What Philosophy Can Reveal About Reality
Tim Maudlin is a professor of philosophy at Rutgers University. He is the author of "Quantum Non-Locality and Relativity," "Truth and Paradox," and "The Metaphysics within Physics," as well as many articles on the foundations of physics, logic, and the philosophy of science. His main areas of study pertain to the ways that physics intersects with philosophy.
Question: What can applying philosophy to the physical world reveal to us about the nature of reality?
Tim Maudlin: Let me give you a very concrete example. When you learn chemistry, or physics in high school or in college, you learn that there are electron shells that in a hydrogen atom, for example, there are various orbitals that an electron can be in, and you explain a lot about how the hydrogen works by talking about the electron jumping between different shells and giving off light or absorbing light, depending upon what these jumps are. And in the books, you’ll see a picture of the shape of these different shells, whether it be an “S” shell that looks like kind of a fuzzy sphere that surrounds the nucleus and these other “P” orbitals, and “D” orbitals that have funny-looking shapes.
Now, one very clear question to ask is, what is that a picture of? You open the book and you see this funny shaped object. Is that – does that mean that an electron at a particular moment in a hydrogen atom forms a kind of spherical shell around the nucleus, or does it mean the electron is somehow moving and what you have is a kind of long exposure picture where you’ve allowed – you’ve watched the orbital motion go on for awhile and you see, oh its tracing out a sphere. Or does it mean that, as often people would say, the electron is sort of popping in and out of existence somehow. It often doesn’t have any location, but sometimes it sort of shows up, and again, we have a long time exposure and the places it shows up it forms this kind of a shell.
Now that’s a physical question. It’s asking, what really is an electron, in this case, how does it inhabit space and time? And you’d think that should be a question that a physicist as a physicist would want to answer in order to understand what their theory is telling them about the world. It’s not a particularly philosophical question, but we’ve gotten to a situation where most physicists would not recognize it as a physical question and would not attempt to answer it and would some how think it was improper for them as physicists to attempt to answer it, or would say it is somehow a meaningless question or something like that. And we arrived at that situation through a sequence of philosophical positions, which no longer anyone thinks are tenable and a sort of crisis in physics where you had a mathematical formalism that worked very well and nobody knew quite what to make of it. And physicists made a fairly self-conscious decision to dissuade their students from thinking about it because they thought that was just going to confuse them and get in their way and prevent them from doing the important physics which involved doing more mathematical calculations and figuring out how to build explosive devices, and so on, which you can do perfectly well without having answers to these questions.
So, insofar as you’re interested in physics as a tool for engineering, you can pretty well ignore all of these questions, but I would think, would hope that most students of physics don’t go into physics in order to become engineers. They go in initially motivated by a simple curiosity about the world and what they’re hoping is that they’ll find out about the world the way if you’re interested in how biological creatures manage to reproduce and you finally understand how DNA works and how the strands separate and how they replicate. You say, “Oh there was a real puzzle about how all this works and now I understand it.” That physics should be like that. There is a real puzzle about how atoms work and find the four molecules and what’s going on. And you would turn to physics to answer those questions.
As I say, the peculiar thing, I think the historical peculiar and conceptually peculiar is that physics as a discipline has tended to turn away from those questions and to some extent now is turning back to them.
Recorded September 17, 2010
Interviewed by David Hirschman
If you're only interested in physics as a tool for engineering, you don't necessarily need to understand the true nature of what you're studying. But why wouldn't you want to?
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Research suggests that aging affects a brain circuit critical for learning and decision-making.
As people age, they often lose their motivation to learn new things or engage in everyday activities. In a study of mice, MIT neuroscientists have now identified a brain circuit that is critical for maintaining this kind of motivation.
Researchers develop the first objective tool for assessing the onset of cognitive decline through the measurement of white spots in the brain.
- MRI brain scans may show white spots that scientists believe are linked to cognitive decline.
