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Life in wartime, continued


Pro-tip: If your daughter gives you a feminine-looking pink mask, you can wear it inside out as a white mask.

We've had new directions from the governor (archived copy here), and, basically, he's changing the restrictions so they are based on sanitation rather than type of business. I think that is a good thing. There's no reason a barber shop can't be as sanitary as a grocery store if it wants to. At the grocery store, you're exposed to a vastly larger number of people's germs.

Contrary to press coverage, Georgia is not "opening everything back up." Georgia is changing over to a more sustainable set of restrictions.

In the long run, sanitation is going to be what saves us. The WHO reports that infection by COVID does not leave people immune. That means "herd immunity" isn't going to work (and, anyhow, millions would have to die before that was achieved). Herd immunity through vaccination is what we hope for; but in the meantime, the winning tactic is to cut down the spread rate so that the virus becomes rare.

The spread rate, R, is the average number of new cases that arise from each case. For COVID it is believed to be about 2.5. That's why it spreads so fast and why we have lockdowns.

Suppose R were 0.5; that is, only half of infected cases led to new cases. Then the virus would die out. In fact, anything below 1.0 will make the virus die out, although obviously, the lower we get it, the faster we win.

And I don't think it's too hard to get R down from 2.5 to less than 1. That is not a huge decrease. It's not hard to reduce your exposure to 1/10 or even 1/100 of what it would have been without precautions. Wash your hands more, avoid crowds, and get other people to do the same.

I think we are headed for a permanent change in many of our national habits. Crowded bars, restaurants, and parties are things we are going to have to view as risky for a long time to come. Young people's social life will be particularly affected. At the other end of the age range, nursing homes need to be smaller, or divided into sections. Enormous high schools aren't such a good idea; nor are enormous churches. In fact, churches are going to need to rethink the role of gregariousness, large crowds, and "small groups" — I'll write more about that later.

[Update:] In the original version of this article I followed numerous other articles that said R0 or R0 instead of R. More properly, R0 is the initial value of R at the beginning of an epidemic, before anything has happened to modify it.

Why modeling the epidemic is so hard

Many of us have been frustrated, or at least bemused, by the way the IHME models change so much from week to week. First we've already peaked, then we're going to peak in two weeks, then we don't know where we stand, then it flips back again... I want to share with you some mathematics to demonstrate why modeling is so hard.

Here's the Georgia raw data for the past few weeks:


Now, clearly, we are looking at noisy data. Even if the case rate were basically constant, we wouldn't expect exactly the same number of cases every day; there's an element of chance involved (what statisticians call a Poisson distribution). In addition, cases don't always get reported promptly. Earlier statistics suggest that there is underreporting on weekends and a catch-up on Monday or Tuesday.

So... Is the trend up or down? How can we smooth out the irregularities and see?

One simple tactic is to take a moving average, in this case a 3-day moving average Average each day's number with the two days either side of it. That will smooth out the weekend lag-and-catch-up, as well as generally making things more even. So here it is:


That's a little better. The biggest thing it tells us is that the spike on day 25 is compensated by unusually low values on the days before and after, so it isn't really a spike. In fact, this is apparently the analysis used by Georgia officials to argue that we meet the federal guideline of a 2-week downward trend.

We can do better by adding some knowledge. We know what other epidemics are like, and we know what this epidemic is like in other places. We expect a definite, smooth hump, not unlike a bell curve. (If there is going to be a second hump, it definitely hasn't shown up anywhere yet, so we won't look for signs of it here.) If we bring in the assumption that there is a hump, can we ask where the hump is?

Yes. Clay Turner suggested that I fit to the data a quadratic equation (a parabola), which is a single symmetrical hump. That will tell us where the peak is and whether the peak is sharp or flat. The peak could perfectly well be off center, even off the whole graph, or even upside down. What a quadratic cannot do is give us multiple peaks or even a lopsided peak. So I also fitted a cubic equation, which allows the peak to be lopsided and even allows two opposite peaks, one right-side-up and the other upside down.

Here you see the quadratic in red and the cubic in green. They agree very closely.


So you might think we have a simple, clear answer: the numbers peaked on day 22 (April 14); as of today we have an 11-day downtrend; and we'll be down to half of maximum by day 41 (May 3).

But wait a minute. What if we didn't have the last two days' data? They are particularly low numbers, but they may be low because it's a weekend. So let's run it again with just the data we had 2 days ago:


Whoa there! The quadratic is not too different, but the cubic doesn't agree with it; it seems to think the curve hasn't peaked, merely flattened! The upturn at the far right means little, but the cubic equation certainly doesn't recognize a definite peak.

Even the quadratic has shifted and now puts the peak on day 25, not 22.

This is why the IHME models are so fickle. Small changes in the data can cause big changes in the model. Now in this case, there are good reasons to believe the quadratic is more accurate than the cubic. But the failure of the two to resemble each other should give us pause. The quadratic assumes a single hump; the cubic doesn't see one.

It is, of course, possible to do much worse. Suppose we were to fit a 10th-degree polynomial (allowed to have 9 humps). Here's the absurd result:


Obviously, the numbers weren't really super-low before the beginning of the series, nor do we expect them to plummet right after the end. The goal of the model was just to keep the curve as close to the data as possible, and it doesn't care what happens outside the range. You can see all 9 humps, four of them upside down. That's what high-degree polynomials are like.

