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How the Tropics Got Their Names
Why the Tropics Are Important
- The Tropics are places within the hemisphere where the sun can be directly overhead.
- This was essential for ancient travelers who used the sun and stars to guide their way.
- The Tropic of Capricorn can be found at latitude 23.5 degrees south, and the Tropic of Cancer at 23.5 degrees north.
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SIMILAR ARTICLES & IDEAS:
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Key Ideas
Vitamin D and sunshine
Vitamin D is essential for calcium absorption and many other biological processes. Lower levels of Vitamin D increase the rates of almost every disease like cancer, diabetes, osteoporosis, cognitiv...
Vitamin D supplementation
Getting vitamin D through supplementation shows zero benefits. A study over a period of 5 years found supplementing with Vitamin D had no impact on cancer, heart disease, or stroke.
A number of researchers now argue that people with high vitamin D levels are healthy not because of the vitamin, but because they get plenty of exposure to the sun. Vitamin D is just a marker of that fact.
Sunlight is good for you
A dermatologist discovered our skin uses sunlight to make nitric oxide, a molecule in the body that dilates blood vessels and lowers blood pressure.
He exposed volunteers to the equivalent of 30 minutes of summer sunlight without sunscreen. The result? The nitric oxide levels in the volunteers went up, and their blood pressure lowered. Because of the connection of high blood pressure to heart disease and strokes, this discovery can prevent millions of deaths globally.
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Key Ideas
Environmental Determinism and Early Geography
- Strabo, Plato, and Aristotle used climatic factors to explain why the Greeks were more developed than societies in hotter and colder climates.
- Aristotle developed a climate classif...
Environmental Determinism and Modern Geography
- In the late 19th Century, environmental determinism was revived by the German geographer Friedrich Rätzel. He was heavily influenced by evolutionary biology and the impact a person's environment has on their cultural evolution.
- Rätzel's student, Ellen Churchill Semple, introduced the theory in the United States in the early 20th Century, where it grew in popularity.
- Another student of Rätzel, Ellsworth Huntington, also worked on expanding the theory, which led to a subset of environmental determinism, called climatic determinism. He said that the economic development in a country could be predicted based on its distance from the equator.
The Decline of Environmental Determinism
Environmental determinism's popularity began to decline in the 1920s as its claims were often found to be wrong. Critics claimed it was racist and perpetuated imperialism.
Carl Sauer said environmental determinism led to premature generalizations about an area's culture. From this critique, geographers developed the environmental possibilism theory to explain cultural development.
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Key Ideas
Wealth Is A Relative Term
The definition of wealth is personal. It may mean something different to everyone.
To some people, wealth is always going to mean money. But it's not t...
How Much You Need to Become Wealthy In Dollars
According to a Modern Wealth Index Survey, the amount needed to be comfortable in America is $1.4 million. To be wealthy, you'll need a net worth of $2.4 million.
An average pre-tax yearly salary of $389,436 is needed to be in the top 1%, although it varies by state.
Buying Time
We all, rich or poor, have the same 24 hours in a day. But we can use our money to buy more time. For example, by eating out, you don't have to decide what to cook, shop for ingredients, cook, and clean it all up.
If you can carve out more time for yourself, you can use it in other ways that will improve your life. You can start a side hustle, exercise, read, or spend time with family and friends.