- Experts have had no objective means of counting and measuring these lesions.
- A new tool counts white spots and also cleverly measures their volumes.
White spots and educated guesses<p>The white spots, or "hyperintensities," are brain lesions—fluid-filled holes in the brain believed to have been left behind by the breaking down of blood vessels that had previously provided nourishment to brain cells.</p><p>Prior to the new research, the quantity of white spots was assessed using an imprecise three-point scale indicating ascending likelihoods of dementia: A minimal number of spots was considered as level 1, a medium number of spots level 2, and a great number of them level 3.</p>
How the new measurements were derived<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTc1OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNDQ1ODExNX0.vqhQJSvL99KjOe24TOs4E8R7c6-pprbXYSrGcIqbVps/img.jpg?width=980" id="c64d9" class="rm-shortcode" data-rm-shortcode-id="002d9b8ef47b5a86c3a387ad2cd90629" data-rm-shortcode-name="rebelmouse-image" />
Credit: sfam_photo/Shutterstock<p>The team of researchers from NYU's Langone's <a href="https://med.nyu.edu/departments-institutes/neurology/divisions-centers/center-cognitive-neurology" target="_blank">Center for Cognitive Neurology</a> and <a href="https://med.nyu.edu/departments-institutes/neurology/divisions-centers/center-cognitive-neurology/alzheimers-disease-research-center" target="_blank">Alzheimer's Disease Research Center</a> were led by <a href="https://med.nyu.edu/faculty/jingyun-chen" target="_blank">Jingyun "Josh" Chen</a>. They analyzed 72 MRI scans from a national database of older people taken as part of the <a href="http://adni.loni.usc.edu" target="_blank">Alzheimer's Disease Neuroimaging Initiative</a> (ADNI). The scans were mostly of white people over age 70, and there were a roughly equivalent number of men and women. Some had normal brain function, some were presenting moderate cognitive decline, and some had severe dementia.</p><p>Without knowing each individual's diagnosis, the researchers analyzed the white spots in their scans. While the team counted each scan's lesions, the innovation they introduced was the production of a 3D measurement for each lesion's fluid volume. The measurement was derived by measuring a lesion's distance from opposite sides of the brain.</p><p>Measurements of 0 milliliters (mL) were assessed for areas without white spots, with other white spots coming up as containing 60 mL of fluid. Chen's team predicted that volumes over 100 mL could signify severe dementia.</p><p>"Amounts of white matter lesions above the normal range should serve as an early warning sign for patients and physicians," Chen told <a href="https://nyulangone.org/news/white-matter-lesion-mapping-tool-identifies-early-signs-dementia" target="_blank">NYU Langone Health NewsHub</a>.</p><p>When the team compared the likely diagnoses derived from their calculations against the individuals' medical records, they found that their predictions were correct about 7 out of 10 times.</p><p>The researchers compiled their formulas into an online tool that's available to physicians for free via <a href="https://github.com/jingyunc/wmhs" target="_blank" rel="noopener noreferrer">GitHub</a>. The researchers plan to further refine and test it using an additional 1,495 brain scans representing a more diverse group of individuals from the ADNI database.</p>
The new tool and its limits<p>Chen notes that white spots alone may not tell the entire story of an individual's cognitive decline or the onset of dementia. Other factors must be considered as well, including memory loss, hypertension, and brain injuries.</p><p>Nonetheless, says senior investigator <a href="https://med.nyu.edu/faculty/yulin-ge" target="_blank">Yulin Ge</a>, "Our new calculator for properly sizing white matter hyperintensities, which we call 'bilateral distancing,' offers radiologists and other clinicians an additional standardized test for assessing these lesions in the brain, well before severe dementia or stroke damage."</p><p>Having an objective means of measuring white hyperintensities will allow physicians not only to get a better handle on the association between white spots and dementia, but also to track the spots alongside changes to a person's tau and beta-amyloid proteins, two chemicals implicated in Alzheimer's disease and dementia.</p>
A Mercury-bound spacecraft's noisy flyby of our home planet.
