never mind the optics

The dust (sorry!) is starting to settle after 2 fantastic nights of participation in the annual Perseid meteor shower.  The event hasn’t actually finished just yet but the number of meteors per hour will fall rapidly now that we have passed peak activity.

So what was it all about?  I’m no astronomer, nor am I presumptuous enough to think I provide a decent explanation.  Basically, our planet just passed through the debris trail left by a comet called Swift-Tuttle.  You can find out more about the phenomenon here.  What I have found astonishing is the sheer number of non-astronomers (myself included) who have been following events and staying up late to view these blazing trails of light as they stream across the night sky.  How do I know that so many people have taken part? Well, that would be down to Twitter.

Many astronomers have seized the publicity available to them through the International Year of Astronomy 2009 to promote their work/research/hobby to people who have never had any dealing with astronomy before.  The 365 Days of Astronomy podcast dedicated an entire episode to the Perseids just before they arrived.  While these would have contributed to a raised awareness, they are not sufficiently mainstream to attract the unprecedented interest surrounding this year’s event – this is where Twitter comes in.

In the UK, a local astronomy group called Newbury Astronomical Society, who tweet from the @NewburyAS twitter account, seized the initiative by setting up the #meteorwatch hashtag for the Perseids event.  The tag caught on and hundreds of people shared their experiences during the shower by tweeting with that hashtag, taking it to 4th place in Twitter’s trending topics.  The organisation of the Newbury club even drew the attention of the BBC (click link on that page to see video footage) who visited “the bunker” during the first evening.

While the south of the UK enjoyed clear skies on the first evening, I was not so lucky.  As there was no way I could see the meteors, I tried to detect them using a very basic radio technique instead.  I connected an FM antenna to the back of an old Pioneer receiver unit and fed the output into a Griffin imic (with RCA to 3.5mm jack adapter) that was plugged into the usb port of a laptop.  The Griffin components were essential to convert the RCA HiFi electrical connections into a standard computer connection.

I tuned the radio to the lowest clear FM frequency available (87.5MHz) and used a virtual chart recorder package call Radio SkyPipe to record the data.  The recording software is quite straightforward and would be a good introduction to signals and measurement for senior pupils, such as those undertaking AH Physics investigations or the new Science Baccalaureate, as it requires several calibration & signal nulling steps before use.

Unfortunately I didn’t capture any exciting data although there was a curious low frequency amplitude modulation (see below) on the signal that I could not explain.

On the second night, I decided to leave the setting up of hardware for radio astronomy to the professionals and concentrated on looking for streamed data from the web.  I found this site broadcasting from Tavistock in Devon.  I downloaded the BS-Tuner application and pasted in the url of the broadcast site.  To my surprise I heard streaming FM static coming from the laptop.

Every now and then this static was pierced by an eerie scream as radio waves were reflected back down towards the Tavistock antenna by the ionised wake of each meteor.  The signals varied in volume, duration, clarity and complexity but due to their unpredictable nature it was difficult to record one.  However I have attached one of the sounds I captured and encourage you to play it using the flash player below.

I was disappointed to view just a single Perseid at around 2.30am last night, the weather just wasn’t right for it.  However, without those clouds I’d never have considered the potential for homemade radio astronomy.

A Nasa podcast on the Perseids is also available.

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I thought I would include a second Animoto video.  What’s interesting is that pupils did not feel it was necessary to extend their videos beyond a minute, even when they had access to the all-areas education pass that allowed for full-length animations.

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So what might we consider to be evidence of achieving a Curriculum for Excellence outcome?  I’ve been working on one of these with a lower ability S2 science class.  The outcome we explored was

I can use my knowledge of the basic needs of humans, and the bodies of our solar system, to put together a reasoned report on whether we can colonise space.

I like the way this ties together aspects of physics and biology.  A lot of people out there have this idea that physics and chemistry go well, as do chemistry and biology.  How many people have experienced the intersection of physics and biology though?  I understand this gap a little as I used to work as principal engineer in a biophotonics instrumentation company developing laser-based laboratory equipment for protein analysis in the drug development sector.  When I attended meetings, I was amazed to see so many presentations from researchers who were using biology and physics to solve their problems.

As I mentioned in another post, my class have researched the bodies of the solar system.  They then reviewed their prior learning on the gases in the air, respiration and photosynthesis to make an informed choice of potential colony – they decided on Mars.  Our timing was spot on, as we were able to follow the European Space Agency’s Mars500 project, looking at the potential effects of long term isolation on astronauts travelling to Mars.

For a lower set, writing a report was a daunting prospect.  So we threw out that idea and I took them to the library and introduced them to Animoto, GoAnimate and Glogster.  Once we got round initial problems of web filtering, pupils experimented with all 3 and unanimously agreed to work with Animoto.  I applied for, and received, a free education all-access pass from the Animoto folks for 6 months.  Without this, their films were limited to 30 seconds.

I’ve attached one of the short films they produced to this post.  Are these clips evidence of achieving an outcome?  I feel that they are at least part of the way.  One of the things I like about them is that there is not a powerpoint presentation in sight.  My concern when I hear people around the school talking about implementing CfE is that too many of the outcomes might be assessed by the quality of a powerpoint presentation to the rest of the class.  If nothing else, I hope I have shown this class a different way of structuring and showing information.

Oh, did I mention that they had fun doing it?

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