If you'd like to experiment with this kind of modeling yourself, the R code and a sample data set are here.


More galaxies than you can count

If you are looking for my reports on the coronavirus situation, scroll down, but note that both epidemiological news and political news is being made fast.

But I recommend contemplating something much farther away instead...


Here you see, beyond the foreground stars, dozens of galaxies in the direction of the constellations Coma Berenices and Virgo, especially a prominent group called Markarian's Chain.

Every small fuzzy object in this picture is a whole galaxy. With your unaided eye, you normally can see only one galaxy, the one we're in (although a very few others can be seen as faint smudges on a dark sky). So think of each of these fuzzy objects as an entire "island universe" or complete starry sky from the viewpoint of anyone who may happen to live there.

My equipment served me well. Stack of 20 2-minute exposures, vintage Nikon 180/2.8 ED AI lens at f/4, Nikon D5500 (H-alpha-modified), AVX mount. I have found that with this lens, if I focus carefully, I can find the optimum point at which chromatic aberration and astigmatism are minimized. Note that you're looking at the whole picture, and it's sharp all the way to the corners.


Misinformation about Georgia

In any war, you can always tell the generals afterward that they did the wrong thing. So it is with the war on COVID-19. But decisions have to be made using information actually available, and different kinds of potential harm have to be balanced against each other.

If it had been up to me, I think I would have waited another week to see where we stand (see below). But the phased reopening of some Georgia businesses is not as loony as many journalists are saying, largely because they're getting the facts wrong. And where journalists stumble, popular chit-chat plunges gleefully into the abyss. I'm hearing from people who just guessed the contents of the governor's order from hearing a few words, and then proceeded to rant about their imaginary version of it.

Surprise: It took President Trump only 24 hours to register his disagreement with Governor Kemp. Maybe the "reopening" can be scaled back and/or delayed.

Misconception: "Georgia is opening everything back up." No; a slightly wider range of businesses is allowed to open, subject to social distancing and sanitation requirements so strict that many of them probably will choose not to.

Going to grocery stores and the like, I actually see tougher restrictions now than under earlier local orders, because stores have started limiting the number of people inside.

Questionable: "It's all to get people off the unemployment rolls." Well, I haven't looked up all the laws, but as far as I know, unemployment applies to laid-off people whether or not their employer was forced by the government to shut down. I don't have enough information to comment further. I don't know whether Georgia has different rules when the employer is forced to close than when it closes voluntarily.

Looking further into this, it's complicated. The main problem is that we are going to have "zombie businesses" that are not legally forbidden to operate, but in fact, for practical reasons, can't actually operate. This does not mix well with unemployment payments and certain kinds of business insurance. I'm not researching it further because I'm expecting the situation to change faster than I can track it.

Misrepresentation of fact:"The order did not include banks, software firms, factories, or schools. It covered businesses usually staffed by poorer people that Kemp wants to keep off the unemployment rolls." (Quote from Facebook columnist Heather Cox Richardson, who is paraphrasing an AJC columnist named Chidi.)

Wait a minute... The governor didn't reopen "banks, software firms, factories, or schools" because he had not closed them! Banks, software firms, and factories stayed open. Schools closed as an operational decision, not because of the governor's order.

Anyhow, don't "poorer people" often work at factories?

Has Georgia peaked? You tell me!

The fickle IHME model has changed again, so now it says we are peaking right now, rather than a few days ago or a few days in the future. IHME continues to predict no overcrowding of ICUs in Georgia.

As I understand it, the federally recommended criterion for starting to reopen businesses is a 14-day downward trajectory (presumably in the new case rate). So...


Those are Georgia's new cases per day, from 91-DIVOC, based on the Johns Hopkins evening reports. Note the logarithmic vertical scale, which reduces the slope. As you can see, Georgia's reporting varies a lot from day to day. To tell what is going on, we need to apply some kind of smoothing, but not too much.

So here's some analysis of my own. These are the number of new cases per day in Georgia from Georgia DPH noon reports (not the evening reports plotted above). The raw data are in black, and the red line is a 3-day moving average.


Looking first at the black line, note that we often have an unusually high or low day, flanked by days that are the opposite (unusually low or high respectively). That indicates irregular reporting; sometimes one day gets two or three days' cases. In particular, our all-time high was April 17, but the two days either side of it were very low. It looks as if three days' cases were all piled together.

That's the rationale for the red line. On each date it plots the average of the three preceding days.

And with that reasonable smoothing function applied, we do meet the federal criterion, just barely. We do have a downslope from about April 8 to the present. I saw a Georgia official quoted pointing this out; they must have done much the same analysis that I did.

One more note. Increased testing will bias the line to slope upward. We may see large increases that are just increases in testing, not the disease. Reportedly, also, Georgia has a backlog of tests a few weeks old that are just now being processed, coming into the statistics at the same time as newer tests that are processed more quickly. That also biases the line to slope up.

So... has Georgia peaked? Maybe. If not, it's at least flat.

