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2017 News

2 December 2017 – Into The Under World

For the last couple of years I've been helping do high resolution 3D laser scanning of Auckland's lava caves. To show off the scanning work, next Friday (8 December) sees the opening of an exhibition: Into The Under World. Apart from the opening night it's a free exhibition, held at Silo 6 in the Wynyard Quarter.

The images are spectacular and well worth seeing at full size, back-illuminated, but be warned the exhibition has a very short run, closing on 24 December.


8 November 2017 – Bright Sparks

Congratulations to intermediate school student Brian Kitchen for his incredible Bright Sparks 2017 entry Xtionberry Pi, which he has been working on for the last two years. Brian is winner of 1st place in the Junior Engineering category and Overall Male Winner.

His project video only shows the first half of his project, and doesn't show the amazing work he's done figuring out how to create apps for MacOS, Windows, Android, iOS and websites, that enable people to move around at will inside his scanned caves.

Keeping cool under fire (literally, as it turned out), he was demonstrating his scanner to Seven Sharp reporter Tim Wilson on the morning of the prize giving (yesterday) when a capacitor on his scanner's homemade power supply burst into flame. But Brian implemented his backup plans and outside the prize giving that afternoon he was showing off his scanning abilities anyway. His persistence, motivation, and ability to stay calm are really quite incredible.

Update: Brian was also interviewed on RadioLIVE on 3 December.

29 October 2017 – Extrasolar visitor

This month the solar system had its first known interstellar visitor – a body from outside the solar system, travelling faster than the Sun's escape velocity, so it's not going to end up in orbit. This hasn't been seen before, so it's presently designated as an asteroid, A/2017 U1 (although it was originally called C/2017 U1 because it was thought to be a comet). Update: Now called ‘Oumuamua, it appears to be unusually elongated – possibly more so than any other* natural object – having approximate dimensions of 30 to 40 m diameter and 180 to 400 m long. *Assumed.

It was first spotted on 19 October 2017 when it was "just" 30 million kilometres from Earth (0.2 AU; Earth's orbit is 1 AU from the Sun), and it has been calculated that it got within 24 million km (0.16 AU) from Earth a few days earlier on 14 October. At its closest approach to the Sun it was closer to the Sun than Mercury is, at about 0.25 AU (Mercury is at an average of 0.39 AU).

An eccentricity of 0 is perfectly circular, while 1 is a parabola (in a sense an infinity long ellipse). A/2017 U1 has an eccentricity of almost 1.2 – firmly hyperbolic, meaning it's not gravitationally bound to the Sun, having come from outside the system and now heading out of the system again. The direction it came from was the constellation Lyra (4½° away from Vega), which is the direction the whole solar system is moving in. More info here.

3 September 2017 – Science Fair

The NIWA Auckland Science & Technology Fair has been and gone for another year, with a huge range of really interesting topics covered. Students in year 8 (intermediate school students moving to secondary school nex year), don't forget that you can enter next year even if your secondary school doesn't participate. Just get in touch through the Sci Fair website (or with me) – the sooner the better.

14 July 2017 – Particulate fireballs

To finish off term 2 I introduced some young scientists to oobleck – a colloquial name for the non-Newtonian fluid made from cornflour in water. It acts like a liquid when treated gently, but as a solid when hit hard (as this video shows very nicely with a golf ball). It's fascinating stuff to play with (even for adults), and was voted the best lesson of the term.

We also had a look at what happens when a cloud of cornflour in air is ignited: a fireball. Increasing the surface area of a substance increases its reaction rate. Cornflour is flammable and is a fine powder, so has a very high surface area and will burn rapidly if given a chance. As a cloud of dust in the air, it's mixed with the oxygen it needs to combust, so at the right concentration all it needs to set it off is a source of ignition.

This is really important to know, because flour and cornflour explosions do happen because of ignorance. Two years ago a cornflour fireball at a water park party in Taiwan caused the death of 15 people, and almost 500 people were injured. Four months later 44 victims were still in hospital. Quite apart from cornflour being really bad to breathe, smoking was allowed at the event – a source of ignition. At the end of this news article a Taiwan government minister is reported saying "if there had been someone with a basic understanding of science at the scene, the tragedy could have been prevented."

Science enriches lives, broadens horizons, and can save lives.

26 May 2017 – New Zealand rocket into space

Yesterday afternoon, 25 May 2017 at 4:20pm, New Zealand company Rocket Lab successfully lauched their Electron rocket into space, getting to a height of about 250 km. Sadly it was short of the 500 km high orbit that was hoped for, but the company claims it marks New Zealand as the 11th nation in the world with the potential to launch payloads into space from their own territory, and the first country in the world to launch an orbital-class rocket from a private launch site.

Rocket Lab CEO said "We're one of a few companies to ever develop a rocket from scratch and we did it in under four years. To get as far as we did on the first test flight doesn't often happen."

It's not the first time Rocket Lab has got to space. On 30 November 2009 Rocket Lab launched a smaller sub-orbital rocket, the Atea-1, to a reported height of 120 km.

Space is defined as starting at 100 km up, a limit known as the Kármán line. It's the altitude at which aeronautic flight no longer gives enough lift to stay up without exceeding the orbital velocity, so basically to get any higher requires a rocket. (Note that a helium balloon carrying a teddy bear, hamburger or Raspberry Pi can only get about one third of the way to space.)

Rocket Lab aims to provide sun-synchronous orbits for small satellites up to 100 kg. For more information on orbits see the Orbits page. A compilation of video clips of the launch can be viewed here (pity about the silly date format they've used). The ice on the rocket in the third clip is on the outside of the liquid oxygen tank, which is rather cold.

4 April 2017 – Gaussian Correlation Inequality solved

The Gaussian Correlation Inequality was an outstanding theorem in mathematics which seems simple, but some mathematicians had been working for more than 40 years to try to prove it. In the middle of 2014 it was solved by a retired German statistician, but his proof didn't become widely known for more than two years.

Thomas Royen's background as a pharmaceutical statistician gave him the tools he needed to do it, and it all suddenly clicked while he was brushing his teeth. The Quanta Magazine article which explains how it all happened is an interesting read.

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