Tag Archives: COVID19

In Uppsala for Elliptics 2021

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I’m in Uppsala in Sweden this week, at an actual in-person conference.

With actual blackboards!

Elliptics started out as a series of small meetings of physicists trying to understand how to make sense of elliptic integrals in calculations of colliding particles. It grew into a full-fledged yearly conference series. I organized last year, which naturally was an online conference. This year though, the stage was set for Uppsala University to host in person.

I should say mostly in person. It’s a hybrid conference, with some speakers and attendees joining on Zoom. Some couldn’t make it because of travel restrictions, or just wanted to be cautious about COVID. But seemingly just as many had other reasons, like teaching schedules or just long distances, that kept them from coming in person. We’re all wondering if this will become a long-term trend, where the flexibility of hybrid conferences lets people attend no matter their constraints.

The hybrid format worked better than expected, but there were still a few kinks. The audio was particularly tricky, it seemed like each day the organizers needed a new microphone setup to take questions. It’s always a little harder to understand someone on Zoom, especially when you’re sitting in an auditorium rather than focused on your own screen. Still, technological experience should make this work better in future.

Content-wise, the conference began with a “mini-school” of pedagogical talks on particle physics, string theory, and mathematics. I found the mathematical talks by Erik Panzer particularly nice, it’s a topic I still feel quite weak on and he laid everything out in a very clear way. It seemed like a nice touch to include a “school” element in the conference, though I worry it ate too much into the time.

The rest of the content skewed more mathematical, and more string-theoretic, than these conferences have in the past. The mathematical content ranged from intriguing (including an interesting window into what it takes to get high-quality numerics) to intimidatingly obscure (large commutative diagrams, category theory on the first slide). String theory was arguably under-covered in prior years, but it felt over-covered this year. With the particle physics talks focusing on either general properties with perhaps some connections to elliptics, or to N=4 super Yang-Mills, it felt like we were missing the more “practical” talks from past conferences, where someone was computing something concrete in QCD and told us what they needed. Next year is in Mainz, so maybe those talks will reappear.

Physics Acculturation

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We all agree physics is awesome, right?

Me, I chose physics as a career, so I’d better like it. And you, right now you’re reading a physics blog for fun, so you probably like physics too.

Ok, so we agree, physics is awesome. But it isn’t always awesome.

Read a blog like this, or the news, and you’ll hear about the more awesome parts of physics: the black holes and big bangs, quantum mysteries and elegant mathematics. As freshman physics majors learn every year, most of physics isn’t like that. It’s careful calculation and repetitive coding, incremental improvements to a piece of a piece of a piece of something that might eventually answer a Big Question. Even if intellectually you can see the line from what you’re doing to the big flashy stuff, emotionally the two won’t feel connected, and you might struggle to feel motivated.

Physics solves this through acculturation. Physicists don’t just work on their own, they’re part of a shared worldwide culture of physicists. They spend time with other physicists, and not just working time but social time: they eat lunch together, drink coffee together, travel to conferences together. Spending that time together gives physics more emotional weight: as humans, we care a bit about Big Questions, but we care a lot more about our community.

This isn’t unique to physics, of course, or even to academics. Programmers who have lunch together, philanthropists who pat each other on the back for their donations, these people are trying to harness the same forces. By building a culture around something, you can get people more motivated to do it.

There’s a risk here, of course, that the culture takes over, and we lose track of the real reasons to do science. It’s easy to care about something because your friends care about it because their friends care about it, looping around until it loses contact with reality. In science we try to keep ourselves grounded, to respect those who puncture our bubbles with a good argument or a clever experiment. But we don’t always succeed.

The pandemic has made acculturation more difficult. As a scientist working from home, that extra bit of social motivation is much harder to get. It’s perhaps even harder for new students, who haven’t had the chance to hang out and make friends with other researchers. People’s behavior, what they research and how and when, has changed, and I suspect changing social ties are a big part of it.

In the long run, I don’t think we can do without the culture of physics. We can’t be lone geniuses motivated only by our curiosity, that’s just not how people work. We have to meld the two, mix the social with the intellectual…and hope that when we do, we keep the engines of discovery moving.

