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Is There Such a Thing as Photographic Memory?

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The best early ‘90s children’s bookshelves were full of books about child detectives, from Nancy Drew to Encyclopedia Brown to Cam Jansen, the fifth grade super-sleuth with a photographic memory. She was called “Cam,” short for “camera,” because she would close her eyes and say, “click!” to instantly memorize every detail of a scene. It’s the kind of thing that seems too good to be true—a perfect fictional device endowing a fifth-grader with nearly foolproof crime-solving skills—but does anyone really have a memory as accurate as a camera?

The short answer, sadly, is no: “photographic memory” is mostly hype and hyperbole. Studies conducted on eidetic memory—the medical term for a super-accurate memory, and the examined phenomenon closest to what popular culture calls photographic memory—have varied in their diagnoses of savants like Stephen Wiltshire, whose feats of applied memorization include drawing entire city skylines unassisted after a brief helicopter ride above them. Despite claims that such diverse figures as physicist Nikola Tesla, composer Sergei Rachmaninoff, and Mr. T of A-Team fame (among others) possessed a photographic memory, scientists have understandably found it difficult to construct a standardized test for it. When documented memory experts like the yearly winners of the World Memory Championships make no secret of the techniques and conscious practice they use to assist their memorizations, it’s hard to determine the difference between a photographic memory and sheer hard work.

Eidetic memory, as distinct from photographic memory, is an uncommon but not unheard-of phenomenon, thought to occur in 2 percent to 15 percent of children. Presented with a 30-second view of an illustration on an easel, “eidetikers” are capable of vividly describing the image after its removal. They describe its details immediately, accurately, and in the present tense; their gaze glances around the empty easel as if the illustration still remains. The true test of their skill is a set of apparently random dots, and a second image shown an appropriate interval of time after the first; those with truly eidetic memories can recall both disparate images and mentally combine them to render a single, 3D image that would require normal viewers to use a stereoscopic viewer. The feat is a remarkable one, but even eidetic memories fade, and very few adults retain the childhood gift into their later years.

The possibility of photographic memory’s existence is fascinating, but has yet to be backed up by anything other than (admittedly incredible) anecdotal evidence. Even if a picture is worth a thousand words, it’s probably still best to use a camera to make sure you remember each one.

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Big Questions
Where Is the Hottest Place on Earth?
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The summer of 2017 will go down as an endurance test of sorts for the people of Phoenix, Arizona. The National Weather Service issued an extreme heat warning, and planes were grounded as a result of temperatures exceeding 120 degrees. (Heat affects air density, which in turn affects a plane’s lift.)

Despite those dire measures, Phoenix is not the hottest place on Earth. And it’s not even close.

That dubious honor was bestowed on the Lut Desert in Iran in 2005, when land temperatures were recorded at a staggering 159.3 degrees Fahrenheit. The remote area was off the grid—literally—for many years until satellites began to measure temperatures in areas that were either not well trafficked on foot or not measured with the proper instruments. Lut also measured record temperatures in 2004, 2006, 2007, and 2009.

Before satellites registered Lut as a contender, one of the hottest areas on Earth was thought to be El Azizia, Libya, where a 1922 measurement of 136 degrees stood as a record for decades. (Winds blowing from the nearby Sahara Desert contributed to the oppressive heat.)

While the World Meteorological Organization (WMO) acknowledged this reading as the hottest on record for years, they later declared that instrumentation problems and other concerns led to new doubts about the accuracy.

Naturally, declaring the hottest place on Earth might be about more than just a single isolated reading. If it’s consistency we’re after, then the appropriately-named Death Valley in California, where temperatures are consistently 90 degrees or above for roughly half the year and at least 100 degrees for 140 days annually, has to be a contender. A blistering temperature of 134 degrees was recorded there in 1913.

Both Death Valley and Libya were measured using air temperature readings, while Lut was taken from a land reading, making all three pretty valid contenders. These are not urban areas, and paving the hottest place on Earth with sidewalks would be a very, very bad idea. Temperatures as low as 95 degrees can cause blacktop and pavement to reach skin-scorching temperatures of 141 degrees.

There are always additional factors to consider beyond a temperature number, however. In 2015, Bandar Mahshahr in Iran recorded temperatures of 115 degrees but a heat index—what it feels like outside when accounting for significant humidity—of an astounding 163 degrees. That thought might be one of the few things able to cool Phoenix residents off.

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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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