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Why Does Getting Hit in the Testicles Hurt So Much?

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More than any other bodily injury, getting hit in the testicles is probably what every man dreads most. Of all the soft, fleshy spots on the human body, none register the same kind of incapacitating, end-of-the-world pain as the family jewels.

What causes such inconceivable pain? Well, for starters, a shot to the balls is just like any other physical strike to the body: because of nerves, it’s gonna hurt. Unlike most other parts of your body, though, your scrotum lacks protection in the form of bones, large muscle mass, and fat. The testes are just wee little glands, and they’re going to absorb the whole force of the blow all on their own.

Another thing that makes a ball shot so painful is the same thing that makes almost every other sensation down there so much fun. Your groin has a ridiculously high number of sensory nerve endings, and such generous innervation makes good and bad touches alike very noticeable sensations.

And the pain doesn’t just stay down there in the scrotum. It insists on radiating throughout the groin and up into the abdomen (and, psychically, out to every other dude standing within a few feet), leading to a weird stomach ache. This is the work of a phenomenon known as referred pain, which is when a sensation originating at one spot travels along a nerve root to other parts of the body and is perceived as happening there, too. It’s the same thing that’s going when you get an ice cream headache. In this case, the pain starts in your balls and travels up the perineal and pudendal nerves and the spermatic plexus, which cover real estate in the groin and abdomen, around the spine and even a little ways down into the anus, to make it feel like death has come for most of your lower body.

Location, Location, Location

Why is such a sensitive and delicate body part just hanging there in the open? The placement of the testicles is inconvenient, but absolutely necessary. The testes’ job is to produce sperm, and sperm are very fragile. They’re extremely sensitive to high and low temperatures, and must be kept away from the rest of the body and relatively exposed to maintain the right climate. They can handle human body temps for only one to four hours, or the average amount of time it takes them to travel through the female reproductive tract and fertilize an egg. Internal testes or any type of significant shielding for them would heat them up too much, too early and make them drop out of the race well before reaching the egg, rendering them useless.

The scrotum isn’t just a dumb sack swaying in the breeze, though. In deference to our genetic interests, our bodies subconsciously thermoregulate our balls by flexing the cremasteric muscle and drawing the scrotum up closer to the body when it gets too cold and dropping it when it’s hot. This optimized, on-the-fly sperm storage is precise enough that each testicle can be repositioned independent of its twin in order to get the temperature just right, explaining their sometimes asymmetrical dangle.

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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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