Table of Contents

2024-12-20

TIL that you can use matrix notation and linear algebra to study conic sections.

Ref:- https://en.wikipedia.org/wiki/Matrix_representation_of_conic_sections

2024-12-17

TIL that Grab designed a special camera called KartaCam in order to build their own maps in Southeast Asia. The camera is mounted on the motorbikes of their delivery drivers. The collected data is then added to OpenStreetMap.

Ref:- https://restofworld.org/2024/grab-google-maps-southeast-asia/

2024-12-12

TIL that ~20% of the fresh water on Earth's surface is in a single lake called Lake Baikal.

Ref:- https://www.britannica.com/place/Lake-Baikal

2024-12-10

TIL that when UAE was becoming a country in 1971, its founders went village to village, tribe to tribe, asking each which ruling family they were loyal to. Then that's where they drew the boundaries between states.

Ref: https://sive.rs/dxb

2024-12-03

TIL that the Japanese have a system called Koseki where all the personal and family details are recorded.

Ref: https://en.wikipedia.org/wiki/Koseki

2024-11-24

TIL that factories in India with over 100 employees require government permission to fire workers.

Ref: https://www.wsj.com/world/asia/to-challenge-china-india-needs-to-get-out-of-the-way-of-its-factory-owners-28cb4a6f

2024-11-04

TIL about Pyrosomes. They are free-floating colonial tunicates that live in the ocean. They are bioluninescent. Here is a nice video on them https://www.youtube.com/watch?v=qis_rfb7fnU .

2024-10-25

TIL: “Kentucky windage” refers to the practice of holding the aim to the upwind side of the target (also known as deflection shooting or “leading” the wind) to compensate for wind drift, without actually changing the existing adjustment settings on the gunsight.

Ref: https://en.wikipedia.org/wiki/Windage#Ballistics → 2nd paragraph

2024-10-20

TIL: The 'IN' in the output of 'dig' command is the “query class” and stands for “internet”. It is basically a relic from the 80s and 90s when there were other networks competing with the internet like “chaosnet”.

Ref: https://jvns.ca/blog/2021/12/04/how-to-use-dig/

2024-10-17

TIL: The risk of down syndrome increases with maternal age.

Ref: https://www.floridahealth.gov/diseases-and-conditions/birth-defects/_documents/Data_Report/_documents/Maternal_Age_and_Down_Syndrome.pdf

2024-10-15

Qanat is an ancient system of water supply which allows water to be transported over long distances in hot dry climates without loss of much of the water to evaporation. Here is a fascinating video on it.

2024-10-12

A polyester textile is the same PET material (polyethylene terephthalate) as a plastic soda bottle, only extruded into a filament rather than molded into a container. Like the bottle, the fiber repels water. It’s hydrophobic.

https://worksinprogress.co/issue/how-polyester-bounced-back/

2024-09-28

There is a special aircraft called “Airbus BelugaXL” which is used to transport very large aircraft components, such as aircraft wings.

https://en.wikipedia.org/wiki/Airbus_BelugaXL

There used to be an anti obesity drug called fen-phen back in the 90s that was initially FDA approved but later found to cause heart valve abnormality and was then taken off the market.

Ref:

2024-09-27

Google’s ‘Project Nightingale’ gathers personal health data on millions of Americans

Ref:

2024-09-25

There is a rule called “business judgement rule” which protects the Board of Directors from personal civil liability when they make business decisions for a company.

Ref: https://www.investopedia.com/terms/b/businessjudgmentrule.asp

2024-08-10

If you are going out of town for an extended period of time, you can ask USPS to hold your mail until you return by putting a “hold mail” request on their website.

More info at https://www.usps.com/manage/hold-mail.htm

2024-08-04

The pressure at the bottom of the Mariana Trench is ~1000 times more than the pressure at the sea level. Even at these levels, the density of water goes up by just ~5%.

I knew water is an incompressible fluid. But did not realize how hard it is to compress it!

See also:

2024-07-28

2024-07-27

Ref:

2024-07-26

Ref:

2024-07-21

Ref:

2024-07-12

2024-07-06

2024-07-05

2024-07-04

2024-06-13

TIL: An earworm is a song that you keep hearing in your head

Ref: https://dictionary.cambridge.org/us/dictionary/english/earworm

2024-06-07

TIL: In order to be listed on Nasdaq, companies need to have a woman, “underrepresented minority” or “LGBTQ+” member in their board - or publicly explain why they don’t. If it is a big company, they require two such candidates.

Ref: https://www.wsj.com/articles/texas-stock-exchange-txse-new-york-blackrock-citadel-securities-james-lee-bb72c36c?mod=hp_opin_pos_1

2024-06-02

2024-05-28

2024-02-09