What’s up with the Sun?

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The Sun (the big floaty fireball, not the awful “newspaper”) has been in the news lately as it’s been predicted that the Sun may interfere with the 2012 Olympics. It’s been suggested that  solar flares, ejections of material from the Sun’s surface; and the solar wind, a fast-moving stream of charged particles (normally responsible for the Northern and Southern Lights (Aurora Borealis and Aurora Australis)), could affect the satellites that are responsible for relaying television footage from the Games around the globe.

Over the last few years the Sun has been in an unusually quiet mood, but recently it seems to be “waking up”. Looking at images from the Solar and Heliospheric Observatory (SOHO) Large Angle Spectrometric Coronagraph (LASCO) you can see a clear difference between images taken now and images taken in past months.

Tuesday:

Last Month:

December:

October:

SOHO picked up its largest solar flare in two years on January 22nd:

At the time of writing the solar wind is running at somewhere between 300km and 400km per second with between 2 and 4 protons per cubic metre [source]; this is nothing to worry about. The concern is that by the time the Olympics come around we might be experiencing periods of solar weather like in January 2005 during a severe solar storm.

Fruit Gums and graphs

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All the data from my Fruit Gums experiment has one continuous variable (the number of gums) and one discrete variable variable (either box number or flavour) so the physicist’s standard graph – the x-y scatter plot – isn’t suitable. This made it a good opportunity to try out some different graph/chart types.

A pie chart shows the relative contribution of each item to the whole.

The doughnut chart builds on the pie chart by enabling more than one set of data to be plotted – in this case all three boxes at once.

Bar charts come in two forms: horizontal and vertical. In this case there are two ways to group the bars: by flavour or by box number.

With lots of data a bar chart can become crowded and confusing and that’s where stacked bar charts become useful. A stacked bar chart overcomes this problem and can be done in two different ways: using absolute values or by percentage.