Plumbing for light

Waveguide
A radio receiver under construction CREDIT: Stuart

In my time I've got my hands dirty with radio astronomy hardware that observes at 30 GHz. That's in the bit of a gap between emission from water vapour and emission from oxygen.

I often prefer to think in wavelengths rather than frequency because 1cm is much more approachable than 30 GHz. 1cm feels holdable. It feels like you could catch the radio waves from distant galaxies in your own hands. As the instrument scales with the waves, the parts which guide them fit nicely in your hands too. Building a radio receiver can feel like plumbing for light.

Posted in astro blog by Stuart on Wednesday 26th Oct 2011 (23:39 BST) | Permalink

What to see in the night sky

It is always a lot of fun to go out onto the streets with telescopes doing guerrilla astronomy. Many people think they know the Moon but seeing it through a 10 cm telescope for the first time often produces a "wow!".

A couple of Saturday's back we took telescopes down to Cardiff Bay and showed over 100 people the Moon through a couple of telescopes for International Observe The Moon Night. That was despite almost total cloud cover. The reactions were great and we even got a double "wow" as two ladies looked through telescopes at the same time. Seeing craters from asteroid impacts and the black bits caused by ancient volcanic eruptions feels more impressive with your own eyes than via a picture in a book.

At the moment, another good object to see is the planet Jupiter. It is the bright object low in the eastern sky not long after sunset. I was admiring it with a cup of tea just the other night. Living in a busy city you might mistake it for an airplane but it is actually the largest planet in the solar system. It is currently about 600 million kilometres (370 million miles) from the Earth. With a telescope you should be able to spot Jupiter's 4 largest Moons and some of the cloud bands in its atmosphere.

The Earth turns. It orbits the Sun. That means our view of the night sky gradually changes. A good source of information about what to see in the ever changing night sky is Ian Morison at Jodrell Bank. He produces a monthly guide which is also available in audio form from The Jodcast.

Posted in astro blog by Stuart on Tuesday 18th Oct 2011 (21:08 BST) | Permalink

Escape From Jupiter

When I was growing up, the BBC aired quite a few live-action children's TV shows from Australia. They included shows such as Round The Twist, The Girl from Tomorrow, and Spellbinder. They often involved science fiction plot lines and had both girls and boys being brave/clever.

One show that seemed to have a particularly realistic portrayal of humans living in the solar system was 1994 drama Escape From Jupiter. It was set on a frontier mining colony on Jupiter's volcanic moon Io. After a deep drill accidentally broke into a massive lava chamber, the colony was threatened with destruction so the colonists (mostly through skills of the kids as this was children's TV) escaped to a decommissioned space station orbiting the little moon.

The space station was dilapidated - a floating rust bucket - but had an amazing set of solar sails that unfolded. That was definitely the first time I'd seen solar sails portrayed in fiction and I remember being quite impressed. The show also seemed to do a good job of explaining how Jupiter's gravity caused Io to be volcanic and how it made it very difficult for the colonists to escape back to Earth. The effects - particularly the animations of Jupiter and the space station - seemed pretty good for the time.



A very belated thanks to the Australian Children's Television Foundation who helped with my burgeoning interest in physics and space.

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Posted in astro blog by Stuart on Sunday 16th Oct 2011 (10:57 BST) | Permalink
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