Dau Lun O Weithwyr G P Lloyd & Co, Dumballs Rd, Caerdydd, Gwneuthurwyr Coesau Pren I Offer, C. 1930,

On March 2, 1903 the Hotel Martha Washington became New York City’s first women-only hotel. Located on 30 East 30th Street, it served the growing population of professional women who otherwise struggled to find safe and socially acceptable lodging in the city. A far cry from the crowded boarding houses, this was a thoroughly modern operation housed in a twelve-story Renaissance Revival building that featured all the amenities, from a ladies’ tailor to electric lights. Upon opening, it was immediately popular, both with the women it served and with the curious onlookers who had a hard time coming to terms with the whole idea of the place.

George P. Hall & Son. Manhattan: Hotel Martha Washington. undated. photographic print. New-York Historical Society.  

Robert L. Bracklow. The Hotel Martha Washington. February 23, 1903. Glass negative. New-York Historical Society.

Superfluid Helium

It was previously thought that superfluid Helium would flow continuously without losing kinetic energy. Mathematicians at Newcastle University demonstrated that this is only the case on a surface completely smooth down to the scale of nanometers; and no surface is that smooth.

When a regular fluid like water is passing over a surface, friction creates a boundary layer that ‘sticks’ to surfaces. Just like a regular fluid, when superfluid Helium passes over a rough surface there is a boundary layer created. However the cause is very different. As superfluid Helium flows past a rough surface, mini tornados are created which tangle up and stick together creating a slow-moving boundary layer between the free-moving fluid and the surface. This lack of viscosity is one of the key features that define what a superfluid is and now we know why it still loses kinetic energy when passing over a rough surface.

Now we can use this information to help our efforts on applications of superfluids in precision measurement devices such as gyroscopes (I think this was on the Big Bang theory where they make a gyroscope using superfluid Helium that can maintain angular momentum indefinitely because it would flow across a smooth surface without losing kinetic energy) and as coolants.

Comedies Histories Tragedies

Mr William Shakespeare

London Iaggard and Blount 1623

Textual reprint of the First Folio published by J Wright 1807

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

In general I am a casual observer and usually do not make comments, especially since I am here to learn and have no background in linguistics. But in this case I feel strongly compelled to put my 2 cents' worth of thoughts in.

Although I cannot say that I am anything like fluent, I do have a reasonable amount of Mandarin Chinese and Japanese, and I have to say the first thing I thought when I saw this article was "ah". Because although I can see how katakana is derived from Chinese, using the rather restricted stroke combinations that is the basis of all Chinese characters, the same cannot be said for hiragana, because at the very least, squiggles do not exist in Chinese, at least by the time it was exported to Japan. What you might think are squiggles in Chinese are in fact just our possibly lazy, or perhaps more elegant way of writing, the way cursive would look compared to printed letters. Hirangana bears only a superficial resemblance to Chinese and always feels like it must have another source of inspiration.

Also keep in mind that Chinese was basically an imported language into Japan, and an attempt to shoehorn Japanese sounds into Chinese characters (which I think I can safely say did not sound the same) must have been unwieldy at best. In fact, today, Japanese pronouciations of kanji differ so much from the Chinese, and often their usage too, that I would use my knowledge of the characters only as a rough starting point as to what they might mean in Japanese.

Also, I looked up Kūkai, and, to cut a long story short, he was a Japanese Buddhist monk who went to China to study the sutras, and, to quote from the Wikipedia page directly:

Kūkai arrived back in Japan in 806 as the eighth Patriarch of Esoteric Buddhism, having learnt Sanskrit and its Siddhaṃ script, studied Indian Buddhism, as well as having studied the arts of Chinese calligraphy and poetry, all with recognized masters. He also arrived with a large number of texts, many of which were new to Japan and were esoteric in character, as well as several texts on the Sanskrit language and the Siddhaṃ script.

And a quick look at the Siddham script shows that it has its roots in the Aramaic alphabet.

This is the man to whom the invention of the kana system is attributed to, and if that is the case, I see a possible connection that is as not as far-fetched as it seems.

The History of Hiragana

In Japanese language, we have three types of letters, Kanji, Hiragana, Katakana.

Hiragana’s root is from old Ivrit and Palmyra letters.

