A brief gallivant about the marketplace of ideas.

Category: Reference


Have a blister? Annoying. Treat it wisely!

A friction blister is “a soft pocket of raised skin filled with clear fluid caused by irritation from continuous rubbing or pressure” [1]. The most pressing concern (no pun intended) is infection. “[T]he skin provides a natural protection against infection” and thus “a blister should be left intact if possible” [1]. In particular, “[d]o not drain the blister”! If the blister breaks naturally, do not remove the skin [2,3]; simply wash with soap and water, pat dry, apply antibacterial ointment, and cover with a bandage [1].

“[M]edical care is needed only if an infection develops. This is more likely to occur if the skin over the blister has been pierced, broken or popped” [1]. If you observe signs of possible infection (intense tenderness, significant redness, warm skin, non-clear (e.g., white or yellow [2]) drainage, fever), then consult a doctor.

  1. Friction blisters” (Harvard Health Publishing, 2019-03).
  2. Understanding blisters — treatment” (Web MD, 2019).
  3. Blisters: First aid” (Mayo Clinic, 2018-02-13).

Adobe Flash Player


Adobe is discontinuing distribution and update of Adobe Flash Player after 2020-12-31 [1]. New web standards make Flash Player largely unnecessary [2,6]. Security flaws (and the end of security updates after 2020) make Flash Player dangerous. Uninstall Adobe Flash Player [3mac,3windows].


A pop-up window titled “Update Adobe Flash Player” (from an application named “Adobe Flash Player Install Manager”) appeared on my computer screen several times a day. (Note : These pop-up windows seem to appear as stand-alone windows in my computer, NOT in a web browser.) I found no evidence that this is malware. It seems to be related to settings in “System Preferences > Flash Player > Updates”, which were set to “Notify me to install updates” [4,5]. The preceding references state that updating these settings to either of the alternatives (“Allow Adobe to install updates (recommended)” or “Never check for updates (not recommended)”) would make the pop-up windows go away. Selecting the radio button for either of these options opened another pop-up window (the same window for both options, with the text “legacyLoader is trying to install a new helper tool.”). I could find no evidence of malware, but I had been sufficiently spooked by reports of malware that I preferred not to enter my admin password to install the helper tool.

Adobe’s website states that “Adobe will stop distributing and updating Flash Player after December 31, 2020” [1].

UPDATE (2020-05-26). I uninstalled Flash Player from my laptop one week ago. The “Update Adobe Flash Player” pop-up prompts stopped immediately, and I have not experienced any content issues (web browsing, etc.).

  1. [1] “Adobe Flash Player EOL general information page” (Adobe).
  2. [2] “You really shouldn’t be running Adobe Flash Player any more” by Brendan Hesse (Life Hacker, 2018-12-10).
  3. [3mac] “Uninstall Flash Player | Mac OS” (Adobe).
  4. [3windows] “Uninstall Flash Player | Windows” (Adobe).
  5. [4] “How to disable update Adobe Flash Player notifications” by Serhat Kurt (macReports, 2019-10-17).
  6. [5] “Remove fake Adobe Flash Player update virus popup from Safari, Chrome, Firefox on Mac” by John Dee (Mac Security, 2020-05-17).
  7. [6] “Comparison of HTML5 and Flash” (Wikipedia).
  8. How to uninstall Flash Player on a Mac” by Serhat Kurt (macReports, 2019-10-17).
  9. Adobe Flash Installer wanted to install helper apps” (Adobe, 2019-02).
  10. How to remove ‘Fake Flash Player Update’ from Mac?” by Tomas Meskauskas (PC Risk, 2019-11-26).
  11. Beware of fake Flash Player update on OSX” (Adobe, 2018-04).
  12. This pop-up keeps popping up: ‘Adobe Reader is not optimized for your Mac and needs to be updated’” (Adobe, 2019-04).
  13. HTML5” (Wikipedia).
  14. Thoughts on Flash” (Wikipedia).

Battery disposal

Today’s selection of articles:

  1. FYI : It’s totally fine to throw away most batteries” by Mike Murphy (Quartz, 2015-01-23). Cites battery manufacturers (Duracell, Energizer) who claim “[a]lkaline batteries can be safely disposed of with normal household waste”.
  2. Yes you need to recycle your old batteries” by Thomas Germain (Consumer Reports, 2019-04-20). This article agrees that “[t]oday, primary batteries are rather benign chemically” but argues you still shouldn’t throw them away.
  3. Duracell care, use, and disposal” (Duracell).