QCD Meets Gravity 2020

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I’m at another Zoom conference this week, QCD Meets Gravity. This year it’s hosted by Northwestern.

The view of the campus from wonder.me

QCD Meets Gravity is a conference series focused on the often-surprising links between quantum chromodynamics on the one hand and gravity on the other. By thinking of gravity as the “square” of forces like the strong nuclear force, researchers have unlocked new calculation techniques and deep insights.

Last year’s conference was very focused on one particular topic, trying to predict the gravitational waves observed by LIGO and VIRGO. That’s still a core topic of the conference, but it feels like there is a bit more diversity in topics this year. We’ve seen a variety of talks on different “squares”: new theories that square to other theories, and new calculations that benefit from “squaring” (even surprising applications to the Navier-Stokes equation!) There are talks on subjects from String Theory to Effective Field Theory, and even a talk on a very different way that “QCD meets gravity”, in collisions of neutron stars.

With still a few more talks to go, expect me to say a bit more next week, probably discussing a few in more detail. (Several people presented exciting work in progress!) Until then, I should get back to watching!

A Taste of Normal

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I grew up in the US. I’ve roamed over the years, but each year I’ve managed to come back around this time. My folks throw the kind of Thanksgiving you see in movies, a table overflowing with turkey and nine kinds of pie.

This year, obviously, is different. No travel, no big party. Still, I wanted to capture some of the feeling here in my cozy Copenhagen apartment. My wife and I baked mini-pies instead, a little feast just for us two.

In these weird times, it’s good to have the occasional taste of normal, a dose of tradition to feel more at home. That doesn’t just apply to personal life, but to academic life as well.

One tradition among academics is the birthday conference. Often timed around a 60th birthday, birthday conferences are a way to celebrate the achievements of professors who have made major contributions to a field. There are talks by their students and close collaborators, filled with stories of the person being celebrated.

Last week was one such conference, in honor of one of the pioneers of my field, Dirk Kreimer. The conference was Zoom-based, and it was interesting to compare with the other Zoom conferences I’ve seen this year. One thing that impressed me was how they handled the “social side” of the conference. Instead of a Slack space like the other conferences, they used a platform called Gather. Gather gives people avatars on a 2D map, mocked up to look like an old-school RPG. Walk close to a group of people, and it lets you video chat with them. There are chairs and tables for private conversations, whiteboards to write on, and in this case even a birthday card to sign.

I didn’t get a chance to try Gather. My guess is it’s a bit worse than Slack for some kinds of discussion. Start a conversation in a Slack channel and people can tune in later from other time zones, each posting new insights and links to references. It’s a good way to hash out an idea.

But a birthday conference isn’t really about hashing out ideas. It’s about community and familiarity, celebrating people we care about. And for that purpose, Gather seems great. You want that little taste of normalcy, of walking across the room and seeing a familiar face, chatting with the folks you keep seeing year after year.

I’ve mused a bit about what it takes to do science when we can’t meet in person. Part of that is a question of efficiency: what does it take it get research done? But if we focus too much on that, we might forget the role of culture. Scientists are people, we form a community, and part of what we value is comfort and familiarity. Keeping that community alive means not just good research discussions, but traditions as well, ways of referencing things we’ve done to carry forward to new circumstances. We will keep changing, our practices will keep evolving. But if we want those changes to stick, we should tie them to the past too. We should keep giving people those comforting tastes of normal.

At “Antidifferentiation and the Calculation of Feynman Amplitudes”

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I was at a conference this week, called Antidifferentiation and the Calculation of Feynman Amplitudes. The conference is a hybrid kind of affair: I attended via Zoom, but there were seven or so people actually there in the room (the room in question being at DESY Zeuthen, near Berlin).

The road to this conference was a bit of a roller-coaster. It was originally scheduled for early March. When the organizers told us they were postponing it, they seemed at the time a little overcautious…until the world proved me, and all of us, wrong. They rescheduled for October, and as more European countries got their infection rates down it looked like the conference could actually happen. We booked rooms at the DESY guest house, until it turned out they needed the space to keep the DESY staff socially distanced, and we quickly switched to booking at a nearby hotel.

