Monthly Archives: March 2015

Planets in the Fourth Dimension

Azimuth

You probably that planets go around the sun in elliptical orbits. But do you know why?

In fact, they’re moving in circles in 4 dimensions. But when these circles are projected down to 3-dimensional space, they become ellipses!

This animation by Greg Egan shows the idea:


The plane here represents 2 of the 3 space dimensions we live in. The vertical direction is the mysterious fourth dimension. The planet goes around in a circle in 4-dimensional space. But down here in 3 dimensions, its ‘shadow’ moves in an ellipse!

What’s this fourth dimension I’m talking about here? It’s a lot like time. But it’s not exactly time. It’s the difference between ordinary time and another sort of time, which flows at a rate inversely proportional to the distance between the planet and the sun.

The movie uses this other sort of time. Relative to this other time, the planet…

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Farewell, Sir Terry Pratchett.

Nessbow

On Friday morning I awoke to the sad news that Sir Terry Pratchett had passed away.  I was heartbroken to hear of the death of one of my all-time favourite authors.  The world seems a little bit duller without the cheeky glint in Sir Terry’s eye.

DSCF8363

Sir Terry’s work has been a part of my life for fifteen years.  I was introduced to his books by a friend at the age of thirteen.  My high school bestie loaned me a well-loved copy of Soul Music to take on holidays.  I quickly fell in love with The Discworld and it’s inhabitants and was eager for more.  I read every Discworld book in the library catalog.  When the film adaptations of several Discworld books were made, I pounced on those and immediately adored seeing my favourite characters come to life on the screen.  In college I discovered two cartoon series based on…

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Fans are petitioning Death to bring back Terry Pratchett

Metro

terry pratchett petition, terry pratchett Terry Pratchett died today aged 66 (Picture: Change.org)

Terry Pratchett fans have begun petitioning Death to bring back the Discworld author.

Pratchett’s death was announced this afternoon with a message from his official Twitter account, which read: ‘Terry took Death’s arm and followed him through the doors and on to the black desert under the endless night.’

His publisher, Penguin Random House, wrote that Pratchett ‘enriched the planet like few before him’.

[metro-thumbnail-link url=”http://metro.co.uk/2015/03/12/12-ways-sir-terry-pratchett-made-our-lives-better-5100594/” title=”12 ways Terry Pratchett made our lives better”]

As friends and fans alike paid tribute to the 66-year-old, who had been suffering from Alzheimer’s disease, one fan launched a petition on change.org to ‘reinstate Terry Pratchett’.

In a move that would surely have brought a smile to the late fantasy legend’s face, the petition politely asks Death to bring back the author.

check mort, paul kidby, terry pratchett Check Mort, by Discworld illustrator Paul Kidby (Artwork copyright Paul Kidby, http://www.paulkidby.net)

It cites a quote from Pratchett:…

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The best salute to Spock

Why Evolution Is True

This is a tw**t from astronaut Terry Virts aboard the International Space Station.  What a great tribute to Leonard Nimoy!

Screen shot 2015-02-28 at 5.55.12 PM

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