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What Are the Seven Seas?

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There more than 100 bodies of water in the world that are either officially named seas or commonly referred to that way. When someone talks about sailing the “seven seas,” which particular seven are they referring to?

It depends on who you ask, and when. A lot of the time, the term isn’t meant to be taken literally, and simply refers to all the seas and oceans of the world. According to the National Oceanic and Atmospheric Administration, though, ever since the term was first recorded in ancient Mesopotamia in a religious poem, different cultures have used the phrase for specific sets of bodies of water. In different places and at different times, it was applied to trade routes, regional waterways or the waters of far-away, exotic places. 

The ancient Greeks, who introduced the term to the West, applied it to the Adriatic, Aegean, Black, Caspian, Mediterranean and Red seas and the Persian Gulf.

To Medieval Arabian geographers and explorers, the seven seas were the bodies of water they travelled on voyages to the Far East, which they called the Sea of Fars (the modern-day Persian Gulf), Larwi (Gulf of Aden and Arabian Sea), Harkand (Bay of Bengal), Kalah or Kalahbar (Strait of Malacca), Salahit (Singapore Strait), Kardanj (the Gulf of Thailand and the part of the South China Sea between Sumatra and Borneo), and Sanji (South China Sea).

Medieval Europeans, meanwhile, had a few different sets of seven seas that included the Adriatic, Aegean, Arabian, Baltic, Black, Caspian, Mediterranean, North and Red seas, as well as the Persian Gulf, Indian Ocean and Atlantic Ocean. 

During the Age of Exploration and the European discovery of the Americas, some sailors began including New World waters into the group, so the seven seas included the Arctic, Atlantic, Indian and Pacific oceans, the Caribbean and Mediterranean seas and the Gulf of Mexico in different groupings.

The term is mainly used figuratively today, but if you wanted to keep it literal, says NOAA, the world has five major oceans—the Arctic, Atlantic, Indian, Southern (Antarctic) and Pacific—and the Atlantic and Pacific are cut into north and south divisions by the equator, giving you seven “seas” to sail. 

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Big Questions
How Does Autopilot Work on an Airplane?
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How does autopilot work on an airplane?

Joe Shelton:

David Micklewhyte’s answer is a good one. There are essentially a few types of features that different autopilots have. Some autopilots only have some of these features, while the more powerful autopilots do it all.

  • Heading Hold: There’s a small indicator that the pilot can set on the desired heading and the airplane will fly that heading. This feature doesn’t take the need for wind correction to desired routing into account; that’s left to the pilot.
  • Heading and Navigation: In addition to holding a heading, this version will take an electronic navigation input (e.g. GPS or VOR) and will follow (fly) that navigation reference. It’s sort of like an automated car in that it follows the navigator’s input and the pilot monitors.
  • Altitude Hold: Again, in addition to the above, a desired altitude can be set and the aircraft will fly at that altitude. Some autopilots have the capability for the pilot to select a desired altitude and a climb or descent rate and the aircraft will automatically climb or descend to that altitude and then hold the altitude.
  • Instrument Approaches: Autopilots with this capability will fly preprogrammed instrument approaches to the point where the pilot either takes control and lands or has the autopilot execute a missed approach.

The autopilot is a powerful computer that takes input from either the pilot or a navigation device and essentially does what it is told to do. GPS navigators, for example, can have a full flight plan entered from departure to destination, and the autopilot will follow the navigator’s guidance.

These are the majority of the controls on the autopilot installed in my airplane:

HDG Knob = Heading knob (Used to set the desired heading)

AP = Autopilot (Pressing this turns the autopilot on)

FD = Flight Director (A form of navigational display that the pilot uses)

HDG = Heading (Tells the autopilot to fly the heading set by the Heading Knob)

NAV = Tells the autopilot to follow the input from the selected navigator

APR = Tells the autopilot to fly the chosen approach

ALT = Tells the autopilot to manage the altitude, controlled by the following:

VS = Vertical Speed (Tells the autopilot to climb or descend at the chosen rate)

Nose UP / Nose DN = Sets the climb/descent rate in feet per minute

FLC = Flight Level Change (An easy manual way to set the autopilot)

ALT Knob = Used to enter the desired altitude

This post originally appeared on Quora. Click here to view.

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Big Questions
What's the Difference Between Vanilla and French Vanilla Ice Cream?
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While you’re browsing the ice cream aisle, you may find yourself wondering, “What’s so French about French vanilla?” The name may sound a little fancier than just plain ol’ “vanilla,” but it has nothing to do with the origin of the vanilla itself. (Vanilla is a tropical plant that grows near the equator.)

The difference comes down to eggs, as The Kitchn explains. You may have already noticed that French vanilla ice cream tends to have a slightly yellow coloring, while plain vanilla ice cream is more white. That’s because the base of French vanilla ice cream has egg yolks added to it.

The eggs give French vanilla ice cream both a smoother consistency and that subtle yellow color. The taste is a little richer and a little more complex than a regular vanilla, which is made with just milk and cream and is sometimes called “Philadelphia-style vanilla” ice cream.

In an interview with NPR’s All Things Considered in 2010—when Baskin-Robbins decided to eliminate French Vanilla from its ice cream lineup—ice cream industry consultant Bruce Tharp noted that French vanilla ice cream may date back to at least colonial times, when Thomas Jefferson and George Washington both used ice cream recipes that included egg yolks.

Jefferson likely acquired his taste for ice cream during the time he spent in France, and served it to his White House guests several times. His family’s ice cream recipe—which calls for six egg yolks per quart of cream—seems to have originated with his French butler.

But everyone already knew to trust the French with their dairy products, right?

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