Update: The next day's reports were not encouraging, but not terrible either. All I can say is, "I don't know."


Are they letting us out too early?

The governor of Georgia is loosening our lockdown in a slightly odd way. Before I get to that, let me give a general update.

I stand by everything I said last time (scroll down to see it) and add that another study, in Los Angeles, also has found a huge number of people who have COVID-19 antibodies but are unaware of having had the disease. If that is correct, it completely changes the game; it means that we have only been tracking severe presentations of COVID-19, not the whole thing. But I am waiting for experts to comment.

I have almost given up Facebook because of the amount of arguing there. I can't referee a 50-person quarrel every time I point out a news item. Everybody's angry, but they're not sure what to be angry about. Deep down, I think, they are angry about uncertainty.

Now, to Georgia. The governor had a press conference yesterday and then issued this document, which is apparently not the whole thing; statements to the press also mentioned reopening restaurants and theaters with people seated far apart.

In the document we have so far, here's what I see:

  • Medical practices are encouraged to get back to normal (performing non-urgent services), and that includes dentists, physical therapists, optometrists, and the like.
  • Gyms, bowling alleys (a kind of gym, I suppose), and a lot of licensed personal-care providers such as hairdressers, massage therapists, and tattoo artists (?) are allowed to resume work, with additional sanitation precautions.
  • The definition of Minimum Basic Operations may have changed; now it seems to include allowing the aforementioned gyms, hairdressers, etc., to serve customers.
  • The definition of Critical Infrastructure is updated to refer to the latest CISA list, a small change. This is the provision that keeps banks, factories, farms, and other businesses open.

What's missing? Well, it seems to me that, for example, furniture stores and clothing stores are safer than tattoo parlors, but they are not being allowed to reopen. I think some further reshuffling of the provisions is imminent.

Actually, the governor's previous order already expanded Minimum Basic Operations to allow other businesses to remain open to the public if sanitation precautions were followed. I missed that. So apparently you can keep a furniture store open if you want to.

More importantly, there is bitter controversy about whether this should be done. People's mindset about the virus has changed.

  • People have almost forgotten about flattening the curve. Our goal was not to exterminate the virus, but rather to keep it down to the level where hospital ICUs will not be overcrowded. And Georgia has achieved that, even if we have a second wave equal to the first.
  • Instead, people are now focused on fear of getting the virus and dying. Of course, we want to prevent as many deaths as possible, but not everyone is at high risk. And Georgia isn't New York.
  • People are so focused on COVID-19 that they have lost sight of other hazards, including damage to the economy, which can also cause deaths through poverty. As I said last time, trading lives for stock market numbers is barbaric, but saving the maximum number of lives from all hazards is better than just vanquishing one hazard leaving others in its place.

One of the most interesting statistics I've seen is that the U.S. weekly death rate is actually lower now than in a normal year. It's normally about 56,000 per week, but now it's running around 51,000 or lower. I don't have a detailed breakdown, but the lockdown has apparently reduced car wrecks, other infectious diseases, and even crime. No avoidable death is acceptable, but this statistic should figure into how you judge your overall safety at this time. Update: This statistic apparently did not hold up; subsequent reports do not confirm it.

[Addendum:] Another issue is whether to trust the IHME models. The model for Georgia has recently made sharp changes, first one way and then the other. The trend of the data did not change. This tells me the models are probably too sensitive to small fluctuations, especially irregularities in day-to-day reporting. More here.

Meanwhile, the guilt-trips have started. "Somebody might die because you went to get supplies to do yard work." A message to that effect is circulating that claims to be from a hospital administrator in South Georgia. No, no, no... We need to live in a world of rules, not guilt-trips. People need to be told what is and is not permitted before they do it, not afterward. We can't play a game of "no matter what you did, it was wrong."

And we can't put everyone out of work, and live on unicorn dust or fairy floss or something, in a mythical country with no economy.

Finally, we've had a bizarre collapse of the world petroleum market with crude oil selling for negative prices yesterday. While I'm glad to see foreign cartels totally lose their power, I fear for the American businesses that are being damaged. We're still going to need gasoline when the epidemic is over.


Some good news and a lot of bitter controversy

Life in wartime is, for us personally, calm and productive. We're feeling some relief at having gotten a lot of medical appointments out of the way, so that now we are a bit less busy. We aren't having any serious supply problems with food or even toilet paper; things are scarce in the stores, but we've found enough, and we've gotten used to doing our shopping a week in advance. At work, I am as busy as ever, and I'm wary of a new trend toward having too many online meetings.

I've finally done a bit of astronomy — visual, not photographic — and have (again) tuned up the declination worm adjustment of my CGEM. (Hint: It needs to be tight enough to have no slop, but loose enough not to put an extra load on the motor. I adjusted mine with an ammeter attached.) Today's project is to undertake the quest of an 8×1.25-mm threading die and deal with some inadequately cut threads on some aftermarket knob screws. Hardware stores are open, but if they are crowded, I will have to wait to get in.

Regarding coronavirus, yesterday there were several pieces of encouraging news. IHME (at the University of Washington) suddenly revised its models for Georgia and many other states. They had been predicting that Georgia would peak around May 1 with about 50% overcrowding of intensive care units; now they say Georgia peaked a few days ago and will never have overcrowded ICUs.