Read : 2020-04-11

Today’s selection of articles:

  1. St John Passion to be live-streamed from Bach’s Leipzig church on Good Friday” (Gramophone, 2020-04-07). The article contains a link to the Bach Archive’s Facebook channel, where you can find a recording of the performance (prefaced by a couple others) in a posts dated 2020-04-10.
  2. How to edit your own writing” by Harry Guinness (NY Times, 2020-04-07). The first step is recognizing that editing is (always) needed.
  3. In cyberwar, there are no rules” by Tarah Wheeler (Foreign Policy, 2018-09-12).
  4. Will we forgive Amazon when this is over?” by Christopher Mims (Wall Street Journal, 2020-04-11).
  5. How to prevent pinholes in T-shirts near your belly button” by Alison Gary (Wardrobe Oxygen, 2018-04-05). So that’s where those holes come from: bottom hardware. Some YouTube videos [1,2] on how to fix them.

And why not? Some classic Federer [1,2], hors contexte, compliments of YouTube.

Reference : OS backup : Windows 10 64-bit

Articles on creating a backup of Windows 10 64-bit operating system:

  1. Backup Windows 10 to USB drive: Two simple ways are here!” by Vera (MiniTool, 2020-01-17). The first way uses MiniTool’s freeware (I have never used this). The second way uses Windows’s built-in Backup and Restore utility.
  2. How to take a full backup of Windows 10 on an external hard drive” (FAQForge).
  3. Create a Windows 10 system image backup” by Aseem Kishore (Help Desk Gee, 2018-01-30).
  4. How to backup Windows 10 64-bit easily and quickly?” by Ivy (Aomei, 2020-02-26).
  5. What is the actual size of Windows 10, 64-bit?” (Quora, 2018-05-03). Best answer: ISO size is approximately 4.5 GB. (To install, at least 20 GB free space required on installation drive.)
  6. How big of a USB do I need for Windows 10?” (Quora, 2019). Best answer (with screenshot of USB partition): 3.99 GB. 120 GB USB, formatted as 32 GB FAT32, remainder “unallocated”. USB 3.0 is recommended, because it is faster than previous USB versions (2.0, 1.1) for data transfer. USB 3.0 devices will work in earlier-version USB ports (see below).
  7. Does USB 3.0 work with USB 2.0? A guide to USB versions and compatibility” (cmd-ltd). “The short answer is yes — USB 3.0 does work with USB 2.0 [and USB 1.1], but you won’t get the speeds of USB 3.0 technology.”

Reference : COVID-19

References related to the SARS-CoV-2 coronavirus and the disease coronavirus disease 2019 (COVID-19) that it causes.


The CDC defines an influenza pandemic as “a global outbreak” caused by viruses that “are able to infect people easily and spread from person to person in an efficient and sustained way” [1].

  1. [1] “Pandemic influenza” (CDC).
  2. COVID-19 situation summary” (CDC).
  3. What we know about the coronavirus, from symptoms to who is at risk” by Betsy McKay (The Wall Street Journal, 2020-02-26; updated frequently).
  4. Tracking COVID-19” (YouTube, Harvard T.H. Chan School of Public Health, 2020-03-02).
  5. Report of the WHO-China joint mission on coronavirus disease 2019 (COVID-19)” (World Health Organization).
  6. Coronavirus” (World Health Organization).
  7. Worldometer : COVID-19 coronavirus outbreak” (Worldometer).
  8. What do antibody tests for SARS-CoV-2 tell us about immunity?” by Katarina Zimmer (The Scientist, 2020-04-15).

Daily Health Recommendations

The CDC [2] and WHO [3] recommends the following daily health precautions:

  • Frequently wash hands.
  • Avoid touching your face.
  • If you are feeling unwell, stay home and call a doctor.
  • Cover your coughs and sneezes, either into your elbow or with a tissue.
  1. [2] “Share facts” (CDC).
  2. [3] “WHO Director-General’s opening remarks at the media briefing on COVID-19” (WHO, 2020-02-28).
  3. Coronavirus disease (COVID-19) advice for the public” (World Health Organization).
  4. Q&A on coronaviruses (COVID-19)” (World Health Organization).

