BHL Book Feature: The Birds Of Singapore Island

Kilroy Was Here!

He’s engraved in stone in the National World War II Memorial in Washington, DC – back in a small alcove where very few people have seen it. For the WWII generation, this will bring back memories. For younger folks, it’s a bit of trivia that is an intrinsic part of American history and legend.

Anyone born between 1913 to about 1950, is very familiar with Kilroy. No one knew why he was so well known….but everybody seemed to get into it. It was the fad of its time!

          At the National World War II Memorial in Washington, DC

So who was Kilroy?

In 1946 the American Transit Association, through its radio program, “Speak to America,” sponsored a nationwide contest to find the real Kilroy….now a larger-than-life legend of just-ended World War II….offering a prize of a real trolley car to the person who could prove himself to be the genuine article.

Almost 40 men stepped forward to make that claim, but only James Kilroy from Halifax, Massachusetts, had credible and verifiable evidence of his identity.

“Kilroy” was a 46-year old shipyard worker during World War II (1941-1945) who worked as a quality assurance checker at the Fore River Shipyard in Quincy, Massachusetts (a major shipbuilder for the United States Navy for a century until the 1980s).  

His job was to go around and check on the number of rivets completed. (Rivets held ships together before the advent of modern welding techniques.) Riveters were on piece work wages….so they got paid by the rivet. He would count a block of rivets and put a check mark in semi-waxed lumber chalk (similar to crayon), so the rivets wouldn’t be counted more than once.

                                     A warship hull with rivets

When Kilroy went off duty, the riveters would surreptitiously erase the mark. Later, an off-shift inspector would come through and count the rivets a second time, resulting in double pay for the riveters!

One day Kilroy’s boss called him into his office. The foreman was upset about unusually high wages being “earned” by riveters, and asked him to investigate. It was then he realized what had been going on. 

The tight spaces he had to crawl in to check the rivets didn’t lend themselves to lugging around a paint can and brush, so Kilroy decided to stick with the waxy chalk. He continued to put his check mark on each job he inspected, but added ”KILROY WAS HERE!“ in king-sized letters next to the check….and eventually added the sketch of the guy with the long nose peering over the fence….and that became part of the Kilroy message.

   Kilroy’s original shipyard inspection “trademark” during World War II

Once he did that, the riveters stopped trying to wipe away his marks.

Ordinarily the rivets and chalk marks would have been covered up with paint. With World War II on in full swing, however, ships were leaving the Quincy Yard so fast that there wasn’t time to paint them. As a result, Kilroy’s inspection “trademark” was seen by thousands of servicemen who boarded the troopships the yard produced.

His message apparently rang a bell with the servicemen, because they picked it up and spread it all over the European and the Pacific war zones.

Before war’s end, “Kilroy” had been here, there, and everywhere on the long hauls to Berlin and Tokyo. 

To the troops outbound in those ships, however, he was a complete mystery; all they knew for sure was that someone named Kilroy had “been there first.” As a joke, U.S. servicemen began placing the graffiti wherever they landed, claiming it was already there when they arrived.

As the World War II wore on, the legend grew. Underwater demolition teams routinely sneaked ashore on Japanese-held islands in the Pacific to map the terrain for coming invasions by U.S. troops (and thus, presumably, were the first GI’s there). On one occasion, however, they reported seeing enemy troops painting over the Kilroy logo!

Kilroy became the U.S. super-GI who had always “already been” wherever GIs went. It became a challenge to place the logo in the most unlikely places imaginable. (It is said to now be atop Mt. Everest, the Statue of Liberty, the underside of the Arc de Triomphe in Paris, and even scrawled in the dust on the moon by the American astronauts who walked there between 1969 and 1972.

In 1945, as World War II was ending, an outhouse was built for the exclusive use of Allied leaders Harry Truman, Joseph Stalin, and Winston Churchill at the Potsdam Conference. It’s first occupant was Stalin, who emerged and asked his aide (in Russian), “Who is Kilroy?”

To help prove his authenticity in 1946, James Kilroy brought along officials from the shipyard and some of the riveters. He won the trolley car….which he attached to the Kilroy home and used to provide living quarters for six of the family’s nine children….thereby solving what had become an acute housing crisis for the Kilroys.

                     The new addition to the Kilroy family home.

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And the tradition continues into the 21st century…

In 2011 outside the now-late-Osama Bin Laden’s hideaway house in Abbottabad, Pakistan….shortly after the al-Qaida-terrorist was killed by U.S. Navy SEALs. 

>>Note: The Kilroy graffiti on the southwest wall of the Bin Laden compound pictured above was real (not digitally altered with Microsoft Paint, as postulated by some). The entire compound was leveled in 2012 for redevelopment by a Pakistani company as an amusement park….and to avoid it becoming a shrine to Bin Laden’s nefarious memory.

