Since Oct 9, 1999

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02 July 2020 Aguments for and against using masks to slow the spread of the coronavrius below. I wear one for work and wear it into stores even though a lot of people don't in rural Virginia.

  1. N95 masks do not filter odors: The argument is made that if they don't filter odors then they don't filter the virus. That's obviously not correct since odors can come from single molecules as small as 0.0004 microns Virus particles are as small as 0.125 microns.
  2. Cloth or surgical masks have gaps. I believe a lot of cotton masks are useless because of the gaps. I tried some and my breath just went around it. OTOH I wear disposable surgical masks and most of my breath goes through the mask.
  3. Like a mosquito going through chain link fence. The masks are supposed to filter droplets not virus particles. Paper says: Acquired data indicates that 97% of droplets, expelled in one second during coughing, are smaller than 1 μm. The virus particles are smaller and are more numerous in smaller droplets:

    We collected samples of exhaled particles (one with and one without a facemask) in two size fractions ("coarse">5 µm, "fine"≤5 µm) from 37 volunteers within 5 days of seasonal influenza onset, measured viral copy number using quantitative RT-PCR, and tested the fine-particle fraction for culturable virus. Fine particles contained 8.8 (95% CI 4.1 to 19) fold more viral copies than did coarse particles. Surgical masks reduced viral copy numbers in the fine fraction by 2.8 fold (95% CI 1.5 to 5.2) and in the coarse fraction by 25 fold (95% CI 3.5 to 180). Overall, masks produced a 3.4 fold (95% CI 1.8 to 6.3) reduction in viral aerosol shedding.

    With speaking, the vast majority of droplets were above 0.5 microns It's not clear what the particle size distribution is and how that relates to the mesh. But cloth is probably inadequate:

  4. Evidence from events. No masks: the church choir practice. See The community choir in Washington State. Even though people were aware of the virus and took steps to minimize transfer; e.g. they avoided the usual handshakes and hugs hello, people also brought their own music to avoid sharing, and socially distanced themselves during practice. They even went to the lengths to tell choir members prior to practice that anyone experiencing symptoms should stay home. A single asymptomatic carrier infected most of the people in attendance. (I would note that it is not clear that it was just a single carrier).

    With masks: the salon where two stylists tested positive: After about 14 days, there were no positive tests: 46 tested out of 140, all negative, so a very low likelyhood (< 0.1% if the 46 are random) that any of the untested are positive.

  5. NEJM article: "We know that wearing a mask outside health care facilities offers little, if any, protection from infection. " But the study has five references, none of which are about masking. The study does not consider masking patients. Generally it's a bad idea to mask a patient who is already suffering from low oxygen. So the study has no applicability and the line is a throwaway line.
  6. Undboutedly there's less oxygen inside the mask, and I have to compensate by consciously breathing deeper. For the first half second I breathe stale warm air, then fresher air through the mask. It's noticeable because the fresher air is cooler, I only wear masks indoors with AC.

Feb 13, 2016: "A system of government that makes the People subordinate to a committee of nine unelected lawyers does not deserve to be called a democracy."

Sep 21, 2008. I'm putting this link: on my home page, not because I want to, and not because it is well written. But it pretty well explains the degree of risk that the financial community has created by credit default insurance. Unlike MBS, there are no assets, no income stream, no regulated reserves, just a promise that money will magically appear right when the economy runs out of money.

But before we tar and feather those insurers, let's properly assign blame where it belongs: the Fed and its creators, FDR (created moral hazards in Fannie and Freddie), Burns, Greenspan, Bernanke and all the apologists for the credit-based economy who can see no wrong with creating multiple dollars of debt for every dollar of GDP. Here's another link with the numbers for the hole we've dug (50 trillion in debt - see table L.1 against a 14 trillion GDP): This level of debt cannot be paid off (think about the proportion of GDP that would be needed, it would eat up the money needed for startups, R&D, etc). The only choices are default (what is looming today) or inflation.

Mar 24, 2007: Here's my web page with what I see as perpetuated myths of global warming: When you find errors, please ping or email. I have already been taken to the woodshed for some and I appreciate the patience of the readers who corrected what I had muddled.

Dec 14, 2003. We've captured Saddam! A big congratulations to our military. Many have sacrificed a lot including their lives to achieve this and I will always remember them.

This is a perfect opportunity to switch to the Afghanistan strategy: a few well protected bases and special forces missions to eliminate specific threats. If the the vast majority of Iraqis want freedom and democracy then they can earn it by keeping the peace, turning in the remaining radicals and building their own government.

Nation-building is mostly liberalism: handouts, price controls, political correctness, and a religious belief in changing people from the top down. We have given the Iraqis the foundation to build a nation, but we can't give them a functioning country, they have to do that themselves