Situation Dashboards

  1. COVID-19 coronavirus outbreak” (Worldometer).
  2. Novel coronavirus (COVID-19) situation” (WHO).
  3. Coronavirus COVID-19 global cases by Johns Hopkins CSSE” (Johns Hopkins).

Financial Impact

  1. The coronavirus is a serious concern but the stock market’s selloff is not” by Howard Gold (MarketWatch, 2020-02-25). “This is certainly a public health emergency — the coronavirus so far has claimed 2,700 lives and infected more than 80,000; more are likely to be afflicted. This is also a full-blown stock market panic, and for investors, a buying opportunity. The epidemic eventually will run its course and world economies, especially the U.S., will resume their decent growth trajectory. So will the U.S. stock market.”
  2. If the coronavirus isn’t contained, a severe global recession is almost certain” by Rex Nutting (MarketWatch, 2020-02-25). This article presents little to no numbers or justification for its (sensational) claims. “In the longer run, of course, a pandemic could have more far-reaching effects, including a smaller and less productive workforce and even a reordering of globalization.” “The more recent pandemics weren’t nearly as widespread or deadly as this one seems to be. People who don’t appear to be sick can transmit the virus, making efforts to contain its spread magnitudes more difficult.”
  3. Warren Buffet says ‘don’t buy or sell’ on the headlines as coronavirus puts stocks under pressure” by Callum Keown (MarketWatch, 2020-02-25). “However, Warren Buffett told investors not to buy or sell stocks, which he referred to as businesses, based on the day’s headlines. ‘The real question is: “Has the 10-year or 20-year outlook for American businesses changed in the last 24 or 48 hours?”‘ the billionaire investor said on CNBC.”
  4. Why the market suddenly got so worried about coronavirus” by Myles Udland (Yahoo Finance, 2020-02-25). “Economists at Goldman Sachs, for instance, this weekend published their latest views on how supply chains could be impacted by the coronavirus. The firm wrote in part that, ‘According to our analysts, no covered US firm has reported any reduction in production in the US due to supply chain disruptions thus far, and the majority of companies in many sectors have enough inventory to continue production as normal for the remainder of the quarter.'”
  5. Here are the worst possible scenarios for corporate America amid the coronavirus” by Brian Sozzi (Yahoo Finance, 2020-02-25). “‘The bottom line is that investors should gauge companies based on their working capital position and not necessarily their earnings profile. There are deflationary and inflationary forces at work simultaneously,’ reminds the Jefferies team.”
  6. How to tell when markets finally reach a bottom” by Jim Bianco (Bloomberg, 2020-02-27). “The way to tell whether the discounting has been fully reached is when the market stops reacting negatively to every bad headline, which has yet to happen. But once it happens, the market can truly bottom and begin to recover when some of the expected negative events fail to materialize, even though it may rally in the face of other ‘bad’ news it already discounted.”
  7. Here’s when you should buy stocks again” by Jonas Elmerraji (The Street, 2020-02-27). A mostly historical analysis, with clear graphs. “Looking back to 1933, the S&P 500 (and its precursors) have seen 57 four-day selloffs as bad as or worse than the one we’re seeing now. And once again they tend to look a lot more like buying opportunities than precursors to market crashes.” “In other words, it makes sense to wait for buying pressure to establish itself again before diving into stocks. But more important, these are asymmetric outcomes. Good years are vastly more frequent and bigger than bad years. That makes betting on upside a lucrative move, on balance…We’re in a ‘heads I win, tails I don’t lose that much’ scenario — at least as of right now.”

    Toward the end of the article, Elmerraji presents a technical analysis of the S&P 500 that suggests monitoring intermediate and primary uptrends around 2950 and 2800. “Simply put, an optimal buying opportunity comes on a bounce off either of those.”