Then Europe’s second wave hit. Cases in Denmark started to rise, so Germany imposed a quarantine on entry from Copenhagen and I switched to remote participation. Most of the rest of the participants did too, even several in Germany. For the few still there in person they have a variety of measures to stop infection, from fixed seats in the conference room to gloves for the coffee machine.

The content has been interesting. It’s an eclectic mix of review talks and talks on recent research, all focused on different ways to integrate (or, as one of the organizers emphasized, antidifferentiate) functions in quantum field theory. I’ve learned about the history of the field, and gotten a better feeling for the bottlenecks in some LHC-relevant calculations.

This week was also the announcement of the Physics Nobel Prize. I’ll do my traditional post on it next week, but for now, congratulations to Penrose, Genzel, and Ghez!

Kicking Students Out of Their Homes During a Pandemic: A Bad Idea

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I avoid talking politics on this blog. There are a few issues, though, where I feel not just able, but duty-bound, to speak out. Those are issues affecting graduate students.

This week, US Immigration and Customs Enforcement (ICE) announced that, if a university switched to online courses as a response to COVID-19, international students would have to return to their home countries or transfer to a school that still teaches in-person.

This is already pretty unreasonable for many undergrads. But think about PhD students.

Suppose you’re a foreign PhD student at a US university. Maybe your school is already planning to have classes online this fall, like Harvard is. Maybe your school is planning to have classes in person, but will change its mind a few weeks in, when so many students and professors are infected that it’s clearly unreasonable to continue. Maybe your school never changes its mind, but your state does, and the school has to lock down anyway.

As a PhD student, you likely don’t live in the dorms. More likely you live in a shared house, or an apartment. You’re an independent adult. Your parents aren’t paying for you to go to school. Your school is itself a full-time job, one that pays (as little as the university thinks it can get away with).

What happens when your school goes online? If you need to leave the country?

You’d have to find some way out of your lease, or keep paying for it. You’d have to find a flight on short notice. You’d have to pack up all your belongings, ship or sell anything you can’t store, or find friends to hold on to it.

You’d have to find somewhere to stay in your “home country”. Some could move in with their parents temporarily, many can’t. Some of those who could in other circumstances, shouldn’t if they’re fleeing from an outbreak: their parents are likely older, and vulnerable to the virus. So you have to find a hotel, eventually perhaps a new apartment, far from what was until recently your home.

Reminder: you’re doing all of this on a shoestring budget, because the university pays you peanuts.

Can you transfer instead? In a word, no.

PhD students are specialists. They’re learning very specific things from very specific people. Academics aren’t the sort of omnidisciplinary scientists you see in movies. Bruce Banner or Tony Stark could pick up a new line of research on a whim, real people can’t. This is why, while international students may be good at the undergraduate level, they’re absolutely necessary for PhDs. When only three people in the world study the thing you want to study, you don’t have the luxury of staying in your birth country. And you can’t just transfer schools when yours goes online.

It feels like the people who made this decision didn’t think about any of this. That they don’t think grad students matter, or forgot they exist altogether. It seems frustratingly common for policy that affects grad students to be made by people who know nothing about grad students, and that baffles me. PhDs are a vital part of the academic career, without them universities in their current form wouldn’t even exist. Ignoring them is like if hospital policy ignored residencies.

I hope that this policy gets reversed, or halted, or schools find some way around it. At the moment, anyone starting school in the US this fall is in a very tricky position. And anyone already there is in a worse one.

As usual, I’m going to ask that the comments don’t get too directly political. As a partial measure to tone things down, I’d like to ask you to please avoid mentioning any specific politicians, political parties, or political ideologies. Feel free to talk instead about your own experiences: how this policy is likely to affect you, or your loved ones. Please also feel free to talk more technically on the policy/legal side. I’d like to know what universities can do to work around this, and whether there are plausible paths to change or halt the policy. Please be civil, and be kind to your fellow commenters.

In Defense of Shitty Code

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Scientific programming was in the news lately, when doubts were raised about a coronavirus simulation by researchers at Imperial College London. While the doubts appear to have been put to rest, doing so involved digging through some seriously messy code. The whole situation seems to have gotten a lot of people worried. If these people are that bad at coding, why should we trust their science?