- There is no sound in space, but if there was, this is what it might sound like passing by Earth.
- A spacecraft bound for Mercury recorded data while swinging around our planet, and that data was converted into sound.
- Yes, in space no one can hear you scream, but this is still some chill stuff.
First off, let's be clear what we mean by "hear" here. (Here, here!)
Sound, as we know it, requires air. What our ears capture is actually oscillating waves of fluctuating air pressure. Cilia, fibers in our ears, respond to these fluctuations by firing off corresponding clusters of tones at different pitches to our brains. This is what we perceive as sound.
All of which is to say, sound requires air, and space is notoriously void of that. So, in terms of human-perceivable sound, it's silent out there. Nonetheless, there can be cyclical events in space — such as oscillating values in streams of captured data — that can be mapped to pitches, and thus made audible.
Image source: European Space Agency
The European Space Agency's BepiColombo spacecraft took off from Kourou, French Guyana on October 20, 2019, on its way to Mercury. To reduce its speed for the proper trajectory to Mercury, BepiColombo executed a "gravity-assist flyby," slinging itself around the Earth before leaving home. Over the course of its 34-minute flyby, its two data recorders captured five data sets that Italy's National Institute for Astrophysics (INAF) enhanced and converted into sound waves.
Into and out of Earth's shadow
In April, BepiColombo began its closest approach to Earth, ranging from 256,393 kilometers (159,315 miles) to 129,488 kilometers (80,460 miles) away. The audio above starts as BepiColombo begins to sneak into the Earth's shadow facing away from the sun.
The data was captured by BepiColombo's Italian Spring Accelerometer (ISA) instrument. Says Carmelo Magnafico of the ISA team, "When the spacecraft enters the shadow and the force of the Sun disappears, we can hear a slight vibration. The solar panels, previously flexed by the Sun, then find a new balance. Upon exiting the shadow, we can hear the effect again."
In addition to making for some cool sounds, the phenomenon allowed the ISA team to confirm just how sensitive their instrument is. "This is an extraordinary situation," says Carmelo. "Since we started the cruise, we have only been in direct sunshine, so we did not have the possibility to check effectively whether our instrument is measuring the variations of the force of the sunlight."
When the craft arrives at Mercury, the ISA will be tasked with studying the planets gravity.
The second clip is derived from data captured by BepiColombo's MPO-MAG magnetometer, AKA MERMAG, as the craft traveled through Earth's magnetosphere, the area surrounding the planet that's determined by the its magnetic field.
BepiColombo eventually entered the hellish mangentosheath, the region battered by cosmic plasma from the sun before the craft passed into the relatively peaceful magentopause that marks the transition between the magnetosphere and Earth's own magnetic field.
MERMAG will map Mercury's magnetosphere, as well as the magnetic state of the planet's interior. As a secondary objective, it will assess the interaction of the solar wind, Mercury's magnetic field, and the planet, analyzing the dynamics of the magnetosphere and its interaction with Mercury.
Recording session over, BepiColombo is now slipping through space silently with its arrival at Mercury planned for 2025.
Why not just divide the United States in slices of equal population?
- Slicing up the country in 10 strips of equal population produces two bizarre maps.
- Seattle is the biggest city in the emptiest longitudinal band, San Antonio rules the largest north-south slice.
- Curiously, six cities are the 'capitals' of both their horizontal and vertical deciles.