  8. Money talks podcast : covid-19 spreads” (The Economist, 2020-02-25). My take-aways :
    • 70-90% Chinese businesses back open, but many operating at 50% capacity
    • China : immediate and drastic approach ; other countries : probably slower, less restrictive — will this work?
    • Supply chain disruptions for at least another month or two, probably into Q2
    • Chain effect from last couple months of “China offline”
    • A lot more uncertainty about how serious it is and how global it will become
    • Government somewhat constrained in economic response : monetary stimulus won’t fix supply shortfalls ; interest rates, extending loans may help
    • “Don’t want to have the economic shortfall turn into a financial crisis”
    • What stops such an outbreak? The start of summer, the start of “properly warm weather”
    • Extreme short-term interruptions ; no long-term change in fundamentals
  9. Coronavirus has ravaged the stock market and the extreme selling may just be starting” by Brian Sozzi (Yahoo Finance, 2020-02-26). “Several sources on the Street have also told me the extreme selling this week…has been fueled mostly by hedge fund selling.” “Up to this point, said long-term minded institutions have stayed upbeat on the markets on the view the coronavirus impact would be isolated to the first quarter. Perhaps some negatives in the second quarter, but by the back half of the year it would be in the rearview mirror. Definitely no 2020 impact, in their view.”
  10. 2 biotech stocks winning the coronavirus race” by Mark Prvulovic (The Motley Fool, 2020-03-01). Gilead Sciences (GILD) and Moderna (MRNA).
  11. Tim Cook and Apple bet everything on China. Then coronavirus hit.” by Tripp Mickle & Yoko Kubota (The Wall Street Journal, 2020-03-03).
  12. How to think about the plummeting stock market” by Joe Pinsker (The Atlantic, 2020-02-28). “What investors think the public is thinking is therefore crucial. Whether the costs of the outbreak turn out to be historically large or not, there is a risk that investors’ worries will snowball during this period of uncertainty, leading them to panic-sell and exacerbate any financial damage. ‘If in the next 20 years [the economy is] only going to be disrupted for three months, that suggests a very small impact on the market,’ says Robert J. Shiller, a Nobel Prize–winning economist and the author of ‘Narrative Economics: How Stories Go Viral and Drive Major Economic Events’. But the situation could be much worse, and when investors think in ‘grandiose terms,’ Shiller told me, that could ‘trigger other worrying.'”
  13. The new coronavirus could have a lasting impact on global supply chains” (The Economist, 2020-02-15).
  14. Wall Street gets worried about the coronavirus” by Ruchir Sharma (NY Times, 2020-02-25).


  1. Report of the WHO-China joint mission on coronavirus disease 2019 (COVID-19)” (WHO, 2020-02-28).
  2. Coronavirus” (WHO).
  3. Q&A on coronaviruses (COVID-19)” (WHO).
  4. Disease modelers gaze into their computers to see the future of covid-19, and it isn’t good” by Sharon Begley (Stat News, 2020-02-14).
  5. Is COVID-19 the dreaded ‘disease X’ World Health Organization experts predicted years ago?” (Japan Times, 2020-02-23).
  6. Could the US contain a coronavirus outbreak?” by Megan Molteni (Wired, 2020-02-25).
  7. The virus is coming” (The Economist, 2020-02-27).
  8. Health authorities are now expecting COVID-19 to spread in the US” by Issam Ahmed (Science Alert, 2020-02-25).
  9. WHO chief on coronavirus: Global markets ‘should calm down and try to see the reality’” by Natasha Turak (CNBC, 2020-03-01).
  10. Dow Jones futures fall amid wild swings as COVID-19 cases rise, U.S. fears grow in coronavirus stock market correction” by Ed Carson (Investor’s Business Daily, 2020-03-02).
  11. Coronavirus update: Global spread hits ‘uncharted territory’ as volatile markets rebound; US death total jumps” by Anjalee Khemlani (Yahoo Finance, 2020-03-02).
  12. Coronavirus may have spread undetected for weeks in Washington state, which reported first two deaths in U.S.” by Joel Achenbach, Katie Mettler, Lena H. Sun, & Ben Guarino (The Washington Post, 2020-03-01).
  13. Risk for transportation of 2019 novel coronavirus disease from Wuhan to other cities in China” by Zhanwei Du et al. (Centers for Disease Control and Prevention, 2020-02-13).
  14. So how bad is coronavirus in U.S.? We don’t know yet” by Alvin Powell (The Harvard Gazette, 2020-03-03). “The U.S. government has announced a dramatic expansion of testing, but Lipsitch said it would likely take weeks to put in place. ‘[The pace of testing’s] still low, and it will take weeks until we have anything like adequate testing capacity,’ said Lipsitch, professor epidemiology and head of the [Harvard Chan] School’s Center for Communicable Disease Dynamics.”
  15. Coronavirus screening may miss two-thirds of infected travelers entering U.S.” by Alvin Powell (The Harvard Gazette, 2020-03-04). “Lipsitch said epidemiology indicates that the sooner ‘social distancing’ steps are taken the better. But he also said that decision is appropriately made by governmental leaders who can balance more than just the science, including such factors as economic impact, effects on children’s education, and implications for societal essentials like food production. There is also the chance that if steps are taken too early, people may be unwilling to adhere to the limits, absent a clear emergency.”
  16. Yes, it is worse than the flu: busting the coronavirus myths” by Hannah Devlin (The Guardian, 2020-02-29).
  17. Experts predict that covid-19 will spread more widely” (The Economist, 2020-02-22).
  18. H1N1 was the last pandemic. Here’s why COVID-19 isn’t yet in that category” by Richard Harris (NPR, 2020-02-24).
  19. Coronavirus updates: CDC announces ‘4 new presumptive cases’ in the U.S.” by Bill Chappell (NPR, 2020-02-28).
  20. Timeline: Swine flu” (Nature, 2009-2010). A chronology of the H1N1 outbreak (2009-2010).
  21. Could the US contain a coronavirus outbreak” by Megan Molteni (Wired, 2020-02-25).
  22. Health authorities are now expected COVID-19 to spread in the US” by Issam Ahmed (Science Alert, 2020-02-25). (No) surprise.