I don’t know much about coronavirus simulations, my knowledge there begins and ends with a talk I saw last month. But I know a thing or two about bad scientific code, because I write it. My code is atrocious. And I’ve seen published code that’s worse.

Why do scientists write bad code?

In part, it’s a matter of training. Some scientists have formal coding training, but most don’t. I took two CS courses in college and that was it. Despite that lack of training, we’re expected and encouraged to code. Before I took those courses, I spent a summer working in a particle physics lab, where I was expected to pick up the C++-based interface pretty much on the fly. I don’t think there’s another community out there that has as much reason to code as scientists do, and as little training for it.

Would it be useful for scientists to have more of the tools of a trained coder? Sometimes, yeah. Version control is a big one, I’ve collaborated on papers that used Git and papers that didn’t, and there’s a big difference. There are coding habits that would speed up our work and lead to fewer dead ends, and they’re worth picking up when we have the time.

But there’s a reason we don’t prioritize “proper coding”. It’s because the things we’re trying to do, from a coding perspective, are really easy.

What, code-wise, is a coronavirus simulation? A vector of “people”, really just simple labels, all randomly infecting each other and recovering, with a few parameters describing how likely they are to do so and how long it takes. What do I do, code-wise? Mostly, giant piles of linear algebra.

These are not some sort of cutting-edge programming tasks. These are things people have been able to do since the dawn of computers. These are things that, when you screw them up, become quite obvious quite quickly.

Compared to that, the everyday tasks of software developers, like making a reliable interface for users, or efficient graphics, are much more difficult. They’re tasks that really require good coding practices, that just can’t function without them.

For us, the important part is not the coding itself, but what we’re doing with it. Whatever bugs are in a coronavirus simulation, they will have much less impact than, for example, the way in which the simulation includes superspreaders. Bugs in my code give me obviously wrong answers, bad scientific assumptions are much harder for me to root out.

There’s an exception that proves the rule here, and it’s that, when the coding task is actually difficult, scientists step up and write better code. Scientists who want to run efficiently on supercomputers, who are afraid of numerical error or need to simulate on many scales at once, these people learn how to code properly. The code behind the LHC still might be jury-rigged by industry standards, but it’s light-years better than typical scientific code.

I get the furor around the Imperial group’s code. I get that, when a government makes a critical decision, you hope that their every input is as professional as possible. But without getting too political for this blog, let me just say that whatever your politics are, if any of it is based on science, it comes from code like this. Psychology studies, economic modeling, polling…they’re using code, and it’s jury-rigged to hell. Scientists just have more important things to worry about.

Zoomplitudes 2020

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This week, I’m at Zoomplitudes!

My field’s big yearly conference, Amplitudes, was supposed to happen in Michigan this year, but with the coronavirus pandemic it was quickly clear that would be impossible. Luckily, Anastasia Volovich stepped in to Zoomganize the conference from Brown.

Obligatory photo of the conference venue

The conference is still going, so I’ll say more about the scientific content later. (Except to say there have been a lot of interesting talks!) Here, I’ll just write a bit about the novel experience of going to a conference on Zoom.

Time zones are always tricky in an online conference like this. Our field is spread widely around the world, but not evenly: there are a few areas with quite a lot of amplitudes research. As a result, Zoomganizing from the US east coast seems like it was genuinely the best compromise. It means the talks start a bit early for the west coast US (6am their time), but still end not too late for the Europeans (10:30pm CET). The timing is awkward for our colleagues in China and Taiwan, but they can still join in the morning session (their evening). Overall, I don’t think it was possible to do better there.

Usually, Amplitudes is accompanied by a one-week school for Master’s and PhD students. That wasn’t feasible this year, but to fill the gap Nima Arkani-Hamed gave a livestreamed lecture the Friday before, which apparently clocked in at thirteen hours!

One aspect of the conference that really impressed me was the Slack space. The organizers wanted to replicate the “halls” part of the conference, with small groups chatting around blackboards between the talks. They set up a space on the platform Slack, and let attendees send private messages and make their own channels for specific topics. Soon the space was filled with lively discussion, including a #coffeebreak channel with pictures of everyone’s morning coffee. I think the organizers did a really good job of achieving the kind of “serendipity” I talked about in this post, where accidental meetings spark new ideas. More than that, this is the kind of thing I’d appreciate even in face-to-face conferences. The ability to message anyone at the conference from a shared platform, to have discussions that anyone can stumble on and read later, to post papers and links, all of this seems genuinely quite useful. As one of the organizers for Amplitudes 2021, I may soon get a chance to try this out.

