Macroscopicity

On steps towards adulthood

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MACROSCOPICITY*

One of the big challenges of modern physics is that, if you zoom out enough, it looks somewhat like a quilt. Instead of there being one big theory of everything, physicists stitch together more specialized, smaller theories and hope that the stitches won’t have to do too much work to keep it all together. Sometimes, however, they are not fully sure how close the squares that make up the quilt should be to each other or whether they should maybe actually glue them together or just put in a few large safety pins. It is normal for the tapestry of any science to keep getting more detailed and dense because the constant updating and self-correcting process is what makes us think science is a viable method for knowing the truths of our worlds to begin with. But some big gaps and loose threads are mystifying enough to have vexed physicists for decades. 

One example is trying to fit together the “physics of very large objects” like Einstein’s general relativity and the “physics of very small objects” like quantum physics. These two theories are infamously incompatible; each gives reliable predictions for one extreme of the physical world but the two contradict each other if you try to use them at the same time, for some object that is in-between the very large and the very small. For the very large, you can imagine the Sun or the Milky Way and not have any doubts about their size being imposing. The very small is less accessible to our senses but there are octillions, or billions of billions of billions, of subatomic particles like electrons and protons in our bodies, and we consider them small enough. There are a myriad of objects that are neither that big nor that small, yet we don’t have a precise notion of exactly when something stops being big or small and becomes middle-sized. And we do not have a “middle size theory” that would seamlessly become either general relativity or quantum mechanics if you turn the size dial one way or the other. 

Laws that govern the behavior of very small things having to change as those things grow in size is not a fully counterintuitive notion. For instance, a snake expert recently explained to me that adult snakes are not just baby snakes multiplied by ten in every direction because if that were true they would probably not be able to move. As animals grow, their proportions change, the ratio of their muscles to their bones changes, and many other adjustments naturally happen so that the engineering problem of an animal being mobile and stable always remains nearly perfectly solved. Similarly, a model airplane blown up in size would likely not fly because its proportions would not necessarily match the way it’s supposed to interact with its environment. A particle of air hits differently depending on whether you’re a toy or big enough to fit a human.

But the disconnect between quantum mechanics and general relativity, even the disconnect between quantum mechanics and so-called classical physics which describes everyday objects, runs deeper than a small thing becoming slow and floppy when made larger. The disconnect here, the gap between the quilt tiles that physicists have been trying to stitch together since the 1930s, has to do with the nature of physical reality itself.

***

These days, the word “adulting” is mostly reserved for quips about millennial humor, but I am just the right age to remember when it was a meme itself instead of being their subject. At one point, it was just common to earnesty complain, in every corner of the Internet, about adulting being hard. The term itself has always been ambiguous enough to apply to both tasks like doing taxes and buying canned tomatoes without having to call a parent to ask what brand is good. And there was an internal tension to it. You wanted to signal that you are an adult now, but also that you are maybe a little mad about it, or maybe a little too cool for it. You did not want your parents to keep doing things for you, like a child, but you did want to draw everyone’s attention to how brave you were being by not acting like one.

A lot has been written about how millennials cannot expect to follow the same trajectory in life that their parents might have. For people my age, college debt, inconsistent jobs, crashing markets, overly expensive housing and dwindling access to affordable healthcare are a reality and have been a feature rather than a bug of our growing up. These things have been a hallmark of the time when the shift from adulting as a performance to being a genuine adult was meant to seamlessly happen for us. We’re both very much aware of the obstacles in our way to becoming the same flavor of adults that our parents modeled for us, and frustrated by the emotional and physical labor of having to either try anyway or invent something altogether new.

I’ve done my share of adulting. I rented apartments, I did my own taxes through many immigration status changes, I navigated international travel, took out loans, negotiated medical bills, met partners’ parents and mentors’ mentors, worked through sickness and depressive episodes, bought furniture, and went to the doctor all by myself even when I knew it would be profoundly uncomfortable. At 31, with a happy marriage and a steady job, I certainly qualify as an adult, but, much like those theoretical overgrown snakes, I feel like many of the muscles I built up through adulting are at odds with how I actually want to move through the world now.