Meanwhile, in both California and Boston there has been some systematic testing of samples of the population, and the results are that a remarkable number of people have had COVID-19 without symptoms. If this leaves them even temporarily immune (as it should), it is very good news. There have also been studies of a U.S. Navy aircraft carrier and of the cruise ship Diamond Princess, both showing that the bulk of cases are asymptomatic. However, these studies don't overrule everything else we know about this and other viruses. Experts aren't jumping onto the herd-immunity bandwagon just yet.

The public mood, in the news media, on social media, in the White House, and on the streets, is one of bitter controversy. Here's a brief summary.

The underlying point of tension is how much more lockdown our economy can sustain before the cure becomes worse than the disease. Trading lives for stock market numbers would be barbaric, but trading lives for lives may be necessary. Economic collapse causes deaths, especially in third world countries that depends on developed countries for trade. Will COVID-19 give us back the world hunger crisis that we had made so much progress on solving? Closer to home, what we could do for two or even four weeks cannot be done forever.

A second issue is how much good the lockdown has done. Obviously, the lockdown has put a real dent in the spread of the virus. But how bad would it have been if we had done less? Was it growing without bound, or was it close to bumping into some epidemiological limit, such as an unexpectedly large number of people already resistant to it? We don't know.

Underlying all of this is the experts aren't sure, and laypeople, taking wild guesses, really shouldn't be confident that they've guessed correctly.

Now we have needless political division. Overreach by a few local authorities (e.g., breaking up a drive-in church service) has provoked concern about the constitutional right of assembly, which has led to protest marches, surprisingly spurred on by our President via Twitter, and now one of them in Michigan is going to be "armed." That does not sound good.

Even pharmacology has become politicized. About half a dozen drugs may help the virus; research is ongoing. If you're right-wing, you're supposed to believe in hydroxychloroquine, and if you're left-wing, you're supposed to be against it. Why should left and right wings have anything to do with it? Hydroxychloroquine is a tricky, dangerous drug that sends some people right into cardiac arrest; there are some indication that it may help with COVID-19; there are other studies showing that it apparently doesn't. Why should political loyalty tell people to believe some of the studies and ignore the others, rather than putting them all together to try to figure out what is going on?

Another issue is distrust of experts. Some people now think all these mathematical models are just lies spread by some oppressive authority. I reply that (1) the models I've been looking at come from independent institutions, not the government; (2) I've been doing some modeling myself and saw the IHME revision coming (and posted about it on Facebook). It's mathematics.

And that raises another issue, propaganda. Yesterday I speculated that hostile foreign powers might be using COVID-related misinformation to keep Americans upset, angry, and scared. After all, we had a flurry of Russian propaganda on Facebook before the election, and I'm starting to see things that resemble it again. Several knowledgeable people replied that yes, indeed, this is happening, and it comes not only from foreign powers but also from extremist groups operating in our country (with or without foreign backing).

Fellow citizens, please do your best to keep in touch with reality — with facts.

Characteristics of foreign or extremist propaganda on social media:

  • Circulates via "memes," copy-and-paste messages, or news stories from unfamiliar sources with ordinary-sounding names (e.g., "World News" or "Breaking News" rather than Fox, CNN, or Reuters).
  • Does not show any obvious connection with a foreign country or extremist group.

    That's right — there are no Russian flags in Russian propaganda. It looks as American as apple pie. It may seem to have been posted by perfectly ordinary American people.
  • Often claims to be patriotic or even pious. (One famous Russian meme showed Trump arm-wrestling the devil.)
  • Arouses emotions but is not clear on facts or plans; makes you angry but does not advocate anything practical. Facts, if any, are often distorted, and plans don't quite make sense.

    For an example of the kind of foggy thinking they dish out, click here, although I do not know the origin of the example. They're going for people who don't stop and think before swallowing something.
  • May insult people who don't play along. "99% of you won't have the guts to share this!"
  • Propagandists may be recruiting people to spread their stuff, by seeing who will spread gossip, obvious fake news, bad medical advice "from a doctor," or other things a smarter person would not spread. If you spread their stuff, they'll send you more, and it will be political.

Important Facebook safety rule: Don't spread it if you do not personally know it's true. Facebook is for speaking for yourself, not for distributing things total strangers have given you.


Coronavirus: Where I think we stand now

[Also posted on Facebook, and addressed to an audience that is eager to reply with comments.]

(1) What is vital is to stay in touch with reality. Coronavirus is not a piece of political ideology that somebody made up. It is a real, physical enemy. Those deaths in hospital corridors are real. Dr. Fauci really does know more about viruses than you do. And so on.

Our enemy is speculation — people who can't distinguish "it might be" from "it certainly is," and who promote unconfirmed possibilities as if they were confirmed truth. See also (9) and (10) below.

(2) Ignoring the virus was never an option. We've had 22,000 deaths. Would you rather have had half a million? You could easily have had that, if there had been no restrictions.

(3) Our restrictions have paid off. Quite possibly, hundreds of thousands of lives have been saved. The national new-case rate peaked a few days ago. State by state, some states are going to have much later and lower peaks, which is a good thing.