Sweeping re-alignments<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTAwOC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYyMzU3ODA1NH0.u_5xakBvkYwgPtiwLU3z-1e082hBeqwS4Rl1uiJqdF4/img.png?width=980" id="23ff1" class="rm-shortcode" data-rm-shortcode-id="24a5b6ec251a11f3ed7aaefc205dde17" data-rm-shortcode-name="rebelmouse-image" alt="Printed in March 1812, this political cartoon was drawn in reaction to the newly drawn state senate election district of South Essex created by the Massachusetts legislature to favor the Democratic-Republican Party candidates of Governor Elbridge Gerry over the Federalists. The caricature satirizes the bizarre shape of a district in Essex County, Massachusetts, as a dragon-like "monster". Federalist newspaper editors and others at the time likened the district shape to a salamander, and the word gerrymander was a portmanteau of that word and Governor Gerry's last name." />
The original cartoon of the 'Gerry-Mander', published in 1812 in the Boston Centinel.
Image: Elkanah Tisdale (1771-1835), Public Domain.<p>One way for a political party to manipulate the outcome of elections is to 'gerrymander' electoral districts: manipulate their boundaries to increase the likelihood of a favorable outcome (see also #<a href="https://bigthink.com/strange-maps/53-ever-been-ger..." target="_blank">53</a>).</p><p><span></span>The term is almost as old as the United States itself, and the practice continues to disfigure the electoral map to this day. Perhaps these maps can serve as the inspiration for a radical solution. </p><p><span></span>They show the contiguous United States (i.e. without Alaska and Hawaii) sliced latitudinally and longitudinally into ten straight-bordered bands of varying size, so that each contains exactly 10 percent of the population. </p><p><span></span>Although certainly not intended as a reflection on electoral redistricting, it's tempting to see these sweeping re-alignments of the U.S. as a suggestion with some potential in that direction. </p>
United Strips of America<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTA4MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzE1MjQ1MX0.WpISo-g15B5O3qXbHXHf-7lQtAainpO7zPuizXWFOGs/img.jpg?width=980" id="d6656" class="rm-shortcode" data-rm-shortcode-id="72ed7c905283f9979ec0f82d451ad261" data-rm-shortcode-name="rebelmouse-image" alt="Reddit user curiouskip used U.S. Census population data to divide the 'Lower 48' into deciles (ten equal parts), each representing about 30.8 million people. Each decile is consigned its most populous city as 'capital'." />
The contiguous United States, divided into horizontal and vertical deciles.
Image: u/curiouskip, reproduced with kind permission.<p>Reddit user curiouskip used U.S. Census population data to divide the 'Lower 48' into deciles (ten equal parts), each representing about 30.8 million people. Each decile is consigned its most populous city as 'capital'.</p><p><span></span>Looking at the top map, which divides the U.S. into 10 longitudinal strips, we see</p><ul><li>Seattle rules the northernmost slice of territory. It is the broadest, and therefore also the emptiest one.</li><li>The Chicago, Omaha, New York City and Indianapolis strips complete the northern half of the country. And indeed: 50 percent of the population occupies roughly one half of the country, from north to south.</li><li>The dividing line between the top and bottom halves of the country runs from just north of the San Francisco Bay to halfway across the Delmarva Peninsula.</li><li>Capital cities of the southern strips are San Jose, Charlotte, Los Angeles, San Diego, and Houston.</li><li>The Houston Strip is divided into two non-contiguous areas. Florida maintains its panhandle, albeit much reduced. </li></ul><p>The bottom map shows the U.S. divided latitudinally into 10 bands of equal population. </p><ul><li>San Jose and Los Angeles both retain their capital status, this time of the two westernmost strips.</li><li>San Antonio is the main city of the Big Empty, more than twice as wide as the second-broadest band.</li><li>The dividing line between America's eastern and western half, population-wise, is far off-center: it skirts the eastern edge of Chicago, making the western half much bigger than the eastern one.</li><li>Houston, Chicago, and Indianapolis also remain the largest cities in their respective bands.</li><li>Further east, Jacksonville and Philadelphia get to rule over their strip of America, while Charlotte and New York City keep winning, both vertically and horizontally.</li></ul><p>Redistricting a country into zones of equal population – and that being your only criterium – will create districts that are randomly diverse, and perhaps also, at least in this case, unmanageably large. </p><p>However, mixing up the political map with a bunch of straight lines as the only instrument is something that has been considered before. Usually, the objective is the wholesale removal of age-old divisions. <br></p>
Perfectly square departments<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTEzOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwOTQyMzIwOH0.kYuf58g0bjsPL9DGPq5PycZ7PDJMnItT0rfrPonOP3k/img.jpg?width=980" id="89a68" class="rm-shortcode" data-rm-shortcode-id="5b81a43e785997bb1f11f72548659a9f" data-rm-shortcode-name="rebelmouse-image" alt="\u200bCh\u00e2ssis figuratif du territoire de la France partag\u00e9 en divisions \u00e9gales entre elles, proposition annex\u00e9e au rapport du 29 septembre 1789 \u00e0 l'Assembl\u00e9e nationale de la commission dite Siey\u00e8s-Thouret" />
France divided into 80-odd geometrical departments: failed proposal by Jacques-Guillaume Thouret (1790).