Zoom itself worked reasonably well. A few people had trouble connecting or sharing screens, but overall things worked reliably, and the Zoom chat window is arguably better than people whispering to each other in the back of an in-person conference. One feature of the platform that confused people a bit is that co-hosts can’t raise their hands to ask questions: since speakers had to be made co-hosts to share their screens they had a harder time asking questions during other speakers’ talks.

A part I was more frustrated by was the scheduling. Fitting everyone who wanted to speak between 6am west coast and 10:30pm Europe must have been challenging, and the result was a tightly plotted conference, with three breaks each no more than 45 minutes. That’s already a bit tight, but it ended up much tighter because most talks went long. The conference’s 30 minute slots regularly took 40 minutes, between speakers running over and questions going late. As a result, the conference’s “lunch break” (roughly dinner break for the Europeans) was often only 15 minutes. I appreciate the desire for lively discussion, especially since the conference is recorded and the question sessions can be a resource for others. But I worry that, as a pitfall of remote conferences, the inconveniences people suffer to attend can become largely invisible. Yes, we can always skip a talk, and watch the recording later. Yes, we can prepare food beforehand. Still, I don’t think a 15 minute lunch break was what the organizers had in mind, and if our community does more remote conferences we should brainstorm ways to avoid this problem next time.

I’m curious how other fields are doing remote conferences right now. Even after the pandemic, I suspect some fields will experiment with this kind of thing. It’s worth sharing and paying attention to what works and what doesn’t.

Thoughts on Doing Science Remotely

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In these times, I’m unusually lucky.

I’m a theoretical physicist. I don’t handle goods, or see customers. Other scientists need labs, or telescopes: I just need a computer and a pad of paper. As a postdoc, I don’t even teach. In the past, commenters have asked me why I don’t just work remotely. Why go to conferences, why even go to the office?

With COVID-19, we’re finding out.

First, the good: my colleagues at the Niels Bohr Institute have been hard at work keeping everyone connected. Our seminars have moved online, where we hold weekly Zoom seminars jointly with Iceland, Uppsala and Nordita. We have a “virtual coffee room”, a Zoom room that’s continuously open with “virtual coffee breaks” at 10 and 3:30 to encourage people to show up. We’re planning virtual colloquia, and even a virtual social night with Jackbox games.

Is it working? Partially.

The seminars are the strongest part. Remote seminars let us bring in speakers from all over the world (time zones permitting). They let one seminar serve the needs of several different institutes. Most of the basic things a seminar needs (slides, blackboards, ability to ask questions, ability to clap) are present on online platforms, particularly Zoom. And our seminar organizers had the bright idea to keep the Zoom room open after the talk, which allows the traditional “after seminar conversation with the speaker” for those who want it.

Still, the setup isn’t as good as it could be. If the audience turns off their cameras and mics, the speaker can feel like they’re giving a talk to an empty room. This isn’t just awkward, it makes the talk worse: speakers improve when they can “feel the room” and see what catches their audience’s interest. If the audience keeps their cameras or mics on instead, it takes a lot of bandwidth, and the speaker still can’t really feel the room. I don’t know if there’s a good solution here, but it’s worth working on.

The “virtual coffee room” is weaker. It was quite popular at first, but as time went on fewer and fewer people (myself included) showed up. In contrast, my wife’s friends at Waterloo do a daily cryptic crossword, and that seems to do quite well. What’s the difference? They have real crosswords, we don’t have real coffee.

I kid, but only a little. Coffee rooms and tea breaks work because of a core activity, a physical requirement that brings people together. We value them for their social role, but that role on its own isn’t enough to get us in the door. We need the excuse: the coffee, the tea, the cookies, the crossword. Without that shared structure, people just don’t show up.

Getting this kind of thing right is more important than it might seem. Social activities help us feel better, they help us feel less isolated. But more than that, they help us do science better.

