Each galaxy lives within its own three-dimensional halo of dark matter whose gravitational field corrals the stars within it. Without the stars, the halo would still be there, albeit invisible to our eyes; but if the halo vanished, the stars would scatter into the depths of the universe – just as a Christmas tree remains a tree with or without the pretty lights. Whereas without the tree, the lights would merely be a puddle of colour on the snowy ground.
Showing visitors around the University of Auckland can be a quick lesson in our colonial history. The University is named for the city, which is named for a spectacularly unsuccessful Governor-General of India. Our oldest streets are centred on Queen Street — which is crossed by Victoria Street. The settlers took a belt and braces approach to honouring their young monarch when the city was laid out in 1841.
Imagine living in a world where walking and biking was as safe – by Commander Hadfield's measure – as flying in space.
No-one seems to dispute that the video was played, but minimising it as a conversation starter or "just one viewpoint" will not inspire confidence. If this was part of a wider programme to slip creationism into science classes, it speaks to a failure of leadership and, I believe, integrity.
Unlike almost any other form of transport, regular cycling leaves you fitter and healthier than sitting in a car, or a bus or a train. Not only that, Auckland's best cycle paths run through parks and incorporate a series of stunning bridges, so you are likely to arrive at work with a smile on your face.