***

Like in Ant-Man movies, to enter the quantum realm you’d have to shrink rather extremely. So imagine that you are the size of an electron, that you’re some Scott Lang type that can go subatomic while keeping it together enough to see it. You are now quantum, and what we may think of the rules for being an object don’t really apply to you anymore. 

One of my colleagues recently wrote about breaking one of those rules with ten thousand billion atoms arranged in a tiny sapphire crystal that weighed about a microgram. This crystal was put into a so-called superposition state, a way of being that only exists in the quantum world with no counterpart in the macroscopic world that we occupy. Superposition states are what is sometimes colloquially referred to as being “in two places at once” but it is really a more broad phenomenon. 

For instance, an electron in a small box can be in a superposition of the state of being at the bottom left corner of the box and the state of being in the top right corner of the box. This does not mean that it breaks into pieces or jumps from one place to another, it really means that instead of being a well-defined, solid object it is a fuzzy cloud of possibility and that cloud envelops the two places in the box. If you look at the box and observe the electron, as if to assure you that objects are still objects as we know them, this potentiality cloud settles into one place only, into something particle-like enough for us to call it an electron and measure its properties. 

Macroscopic objects do not do this: an orange is never a cloud of possibility stretching between your kitchen counter and the fruit bowl on the kitchen table even if you turn your back to it and look at something else. But everyday objects like oranges are made up of particles like electrons that do. So how do tiny things lose the ability to be a fuzzball of potentiality as they are combined into something bigger? 

The tiny sapphire crystal, so tiny that you would need 20,000 of them to rival the mass of a single grain of rice, from my colleague’s reporting was still so small compared to the tip of a pinhead or a human hair, but it had enough structure to be called a crystal. It was also big enough for scientists to have to really do their absolute experimental best to make it go quantum. In fact, the whole thing was one of the biggest objects of this kind to be put in a superposition state yet. Certainly, someone will soon go even bigger in an experiment of this sort, I thought to myself. A few days later, as if the universe wanted to tantalize the little cockiness I have left from having once been a real physicist, I saw that another story about macroscopic quantum matter appeared on the list of articles that will run in the magazine I work for the following week.

***

What you think it means to both grow and be grown up is based on how you see people around you do it. 

For instance, a few weeks ago, at a family function a relative who is roughly my age was updating my partner and me on the steps they have recently taken to move their life forward. Get a job? Check. Enter a steady relationship? Check. Move in with a partner? Check. The next step, they told us, would be to buy a house. We spent a few minutes discussing how high property prices are then returned to our dinner plates filled with glossy pasta and unnecessarily soft greens. Chewing on an overcooked green bean, I thought about how much I envied this person’s clarity as to what they have to do to grow up. They seemed to know what it would take for them to cross some magic boundary into their life being big enough, complex enough, and structured enough to be an adult life.

This is just the norm on this side of the family, my partner pointed out, crushing an arancini with his fork, laying bare its soft and gooey center. The reminder that not everyone lives like we do hung in the air as we chewed against the background of shrieking children whose parents we were somehow related to.

My parents did try to model this to me, the steps of becoming an adult. They dated for a long time, they got jobs, they got married, they had me and my brother, and for years they were getting ready to buy the apartment that we all used to live in. Except that their marriage dissolved, I left them at sixteen, and my brother forewent both education and steady employment in favor of so-called unskilled labor whenever it’s really necessary. I don’t own property, and he has never even rented an apartment of his own. Following the steps did turn my parents into adults, but that state of adulthood seemed to not make them particularly happy. My brother and I each got stuck at one step, with little desire to jump to the next, but the years kept going and this relentless passage of time helped us cheat our way into some semblance of adulthood too.

We are privileged to have been able to do so, and to do it fairly nonchalantly. Childhood itself is a modern invention. Until the 18th century children were treated as miniature adults and received no more care or sympathy than someone who was just small and incompetent. Though these days there is lots of punditry about how everyone being encouraged to go to college extends their childhood and adolescence, my experience of having been a teacher taught me that being a kid who wants to do adulthood right is now basically a new kind of full time job for them. Their days have to be filled with service, self-betterment and academics, and they are project managed by parents, tutors and coaches of all sorts. 

