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Because of black holes, we have wifi

26 November 2013

Mathematicians and physicists predicted the existence of black holes before we ever found them; perhaps unsurprising since they don’t give off any light. But eventually we figured out that they really could exist, and then we predicted that they should in fact emit radiation, and then we found that radiation and all sorts of other hints that tell us they’re actually there.

Black hole (don't be scared, it's just an artist's rendering)

Black hole (don’t be scared, it’s just an artist’s rendering)

That makes it sound easy, but it was extremely hard. Filtering out all the radiation we get from space to identify just some bits of it as coming from matter as it falls into a black hole is very tricky. Scientists used a mathematical technique called Fourier analysis which can identify different frequencies of signal from one incoming mashed-up signal. And their analysis worked in identifying stuff that was radiating as a result of black holes.

Fourier analysis can tell you that one signal contains three discrete ones

Fourier analysis can tell you that one signal contains three discrete ones

Later on some clever scientists at CSIRO in Australia were trying to solve the problem of how lots of people in the same space, or that were moving around, could have their computers all networked. Running a wire to everyone is impractical. Using a radio signal would be possible but at the relatively low powers, short ranges, and confined spaces needed they got lots of signal reflections that made the incoming signal a bit mashed-up.

But these clever folks remembered what the black hole scientists had done and used Fourier techniques to disentangle the signals they needed from that mashed-up mess. And wifi communication was born.

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Engineering toys for girls

24 November 2013

Your little girl doesn’t have to grow up to be a princess. Maybe she wants to be an engineer.

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Quantum physics made relatively* simple

21 November 2013

BETHE #1

Hans Bethe was a nuclear pioneer, a contributor to the Manhattan Project, a founder of Cornell’s physics program, and a Nobel prize winner. And in 1999 – at the age of 93 and from his retirement community - he recorded three videos as an introduction to quantum physics.

Cornell now has those videos free to watch online.

*Pun intended.

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Dave Hole at the Bridge Hotel

2 November 2013

I spent Halloween evening at the Bridge Hotel in Rozelle, Sydney, listening to the blues. This should come as a surprise to no one.

The Bridge is a no-frills place. It’s not sawdust-on-the-floors, but it’s not too far beyond that either. It’s a simple pub on one side and a small room with tables and a stage for music events on the other. The crowd the other night was, in the words of one of the performer, “small but select”. I and the two friends I went with would agree.

The first act was Canadian Charlie A’Court. I didn’t know until I looked him up, just before going into the room, that he’s actually a Nova Scotian like me. From Truro, in fact, so not far at all from where I grew up. Charlie’s got a powerful voice and plays a good acoustic guitar. He sounded great, and performed a good mix of blues, soft folk, and soul tunes.

DH

The main event was Dave Hole, an Australian slide guitarist I’ve been keen to see since I heard him on an Alligator blues collection I picked up in the early ’90s. He hasn’t toured much in recent years, and this mini-tour around Oz is an acoustic one. He came on stage with a Dobro steel guitar; he was later joined by a drummer on snare and high hat, and a bass player, so not the stack of Marshalls he admitted he usually uses.

But no matter what sort of guitar he has in his hands, Dave Hole can play a slide guitar. He coaxes all those emotive slide sounds from his instrument, the wails and shouts, the glissandos of mourning.

And Dave plays from his guts. There’s no artifice about his performance. His singing isn’t polished. He makes an effort, and grimaces and gestures and shouts, but not in a put-on way. He just has the air of someone who’s self-taught, who loves the old roadhouse blues tunes, and who loves playing them.

By the end of the night it was perhaps getting to be a bit too much of the same sliding trills, over and over, for me. But then he ended with his version of “Purple Haze” and left me with a smile. Thanks Dave.

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A lot of Australia’s media coverage on climate change is political and wrong

31 October 2013

The facts are simple:

  1. There is scientific consensus on human-caused climate change. Looking at 12,000 peer-reviewed abstracts on the subjects of ‘global warming’ and ‘global climate change’ published between 1991 and 2011, where those papers took a position on the cause of global warming over 97% agreed that humans are the substantial cause of it.
  2. One third of articles in Australia’s major newspapers rejected or cast doubt on the overwhelming findings of climate science. Also, Andrew Bolt indulges in humanity-baiting for ratings.

ab

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If you believe you can get better at math through hard work, you’re more likely to do so

30 October 2013

scaryM

Quartz is a digital news channel on economics and business. Two academics have written an interesting story in it about ability and achievement at mathematics.

People’s belief that math ability can’t change becomes a self-fulfilling prophecy.

For almost everyone, believing that you were born dumb—and are doomed to stay that way—is believing a lie. IQ itself can improve with hard work.

They found that students who agreed that “You can always greatly change how intelligent you are” got higher grades.

Math education, we believe, is just the most glaring area of a slow and worrying shift. We see [the USA] moving away from a culture of hard work toward a culture of belief in genetic determinism.

This problem happens outside the US too. I know a lot of people who believe they’re just naturally bad at maths. They seem resigned to it. The research – and professor anecdotes – presented in the article suggests that’s not the case.

It’s a shame then that people believe they’re just innately, genetically, unsuited to mathematics. In today’s high-tech world not being able to speak the language of science, technology, finance, and engineering means you’ll never understand what’s under the hood. And you’re probably limiting your well-paying career choices, if that’s important to you.

I’ve always been prejudiced towards mathematics but I’ve been reminded of its importance in the last couple of weeks during my Interactive Python course. People in the discussion forums for that course are complaining because while they expected to learn a new programming language they didn’t expect to have to understand and apply modulo operations and logarithms. But you need to use these concepts to create on-screen graphics and interactive elements in event-driven programming.

Maths is important. If you think you can’t do it you’re probably wrong.

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Remembering Lou Reed

28 October 2013

lou

Lou Reed, member of The Velvet Underground, solo musician, and New Yorker, died earlier today. It’s been very big news – and rightly so – so if you want to review the man’s huge contribution to the rock music scene since the late ’60s you can easily find those sort of articles on the ‘net, written by bigger fans than me. You could do worse than this one.

My personal reminisces of Lou always come down to two memories:

1. His performance of Bob Dylan’s “Foot of Pride” at the Dylan 30th anniversary concert in 1992. The song sounds like it was written for Lou, which is maybe why Bob didn’t include it on Infidels.

2. His hilarious views on his life in New York, from ad-libbed film Blue In The Face.

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