Wednesday, July 29, 2026

Some common birds around me

 Cockatoo



Common Myna





Rainbow Lorikeet



King Parrots



Crested Pigeon




Kookaburra




Willy Wagtail


Magpie





Silver Gull




Ibis





Above I can recall seeing frequently easily. And for reference, next time out walking, to identify a few:





About Oceans

 Mostly from here.

Some physical consequences have vast biological effects. Nutrients, as well as oxygen, are in short supply in the Ocean. Deep waters accumulate such nutrients from organisms living near the surface and sinking after death. In certain regions, currents bring these deep waters up to the surface, cooling surface waters and enriching them with nutrients, which favour the growth of phytoplankton. 

This is called upwelling, and the end result is a much richer food chain: approximately 40% of the total global fish catches comes from four upwelling areas, which occupy only 3% of the total ocean area: the Humboldt current, off Peru and Chile, the California current, the Canary current, off Northwest Africa, and the Benguela current, off Southwest Africa. 





Plastics globally (A lot of plastic finds its way to oceans)





Monday, July 27, 2026

Africa

  • A continent of 54 countries
  • More than 2000 languages
  • And 1.58 billion people.

“In reality Africa is a rich mosaic of experience, of diverse communities and histories, and not a singular monolith of predetermined destinies. We sound different, laugh differently, craft the mundane in uniquely mundane ways, and our moral compasses do not always point in the same direction.” - Dipo Faloyin


POPULATION


Following is the population density map of Africa.






And following are the largest cities in Africa









Wednesday, July 1, 2026

S&P 500 in charts

 


S&P 500 represents over 54% of the listed global equity markets. 


















Documents
https://pwm.gs.com/docs/shared/pdfs/insights/2025-isg-outlook.pdf














https://www.gspublishing.com/content/research/en/reports/2025/10/15/21c88473-1287-408f-97f8-36c7a80340cb.pdf







Sunday, June 28, 2026

A collection of Mental Models

I personally believe that one needs to arrive at mental models through experience and insight. A sort of personal arrival of synthesis of one's own lived experience, understanding, knowledge, information yielding some sort of lived insight. 

Still, feeding oneself on wisdom of the ages and wisdom of the sages is also a path. A knowing, that is still far away from lived experience or lived understanding. Still, it is a thought, someone else's lived understanding illuminated for you. 

Here is a collection of such mental models from all over the internet:

A couple of good collections - At Farnam Street  (100 models explained) and at James Clear


Then some on internet:

from https://career-advising.ndsu.edu/blog/2022/11/01/the-importance-of-mental-models/






Thursday, June 18, 2026

Atmospheric Carbon

"variations in CO2 affect not only climate, but ecosystems."


One of the common themes in the previous pages is the carbon dioxide, CO2, in our atmosphere and oceans. CO2 is it is one of the major drivers of long-term atmosphere and ocean changes on our Earth through time and is often mentioned when discussing climate change. Many people, for good reason, misunderstand why increasing amounts of CO2 in our atmosphere and oceans are harmful. Commonly, scientists hear “CO2 was much higher at other times in Earth’s history, so the current increase in CO2 is the Earth’s natural variation”. The first part of this statement is correct: CO2, at times, was much higher than today in the geologic past. The other part of the sentence “the current increase in CO2 is the Earth’s natural variation” is not correct. Human activity on Earth has increased the amount of CO2 entering the atmosphere and oceans, altering the natural cycling of CO2 in the Earth’s systems (oceans, atmosphere, rock, and biosphere). From here







From here

The giant caveat: Earth system sensitivity describes climate changes over hundreds of thousands of years, not the decades and centuries that are immediately relevant to humans. The authors say that over long periods, increases in temperature may emerge from intertwined Earth processes that go beyond the immediate greenhouse effect created by CO2 in the air. These include melting of polar ice sheets, which would reduce the Earth’s ability to reflect solar energy; changes in terrestrial plant cover; and changes in clouds and atmospheric aerosols that could either heighten or lower temperatures.


The researchers confirmed the long-held belief that the hottest period was about 50 million years ago, when CO2 spiked to as much as 1,600 ppm, and temperatures were as much as 12 degrees C higher than today. But by around 34 million years ago, CO2 had dropped enough that the present-day Antarctic ice sheet began developing. With some ups and downs, this was followed by a further long-term CO2 decline, during which the ancestors of many modern-day plants and animals evolved. This suggests, the paper’s authors say, that variations in CO2 affect not only climate, but ecosystems.

The new assessment says that about 16 million years ago was the last time CO2 was consistently higher than now, at about 480 ppm; and by 14 million years ago it had sunk to today’s human-induced level of 420 ppm. The decline continued, and by about 2.5 million years ago, CO2 reached about 270 or 280 ppm, kicking off a series of ice ages. It was at or below that when modern humans came into being about 400,000 years ago, and persisted there until we started messing with the atmosphere on a grand scale about 250 years ago.


Of modern ages:

In the late 1700s, the air contained about 280 parts per million (ppm) of CO2. We are now up to 420 ppm, an increase of about 50%; by the end of the century, we could reach 600 ppm or more. As a result, we are already somewhere along the uncertain warming curve, with a rise of about 1.2 degrees C (2.2 degrees F) since the late 19th century.



From here





Another reason carbon dioxide is important in the Earth system is that it dissolves into the ocean like the fizz in a can of soda. It reacts with water molecules, producing carbonic acid and lowering the ocean's pH (raising its acidity). Since the start of the Industrial Revolution, the pH of the ocean's surface waters has dropped from 8.21 to 8.10. This drop in pH is called ocean acidification, and it interferes with the ability of marine life to extract calcium from sea water to build skeletons and shells.

A timelapse here of global emissions





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