Image: Centre historique des Archives nationales – Atelier de photographie; public domain.
European Pie<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTQ0Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTE5NDE3OX0.dPcY1tkO7nwkx6IX98Sleh7AmBpDnwlcJLfC_Z-WBlY/img.jpg?width=980" id="b35d7" class="rm-shortcode" data-rm-shortcode-id="84509a9425e13c0dd8fbe00df28a197e" data-rm-shortcode-name="rebelmouse-image" />
In this rather outlandish proposal, continental Europe's 24 cantons center on Vienna.
Image: PJ Mode Collection of Persuasive Maps, Cornell University.<p>And in 1920, an anonymous author – possibly the Austrian P.A. Maas – proposed slicing up Post-World-War-I Europe as a pie, into 24 slices that would center on Vienna's St. Stephen's Cathedral. Each of those slices would be made up of a wide and random variety of linguistic, ethnic, and religious groups – and that would be the point: the better to unite them all into one massive superstate (see also #<a href="https://bigthink.com/strange-maps/a-bizarre-peace-proposal-slice-europe-up-like-a-pie" target="_blank">851</a>).</p><p>Needless to say, both plans never left the drawing board. Would a proposal for the longitudinal and/or latitudinal redistricting of the U.S. have more traction? <br></p>
Coast-to-coast precedents<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTIwOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MDM2OTE0OX0.52UjcA_YD9Y9UB9_hoSctI_xBrRDALZ2DRLkIo9a8RM/img.jpg?width=980" id="10784" class="rm-shortcode" data-rm-shortcode-id="1999808ea21e11162fdb9181c3912753" data-rm-shortcode-name="rebelmouse-image" alt="Illustration of the Connecticut Charter boundary, 1662" />
Putting the 'connect' into Connecticut: the Nutmeg State extending from the Pacific to the Atlantic.
Image: Connecticuthistory.org<p>Well, for one, coast-to-coast polities have some pedigree in America's past: some of the first colonies had claims that extended from the Atlantic all the way to the Pacific. </p><p>If history had gone entirely the way Connecticut would have wanted, the state would include such inland cities as Detroit, Chicago, and Salt Lake City, and extended to what is now the northern part of California.</p><p>Is such geopolitical weirdness reasonable or feasible today? Absolutely not. But in its randomness, would it be it as unfair as gerrymandering? </p><p><em><br></em></p><p><em>Decile maps of the contiguous United States reproduced with kind permission by u/curiouskip; found <a href="https://www.reddit.com/r/dataisbeautiful/comments/ijyn7p/oc_us_population_deciles_by_latitude_and_longitude/" target="_blank">here</a> on <a href="https://www.reddit.com/" target="_blank">Reddit</a>.<br></em></p><p><strong>Strange Maps #1054</strong></p><p><em>Got a strange map? Let me know at </em><a href="mailto:email@example.com">firstname.lastname@example.org</a><em>.</em></p>