That’s because science works, at least in part, through serendipity.

You might think of scientific collaboration as something we plan, and it can be sometimes. Sometimes we know exactly what we’re looking for: a precise calculation someone else can do, a question someone else can answer. Sometimes, though, we’re helped by chance. We have random conversations, different people in different situations, coffee breaks and conference dinners, and eventually someone brings up an idea we wouldn’t have thought of on our own.

Other times, chance helps by providing an excuse. I have a few questions rattling around in my head that I’d like to ask some of my field’s big-shots, but that don’t feel worth an email. I’ve been waiting to meet them at a conference instead. The advantage of those casual meetings is that they give an excuse for conversation: we have to talk about something, it might as well be my dumb question. Without that kind of causal contact, it feels a lot harder to broach low-stakes topics.

None of this is impossible to do remotely. But I think we need new technology (social or digital) to make it work well. Serendipity is easy to find in person, but social networks can imitate it. Log in to facebook or tumblr looking for your favorite content, and you face a pile of ongoing conversations. Looking through them, you naturally “run into” whatever your friends are talking about. I could see something similar for academia. Take something like the list of new papers on arXiv, then run a list of ongoing conversations next to it. When we check the arXiv each morning, we could see what our colleagues were talking about, and join in if we see something interesting. It would be a way to stay connected that would keep us together more, giving more incentive and structure beyond simple loneliness, and lead to the kind of accidental meetings that science craves. You could even graft conferences on to that system, talks in the middle with conversation threads on the side.

None of us know how long the pandemic will last, or how long we’ll be asked to work from home. But even afterwards, it’s worth thinking about the kind of infrastructure science needs to work remotely. Some ideas may still be valuable after all this is over.

This Is What an Exponential Feels Like

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Most people, when they picture exponential growth, think of speed. They think of something going faster and faster, more and more out of control. But in the beginning, exponential growth feels slow. A little bit leads to a little bit more, leads to a little bit more. It sneaks up on you.

When the first cases of COVID-19 were observed in China in December, I didn’t hear about it. If it was in the news, it wasn’t news I read.

I’d definitely heard about it by the end of January. A friend of mine had just gotten back from a trip to Singapore. At the time, Singapore had a few cases from China, but no local transmission. She decided to work from home for two weeks anyway, just to be safe. The rest of us chatted around tea at work, shocked at the measures China was taking to keep the virus under control.

Italy reached our awareness in February. My Italian friends griped and joked about the situation. Denmark’s first case was confirmed on February 27, a traveler returning from Italy. He was promptly quarantined.

I was scheduled to travel on March 8, to a conference in Hamburg. On March 2, six days before, they decided to postpone. I was surprised: Hamburg is on the opposite side of Germany from Italy.

That week, my friend who went to Singapore worked from home again. This time, she wasn’t worried she brought the virus from Singapore: she was worried she might pick it up in Denmark. I was surprised: with so few cases (23 by March 6) in a country with a track record of thorough quarantines, I didn’t think we had anything to worry about. She disagreed. She remembered what happened in Singapore.

That was Saturday, March 7. Monday evening, she messaged me again. The number of cases had risen to 90. Copenhagen University asked everyone who traveled to a “high-risk” region to stay home for fourteen days.

On Wednesday, the university announced new measures. They shut down social events, large meetings, and work-related travel. Classes continued, but students were asked to sit as far as possible from each other. The Niels Bohr Institute was more strict: employees were asked to work from home, and classes were asked to switch online. The canteen would stay open, but would only sell packaged food.

The new measures lasted a day. On Thursday, the government of Denmark announced a lockdown, starting Friday. Schools were closed for two weeks, and public sector employees were sent to work from home. On Saturday, they closed the borders. There were 836 confirmed cases.

Exponential growth is the essence of life…but not of daily life. It’s been eerie, seeing the world around me change little by little and then lots by lots. I’m not worried for my own health. I’m staying home regardless. I know now what an exponential feels like.

P.S.: This blog has a no-politics policy. Please don’t comment on what different countries or politicians should be doing, or who you think should be blamed. Viruses have enough effect on the world right now, let’s keep viral arguments out of the comment section.