Thursday, April 9, 2020

Fluid Dynamics and virus transmission

Here are some articles that I want to remember

https://www.usatoday.com/story/news/health/2020/03/30/coronavirus-social-distancing-mit-researcher-lydia-bourouiba-27-feet/5091526002/

Bourouiba models exhalation gas clouds and finds that they can travel up to 27 feet.  The CDC poo-poos this and says it's misleading.

In a Journal of the American Medical Association article published last week, Bourouiba said peak exhalation speeds can reach 33 to 100 feet per second and "currently used surgical and N95 masks are not tested for these potential characteristics of respiratory emissions."

Pottinger says that if the virus were effective at 27 feet more people would be sick. But we don't know how many people are sick. There are so many who are not being tested. This is a specious argument.

https://www.propublica.org/article/what-we-need-to-understand-about-asymptomatic-carriers-if-were-going-to-beat-coronavirus?fbclid=IwAR26XkDAb_EfR-SPnlu-v2_ilBD_05JzuxtRlupaat6fB4ccubCy-LLghJ4

https://medium.com/@jurgenthoelen/belgian-dutch-study-why-in-times-of-covid-19-you-can-not-walk-run-bike-close-to-each-other-a5df19c77d08

https://cee.mit.edu/people_individual/lydia-bourouiba/

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Statement by one interlocutor

The Media has done exactly what it intended to do invoke FEAR in everyone.. I advise everyone to do your own research on the subject of viruses... this virus is not AIRBORNE!! Additionally, for those of you who think the masks are a shield here is another tidbit the size of the virus is so small it can easily goes through these masks... nothing other than a hazmat suit will protect you. Again, that is if its airborne.
I suggest that you ask our
Heavenly Father to give you clarity on this. I assure you He will.
For God has not given us the spirit of Fear but of power, and of love and of a sound mind
Timothy 1:7
Believe & Receive!

My response

There is an issue of wording here.  This virus is larger and heavier than, say, the measles virus.   The measles virus is considered "airborne" in the sense that it can rise, unaided, into the air and move freely about.

This virus is heavier than air and tends to want to fall on the ground.  It is believed to travel on respiratory droplets, not to be independently airborne, unlike the measles virus.

However, how far respiratory droplets can travel, how long they can stay airborne, and how far a virus can be effective on such a droplet is still a matter of active research.

This peer-reviewed study cosponsored by several prominent research institution found that the virus could be effective in the air on respiratory droplets for three hours.

https://www.nejm.org/doi/full/10.1056/NEJMc2004973

However, Lydia Bourouiba, an MIT researcher in fluid dynamics, has found that respiratory droplets can travel up to 27 feet. Fauci, who works for the CDC, which you so distrust, discounts this research as misleading, because he doesn't believe that the virus could be effective on droplets that travel so far.

https://www.usatoday.com/story/news/health/2020/03/30/coronavirus-social-distancing-mit-researcher-lydia-bourouiba-27-feet/5091526002/

In fact, the CDC and the WHO are conservative about how far the virus can travel in air.  Many researchers think it can go farther than what they say, as in the article that I cited above.

In the USA Today article, Pottinger is cited as saying that if the virus were effective at 27 feet more people would be sick.  But we don't know how many people are sick.  There are so many who are not being tested.  This is a specious argument.

Also, because the virus travels on droplets, which are larger than the virus -- its travel, upon exiting the mouth and nose, is limited. The masks are not to protect the wearer. The masks are to protect others.

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