Latest news from Plus magazine! - http://plus.maths.org

In this newsletter:

* Latest news - desert survival
* Browse with Plus - ask an astronomer
* Mathematical moments - taking chances with De Moivre
* Live maths - see what's on this month

**********

Latest news

How plants halt sands
   Maths helps vegetation stop desertification
http://plus.maths.org/latestnews/sep-dec06/dunes/index.html

Building Newton's nest
   Nurturing the future of observational cosmology
http://plus.maths.org/latestnews/sep-dec06/CTC/index.html

Plus ... more news from the world of maths in the Plus blog
      More or Less is back for more
      Mathematical moments - Abraham De Moivre
http://plus.maths.org/blog/index.html

**********

Browse with Plus

Ask an astronomer - If the Universe is expanding, then what does it expand 
into? What is dark matter? Do astronauts use maths? What colour is Venus? If 
questions like these keep you awake at night, then have a look at Cornell 
University's Ask An Astronomer website. Here you can put your questions to the 
volunteers from the Cornell University Astronomy department, or browse through
questions previously posted by other inquiring minds. There also is an archive 
of articles on the most fascinating topics, from the Big Bang to relativity, 
and information on careers as an astronomer.

http://curious.astro.cornell.edu/index.php

You can also read about astronomy on Plus:
http://plus.maths.org/indices/topic_urls.html#ASTRONOMY

**********

Mathematical moments

Abraham De Moivre
Born on the 26th of May 1667 in Vitry-le-Francois, France
Died on the 27th of November 1754 in London, England

When De Moivre first came across Newton's famous work the "Principia" he was so 
struck by its depth and rigour that he immediately bought a copy and cut it 
into pieces - carrying just a few pages at a time was the only way he could 
study the work while making his rounds tutoring private students in London.

But it wasn't just dedication that gained him full marks. Since an early age he 
had been interested in maths, especially in games of chance, and he is today 
known as a pioneer of probability theory and of analytic geometry. His 
"Doctrine of chance" presented the broadest and most rigorous treatment of 
probability of its day, and he is credited with deriving the normal curve and 
developing the concept of standard deviation. His name is famously attached to 
a formula that gives geometric meaning to powers of complex numbers by 
expressing them in terms of trigonometry.

De Moivre's eminence as a mathematician was recognised by many of his most 
prominent contemporaries, including Newton, who he was friends with, and 
Leibniz. Interestingly, the Royal Society called upon him to referee Newton and 
Leibniz's dispute about who had first invented the calculus.

Sadly, though, De Moivre's genius was never rewarded professionally. As a 
French national who had been expelled from France (after a prison sentence) 
because of his protestant religion, he remained a foreigner in London. Despite 
the support of his prominent friends he was never employed by a university. He 
made a living as a private tutor and died in poverty.

Death played an important role in his mathematics. Together with Halley, who 
gave his name to the comet, he set about investigating mortality statistics, 
laying the foundations for actuary theory used by life insurances.

Most curiously, De Moivre reportedly used maths to predict his own death. He 
had noticed that he was sleeping 15 minutes longer every day. Analysing the 
arithmetic progression 15, 30, 45, .... , he calculated that on the 27th of 
November 1754 he would sleep through the full 24 hours. He was right - it was 
the day he died.

Find out more about De Moivre on the MacTutor history of maths archive:
http://www-history.mcs.st-andrews.ac.uk/Biographies/De_Moivre.html,

about De Moivre, death and statistics in this Plus article:
http://plus.maths.org/issue12/features/annuities/index.html,

and about complex numbers and trigonometry on cut-the-knot:
http://www.cut-the-knot.org/arithmetic/algebra/TrigonometricForm.shtml


**********

Live maths

More or less

Plus's favourite radio show on all things mathematical is back on the air. More 
or Less has two series a year on BBC Radio 4, exploring maths in politics, 
health, avalanches, and much more. In the first shows of this season they have 
already covered drug testing in sport, the economics of climate change, 
uncovered the games behind hospital waiting times, and the perverse nature of 
randomness.

The show is produced in association with the Open University, which provides 
additional material on their site. You can hear all the past shows online at 
the More or Less site, and listen live every Monday at 4.30pm on BBC Radio 4.

The More or Less site: http://news.bbc.co.uk/1/hi/programmes/more_or_less/
The Open University site: http://www.open2.net/moreorless/

You can read more about More or Less from presenter Andrew Dilnot in a past 
article on Plus: http://plus.maths.org/issue22/features/dilnot/index.html



The Clay Institute public lectures

The Clay institute is best known for offering a prize of 1 million Dollars to 
anyone who solves one of seven open questions in maths. The institute also 
supports public lectures and two of these will take place at the University of 
Cambridge this month.

Adding prime numbers

Many famous open problems in number theory are concerned with adding primes, 
and the study of these problems has led to some fascinating mathematics. In 
this talk Professor Ben Green gives you a flavour of some of these.

30th of November 2006 at 6:30 pm

Adding square numbers

This simple operation of adding square numbers like 1, 4, 9, 16, etc, gives 
rise to complex and beautiful patterns, which have motivated mathematicians 
from ancient times to the present. Professor Akshay Venkatesh explains.

30th of November 2006 at 8:00 pm

Both lectures take place at:
The Centre for Mathematical Sciences,
Wilberforce Road
Cambridge
CB3 0WB

Telephone: 01223 337996
Information: http://www.dpmms.cam.ac.uk/Seminars/Specials/Clay2006.html

Both lectures are free.



Gravitational-wave astronomy

Einstein predicted that gravitational waves exist. But what are they, how are 
they produced, and what is the evidence for their existence? Pofessor John D 
Barrow FRS will answer these questions and explore what this might tell us 
about the first moments of the universe, cosmic 'strings' and the highest 
energy events.

When: 30th of November 2006, 1 pm
Where: The Lecture Theatre, The Museum of London, London EC2
Information: http://www.gresham.ac.uk/event.asp?PageId=45&EventId=525
Tickets: free

Happy reading from the Plus team!

**********

If you received this message you have subscribed yourself to the
PLUS-ANNOUNCE mailing list via our website. If you do not wish to remain on
the list please visit

http://www.jiscmail.ac.uk/cgi-bin/wa.exe?SUBED1=plus-announce&A=1


and follow the instructions to leave the list.

If you have any comments on this newsletter, or Plus Magazine, please
contact us at [log in to unmask] - we are always happy to hear from our
readers!

Feel free to forward this email to anyone you think might be interested.