Plus Blog
February 17, 2010
Wednesday, February 17, 2010
A central prediction of Albert Einstein's general theory of relativity is that gravity makes clocks tick more slowly — time passes slower when you're close to a massive body like the Earth, compared to when you're further away from it where its gravitational pull is weaker. This prediction has already been confirmed in experiments using airplanes and rockets, but a new experiment in an atom interferometer measures the slowdown 10,000 times more accurately than before — and finds it to be exactly what Einstein predicted. Labels: Latest news posted by Plus @ 12:27 PM 3 Comments:

February 17, 2010
Wednesday, February 17, 2010
Maths in a minute — Achilles and the tortoiseAchilles and a tortoise are competing in a 100m sprint. Confident in his victory, Archilles lets the tortoise start 10m ahead of him. The race starts, Achilles zooms off and the tortoise starts bumbling along. When Achilles has reached the point A from where the tortoise started, it has crawled along by a small distance to point B. In a flash Achilles reaches B, but the tortoise is already at point C. When he reaches C, the tortoise is at D. When he's at D, the tortoise is at E. And so on. He's never going to catch up with the tortoise, so he has no chance of winning the race. Something's wrong here, but what? Let's assume that Achilles is ten times faster than the tortoise and that both are moving at constant speed. In the times it takes Achilles to travel the first 10m to point A, the tortoise, being ten times slower, has only moved by 1m to point B. By the time Achilles has travelled 1m to point B, the tortoise has crawled along by 0.1m to point C. And so on. After n such steps the tortoise has travelled And this is where the flaw of the argument lies. The tortoise will never cover the 90m it has to run using steps like these, no matter how many of them it takes. In fact, the distance covered in this way will never exceed 10/9=1.111... metres. This is because the geometric progression converges to 10/9. Since the tortoise is travelling at constant speed, it covers this distance in a finite time, and it's precisely when it's done that that Achilles overtakes it. This problem is known as one of Zeno's paradoxes, after the ancient Greek philosopher Zeno, who used paradoxes like this one to argue that motion is just an illusion. Find out more about Zeno's paradoxes in the Plus article posted by Plus @ 12:10 PM 0 Comments: 
February 12, 2010
Friday, February 12, 2010
Maths at the Cambridge Science FestivalIf you're wondering how to feed your maths habit between the 8th and 21st of March, then why not head to Cambridge for the 2010 Cambridge Science Festival? There'll be plenty of free maths events, including:
To find out about all the Cambridge Science Festival events go to the festival website. posted by Plus @ 1:01 PM 0 Comments: 
February 10, 2010
Wednesday, February 10, 2010
Unintended consequences of mathematicsMathematicians (and Plus authors) John Barrow, Colva RoneyDougal and Marcus du Sautoy will be discussing unintended consequences in mathematics with Melvyn Bragg on his BBC Radio 4 programme In Our Time tomorrow morning at 9am. Image courtesy NASA
Many of the most exciting developments in science is is when knowledge from one area such as pure mathematics unexpectedly crosses boundaries to provide deeper understanding of a previously unconnected problem in another area. The programme will explore many such unintended consequences, including how the ancient purely geometric study of conic sections turned out to be vital in understanding the orbits of the planets, how Einstein used the theoretical concepts from nonEuclidean geometry for his groundbreaking work on special relativity, and how the number theory provided the security necessary for our digital age. You can read more from John, Colva and Marcus on Plus, as well as articles on conic sections and planetary orbits, noneuclidean geometry and special relativity, and number theory and chryptography. posted by Rachel @ 2:09 PM 
February 4, 2010
Thursday, February 04, 2010
Putting the magic back into classroom mathsMathematics and magic may seem a strange combination, but Queen Mary's Matt Parker and Peter McOwan want to show students otherwise. They have produced many of the The Manual of Mathematical Magic, a unique kit of magical miracles, to show that the most powerful magical effects performed today have a mathematical basis. Freely available to any school in England, the Manual exposes the secrets behind street magic, closeup and stage tricks, revealing the varied and exciting everyday uses for the mathematics powering your magic. It gives young mathematicians the chance to be creative, finding new ways to solve problems and discovering the key to the perfect magic trick. Along the journey they will also uncover the skills of a good mathematician, one with the useful employment skills you get from being good at mathematics. Both McOwen and Parker regularly visit secondary schools to do Mathematical Magic shows for students. “Our goal is to help more students engage with Mathematics," reveals Parker, who is also involved with the More Maths Grads programme. "Magic tricks get the students excited and then we show them the mathematical principles that make the whole trick hang together. We also reveal how the same Mathematics underpins everything from medical scans to sending text messages.” As well as The Manual of Mathematical Magic, the kit also contains a pack of cards, notebook and pencil – all of which have hidden Mathematical Magic. Teachers can use the tricks in the book in their lessons and then explain the Mathematics and its applications. “Maths is magic. But too often school maths is a dull diet which sucks the joy out of what should be a thrilling and beautiful subject," said Paul McGarr, Deputy leader Maths Faculty at Langdon Park School where Parker gave a magical lesson to Year 10 pupils this week. "This new pack, quite literally, helps put the magic back into classroom maths. My pupils really loved it, they were engaged, excited and happy – not bad for last period of a long day! The 'wow' was audible when they saw some of the tricks demonstrated, and you could almost taste their intense curiosity to find out how it was done using maths. I would strongly recommend teachers to get hold of this pack and use it.” For more information and to conjure up a kit for your school, visit http://www.mathematicalmagic.com. And for more on maths and magic you can read 1089 and all that and Maths and magic on Plus, and learn mathematical magic tricks at the Magic of Computer Science. posted by Plus @ 2:28 PM 0 Comments:
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February 4, 2010
Thursday, February 04, 2010
Catching sight of a cockroach tends to make us behave chaotically, what with the running and screaming and throwing of shoes. But it appears that chaos might actually explain how we, and the cockroach itself, behave. An interdisciplinary team of scientists from Germany have created a robotic cockroach that autonomously behaves in a way reminiscent of a real cockraoch. The robot independently changes gait depending on the surface it is walking on, avoids obstacles and can even extricate its leg from a hole or run away from predators. Recreating lifelike behaviour is not new, but this robot reproduces a huge range of behaviours and quickly reacts to new situations and switch between them. And the secret to its success is controlled chaos in its robotic brain. Labels: Health and medicine, Latest news posted by Rachel @ 10:40 AM 2 Comments:
