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A brief history of gravitational waves

On 11 February 2016, it was announced by the  Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration that gravitational waves had been discovered, finally confirming a century old prediction. This was very exciting, and the story was big news, making the front page of national newspapers and magazines, with even President Obama tweeting about it. The history of gravitational waves up to their discovery is rather interesting, so I thought I’d share some of it here.

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In conversation with Ian Stewart

In an airy office in the Mathematics Institute of the University of Warwick we find Ian Stewart, the prominent maths professor, Fellow of the Royal Society and one of the UK’s most prolific popularisers of mathematics. He has published over 80 books, between 1991 to 2001 took over Martin Gardner’s original Mathematical Games column for the magazine Scientific American, and in 1995 won the Michael Faraday Prize for excellence in communicating science to UK audiences. He greets us with a kind smile, a warm handshake and leads us to his desk.

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New largest prime number discovered!

Here at Chalkdust we’re very excited by the latest discovery of the new largest prime number, which is the Mersenne prime $2^{74,207,281}-1$. So to celebrate this discovery by the Great Internet Mersenne Prime Search, we thought we’d publish the number.

7 floppy disksFun facts first:

  • All Mersenne primes are of the form $2^p – 1$, where $p$ is prime (the first four are 3, 7, 31, and 127).
  • Mersenne primes are named after Marin Mersenne (whose face is in the banner at the top!).
  • In binary, the number is ‘1’ repeated 74,207,280 times!
  • This means it requires 8.85MB of disk space to store, or 7 floppy disks!
  • Using the “million, billion, trillion” naming system, you could call this number 300 septillisensquadragintaquadringentiilliquattuorducentillion!

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What’s your favourite function? Part II

A few weeks ago on this blog we featured some of the Chalkdust team’s favourite functions. Since then we have received loads of feedback from people telling us their favourite function, so in part II of this blog we’re featuring some of the best of the contributions we have received. Our reddit thread got many other excellent contributions, from the Cantor function to the zeta function, and there was a heated debate about whether the Dirac delta function is actually a function (it is). Continue reading

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Why is it so hard to pull two phone books apart?

intertwineTake two phone books and interleave all their pages one by one. Now try and pull them apart by their spines. Impossible, right? You may have seen this trick before: it’s used as a classic example of the extreme power of friction. There’s some great videos online of two trucks each tethered to one of the books, trying and failing to pull them apart. You can even lift a car with a crane by using a pair of phone books instead of a strap.

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Will the Universe actually end in a big rip?

Yesterday, the Guardian published an article with the headline “Not with a bang, but with a Big Rip: how the world will end”. In it they discuss a recently published paper by some physicists in Tennessee, claiming “scientists have concluded that we could be heading for an equally dramatic cosmic finale: the Big Rip”. Now part of my PhD is on this exact topic of cosmology, and I find it really interesting to see how the mainstream media report my own field. So I thought I’d write a blog post putting the article in context, and explaining what the Guardian got wrong.

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Can we do good more effectively?

Here at chalkdust HQ one of our philosophies is that mathematical thinking and reasoning can be applied to all walks of life. For example, in our first issue we had an interview with Dr Hannah Fry, who discussed the mathematics of love. In this blog post, I’m going to talk about a growing movement of people applying mathematical reasoning to another area of life that is often considered emotional: donating money to charity. This group of people, called “effective altruists”, believe that choosing which charity we donate money to shouldn’t be an entirely emotional decision, dictated by which organisation can best tug at your heartstrings. Instead we should be guided by evidence and find a way of rationally measuring which charities do the most good.

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