[Afterthought: Models may have been inaccurate, but there's no denying that the virus spread a lot less with our lockdowns than it would have without them.]

(4) The virus would have damaged our economy no matter what we did (even if we had ignored it and just let a lot of people die). The reason you didn't hear economists objecting to those stimulus payments is that knowledgable people recognized that a rise in the national debt would be better than sudden mass poverty.

(5) Our economy can't sustain forever what it sustained for a month. Damage to the economy itself causes deaths, not only here but (perhaps even more so) in poorer nations that rely on us for trade.

(6) We are going to have to do some kind of gradual, careful reopening of the economy, starting with businesses that don't involve crowds of strangers.

(7) With the wider availability of coronavirus tests, some experts are recommending a shift to a strategy of restricting only people who are known to be infected and their immediate contacts. I hope this proves feasible.

(8) The virus will linger. For a couple of years, we are going to have to behave as if we were in a bad flu season, continuing to take some precautions.

(9) I know you've heard that some people say the virus escaped from a lab in China. Please be assured that many governments around the world are looking at this, and that they know more about it than you do, and are going to pay attention. In the meantime, it doesn't affect what we need to do going forward.

[Afterthought: The lab thing is a red herring. Even if it was just bad sanitation, it was an international hazard that came from China. Flu epidemics have been coming from China with some regularity. This can't go on.]

(10) There is research on hydroxychloroquine and other drugs that might kill the virus. Please let medical research proceed, and don't spend your time trumpeting one success story without knowing whether others have gotten the same results.

I was up until 3:30 a.m. listening for tornado warnings, and Middle Georgia had several tornadoes, one of which picked up a house and put it down on a road, Wizard of Oz-style. Never a dull moment!



Life in wartime

Yesterday we had a typical wartime grocery-shopping experience. Melody placed a large order (after making a reservation a week earlier!) to be picked up at Kroger. We arrived, and it was loaded into the car. Meanwhile I went inside to pick up things at the pharmacy. That went very smoothly, and I took a quick look at the grocery store: Scattered depletion of all sorts of things, and absolutely no toilet paper or paper towels. Fortunately we are well supplied with both of those things thanks to, respectively, Amazon and Dollar General.

Our $348 grocery order had turned into $278, and on arriving home, we found that quite a few things were not there. One of them was coffee. After dinner, Melody sent me out for coffee (in Keurig cups), and this was a surprisingly difficult quest. I also needed a pharmacy item, so I headed first to CVS Pharmacy, which ought to have both items. No luck. Closed at 6 p.m. — you're not supposed to shop at night in time of pestilence. Next I tried the Publix supermarket — closed at 8, and it was 8:10.

Third, I tried the Golden Pantry across the street. I rarely go inside Golden Pantry, but my recollection was that, as its name indicates, it was a convenience store that sold common grocery items to save people a trip to the supermarket. Not any more! Nothing but ready-to-eat snacks. Maybe being across from Publix required them to position themselves differently.

Finally, Target came through for me by being open until 9. I completed my purchase around 8:30 and headed home.

We made one other excursion yesterday afternoon. A friend who is shutting down a photography studio has given me a lifetime supply of T-Max 400 film. Picking up business supplies is legal, and this was done without any human contact, by just picking up the package from her porch. On the way home, we looked at FormFree's new building, which is coming right along (construction is legal). I also peered into FormFree's temporary space, a former bridal salon (whatever that is; I already have a bride!). I recognized FormFree's furniture (and Pringles box) piled inside, but nothing was set up for use, and the signage had not been changed. We may never actually work there, because the new building may be ready by the time we get out of lockdown.

Today (Easter Sunday) we slept late, and then, in the afternoon, viewed the church service on YouTube. Holly (Sharon's dog) tried to sing along with the Hallelujah Chorus.

Tonight's excitement is that severe storms and tornadoes are predicted — a one-in-ten-years kind of event, according to my friends who are meteorologists. Just in case, I took my computer backup disk off the computer and put it in the car. Normally it would be in a bank vault, but I haven't made arrangements to get to my safe deposit box.

Easter without being allowed to go to church

[From Facebook, with extensions.]

For any of my fellow Christians who are still troubled by not being able to go to church today:

If the authorities were not restricting us, it would still be our duty to protect our fellow citizens from disease by not holding meetings.

We are not knuckling under to authoritarian government — we are willingly following their plans for something that we would in any case already need to be doing.

There have been a couple of cases of local authorities going beyond reasonable limits. I don't think their intent was to persecute Christians; rather, they were a bit too wrapped up in asserting their authority and had lost sight of the goal of containing the virus. For example, a court in Louisville, Kentucky, has to overrule local authorities that wanted to prohibit a drive-in church service, with the cars spaced well apart.

There have also been a handful of reports of individual churches or pastors refusing to obey restrictions. All the ones I have seen were from independent churches that were under no denominational authority. The major denominations have done quite the opposite — to protect the public, they have in many cases adopted restrictions stricter than those imposed by government.

