Random Quarks

Random quarks of information of relevance to me and hopefully to the random reader of this blog. You may encounter posts on math, science, history, film noir, baseball, economics, and whatever else catches my eye.
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Your analysis may be top notch, but if you don’t communicate it clearly it’s worthless. Read this short blog piece.

Apple today (28 August 2014) issued media invitations to the previously rumored September 9 event where the company is expected to show off not only the iPhone 6 but also its first wearable device, popularly referred to as the iWatch. The invitations carry the tagline “Wish we could say more.

Beauty and Brains

Maggie Bridges realizes beauty pageants may not be the first thing you might associate with a Georgia Tech student.

“I feel like being a female at Tech, it’s kind of your duty to break stereotypes.”

While she busts down those stereotypes in preparations for the Miss America pageant in September, she has built up a wide network of support.

“I’ve had an incredible response. I’m so thankful that our school has been so supportive,” she explains.

Bridges is well known across campus. She has served as a campus tour guide welcoming potential students and as a student ambassador. She says it’s been the perfect opportunity to share her love of Georgia Tech with others.

http://www.news.gatech.edu/features/yellow-jacket-competing-miss-america-title 

How it Works: F-35 High Angle of Attack Testing

For every student who doesn’t care much for Geometry, there’s a fighter pilot who ‘gets’ its importance. Angles and equations determine speed and position in modern air combat. They become the difference between the ‘quick’ and the ‘dead’ once the fight is engaged. The 5th Generation tactical fighter aircraft men and women will operate in the coming decades must be able to handle the toughest flight regimes for mission success and survival.
Flying at high angles of attack (AoA), or “High Alpha,” a modern fighter aircraft gains enhanced nose-pointing capability, which allows the pilot to track and acquire enemy aircraft in aerial combat. The ability to accurately and rapidly point their aircraft’s nose is key to outmaneuvering their enemy, while locking on to them with their radar or heat-seeking missiles to take the decisive shot, most likely at a beyond-visual range.
‘Angle of Attack’ is the angle between an aircraft wing’s chord line, or the imaginary straight line joining the wing’s leading and trailing edges, and the aircraft’s flight path. It is not to be confused with the relation of the aircraft to the Earth as this is called the attitude, which is seldom, if ever, the same as the angle of attack. When the angle is small, the aircraft is said to be at a low angle of attack. When the angle is large, the aircraft is said to be at a high angle of attack. Two variables can change the amount of lift generated by a wing in a given configuration: the speed of air flowing over the airfoil and the angle of attack. Some military aircraft are able to achieve very high angles of attack, but at the cost of drag. This provides the aircraft with great agility, although such maneuvers slow the aircraft down.
The aircraft, when pushed beyond its control, can seem to defy the laws of physics and the principles of flight. The inadvertent loss of control at high angles of attack happens frequently and the aircraft and pilot can be killed due to their failure to recover from out-of-control flight conditions. ‘Departures’ from controlled flight may occur unintentionally in high-G maneuvers (aka “pulling Gs”). The gravitational load bearing on the pilot can cause him or her to pass out from the rapid onset as it drains the blood flow to their brain, removing oxygen. It could happen from a nose-high deceleration to zero airspeed in trying to gain the geometric advantage over their enemy in combat maneuvering. Or a steep spiral may be mistaken to be a spin, causing the recovery flight control surfaces to be misapplied. Whatever the circumstances, departures from controlled flight all too often end in catastrophe. For this reason, pilots must be familiar with every facet of high angle of attack flying and their aircraft must be checked out to the limits of its endurance.
The F-35’s high AoA testing pushes the aircraft beyond both the positive and negative maximum command limits, including intentionally putting the aircraft out of control in several configurations. This includes initially flying in the stealthy ‘clean’ wing configuration, followed by testing with external air-to-air pylons and missiles, and then with open weapon bay doors, all creating additional drag on the aircraft.
The F-35’s high angle of attack testing began in late October 2012, with the aircraft pushing to its production AoA limit of 50 degrees nose high. Test pilots take the aircraft beyond this limit to evaluate its characteristics in recovering from out-of-control flight conditions.
“High AoA testing produces some of the most challenging environments for the engine because the intake gets bad air,” explained David Nelson, lead F-35 test pilot for Lockheed Martin at the U.S. Air Force Flight Test Center at Edwards AFB, California. “The bad air creates a potential for producing a flameout, which is basically an engine shutdown. For that reason, air start testing preceded high AoA testing.”
For all testing, recovery from ‘out of control’ flight has been 100 percent successful without the use of the spin recovery chute, which was installed to maximize safety.

