottom, charmed, strange.  His commentary was something of a sneer: "When scientists spend their times giving ridiculous names to physical phenomena, you know there must not be much in the way of new things waiting to be studied."

Even at the time -- I was about twenty -- it seemed humorless and mean-spirited to claim that just because scientists are having a little fun with naming stuff, they're wasting their time playing around rather than engaging in actual science.  Much later, I ran into Lord Kelvin's statement along the same line, that "There is nothing new to be discovered in physics now.  All that remains is more and more precise measurement."  

The problem was that Kelvin said this in 1900 -- immediately before Einstein and Schrödinger turned all of physics on its head with the theories of relativity and quantum mechanics, respectively.

So saying "there's nothing left to study" is not only arrogant, it's entirely inaccurate.  The preposterous implication is that right now we have a good idea of how much is left that we don't know.  It reminds me of Donald Rumsfeld's much-ridiculed statement about "known knowns, known unknowns, and unknown unknowns."  Yeah, he could have phrased it a little better, but honestly, he had a point.  There isn't any way to estimate the extent of what we're not even aware that we don't know.  The only thing we can go by is the history of science -- which pretty clearly shows that every time we think we have everything explained, the universe steps in a with a well-aimed dope slap.

I started thinking about all this because of a press release in Science Alert about a mysterious radio source near the center of the Milky Way that has astrophysicists scratching their heads.  To quell the immediate reaction a lot of folks are having, no one at this point is saying anything about aliens, or at least no one with any credibility.  But the behavior of the source is odd enough even without bringing in the Daleks or the Andorians or the Stenza or whoever your favorite extraterrestrial bad guys are.

The radio source is euphoniously named ASKAP J173608.2-321635.  (I wonder if my long-ago physics professor would have approved of that name as sufficiently serious.)  The radio emissions from ASKAP-etc. are odd in a variety of respects.  The source emits radio waves for weeks, then will suddenly "turn off" for a while before just as suddenly beginning to shine again.  The electromagnetic radiation from it is highly polarized -- the waves line up, all vibrating in the same direction, like a bunch of people creating waves in long springs, and everyone oscillating the springs up-and-down rather than each spring moving in some randomly-chosen plane of vibration.

The source was discovered through a collaboration between the Australian Square Kilometre Array Pathfinder (that's where "ASKAP" comes from) and the  MeerKAT radio telescope, near Cape Town, South Africa (speaking of whimsical names; the "KAT" part of the name stands for "Karoo Array Telescope;" "meer" is Afrikaans for "more."  It also, of course, riffs on the name of the comical little African mammal of the same name).  This isn't the first time this combo has found something strange.  Earlier this year, they found another yet-to-be-explained interstellar object, the aptly-named "Odd Radio Circles" that have bright edges and dimmer interiors, like giant gossamer soap bubbles.

A MeerKAT image of the center of the Milky Way, as viewed in radio wavelengths

Astrophysicists have considered a number of explanations for these strange objects, and so far, none of them have panned out.  "Possible identifications [include] a low-mass star/substellar object with extremely low infrared luminosity, a pulsar with scatter-broadened pulses, a transient magnetar, or a Galactic Center Radio Transient," the research team writes, "[but] none of these fully explains the observations, which suggests that ASKAP J173608.2-321635 may represent part of a new class of objects being discovered through radio imaging surveys."

So once again, we're confronted with how little we know.  We've come a long way, there's no doubt about that; our scientific achievements as a species are pretty damn impressive, especially considering that serious research has only been going on for a couple of centuries of the tens of thousands of years humans have been at least somewhat technological.  But there will always be more mysteries to solve, more puzzles to put together, more questions to ask.

I'll end with a quote from astrophysicist John Bahcall, whose research into the behavior and properties of neutrinos in the 1960s gave us a new window into why stars shine:

I do not personally want to believe that we already know the equations that determine the evolution and fate of the universe; it would make life too dull for me as a scientist…  I hope, and believe, that the Space Telescope might make the Big Bang cosmology appear incorrect to future generations, perhaps somewhat analogous to the way that Galileo’s telescope showed that the earth-centered, Ptolemaic system was inadequate...  Every time we get slapped down, we should thank Mother Nature -- because we're about to learn something important.


London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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