To the renegade churches I would say loudly that the rest of us Christians don't trust you. We wonder if your real goal is to make a political point at the risk of some people's lives. As for the heretical notion that "Jesus protects you" when you go to church, where do you find that in your Bible, and anyway, don't your people get colds and flu? I smell wolf in sheep's clothing.

[Addendum: There is a known instance of the virus spreading at a church service in Cartersville, Georgia, on March 1, before restrictions were in place. There must also be others.]

Gossip, conspiracy theories, and epistemology

[From Facebook.]

The other day I opined on Facebook that gossip and conspiracy theories often involve bad logic along the lines of "guilty until proven innocent" or "this strange thing is true unless YOU can prove it's not."

Subsequent discusion showed that I need to explain this better, so let me try again.

I had in mind Mark Twain's description of a tourist trap that must be the site of the Garden of Eden "because nobody can prove it isn't."

More technically, my point is something that is neglected in epistemology courses but looms large in machine learning: You need to have a positive reason for every belief. If you just make random guesses, and retain all of them until they are proven false, you will quickly have a huge stock of beliefs that are almost certainly false but haven't been proven false yet.

Popperian falsificationism doesn't talk about this, I think largely because Popper was studying how scientific method applies to hypotheses that already have substantial prima facie credibility. But we sometimes hear my point expressed imprecisely as "Ockham's razor" ("entities are not to be multiplied beyond necessity"). Bayesian reasoning deals with it by insisting that the prior probability be nonzero (if it's flat zero, the formula cannot increase it). In law, it's related to the concept of probable cause.

I distinguish between suspicion and accusation. If you are a security guard, it is your job to suspect that anyone might be a burglar. But that is not the same as believing or saying someone is a burglar, or even that they might be a burglar. That is why, in law enforcement, suspicions are not voiced, except to colleagues who have the same responsibilities.

I also realize that, in a political situation, it might be appropriate to voice suspicions that are of concern to the public. But even then, great caution is required. Don't let people think there's evidence when there isn't.

And returning to my original point: A lot of gossip is of the form, "This might be true, and nobody can prove it isn't." And conspiracy theorists often say, "YOU have to prove this wrong or I'll keep believing it."

To which I reply: "If you really wanted to know whether it is true, you'd keep an open mind yourself. It's not my job to wrestle you about it."


Feast day of the Resurrection of Our Lord



Farewell to Orion — but Betelgeuse is back


The earth has moved around in its orbit so that we can no longer see Orion in the night sky, at least not if we have trees to the west, as I do. In a few more weeks it will be hidden even from places with flat horizons.

Nonetheless, Betelgeuse — the star that dimmed mysteriously — has brightened back up. It's the bright star above the middle of the picture, and in the real sky, it stands out even more than the picture shows.

Single 4-second exposure, Nikon D5300 (unmodified), AF-P 18-55-mm lens at 22 mm, f/4, ISO 800, on an iOptron SkyTracker.

So how are we coming?

Latest projections are that the epidemic will peak slightly earlier, and with considerably fewer deaths, than was predicted just a short time ago. Our "social distancing" (as we call it) is apparently going to save many, many lives.

The nationwide new-case rate is expected to peak in just a couple more days. You can see that it's almost flat:


Georgia is harder to size up. The problem is that reporting of new cases is irregular. We'll have a few days of suspiciously low numbers followed by a big catch-up. Here's the latest graph:


The new-case rate in Georgia is expected to peak around April 22.

Life in wartime

What's it like nowadays? Busy, at least for me. Work has not abated at all, and now I'm never away from the office. Last week we had a flurry of teleconferences (some with video) and also a flurry of medical appointments for Melody and Sharon as things needed to be gotten out of the way. Now the schedule is much clearer, but I have plenty to do.

The other thing going on is that I'm besieged by e-mail and social media communications, especially the latter. I use Facebook to keep in touch with friends, but they are at home with time on their hands, and I'm not! Every time I open my mouth (or rather post a comment on anything) I get 500 replies, 200 of which are thoughtful enough to deserve answers. Or so it seems. And some people are really in an arguing mood; if they can think of an opinion different from mine, they challenge me, even if it's not their own considered position. To them I say: Please continue thinking critically, but do more of it inside your own head!

I had a Skype video call with the grandchildren this afternoon and will have a Skype audio call and then a Microsoft Teams video call with clients tomorrow.

Trips out of the house (by car) are down to about one every 48 hours now that the medical appointments are over. We still get out to buy groceries, go to the pharmacy, and pick up take-out meals. (Yesterday, for instance, I went to La Parrilla.) We attend church services via YouTube (video streaming) and did so for Maundy Thursday this evening. We are permitted to get out to walk for exercise anywhere we want, as long as it's not with other people, and I may visit the University under that pretext and to take some pictures of its empty state.

For exercise, I walk around the neighborhood. Fortunately, the weather is suitable. I walk part way east on Saint George Drive, then back westward to St. George Court, turn left, go up Fox Trace to Timothy Road, turn right, and make my way back home on Saint George Drive. That is one mile. I often do it more than once in a day.

Hobby time and free time are scarce.

How America is going to change

The following quote was shared with me and attributed to Tom Nichols, a professor at the U.S. Naval War College. I have not confirmed the source, but nonetheless, I think it's worth reading.

