# (Roughly) Daily

## “The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth.”*…

Zeno shows the Doors to Truth and Falsity (Veritas et Falsitas). Fresco in the Library of El Escorial, Madrid (source)

As Joel David Hamkins explains, an ancient puzzle leads ultimately to a remarkable observation on the malleable nature of infinite sums…

The Greek philosopher Zeno of Elea (c. 490–430 BC) argued in antiquity that all motion is impossible. It is simply impossible to walk through town or even across the room, to go from here to there. What? We know, of course, that this is possible—we walk from here to there every day. And yet, Zeno offers us his proof that this is an illusion—we simply cannot do it.

Zeno argued like this. Suppose it were possible for you to move from some point A to another distinct point B.

Before you complete the move from A to B , however, you must of course have gotten half way there.

But before you get to this half-way point, of course, you must get half way to the half-way point! And before you get to that place, you must get half way there.

Thus, to move from A to B , or indeed anywhere at all, one must have completed an infinite number of tasks—a supertask. It follows, according to Zeno, that you can never start moving—you cannot move any amount at all, since before doing that you must already have moved half as much. And so, contrary to appearances, you are frozen motionless, unable to begin. All motion is impossible.

Is the argument convincing? On what grounds would you object to it? Do you think, contrary to Zeno, that we can actually complete infinitely many tasks? How would that be possible?

It will be no good, of course, to criticize Zeno’s argument on the grounds that we know that motion is possible, for we move from one point to another every day. That is, to argue merely that the conclusion is false does not actually tell you what is wrong with the argument—it does not identify any particular flaw in Zeno’s reasoning. After all, if it were in fact an illusion that we experience motion, then your objection would be groundless…

Learning from an enigma– plus “the most contested equation in middle school” and more: “Zeno’s paradox,” from @JDHamkins.

* Niels Bohr

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As we interrogate infinity, we might send-well-groomed birthday greetings to Frank Joseph Zamboni, Jr.; he was born on this date in 1901.  An engineer and inventor, he is best known for the modern ice resurfacer, seen at work at hockey games and figure skating competitions (completing its rounds, Zeno notwithstanding); indeed, his surname is the registered trademark for these devices.

source

Written by (Roughly) Daily

January 16, 2023 at 1:00 am

Posted in Uncategorized

## “Water, water everywhere”*…

On November 14, 2016, six days after Donald Trump was elected president, a man named Richard Conlin found an octopus in the parking garage of his Miami Beach apartment building. The translucent creature, which a viral photo showed sitting in a small puddle by a row of cars, had been brought ashore by an unusually large high tide that sent sludgy water rushing through nearby streets. A local biologist speculated that the octopus had found its way inside one of the apartment building’s drainage pipes: the pipes had been positioned well above the waterline when the condo complex was constructed, but rising sea levels meant they were now submerged at high tide, allowing aquatic creatures to make their way inside. (Conlin wrote on Facebook that he spotted a small school of fish swimming in another puddle.)

The octopus makes for an apt little parable not just about the extent to which climate change is already changing daily life in the United States, but about the way in which it is doing so. The cephalopod did not arrive in the parking garage Day After Tomorrow-style, on the crest of an apocalyptic wave, but by means of a crucial yet neglected piece of infrastructure. The alarming fact the octopus represents is not that the ocean threatens to destroy us, but that it threatens to destroy the structures we have built in its midst.

Miami, as you may have heard, is doomed: depending on which study you prefer, the city will be underwater by 2100, 2060, 2050, or whenever the next hurricane hits. It is poised to see two, five, eight, ten, or twelve feet of sea-level rise in the next century. Even numbers on the low end of that range would be enough to inundate Conlin’s apartment building, not to mention billions more dollars of real estate. Tidal flooding events of the kind that brought the octopus ashore increased by more than 400 percent between 2006 and 2013, and the city has only barely been spared by a number of major hurricanes in that same time span. The right storm—The Big One, as they call it in Florida—could raze whole swaths of Miami, send its property market and tourism industry into a death spiral, and spur a mass exodus of domestic climate refugees. Even in the absence of such a storm, the city’s lowest-lying neighborhoods may need to be abandoned by midcentury if the rest of it is to be preserved…

The coming scramble for free space won’t be as bad as it could have been, though, because many of the most vulnerable homes in the city don’t have anyone living in them in the first place. The glistening condo towers that make up the high end of Miami’s housing market serve predominantly as parking lots for foreign capital, much of it of dubious origin. The absentee ownership rate in many of these buildings is well above 50 percent, and even as the streets of Miami Beach begin to flood, the emirs and mafiosi who own these apartments will be somewhat insulated from the crash in the rest of the city’s housing market, since the selling point of these condos is not their view of the Biscayne Bay but their ability to serve as storage units for foreign capital.

For everyone who actually lives in Miami, though, it’s going to get ugly, and there isn’t much the city can do about it. [Journalist Mario Alejandro] Ariza opens the book [Disposable City: Miami’s Future on the Shores of Climate Catastrophe] with the image of an enormous water pump designed to flush out water from the streets in the event of a high tide or a hurricane; the city has installed a number of these pumps in the past few years, financing them with a new climate-oriented municipal bond, and has also endeavored to raise dozens of miles of streets. Even if these interventions always worked out, which they don’t—a former mayor of Miami Beach prioritized installing pumps and raising roads near property he owned, inadvertently increasing flooding in nearby businesses he didn’t own—they wouldn’t be enough to forestall a crisis that is coming sooner rather than later. With enough money from the federal government, the city could in theory move the most vulnerable homeowners out of harm’s way before it’s too late, build green infrastructure to absorb floodwaters, and sponsor high-density affordable housing for those who want to stay, but a hat trick in that regard seems unlikely. If sea level rise reaches nine feet by the end of the century, though, none of these interventions will matter: all of Miami and much of South Florida will be underwater. Even if the city doesn’t sink altogether, hundreds of thousands of Miamians will likely be displaced to Orlando, Atlanta, and other nearby cities, none of which are going to feel exactly like paradise in the year 2100…

Miami’s bleak future on the front line of climate change; “The City That Lived.”

And to put it into a broader context: “2020 Is our Last, Best Chance to Save the Planet” and  “The Great Climate Migration Has Begun.”

* Samuel Taylor Coleridge, “The Rime of the Ancient Mariner”

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As we search for a drop to drink, we might spare a thought for a man who successfully manged water in a different physical state, Frank Joseph Zamboni, Jr.; he died on this date in 1988.  An engineer and inventor, he is best known for the modern ice resurfacer, seen at work at hockey games and figure skating competitions; indeed, his surname is the registered trademark for these devices.

Written by (Roughly) Daily

July 27, 2020 at 1:01 am

Posted in Uncategorized