Why are you more buoyant in salt water?
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So both the density of the object (you) and the density of the fluid (water) matter in terms of how positively buoyant you are while swimming. Keep this in mind as we tackle the key question:
The answer comes down to the increased density of the water.
Salt water = salt + water. Adding salt to water increases the density of the fluid. A cubic foot of salt water weighs (on average) about 64.1 lbs, while a cubic foot of fresh water only weighs around 62.4 lbs.
So the added density of the salt water increases the force of buoyancy pushing you against gravity, letting you feel more floaty.
Not all salt water is equal though. Famously, the Dead Sea has a much higher density because it's a lot saltier than other salt water: a cubic foot of water there weighs about 77.3 lbs!
Temperature also affects the density of water. Cold water is denser than warm water, so you'll float more easily in frigid waters (but hopefully you also float more easily because you're wearing a wet suit!).
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Sources for this week's newsletter
If this post didn't satisfy your salty craving, I have just the book for you.
Salt takes readers on a journey through the history of the world's most ubiquitous seasoning. From ancient times to the modern day, Kurlansky explores the impact that salt has had on human civilization, from the development of trade routes and empires to the rise of mass production and processed foods. I particularly enjoyed learning about how salt is found in many words we use today like "soldier" and "salad."
Take this recommendation with a grain of salt: The book is nearly 500 pages long, so it's not book club material. But I greatly enjoyed it despite skipping a few less than captivating sections.
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