America for several years has become a fundamentally unserious country. This is the luxury afforded us by peace, affluence and high levels of consumer technology. We didn’t have to think about the things that once focused our minds — nuclear war, oil shortages, high unemployment, skyrocketing interest rates. Terrorism has receded back to being a kind of national threat for which we dispatch volunteers...

The COVID-19 crisis could change this in two ways. First, it has already forced people back to accepting that expertise matters. It was easy to sneer at experts until a pandemic arrived, and then people wanted to hear from medical professionals like Anthony Fauci. Second, it may — one might hope — return Americans to a new seriousness, or at least move them back toward the idea that government is a matter for serious people...

Food for thought. The thing I hope it returns Americans to is reality. For ten years it has been widely felt that you have a right to live in a fantasy world, and that if you don't like facts, you can just call them "fake" and refuse to believe them. Not any more. At least some people are finally realizing that you can't wish or imagine your way out of the epidemic — it is not just an abstract idea that people are trying to sell — it's physically real and is killing people.

Also, as Professor Nichols observes, people are realizing the value of experts. Experts really do know more than laymen or showmen running their mouths.

Third, sometimes you need to sacrifice for the benefit of other people. I am heartened by the sacrifices Americans have made to save other people, not just themselves.

And fourth, there is a new move away from rugged individualism toward the idea that a civilized society should organize to take care of its citizens. In practical terms, that means more of a social safety net, and maybe a national health insurance system; more generally, government investment in things that directly benefit the people.


Palm Sunday


We wish you a blessed Palm Sunday. Since we cannot attend church today, we are joining many of our fellow church members in putting greenery (not necessarily palm branches) on our front doors.

Blessed is He who comes in the name of the Lord!

Out of COVID-19 on the other side

Some encouraging news: Two friends of mine had COVID-19, were not seriously ill, and have recovered, with evidence that they are probably at least temporarily immune.

There is now a rapid test available that detects both IgM and IgG antibodies. That means it detects both the initial onslaught of the disease and the immune response.

We are soon going to have a substantial and fast-growing number of people who had COVID-19, no longer have it, and are resistant to it.

In other news, Georgia's new-case-per-day rate continues to fall nicely. A few days ago there was a sudden pop-up in the amount of testing (or a catch-up on completion and reporting of tests administered a while back), and it shows on all the graphs. But apart from that, the rate in Georgia is falling steadily.

This epidemic is not going to last forever.


Pleiades, Venus, and clouds


This evening Venus was even closer to the Pleiades star cluster, but some thin high clouds wanted to get into the picture. The overall result is, I think, pleasing despite the clouds. Nikon D5500 (H-alpha mod.) on fixed tripod, single 1-second exposure at ISO 400, Sigma DG EX 105/2.8 lens at f/3.2.

Toilet-paper famine explained

Currently, toilet paper is scarce, paper towels are absolutely unavailable, and there are spotty gaps in the selection at grocery stores.

The toilet-paper shortage started around March 12. At the time, survivalists were making noises about buying a 3-month supply of everything, and there was some hoarding, so a lot of us thought those behaviors were the cause. But that should have sorted itself out in a week or so — eventually they'd buy all they wanted, and there would be plenty for the rest of us. Yet the shortage persisted.

Another explanation was that people were moving to shopping less often and buying more at each shopping trip. But that, too, should have smoothed out in a couple of weeks.

At that point we began to understand, dimly, that the supply chain was fragile and was failing us in some unanticipated way.

Now this article in Marker (a business news site I had not seen) explains what's really going on.

Very simply: People are going to the bathroom at home rather than at the office or at school.

And home toilet paper isn't the same thing as institutional or commercial toilet paper. It is supplied on a different kind of roll (to discourage pilferage) and is made in different factories, even by different companies.

If the shortage gets worse, I suppose people could buy the commercial stuff for home use. The rolls are large and awkward, and the minimum purchase is normally large.

I'm guessing the situation with paper towels is simply that people staying at home more of the time use a lot more of them. As for groceries, the ones sold to restaurants and institutions aren't the same as the ones for home use. Not only is the packaging very different, they are different sizes and grades of fruit and vegetables and cuts of meat.

Manufacturers can adapt, but how long before we revert to our previous habits? Nobody knows! Retooling everything just for two weeks of changed habits is expensive.

At least now we know where to look for temporary solutions.

Brief notes on life in wartime

Today's theme, both in the media and in Facebook chit-chat, is, "You should be afraid. You're not afraid enough."

Some of this is cowards wallowing in their emotions, and some of it, I think, is because some people won't take precautions unless they're scared. So everyone is trying to scare everybody else.

Meanwhile, while running a couple of essential errands lately, we've noticed a lot of people driving incompetently, as if they don't know how. People go down a one-way lane in a parking lot the wrong way and give angry looks to the people going the right way; they weave out of their lanes on the highway; they honk rather than going around the car in front; they hang on to their cell phones. What is going on?