April is at the tail end of admissions season at many graduate programs in science so I have been seeing some familiar feathers get ruffled online about students that have already done numerous projects and published papers in peer reviewed journals getting rejected. This also reflects my experience with counseling students through college admission. The bar has been set so high that it’s unclear when exactly a young person is supposed to have time to be growing up instead of just being asked to do grown up things right away. I personally did enter graduate school with a few publications under my belt, but I was still, at 23, a lot more wide-eyed about what my future could be like. I think I maybe still am - unlike many of my former students I for sure do not have a 5 year plan for my career, or anything else at all.

I’ve grown both bored and annoyed with the idea that I have to be a better adult than my parents, and that I should learn from their mistakes in order to do the same but better. And though no-one really taught me, or showed me, that this is allowed, I’ve found myself living in a state that masquerades as adulthood in number only. Really, for the last few years, I have been trying to squint and see what could exist beyond the pre-prescribed steps, perching on the edge of one or the other with no real desire to fly away. I know adulting all these years was supposed to condition me for another painful but brave leap, but it feels more like I have grown bitter and my emotional muscles stiff and useless instead.

This is common for queer people, a friend tells me and goes on to conjecture that the old norms of staying in the closet combined with our parents not being queer have robbed us of realistic role models. You may have heard this before, that there are more queer people now than ever, but that is not necessarily true, it’s just that more people feel like they can be true to themselves out loud, or more people are finding the language to describe themselves to begin with. My generation has been part of that now, and I often wonder whether we have been and are good role models for kids who are just discovering their queerness. Maybe they can be spared from thinking that there is some special age, some special salary numbers, or a special act that pushes you into being a grown up adult instead of continuing to grow.

***

It is hard to say what exactly would happen if physicists found the exact boundary between objects that are small enough to have quantum properties, and those that are big enough for those properties to become hidden, or maybe even fully vanish. If someone built a tiny crystal that could be put into a superposition state then added just one more atom to it and now suddenly that state became impossible, what would that mean for the nature of our world?

Niels Bohr, one of the foundational figures of quantum physics, tried to more or less sidestep the issue by devising a so-called correspondence principle. According to this principle, if you try to use equations that describe an electron to describe a baseball you won’t necessarily find that they are incorrect, you will just find that they mathematically morph into everything we already know about baseballs. It’s not that it’s impossible for the baseball to be quantum, it’s just that its quantumness does not look any different than “normal” baseball-ness. So the complementarity principle gives us permission to think that the world is coherent, that we can make sense of all its parts in one go. The rub, however, is in the idea of “looking” as many physicists would like to find a way to “look” at the baseball just right to see some hint of quantumness and have empirical confirmation that, yes, all of the world really is quantum and maybe theories that contradict quantum mechanics are incomplete or just plain wrong.

I recently reported on another experiment where 700 extremely cold rubidium atoms were also shown to maintain odd quantum characteristics, somehow even more odd than being a superposition state, that the researchers thought they may actually be too big for. “Is 700 some sort of a magic number,” asked one of my editors. “I guess not, but maybe 701 could be,” I replied only somewhat jokingly. 

If 701 atoms seemed to have no quantum properties whatsoever, the issue of whether we are doing the right experiments to try and see them would still be relevant. But if repeated experiments by different teams and in different contexts showed it again and again, at least some physicists would probably feel comfortable arguing that quantum mechanics just breaks at 701. That after 701 atoms we don’t actually know how to best describe our world. That an object can grow to a size where what we have is not the cloud of possibilities offered to us by quantum theory or the precise, deterministic knowledge of the object and its future and past behavior that classical physics promises to give, but something completely different. As the meme goes, the third more sinister thing, and physicists are very much looking for it.

