Chien-Shiung Wu (1912-1997, Chinese-born American physicist, whose nicknames included the “First Lady of Physics”, “Chinese Marie Curie,” and “Madame Wu”) came up with a truly beautiful experiment to test whether the weak force conserves parity (whether beta decay would be the same if reflected in the mirror). In my print on the left I show Mme. Wu in her lab and a schematic diagram in the box of her beautiful experiment in the box. On the right I show her reflection, as in the mirror, and in the box I show the mirror reflection of the experimental set-up and the shocking result, that the reaction is not the mirror opposite. The print is in an edition of 10 printed on ivory Japanese kozo (or mulberry) paper, 12.3 inches by 12.5 inches (31.2 cm by 31.8 cm).
In 1956, theoretical physicists Tsung Dao Lee and Chen Ning Yang suggested that perhaps the weak force might not be the same ‘through the looking-glass’. The idea that the “Law of Conservation of Parity” might be broken was hard to believe. The laws of physics are the same in the mirror for anything else. Face a friend, as in the mirror. If you drop a pencil from your right hand, and your friend mirrors you and drops a pencil with his or her left, the pencils will fall at the same rate. This is because Parity is conserved by the force of gravity - as it is with the electromagnetic force and even the strong (nuclear) force within atomic nuclei. Lee and Yang pointed out that no one had checked to make sure that the weak force, which controls beta decay in radioactive materials, also conserves parity. Lee convinced the brilliant experimentalist to test this.
Madame Wu did a subtle and technically difficult experiment will her collaborators which is shown schematically in the print. She took Cobalt-60 (shown as the cobalt blue sphere in the box), which is radioactive. Its neutrons spontaneously give off electrons and become protons. The electrons are the tiny blue dots. On the left, we see that the Cobalt-60 in an electromagnet (a wire wrapped metal horseshoe with a source of power). Because of the spiral-wrap of the wire, we know that the North pole of the magnet will be on the bottom (you can figure this out by mimicking the curl of the wire with the fingers of your right hand and look at the direction your thumb points). It turns out that the emitted electrons are given off preferentially towards the North pole.
Next, she reversed the set-up as in the mirror. On the right you see the horseshoe and wire spiral reflected. If you use your right hand to check the direction of the magnet field, you’ll see that it is the opposite way; the North pole is now on the top. It turns out that the electrons are preferentially emitted upwards toward the North pole. Thus, beta decay IS NOT the same in the mirror! Madame Wu showed that a “Law” of physics did not hold! This result was staggering and shocked the physics world. Lee and Yang won the Nobel prize for their theoretical work. Many physicists thought Mme. Wu should have been included in this win.- minouette on etsy, via joelleworkman
this artist has a lot of great science-related prints! I chose to post this particular one in the hope that I will eventually understand it.
Whoa, it is pretty rare for me to not even have heard of a lady physicist, especially one this boss. I…really want this print now.
![selchieproductions:
Ghana calls an end to tyrannical reign of the Queen’s English
© Afua Hirsch, reporting from Accra for the Guardian
Voice of colonialism gives way to local form of English that’s ‘flexible and fun’ as opposed to giving language ‘a good beating’
Question: “Have you eat?” Reply: “No I go eat after small small.” This is just one of the turns of phrase Ghanaians employ, in the words of one local commentator, “to give the Queen’s English a good beating”.
But as Ghanaians join their west African neighbours – following the examples of Nigerian Pidgin and Sierra Leonean Krio – in speaking their inherited colonial tongue with growing creative licence, a row is breaking out about what really is the proper way to speak English.
On one side of the fence are the old-school Ghanaians who were taught throughout their education to mimic received pronunciation – or BBC English, as it is popularly known – with varying degrees of success.
On the other side, a backlash is growing against the old mentality of equating a British accent with prestige. Now the practice has a new acronym, LAFA, or “locally acquired foreign accent”, and attracts derision rather than praise.
“In the past we have seen people in Ghana try to mimic the Queen’s English, speaking in a way that doesn’t sound natural. They think it sounds prestigious, but frankly it sounds like they are overdoing it,” said Professor Kofi Agyekum, head of linguistics at the University of Ghana.
“There has been a significant change now, away from those who think sounding English is prestigious, towards those who value being multilingual, who would never neglect our mother tongues, and who are happy to sound Ghanaian when we speak English.”
Ghana has nine indigenous languages that are officially sponsored by the government, including Akan languages spoken widely in the south. A further 26 languages are officially recognised and at least double that number are also spoken. Unlike its francophone neighbours, which were forced under colonialism to teach only in French, Ghana has alwaysmaintained the use of African languages in its primary school education.
But the idea that sounding “British” carries prestige also has a long history in Ghanaian society, manifesting itself in the country’s struggle for independence in the 1940s and 50s, when an ideological difference emerged between an Oxbridge-educated Ghanaian elite and more radical, left-leaning leaders.
Now, more than 50 years later and more than 200 years after the abolition of the slave trade saw an influx of Christian missionaries imposing British language and literature, Ghanaians are embracing a new standard: Ghanaian English.
“The idea that intelligence is linked to English pronunciation is a legacy from colonial thinking,” said Delalorm Semabia, 25, a Ghanaian blogger. “People used to think that if you speak like the British then you are as intelligent as the British. But now we are waking up to the fact that we have great people here who have never stepped outside the borders.”
“The best example of Ghanaian English on the international scene is [former UN secretary general] Kofi Annan’s clear diction,” said Ghanaian columnist Kofi Amenyo. “The man maintains the Ghanaian features in his pronunciation and yet succeeds in being easily understood by the peoples of the world.”
For Ghana’s younger generation, though, the move towards Ghanaian English is less about elder statesmen, and more about music and technology.
“In the 90s many local artists wanted to sound like Usher or Jay-Z, but now they are taking local names and branding themselves locally,” said Semabia. “Little by little, people are embracing the use of our own languages – for example, now we can Google in Akan.
“For us, English is our language – we want to break away from the old strictures, to personalise it, mix it with our local languages, and have fun with it. The whole point of language is that it’s supposed to be flexible and it’s meant to be fun.”](http://25.media.tumblr.com/tumblr_m2h8ikjqJG1qa9j9oo1_r1_500.png)




