10 February
2021
9 February
2021
Ballground ride
7 February
2021
Football or not
Penning a two page letter to a dear friend explaining how I went from being a lover of American football to virtually completely avoiding it. How the statistics on violent injuries and how it has affected players’ lives after they are done playing is too mind numbing for me. This is while Super Bowl is going on right now…
Used a new pen that I got a couple of months back from China.
7 February
2021
From the bartender’s corner – Oaxaca’s Guavarita
Tried a variant on margarita. First off, used the guava juice that Sharmila got. Still experimenting with it. Second, instead of Tequila, used Casamigos Mezcal. And finally, used kiln fired rock salt for the rim of the glass.
Wet the rim of the margarita glass with a slice of lime and rotate the rim on a small pile of kiln fired rock salt so a little of it sticks all around. In a mixing glass, put ice, three ounces of guava juice, one and a half ounce of mezcal, three quarters ounce of cointreau and squeeze a slice of lime in it. Thoroughly shake it and pour in the glass.
7 February
2021
Ride to coffee
7 February
2021
Pushed back old age a little
6 February
2021
I am getting old
30 January
2021
From the bartender’s corner – Guava cocktail
This one is improvised from a recipe I found in a rather humorously named website.
Take two slices of lime in a muddling glass and throw in a spoonful of sugar in it. Muddle it very well. Add ice to it. Pour two ounces of rum and four ounces of guava juice in it and then shake it well.
Pour it in a glass of your choice (I used a margarita glass) and serve.
Great tropical drink. Probably more suited to summer days but I enjoyed it anyways.
30 January
2021
Puzzle: Want to feel better after a Covid test?
This math puzzle about Covid will make your jaw drop (also make you feel better after getting a test)
First, please take all precautions again Covid. If you think you got exposed or have symptoms, get yourselves tested, quarantined and everything else CDC is asking us to do. Once you have done so, think about this puzzle…
The following puzzle – which is a very real one in Covid days – is an adaptation from a puzzle I had posted last year.
The end question I am going to ask you is this:
Q1. Your Covid test came positive. What is the probability that you really have the infection?
Q2. Your Covid test came negative. What is the probability that you really do not have the infection?
As Narayan had pointed out last year, most doctors do not get this. The fact that all tests have false positives and false negatives (they are not perfect) makes the real probability unintuitively high or low.
The real answers will knock your socks off.
Ok, let’s start this:
——
1. The COVID PCR test has a false positive of about 0.5% (*See Source). Which would mean in about 200 people without the virus, the test will make a mistake in one case and say he/she has the virus.
2. The test has a false negative of 10% (** See Source) This means of 10 people who actually have the virus, the test will miss out 1 of them.
3. Assume 2% of Americans at any point of time has the virus (*** See Source)
You went to get a PCR test done. Test showed positive. What is the real probability you have the virus? Hint: It is NOT 99.5%
Take the other case – the test showed negative. What is the real probability you do not have the virus? Hint: It is NOT 90%
Both the answers will make you feel much better.
That should be good enough reason why we should LOVE math! And at the risk of Tammi – the math teacher in my friend circle – slapping my wrist, I would say, you will love the chapter on Conditional Probability.
——
Sources:
* (in reality 0.2%-0.9% per https://www.icd10monitor.com/false-positives-in-pcr-tests…)
** the actual number can widely vary – as high as 67% – depending on when you got tested after exposure. The more time you give after exposure, the more the virus gets to establish itself and lesser the false negative number. https://www.acc.org/…/variation-in-false-negative-rate…
*** I took CDC’s 25% estimated US population had it https://www.cdc.gov/…/2019-ncov/cases-updates/burden.html over 11 months and took the average as 2%. (It will be slightly higher due to ramp ups)
29 January
2021