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A personal note….

My Dad’s trademark signature on cards, letters and notes to my sisters and I for the first 50 or so years of our lives (until we lost him to cancer) was to add the image of “Kilroy” at the end. We kids never ceased to get a thrill out of this….even as we evolved into adulthood. 

To this day, the “Kilroy” image brings back a vivid image of my awesome Dad into my head….and my heart!

Dad: This one’s for you!

12 snipers from the Soviet 3rd Shock Army with 775 confirmed kills. Germany, May 4th 1945.

via reddit

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CHAUVET CAVE: 

THE  Chauvet Cave (also known as the Chauvet-Pont-d’Arc Cave) is a Palaeolithic cave situated near Vallon-Pont-d’Arc in the Ardèche region of southern France that houses impeccably preserved, exquisite examples of prehistoric art. 

Now reliably dated to between c. 33,000 and c. 30,000 years ago, the numerous and diverse animals that dot the interior walls of the cave – both painted and engraved – show such high artistic quality that they were initially thought to have been closer in age to the similarly stunning, but much younger art in caves such as the Lascaux Cave. Its age and artistry have made us reconsider the story of art as well as the capabilities of these humans. The cave has been granted UNESCO World Heritage status.

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Article by Emma Groeneveld on AHE

The math trick that college will never teach you! : Parametric Integration

Parametric integration is one such technique that once you are made aware of it, you will never for the love of god forget it. It goes by many names : ‘Differentiation under the Integral sign’, ‘Feynman’s famous trick’ , ‘Parametric Integration’ and so on.

Let me demonstrate :

Now this integral might seem familiar to you if you have taken a calculus course before and to evaluate it is rather simple as well.

Knowing this you can do lots of crazy stuff. Lets differentiate this expression wrt to the parameter in the integral – s (Hence the name parametric integration ). i.e 

Look at that, by simple differentiation we have obtained the expression for another integral. How cool is that! It gets even better.

Lets differentiate it once more: 

.

.

.

If you keep on differentiating the expression n times, one gets this : 

Now substituting the value of s to be 1, we obtain the following integral expression for the factorial. This is known as the gamma function.

There are lots of ways to derive the above expression for the gamma function, but parametric integration is in my opinion the most subtle way to arrive at it. :D

This is a really powerful technique and I strong suggest that if you have taken calculus, then please do read this article.

Have a great day!

EDIT:  It had to be gamma(n+1) not gamma(n) .Thank you @mattchelldavis

The anime ‘Romeo’s Blue Skies’ is based on a book about a true event which happened in the south of Switzerland unti the 19th century: young boys being sold to Milano to work there as chimney sweepers. There is also a German movie about it called ‘Die Schwarzen Brüder’ [the Black Brothers]. You can watch the trailer here

Could you explain this tfw no ZF joke? I really dont get it... :D

Get ready for a long explanation! For everyone’s reference, the joke (supplied by @awesomepus​) was:

Q: What did the mathematician say when he encountered the paradoxes of naive set theory?A: tfw no ZF

You probably already know the ‘tfw no gf’ (that feel when no girlfriend) meme, which dates to 2010. I’m assuming you’re asking about the ZF part.

Mathematically, ZF is a reference to Zermelo-Fraenkel set theory, which is a set of axioms commonly accepted by mathematicians as the foundation of modern mathematics. As you probably know if you’ve taken geometry, axioms are super important: they are basic assumptions we make about the world we’re working in, and they have serious implications for what we can and can’t do in that world. 

For example, if you don’t assume the Parallel Postulate (that consecutive interior angle measures between two parallel lines and a transversal sum to 180°, or twice the size of a right angle), you can’t prove the Triangle Angle Sum Theorem (that the sum of the angle measures in any triangle is also 180°). It’s not that the Triangle Angle Sum Theorem theorem is not true without the Parallel Postulate — simply that it is unprovable, or put differently, neither true nor false, without that Postulate. Asking whether the Triangle Angle Sum Theorem is true without the Parallel Postulate is really a meaningless question, mathematically. But we understand that, in Euclidean geometry (not in curved geometries), both the postulate and the theorem are “true” in the sense that we have good reason to believe them (e.g., measuring lots of angles in physical parallel lines and triangles). Clearly, the axioms we choose are important.

Now, in the late 19th and early 20th century, mathematicians and logicians were interested in understanding the underpinnings of the basic structures we use in math — sets, or “collections,” being one of them, and arithmetic being another. In short, they were trying to come up with an axiomatic set theory. Cantor and Frege were doing a lot of this work, and made good progress using everyday language. They said that a set is any definable collection of elements, where “definable” means to provide a comprehension (a term you’re familiar with if you program in Python), or rule by which the set is constructed.