***

Though we live on different continents, I had the privilege of being with my mom on her 56th birthday last July. She was visiting New York, forgiving me for the pricey plane tickets and having to wedge a comically large blow-up mattress into a barely big enough living room every night, and we stretched out the celebration as much as we could, defying time’s forging ahead as much as celebrating it. There was a dinner in a high dining establishment, a rave, a trip upstate, disco dancing, large sticky donuts, early Basquiat, and an evening spent eating small bites from around the world in a busy park in Queens. My mom looks young and radiant in all of our pictures, like this was not her birthday week, or three, but just how she is, how she turns sun into smiles. During a harrowingly busy week this April she messaged me about coming back this summer, and I immediately made a mental note about having to throw her a proper birthday party on top of everything else this time around. 

“Ask mom about cake” I scribbled on a blue Post-It, right next to “Unruh deWitt detectors” and stuck it to my desk, fully knowing that I will completely lose track of it by July. The word adult is derived from the Latin word “adolescere” which translates as “to grow to maturity,” but as I was trying to think of fresh fruits that I may be able to buy for a birthday cake at the farmer’s market in July it hit me that what my mom was doing, and what I wanted to do too, was to grow into joy.

Because we live in a world that values us as workers and consumers before we are allowed to find our own value in being people, it is easy to confuse maturity, or adulthood, with an ability to follow rules and make sacrifices. Often, sadly, those sacrifices are in service of amassing either wealth or power, even if the two are mostly inaccessible for many of us and often just mean rising slightly above someone who can now be marked as being below. Adults have difficult conversations, they’re good at suppressing their feelings when in crisis, they have those stern eyes that tell you they’ve seen just enough of the world to not make rash decisions. As a young person, especially one perceived as female, you never want people to call you mature; it’s never really a compliment and almost always an indication that someone thinks you can do emotional labor for them, or worse. (Living in America, I’d be remiss to not mention that Black children are seen as adults at a younger age than their white counterparts too, often with terrible consequences.)

I don’t wish to be irresponsible or self-centered as a child nor do I crave any of my past fragility and naivete, but I do remember a more courageous version of me, one that could dream about unrealistic and unreal happenings and geometrically forbidden twists and zags in my life’s path.  I think of the Jungian idea of an inner child, a personality within us that reflects who we were as children and can cause pain when ignored or suppressed, that has really entered the lexicon of self-help enthusiasts and social media wellness influencers in past years. It gave some of their fans permission to dress a little more silly or stop trying to like something that is only ironically cool. For a while, it was a TikTok meme to say your inner child picked your outfit.

Beneath one of my photographs from a work trip to Las Vegas that I shared on social media, a former high school teacher wrote about being shocked to see me not only in Vegas, but also wearing pink. It made me uncomfortable to read the words, but they were right, the younger me would have hated both. But I don’t want to dwell on past versions of me and their quirks or shortcomings nor do I want to copy their virtues one-for-one. I have waged enough wars with my past selves to know that there is never a magic moment where you have grown just big enough to instantly be someone else. So, lots of hate for past selves is just another mode for self-hate in the present. 

Because of this, as I think about growing even more mature, about amassing more and more of whatever it is that I am currently made of, I chose to look forward and find courage and joy in my future not as recycled ideas from childhood but as something so new that it could truly be transformative. A third thing, separate from ideas I had when I was operating at a smaller size, separate from what I think I know now, a feeling and a way of being that still needs to be discovered.

Best,

Karmela

*In quantum physics, macroscopicity is a number that reflects how close to being large enough to behave in conventional, classical ways an object is. It is calculated based on the number of atoms that make up the object, its mass and properties of quantum states that it can assume. The largest macroscopicity measured to date is 14 while objects like the cat from Schrodinger’s infamous thought experiment are thought to hypothetically have macroscopicities around 60.

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ABOUT ME LATELY

WRITING

I really liked reporting and writing this story about a nascent quantum Internet that sprung up in more or less my neighborhood in the last few years. I report on emerging quantum technologies pretty regularly, but rarely do they feel as real as it felt to visit a lab where a researcher showed me the exact cable that led quantum light out of the room and underneath the chaotic streets of New York City. I also spoke about this on the New Scientist Weekly podcast.