Chinese research labs

  1. An unsubstantiated theory suggests the coronavirus accidentally leaked from a Chinese lab — here are the facts” by Aylin Woodward (Business Insider, 2020-04-15).
  2. Evidence that coronavirus originated at Chinese lab is ‘inconclusive’, top general says” by Lara Seligman (Politico, 2020-04-14).

Reference : Gospels for Lent

A roughly chronological reading of the four Biblical Gospels during Lent.

W.D Date Matt Mark Luke John
0.W 26 Feb 1,2
0.R 27 Feb 1,2
0.F 28 Feb 1
0.S 29 Feb 3 1 3
0.N 01 Mar 4 4
1.M 02 Mar 5 2
1.T 03 Mar 3,4
1.W 04 Mar 5,6
1.R 05 Mar 7
1.F 06 Mar 8 2
1.S 07 Mar 5
1.N 08 Mar 12 3 6
2.M 09 Mar 11 7
2.T 10 Mar 13 4 8
2.W 11 Mar 5
2.R 12 Mar 9,10
2.F 13 Mar 14 6
2.S 14 Mar 9 6
2.N 15 Mar 15 7
3.M 16 Mar 16 8
3.T 17 Mar 17 9
3.W 18 Mar 18
3.R 19 Mar 10,11
3.F 20 Mar 7,8
3.S 21 Mar 9,10
3.N 22 Mar 12,13
4.M 23 Mar 14,15
4.T 24 Mar 16,17
4.W 25 Mar 11
4.R 26 Mar 19,20
4.F 27 Mar 10 18
4.S 28 Mar 21 11
4.N 29 Mar 19 12
5.M 30 Mar 22,23
5.T 31 Mar 24,25
5.W 01 Apr 12,13
5.R 02 Apr 20,21
5.F 03 Apr 14,15
5.S 04 Apr 16,17
5.N 05 Apr 27 15
6.M 06 Apr 23
6.T 07 Apr 18,19
6.W 08 Apr 28 16
6.R 19 Apr 24 20
6.F 10 Apr 21
6.S 11 Apr
6.N 12 Apr


Reference : Alexander Grothendieck and the 1988 Crafoord Prize

Related articles:

  1. Lettre d’Alexandre Grothendieck” (Le Monde, 1988-05-04).
  2. Letters from A. Grothendieck” (Mathematical Intelligencer, 1988).