Yesterday's war story is that Melody had to go to a doctor's office (unrelated to the epidemic) and the elevator was broken. We were sent to "the stairs behind the building," so upon climbing the stairs behind the building, we found a door locked. I went back to the main entrance to ask directions. They sent me to another door, with no visible stairs, with a sign on it saying emphatically to go somewhere else. But that was it, and inside were two big flights of stairs. Melody, who as you recall has had six hip operations, managed to climb them.



Venus and the Pleiades


Here is Venus passing almost in front of the Pleiades star cluster on the evening of April 2 (April 3 UTC). Venus is blurred into a large irregular orb because it's overexposed. Single 1-second exposure, Nikon D5500 (H-alpha mod.) at ISO 400, Sigma 105/2.8 DG EX lens at f/3.2, fixed tripod.



A couple of weeks ago, two of my neighbor's cedar trees started trying to force their attentions impolitely upon my garden shed and fence. Today (April 2) they were removed.

Some COVID-19 raw data

Those of you who saw my surprisingly encouraging graphs from 91-DIVOC the other day may want to know what happened next.



The answer is still encouraging, though not as good as it first looked. Testing is very irregular and what happened in Georgia was simply a lack of testing, followed by a catchup.

The number of new cases per day is still rising, but the rate of rise seems to be decreasing, as I said.

For more and better analysis, scroll down.


So how are we holding up?


The answer is, we're holding up fine, and FormFree is very productive, but other people are uneasy — Facebook was full of rants and raves today. I think a lot of people are finally realizing they can't deny COVID-19. We're starting to get high-profile reports of people dying from it. I know someone whose friend died of it, and others whose relatives are hospitalized.

Now people know it's real. It comes as a real shock to people who were accustomed to believing their fantasies and calling everything else "fake news."

In response, some people are panicking competitively. Others are trying to reinstitute denial. As a result, if you say anything nuanced or realistic about what to expect, both sides come at you! When I say 100,000 COVID-19 deaths are predicted, which is 1/30 of the number of Americans that normally die in a year, the left thinks I'm encouraging denial and the right thinks I'm encouraging panic. Can't win.

Georgia now has statewide restrictions, which you can see here (my archived copy); they are very similar to the restrictions for Athens, which I blogged about last month, but now they have teeth, because violators can be charged with a misdemeanor. I gather the goal is to deal with a hard core set of people who insist on gathering in crowds despite the danger to others.

The real hazard right now is not the disease itself, but the overcrowding of hospitals, with makes the disease much more damaging, and also costs lives by preventing treatment of other medical problems. That is the tragedy we are trying to minimize. Imagine what the death rate would be, from all causes, if all our hospitals were non-functional for a few weeks!

I continue to watch statistics, but I also recommend covid19.healthdata.org, recommended to me by a colleague who is an eminent medical researcher in a relevant field.

The current predictions from that site are:

U.S.A. New York Georgia California Kentucky
Peak hospital
April 15 April 8 April 23 April 27 May 17
Peak death rate April 15 April 10 April 25 April 28 May 18
Total deaths per
million population
287.4 835.9 304.4 128.3 183.8

For the last row, I divided the totals on healthdata.org by populations from Wikipedia.

So what does this tell us?

(0) These models take into account the lockdowns and other precautions that we are already taking. Without them, things would be gigantically worse.

(1) An early peak is a bad thing. New York has an early peak and terribly overcrowded hospitals. Kentucky has a very late peak, and its hospitals may not be crowded beyond capacity at all. Most states are in between.

(2) Most places are not like New York. For both physical and cultural reasons, New Yorkers are very crowded together. The disease has spread like wildfire — no, like wildfire on gasoline — in New York; it only spreads like ordinary wildfire elsewhere. The results are tragic.

(3) We need to keep trying to slow down the virus even though it results in longer quarantines. "Getting it over with" is not the goal. This is a war to be won by being more patient than the enemy.

(4) If we take reasonable measures, the total number of deaths is small, but if we stop fighting too soon, the situation will get a lot worse. Nationally, less than 300 deaths per million people are forecast. That's one person in 3000. Yes, someone in your town will die; no, you are not going to lose half your neighbors. If we keep taking good precautions. There will be collateral damage from other diseases not adequately treated, but there will also be collateral benefits from not spreading other diseases.

About those graphs I posted a few days ago: It turns out that the big falloff in Georgia was due to a reporting problem, but the overall flattening trend is real. We are dealing with very unreliable measurements, and it's good to have models with a theoretical basis (like those on healthdata.org) rather than just extrapolation of raw numbers.


Microsoft LifeCam VX-5000 under Windows 10

Picture There's a shortage of webcams for videoconferencing right now. I briefly thought about using my ASI120MM-S astrocamera (monochrome, in infrared) with its fisheye lens but concluded I would look too strange, so I snapped up a Microsoft LifeCam VX-5000 on eBay.

Many web sites give the impression that this camera doesn't work under Windows 10.

But in fact it works perfectly. The secret? Don't install the drivers or software that come with it. It's a Microsoft product and Windows is already ready for it! Just plug it in. The Camera app in Windows 10 can be used to test it.

The above information is perfectly serious, even though today is April 1. But for a couple of amusing spoofs of an ecclesiastical nature, use a search engine to find references to a papal bull titled Stultus Aprilis.

If what you are looking for is not here, please look at previous months .