How it Works: F-35 High Angle of Attack Testing

For every student who doesn’t care much for Geometry, there’s a fighter pilot who ‘gets’ its importance. Angles and equations determine speed and position in modern air combat. They become the difference between the ‘quick’ and the ‘dead’ once the fight is engaged. The 5th Generation tactical fighter aircraft men and women will operate in the coming decades must be able to handle the toughest flight regimes for mission success and survival.
Flying at high angles of attack (AoA), or “High Alpha,” a modern fighter aircraft gains enhanced nose-pointing capability, which allows the pilot to track and acquire enemy aircraft in aerial combat. The ability to accurately and rapidly point their aircraft’s nose is key to outmaneuvering their enemy, while locking on to them with their radar or heat-seeking missiles to take the decisive shot, most likely at a beyond-visual range.
‘Angle of Attack’ is the angle between an aircraft wing’s chord line, or the imaginary straight line joining the wing’s leading and trailing edges, and the aircraft’s flight path. It is not to be confused with the relation of the aircraft to the Earth as this is called the attitude, which is seldom, if ever, the same as the angle of attack. When the angle is small, the aircraft is said to be at a low angle of attack. When the angle is large, the aircraft is said to be at a high angle of attack. Two variables can change the amount of lift generated by a wing in a given configuration: the speed of air flowing over the airfoil and the angle of attack. Some military aircraft are able to achieve very high angles of attack, but at the cost of drag. This provides the aircraft with great agility, although such maneuvers slow the aircraft down.
The aircraft, when pushed beyond its control, can seem to defy the laws of physics and the principles of flight. The inadvertent loss of control at high angles of attack happens frequently and the aircraft and pilot can be killed due to their failure to recover from out-of-control flight conditions. ‘Departures’ from controlled flight may occur unintentionally in high-G maneuvers (aka “pulling Gs”). The gravitational load bearing on the pilot can cause him or her to pass out from the rapid onset as it drains the blood flow to their brain, removing oxygen. It could happen from a nose-high deceleration to zero airspeed in trying to gain the geometric advantage over their enemy in combat maneuvering. Or a steep spiral may be mistaken to be a spin, causing the recovery flight control surfaces to be misapplied. Whatever the circumstances, departures from controlled flight all too often end in catastrophe. For this reason, pilots must be familiar with every facet of high angle of attack flying and their aircraft must be checked out to the limits of its endurance.
The F-35’s high AoA testing pushes the aircraft beyond both the positive and negative maximum command limits, including intentionally putting the aircraft out of control in several configurations. This includes initially flying in the stealthy ‘clean’ wing configuration, followed by testing with external air-to-air pylons and missiles, and then with open weapon bay doors, all creating additional drag on the aircraft.
The F-35’s high angle of attack testing began in late October 2012, with the aircraft pushing to its production AoA limit of 50 degrees nose high. Test pilots take the aircraft beyond this limit to evaluate its characteristics in recovering from out-of-control flight conditions.
“High AoA testing produces some of the most challenging environments for the engine because the intake gets bad air,” explained David Nelson, lead F-35 test pilot for Lockheed Martin at the U.S. Air Force Flight Test Center at Edwards AFB, California. “The bad air creates a potential for producing a flameout, which is basically an engine shutdown. For that reason, air start testing preceded high AoA testing.”
For all testing, recovery from ‘out of control’ flight has been 100 percent successful without the use of the spin recovery chute, which was installed to maximize safety.

wjsginternetradio:

Celtic Woman - Amazing Grace

If you’ve not been to one of their concerts, you are missing something special.

(via lisakellyfan)

The brachistochrone

This animation is about one of the most significant problems in the history of mathematics: the brachistochrone challenge.

If a ball is to roll down a ramp which connects two points, what must be the shape of the ramp’s curve be, such that the descent time is a minimum?

Intuition says that it should be a straight line. That would minimize the distance, but the minimum time happens when the ramp curve is the one shown: a cycloid.

Johann Bernoulli posed the problem to the mathematicians of Europe in 1696, and ultimately, several found the solution. However, a new branch of mathematics, calculus of variations, had to be invented to deal with such problems. Today, calculus of variations is vital in quantum mechanics and other fields.

This is fascinating. I imagine some of this is used in the mathematics of roller coasters.

(via curiosamathematica)

cobra-23:

Wow…

(via militarymom)

asapscience:

Joke via badsciencejokes

And the statistician says the sample size is too small to draw any statistically significant conclusions about the population under study.

(via likeaphysicist)

The origin of the animation. Well played.

twocubes:

anyways, here’s an explanation of why that one thing is true

hyrodium:

Inspired by this twocubes’ post and asked to make a animation of it, I made a gif.

Sweet!

utnereader:

Class War Continues

Can a maximum wage help bridge the income inequality gap?

This idea is horrifying. Who decides how much is enough? How much innovation would be stifled? Unemployment would likely rise faster than one can imagine.

staceythinx:

These space colony concept drawings were the result of collaboration between Princeton physicist Gerard O’Neill, the NASA Ames Research Center and Stanford University in the 1970’s. They held a series of space colony summer studies which explored the possibilities of humans living in giant orbiting spaceships. 

I wonder how many generations before we arrive.

(via house-of-gnar)