Thursday 31 July 2008

Eclipse 01-August-2008

There's a solar eclipse tomorrow, partial here in the UK.

According to http://www.physorg.com/news136197476.html

"From the whole of the British Isles observers will see a partial solar eclipse, with between 1/10th and 1/3rd of the Sun obscured by the Moon. ...

In London the partial phase of the eclipse begins at 0933 BST (0833 GMT). Maximum eclipse is at 1018 BST (0918 GMT) when 12% of the Sun will be blocked. The partial eclipse ends at 1105 BST (1005 GMT)."


The further north you are in the UK, the more the Sun should be blocked.

There are also some rather wonderful diagrams and animations showing how the shadows travel for day/night, total and partial eclipses for the August 1 event at http://www.eclipse.org.uk/eclipse/0312008/ If you prefer static maps, you might like to look at the NASA maps at http://eclipse.gsfc.nasa.gov/eclipse.html

As you will gather as these posts progress, some strands which are likely to recur are teaching, science and something called the 'Theory of Knowledge' (TOK). TOK is a course which I am preparing to teach as part of the International Baccalaureate when it begins to be offered at the school where I work in 2009. The prediction made in this post is what TOK might call a 'Knowledge Claim'. TOK would encourage students to not necessarily take such a claim at face value but recognise the basis of the claim, which is often implicit. TOK asks ... "How do we know what we know?"

Well, as a scientist I'm pretty condfident that the models of the universe used to predict eclipses are robust enough for me to rely on. Of course there are elements of trust.

First there is the trust implicit in the scientific process. Does the fact that the day has followed night for as long as anyone can remember guarantee that day will break again tomorrow? If dawn didn't appear, science would be in some short-lived turmoil while it scrabbled around for a better model of the universe but the scientific process would not be broken ... at least, that's the way it seems to me. There's an implicit get out for all of scientific predictions that if the evidence doesn't fit, then we should look for a better model, or at least recognise the limitations of the ones that we are currently using.

There's another level of trust in the eclipse prediction though. While I know that science can apply reason to predict eclipses accurately, I'm not an astronomer myself. I haven't been making measurements of the moon's appearance over the past months in order to predict just when an eclipse will occur. I'm trusting that the culture that I live in is giving me accurate information based on the scientific reasoning; that there isn't some anarchic group behind the websites I've referred to in some bizarre global conspiracy to mislead me into believing that there will be an eclipse when there won't be.

In TOK we look for things called Knowledge Issues as the basis for interesting discussions, reflections ... and essays/presentations for assessment. A knwoledge issue here might be one that asked 'How do you judge whether a source of information is reliable?'

I'm still very new to TOK. I'm hoping that I can develop some ideas and resources through this blog. Feel free to feedback through comments.