But along came Bertrand Russell. He pointed out a big problem in Cantor and Frege’s work, which is now called Russell’s paradox. Essentially, he made the following argument:

Y’all are saying any definable collection is a set. Well, how about this set: R, the set of all sets not contained within themselves. This is, according to you, a valid set, because I gave that comprehension. Now, R is not contained within itself, naturally: if it is contained within itself, then it being an element is a violation of my construction of R in the first place. But R must be contained within itself: if it’s not an element of itself, then it is a set that does not contain itself, and therefore it is an element of itself. So we have that R ∈ R and also R ∉ R. This is a contradiction! Obviously, your theory is seriously messed up.

This paradox is inherently a part of Cantor and Frege’s set theory — it shows that their system was inconsistent (with itself). As Qiaochu Yuan explains over at Quora, the problem is exactly what Russell pointed out: unrestricted comprehension — the idea that you can get away with defining any set you like simply by giving a comprehension. Zermelo and Fraenkel then came along and offered up a system of axioms that formalizes Cantor and Frege’s work logically, and restricts comprehension. This is called Zermelo-Fraenkel set theory (or ZF), and it is consistent (with itself). Cantor and Frege’s work was then retroactively called naive set theory, because it was, of course, pretty childish:

There are two more things worth knowing about axiomatic systems in mathematics. First, some people combine Zermelo-Fraenkel set theory with the Axiom of Choice¹, resulting in a set theory called ZFC. This is widely used as a standard by mathematicians today. Second, Gödel proved in 1931 that no system of axioms for arithmetic can be both consistent and complete — in every consistent axiomatization, there are “true” statements that are unprovable. Or put another way: in every consistent axiomatic system, there are statements which you can neither prove nor disprove.For example, in ZF, the Axiom of Choice is unprovable — you can’t prove it from the axioms in ZF. And in both ZF and ZFC, the continuum hypothesis² is unprovable.³ Gödel’s result is called the incompleteness theorem, and it’s a little depressing, because it means you can’t have any good logical basis for all of mathematics (but don’t tell anyone that, or we might all be out of a job). Luckily, ZF or ZFC has been good enough for virtually all of the mathematics we as a species have done so far!

The joke is that, when confronted with Russell’s paradox in naive set theory, the mathematician despairs, and wishes he could use Zermelo-Fraenkel set theory instead — ‘that feel when no ZF.’

I thought the joke was incredibly funny, specifically because of the reference to ‘tfw no gf’ and the implication that mathematicians romanticize ZF (which we totally do). I’ve definitely borrowed the joke to impress friends and faculty in the math department…a sort of fringe benefit of having a math blog.

– CJH

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(Image caption: This type of electrocorticography (ECoG) grid, which is implanted in patients about to undergo epilepsy surgery, enables researchers to record and transmit electrical signals to and from the surface of the brain. Credit: Mark Stone/University of Washington)

For the first time in humans, researchers use brain surface stimulation to provide ‘touch’ feedback to direct movement

In the quest to restore movement to people with spinal cord injuries, researchers have focused on getting brain signals to disconnected nerves and muscles that no longer receive messages that would spur them to move.

But grasping a cup or brushing hair or cooking a meal requires other feedback that has been lost in amputees and individuals with paralysis — a sense of touch. The brain needs information from a fingertip or limb or external device to understand how firmly a person is gripping or how much pressure is needed to perform everyday tasks.

Now, University of Washington researchers at the National Science Foundation Center for Sensorimotor Neural Engineering (CSNE) have used direct stimulation of the human brain surface to provide basic sensory feedback through artificial electrical signals, enabling a patient to control movement while performing a simple task: opening and closing his hand.

It’s a first step towards developing “closed loop,” bi-directional brain-computer interfaces (BBCIs) that enable two-way communication between parts of the nervous system. They would also allow the brain to directly control external prosthetics or other devices that can enhance movement — or even reanimate a paralyzed limb — while getting sensory feedback.

The results of this research will be published in the Oct.-Dec. 2016 issue of IEEE Transactions on Haptics. An early-access version of the paper is available online.

“We were able to provide a baseline degree of sensory feedback by direct cortical stimulation of the brain,” said lead author and UW bioengineering doctoral student Jeneva Cronin. “To our knowledge this is the first time it’s been done in a human patient who was awake and performing a motor task that depended on that feedback.”

The team of bioengineers, computer scientists and medical researchers from the CSNE and UW’s GRIDLab used electrical signals of different current intensities, dictated by the position of the patient’s hand measured by a glove he wore, to stimulate the patient’s brain that had been implanted with electrocorticographic (ECoG) electrodes. The patient then used those artificial signals delivered to the brain to “sense” how the researchers wanted him to move his hand.