Reference : Bicycle repair

I recently tried my hand(s) at some maintenance work on my bicycle, an old Diamondback mountain bike. The rear brake pads were routinely wearing down quickly, in large part because the rear wheel knocked (wobbled side-to-side on its axle) significantly (several millimeters), which turned out to be related to a chipped cone and missing (!) bearings in the back wheel… And while we’re there, might the internals of the freewheel be scrambled, too? And the cassette cries for a cleaning…


With Park Tool’s “Big blue book of bicycle repair” [1,2] and YouTube (videos linked below) as my shop masters, I did the following:

  • Replaced the bearings and realigned cones, lock nuts, etc. on rear axle [3,4]. A few remarks.

    Cone adjustment. My rear wheel is a quick-release (QR), and getting the cones and lock nuts set just right took many, many adjustments. In particular, if the cones and lock nuts are set too tight on the axle prior to tightening the QR, the compression from the QR mechanism will tighten the cones into the wheel even more, causing the wheel to not spin freely [5]. The rule of thumb for QR wheels from the Park Tool book is helpful: You want just a trace of knocking when the wheel is off the frame, and no knocking when the wheel is on the frame with the QR mechanism closed. At the end of the day, what I looked for was, when the wheel is on the frame with the QR closed, (i) there is no knocking and (ii) the wheel spins freely.

    Dust caps. Be gentle when removing and replacing the dust caps! On my bike, these turned out to be fragile, and I bent one badly out of shape. Fortunately, the dust caps don’t seem to touch any parts of the wheel inners — they sit off the bearings, and are just to keep debris out of the wheel inners — so so far the bent-up dust cap hasn’t caused me any issues. Though if it’s so bent up it falls out, then the wheel inners get clogged up, that would be an issue… The dust caps on my wheel seem to have a rigid outer ring, but the rest of the cap is bendable metal. When putting the dust cap back in place, gently tap around the edges, ideally with something soft (e.g., plastic), until the dust cap sits snug.

    Personal reference. On my bike, the rear axle shows 6 threads on either side, beyond the lock nuts.

  • Deconstructed, cleaned, and rebuilt freewheel and cassette [6]. Getting the freewheel off the wheel was the hardest thing I did. You need a special freewheel removal tool, you need a large wrench (go go Gadget torque!), and even then, you need upper body strength — the freewheel can be on there tight!

    Personal reference. The Shimano MF-Z012 cassette on my bike has 30 bearings on the outside and 40 on the inside [7]. All bearings appear to be the same size. One of the pawls seemed to be oriented backward.

  • Replaced all brake pads and brake cables [8]. Installing and adjusting the brakes went fast and smoothly for me.

    Personal reference. The cantilever smooth post brake calipers on my bike were installed with a Shimano link unit, which comes in different sizes. The A link unit — with a 7.0 mm rigid arm — is the correct size for my bike.

  • Retaped handlebars [9]. Pay attention to the direction of taping. You want the tape to rotate the same way as the rider’s hands on the handlebars, so that the rider’s natural motion will tighten, not loosen, the tape. On the outside of the handlebars, wrists tend to rotate outward (away from the rider). On the uppers (inside) of the handlebars, wrists tend to rotate down (toward the rider). Tape correspondingly.


  1. Park Tool’s “Big blue book of bicycle repair” at Park Tool.
  2. Park Tool’s “Big blue book of bicycle repair” at Amazon.
  3. Repairing a loose bike wheel — hub overhaul” by RJ The Bike Guy (YouTube, 2013-10-04).
  4. Knock knock, loose hub : Tech Tuesday #117” by Park Tool (YouTube, 2018-10-16).
  5. Very stiff rear wheel” (Bike Radar, 2011-07).
  6. Bicycle freewheel disassembly/assembly” by RJ The Bike Guy (YouTube, 2014-04-03).
  7. How many balls in a MF-Z012 cassette : Post #11 (Bike Forums, 2011-07-02).
  8. Brake caliper mounting & adjustment — cantilever smooth post” by Park Tool (YouTube, 2016-04-05).
  9. How to wrap handlebars for road bikes” by Park Tool (YouTube, 2016-01-07).

Reference : Apple’s Time Machine

  1. Back up your Mac with Time Machine” (Apple Support).
  2. Delete a file from your Time Machine backup disk” (Apple Support).
  3. What to do when Time Machine backup is full” by Karen Haslam (MacWorld, 2018-05-07).
  4. Here’s how to delete Time Machine backups” by Darina Stavniychuk (MacPaw, 2018-12-21).