The first column:  Phoenician alphabet The second column: Ostracon The third column: Old Aramaic The forth column: Imperial Aramaic The fifth column: Dead Sea scrolls The sixth column: Palmyrene script The seventh column: Palmyra

The first column: Hiragana The second column: Consonants The third column: Vowels The forth column: combined with the consonant and the vowel The fifth column: Sousho-tai (a hand writing style) The sixth column: Kanji

In slow motion, vortex rings can be truly stunning. This video shows two bubble rings underwater as they interact with one another. Upon approach, the two low-pressure vortex cores link up in what’s known as vortex reconnection. Note how the vortex rings split and reconnect in two places – not one. According to Helmholtz’s second theorem a vortex cannot end in a fluid–it must form a closed path (or end at a boundary); that’s why both sides come apart and together this way. After reconnection, waves ripple back and forth along the distorted vortex ring; these are known as Kelvin waves. Some of those perturbations bring two sides of the enlarged vortex ring too close to one another, causing a second vortex reconnection, which pinches off a smaller vortex ring. (Image source: A. Lawrence; submitted by Kam-Yung Soh)

Note: As with many viral images, locating a true source for this video is difficult. So far the closest to an original source I’ve found is the Instagram post linked above. If you know the original source, please let me know so that I can update the credit accordingly. Thanks!

On this day, 6th May 1840, the first adhesive postage stamp in the world, the Penny Black, came into official use in Great Britain.

It depicted a portrait of Queen Victoria and stamps continued with her image until her death in 1901.  All British stamps still show the monarch somewhere on the design. They are the only postage stamps in the world that do not indicate a country of origin; the monarch’s image symbolises the United Kingdom.       

The Penny Black lasted less than a year. A red cancellation was hard to see on the black design and the red ink was easy to remove; both made it possible to re-use cancelled stamps. In February 1841, the Treasury switched to the Penny Red and began using black ink for cancellations instead, which was more effective and harder to remove.

The State Library of New South Wales holds significant postage stamp collections, which include a number of penny black stamps -

Sir William Dixson Stamp Collection

1840 One Penny black Queen Victoria Recess printed Watermark Small Crown Imperf ( 1 mint, 3 used, 1 forgery )    and 

DP/M014 Series 02: Sir William Dixson Stamp Collection : Great Britain and Commonwealth Countries issued to 1952 Great Britain 1840

1840 One Penny black Recess printed Watermark Small Crown Imperf ( 6 used ) DP/M010 :- Box with miscellaneous items mounted on pages, numbered DP/M011 to DP/M127

Idempotence.

A term I’d always found intriguing, mostly because it’s such an unusual word. It’s a concept from mathematics and computer science but can be applied more generally—not that it often is. Basically, it’s an operation that, no matter how many times you do it, you’ll still get the same result, at least without doing other operations in between. A classic example would be view_your_bank_balance being idempotent, and withdraw_1000 not being idempotent.

HTs: @aidmcg and Ewan Silver who kept saying it

I am pretty sure that this cannot be true because I saw an ad from the corn industry that said high fructose corn syrup is good for you…

Fructose alters hundreds of brain genes, which can lead to a wide range of diseases

A range of diseases – from diabetes to cardiovascular disease, and from Alzheimer’s disease to attention deficit hyperactivity disorder – are linked to changes to genes in the brain. A new study by UCLA life scientists has found that hundreds of those genes can be damaged by fructose, a sugar that’s common in the Western diet, in a way that could lead to those diseases.

However, the researchers discovered good news as well: An omega-3 fatty acid known as docosahexaenoic acid, or DHA, seems to reverse the harmful changes produced by fructose.

“DHA changes not just one or two genes; it seems to push the entire gene pattern back to normal, which is remarkable,” said Xia Yang, a senior author of the study and a UCLA assistant professor of integrative biology and physiology. “And we can see why it has such a powerful effect.”

Qingying Meng, Zhe Ying, Emily Noble, Yuqi Zhao, Rahul Agrawal, Andrew Mikhail, Yumei Zhuang, Ethika Tyagi, Qing Zhang, Jae-Hyung Lee, Marco Morselli, Luz Orozco, Weilong Guo, Tina M. Kilts, Jun Zhu, Bin Zhang, Matteo Pellegrini, Xinshu Xiao, Marian F. Young, Fernando Gomez-Pinilla, Xia Yang. Systems Nutrigenomics Reveals Brain Gene Networks Linking Metabolic and Brain Disorders. EBioMedicine, 2016; DOI: 10.1016/j.ebiom.2016.04.008

Americans get most of their fructose in foods that are sweetened with high-fructose corn syrup, an inexpensive liquid sweetener made from corn starch, and from sweetened drinks, syrups, honey and desserts. The Department of Agriculture estimates that Americans consumed an average of about 27 pounds of high-fructose corn syrup in 2014.  Credit: © AlenKadr / Fotolia

The beautiful stone church at Gallarus, Dingle, Co. Kerry, Ireland. It’s circa 1000 years old