“The question is: Can humans use novel electrical sensations that they’ve never felt before, perceive them at different levels and use this to do a task? And the answer seems to be yes,” said co-author and UW bioengineering doctoral student James Wu. “Whether this type of sensation can be as diverse as the textures and feelings that we can sense tactilely is an open question.”

They would also allow the brain to directly control external prosthetics or other devices that can enhance movement — or even reanimate a paralyzed limb — while getting sensory feedback.

It’s difficult for a person to mimic natural movements — whether using a prosthetic device or a limb that has become disconnected from the brain by neurological injury — without sensation. Though there are devices to assist patients with paralysis or who have undergone amputations with basic function, being able to feel again ranks highly on their priorities, researchers said.

Restoring this sensory feedback requires developing an “artificial” language of electrical signals that the brain can interpret as sensation and incorporate as useful feedback when performing a task.

The UW CSNE team frequently works with patients about to undergo epilepsy surgery who have recently had an ECoG electrode grid implanted on the surface of their brain. For several days or weeks, doctors constantly monitor their brain activity to pinpoint the origin of their seizures before operating.

By consenting to participate in research studies during this period when their brain is “wired,” these patients enable researchers to answer basic neurological questions. They can test which parts of the brain are activated during different behaviors, what happens when a certain region of the brain’s cortex is stimulated and even how to induce brain plasticity to promote rehabilitation and healing across damaged areas.

The potential to use ECoG electrodes implanted on the surface of the brain in future prosthetic or rehabilitative applications offers several advantages — the signals are stronger and more accurate than sensors placed on the scalp, but less invasive than ones that penetrate the brain, as in a recent study by University of Pittsburgh researchers.

In the UW study, three patients wore a glove embedded with sensors that provided data about where their fingers and joints were positioned. They were asked to stay within a target position somewhere between having their hands open and closed without being able to see what that target position was. The only feedback they received about the target hand position was artificial electrical data delivered by the research team.

When their hands opened too far, they received no electrical stimulus to the brain. When their hand was too closed – similar to squeezing something too hard – the electrical stimuli was provided at a higher intensity.

One patient was able to achieve accuracies in reaching the target position well above chance when receiving the electrical feedback. Performance dropped when the patient received random signals regardless of hand position, suggesting that the subject had been using the artificial sensory feedback to control hand movement.

Providing that artificial sensory feedback in a way that the brain can understand is key to developing prosthetics, implants or other neural devices that could restore a sense of position, touch or feeling in patients where that connection has been severed.

“Right now we’re using very primitive kinds of codes where we’re changing only frequency or intensity of the stimulation, but eventually it might be more like a symphony,” said co-author Rajesh Rao, CSNE director and UW professor of computer science & engineering.

“That’s what you’d need to do to have a very natural grip for tasks such as preparing a dish in the kitchen. When you want to pick up the salt shaker and all your ingredients, you need to exert just the right amount of pressure. Any day-to-day task like opening a cupboard or lifting a plate or breaking an egg requires this complex sensory feedback.”

Liu Chuyu was the first-born daughter of Emperor Xiaowu and his empress, during the Liu Song dynasty. Never heard of it? Neither had I. Lasting just 60 years in the 400s CE, it was one of the four southern kingdoms which succeeded the Eastern Jin Empire. While it was going, the Liu Song dynasty ruled most of southern China, but a string of incompetent or tyrannical emperors led to internal instability and the dynasty’s quick downfall.

Luckily for her, Liu Chuyu was born during a relatively stable period. Her father became Emperor Xiaowu by force, but his reign was more or less stable, and he died of natural causes when she was 17 or 18. The transition of power was bloodless and his son, Liu Chuyu’s younger brother, followed Emperor Xiaowu upon the throne.

Before he died, her father married her to He Ji, son of a prominent official. Liu Chuyu doesn’t seem to have been so happy about this. History records that when her brother left the palace she would often go to see him. One of those visits, Liu Chuyu said to him “While our genders are different, we are born of the same father. However, you have more than 10,000 women in your palaces, and I only have one husband, and this is unfair.” In response, her younger brother selected 30 young handsome men for her to keep. (Doesn’t it sound weird when put like that?) Liu Chuyu … enjoyed… them for a year before her brother was assassinated. Her uncle took the throne, denounced Liu Chuyu for her immorality, and ordered her to commit suicide. No more male harems for princesses.

It’s easy:  Form a triangle, then a hexagon, then a bicycle wheel

This is the general mechanism on how a spider spins its web (talk about engineering, right?). When an insect gets caught in its web, the vibrations caused by the insect is felt by the spider which then rushes to engulf its prey.

Now here is the trippy part ; This is the effect of drugs on the pattern of the web.

Hope you are having a great week. Have a good one!

* Spider spinning a web (video) (if you find a better full video let us know)

** Spiders on drugs -  NASA article ; Video