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Could Cockroaches Really Survive a Nuclear War?

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Some say the world will end in fire, some say in ice; still others say in a nuclear apocalypse that will annihilate humanity while leaving cockroaches intact. It’s an unhappy picture, homo sapiens being completely wiped out by its own technology as the little pests inherit the Earth, but is the possibility fact, or just science fiction?

Unfortunately, it looks like the bugs win this one. They’ve already survived one nuclear attack: The cockroach survival theory surfaced in the wake of the 1945 atomic bombings at Hiroshima and Nagasaki, when reports began to circulate that the only signs of life remaining between the two cities were cockroaches scurrying among the ruins. With that kind of evidence, it’s reasonable enough to infer that even more nuclear weapons won’t be enough to keep them down, but it always helps to test a hypothesis. As usual, that’s where the Mythbusters stepped in

The Discovery Channel team conducted an experiment on German cockroaches to see just how much radiation they can stand before kicking the tiny bucket, and it’s a lot—more than we frail humans can handle, for sure. A month after their initial exposure to 1000 radon units (rads) of cobalt 60—an amount sufficient to kill a human in just 10 minutes of exposure—about half of the cockroach sample was still alive and thriving, which is all the more impressive considering the normal mortality rate of insects with only a 6-to-9-month life span. The second condition upped the dose of radiation to 10,000 rads, about the equivalent amount of exposure that would result from an atomic bomb, and 10 percent of the cockroaches were still around to tell the tale a month later. The 100,000 rads condition, thankfully, proved that at least cockroaches aren’t invincible: None of them made it through, which would be more tragic if they didn’t still possess superhuman levels of radiation immunity.

Detractors from the theory that roaches will someday rule the Earth don’t disagree with the findings that the little creepy-crawlies would easily outlive us after nuclear fallout; their argument is that there are other, even more radiation-resistant insects out there. Wood-boring insects, as well as their eggs, can survive exposure to as much as 68,000 rads, while it would take about 64,000 to take out the common fruit fly. The Habrobracon, a type of parasitic wasp, easily takes the radiation-resistance championship with its ability to survive up to 180,000 rads—somewhere around 200 times as much resistance as any human possesses.

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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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