Quanta Physics World  December 2017

Seen and heard

Weird and wonderful stories from the world of physics

(Andrea Voß-Acker / ESA)

Gravitational waves make their mark

If you want to add a physics twist to your seasonal greetings cards, you now can thanks to Germany’s Federal Ministry of Finance. They have announced two new postage stamps that will go on sale in the country on 7 December. A 0.40 stamp will feature the European Space Agency’s Gaia satellite and will be the first German stamp to include a metallic coating. Gaia was launched in 2013 to measure the positions and distances of astronomical objects, including stars and planets as well as comets. A 0.70 stamp, meanwhile, depicts the gravitational waves that emerge from the collision of two black holes based on simulations carried out by researchers at the Albert Einstein Institute (AEI) in Potsdam, Germany. “The ministry did not announce whether letters equipped with the new gravitational-wave stamp will be transported at the speed of light,” quipped the AEI.

Zeroing in on the answer

How old is zero? That question has opened up a row between an international group of researchers and the University of Oxford after the Bodleian Library in Oxford noted that an ancient Indian text, known as the Bakhshali manuscript, had been dated to between 300 and 900 CE. The manuscript was discovered in 1881 in a field in Bakhshali, near Peshawar in present-day Pakistan, and was acquired by the library in 1902. The document includes arithmetic and was a manual for merchants trading across the Silk Road. The library noted that the text contained the oldest known written zero but it could not be classed as a “true” zero as it was only shown as a marker for an empty decimal place and not as a fully-fledged number. Now a group of historians from Canada, France, Japan, New Zealand and the US have voiced their disapproval over such a stance. They say that as the historical manuscript contains calculations such as long multiplication, it would have been necessary to use zero as a number. They also claim that the document includes statements such as “having added one to zero”. The debate is sure to continue before, er, zeroing in on a solution.

Theory of happiness

How much would you pay for a short letter written by Albert Einstein on the pursuit of happiness? Einstein wrote the letter during a lecture tour in Japan in 1922 after a bellboy at the hotel where he was staying – the Imperial Hotel in Tokyo – delivered a message to the physicist. When Einstein went to tip the boy, he realized he didn’t have any money so instead wrote a note to him on hotel letterhead that read (in German): “A calm and modest life brings more happiness than the pursuit of success combined with constant restlessness.” The letter, dubbed his “theory of happiness”, went on sale in October at the Winner’s Auctions and Exhibition in Jerusalem. While it was only estimated at $5000–8000, the price rocketed after intense bidding, eventually going for an eye-popping $1.56m. A second note that Einstein wrote at the time on a second sheet of paper with the words “Where there’s a will, there’s a way” sold at the same auction for only $250,000.


(University of Cambridge)

Free for all

Still on famous physicists, the PhD thesis of the University of Cambridge physicist Stephen Hawking has been made freely available to read by the university library’s Office of Scholarly Communication. Hawking completed his PhD – entitled “Properties of expanding universes” – in 1966 when he was 24 years old. To mark Open Access Week 2017, in late October, the 117-page tome was posted on the university’s Apollo open-access repository, which is already home to some 15,000 research articles and 2400 theses. Within hours of Hawking’s opus being posted online, demand was so great that the site crashed. However, according to the university, it was still downloaded more than 60,000 times in the first 24 hours before access was restored. “By making my PhD thesis open access, I hope to inspire people around the world to look up at the stars and not down at their feet,” Hawking noted.