Though I am skeptical of all the hype around AI and will often defer to my more knowledgeable colleagues when it comes to reporting on anything related to it (and New Scientist really does do great work on this font), I am sometimes really taken by use cases for methods like machine learning in science itself. I have previously reported on using AI that usually process and write text to design proteins with antibiotic properties and now a similar story came across my desk except that this AI that usually plays chess was folding proteins into little cages that useful molecules could be added to. When I reported this story I asked everyone I interviewed, from graduate students to chemists with decades of experience, whether this collaborative approach between AI trying out more structures than a human scientist could ever even think of and a biologist or a chemist testing a select few in the lab is the future  and they all empathically answered in the affirmative. 

I was also unexpectedly delighted to get to report on this stunning intersection of active soft matter physics, biology and mathematics of knots embodied in blackworms figuring out how to shape shift through tangling and untangling with each other in ways researchers are just starting to grasp. If you’re not squeamish, it’s worth clicking through just for the .gif that the researchers generously shared with New Scientist.

LISTENING

In the last week or so I fell back into listening to the boygenius’ latest record more or less on repeat, but for most of April I have been reaching for heavier fare. 

Mars Red Sky, a French stoner metal outfit has been a discovery for me and both their 2011 self-titled debut and their latest, The Task Eternal from 2019, have made it into my rotation during more than a few workdays busy with writing. This is a more melodic and less sludgy version of stoner metal than some classics of the genre, but that does not dilute its appeal. 

I’ve also quite liked Macedonian Lines and The Revolt Against Tired Noises by Yawning Man, an experimental rock band that interprets the experimental adjective very broadly, delivering both really solid sprawling and jazzy tunes and more atmospheric and heavy numbers. 

Finally, I spent some time revisiting Pharaoh Overlord records and got stuck at 5, a tour de force in a mix of electronic music and something resembling death metal that would be a perfect soundtrack for any dystopian science fiction epic.

WATCHING

Inspired by our recent trip to Las Vegas, we watched Martin Scorsese’s 1995 film Casino and there is so much going on in this film that it is hard to say that it is not worth watching, but if you have seen Goodfellas you will recognize most of its beats repeated here. I loved the tidbits about gambling fraud and all of the pastel colored suits that Robert DeNiro wrote, but much of Casino’s three hour runtime does seem to be committed to another story of crime, violence, and mildly toxic masculinity where there not so much of a plot as much as extensive and never-ending vibe setting.

We are still watching Kindred and I am still really impressed by how it manages to be both compelling and discomforting. And we are watching Succession and singing praises to its darkness and it wit as much as anyone else who thinks that being rich is almost always the same as being immoral and grotesque. 

On a similarly predictable note, we also finished the latest season of the Mandalorian. While I agree that this wasn’t the show’s best run, I was less upset with it than some of the louder fans on the Internet. Lots of the Mandalorian’s initial appeal was in being an episodic adventure featuring someone very cold and someone very cute and clumsily weaving in all of the many strands of broader Star Wars lore definitely muddled and diluted that. However,  I have always loved the later properties within this franchise because of their ability to world-build where Lucas et al. left gaps. This season was an imperfect example of how that can be done, even more imperfect than some arcs in the animated Clone Wars series which I love despite some of its really low lows. This could be a function of my not needing Star Wars to be more than what it seems to have been for quite a while, with the exception of Andor which was a story that could have transcended Lucas’s world, but I’m still interested in what will happen next to Djin, Grogu and the galaxy alike.

EATING

White bean and potato soup with a really good herb oil at Queer Soup Night. 

A surprisingly light and pillowy ‘buttermilk’ cake with a grapefruit frosting from a copy of the Cake Bible I thrifted a while back. 

For Easter, I made hot cross buns adapted from this recipe and a two layer carrot cake based on this write up topped with a lemony, cream-cheese adjacent buttercream.

Banh mi’s, paella and rice rolls at the first Smorgasburg of the season, delightfully spicy and umami ramen on a rainy lunch date with my partner at a restaurant conveniently located next door to my office, and the best cauliflower sandwich of my life in a small market in Queens, thanks to my best friend’s impeccable taste.