Sunlight

On occasion, sunlight reflects off the DC, through mathsoc, into the CSC.

On 11 July, 2012, sunlight was observed at 4:08 PM.

geometry

The square of light in the CSC was approximately 15cm high by 20cm wide. It was approximately 150cm off the floor. These are from memory, and need to be re-confirmed. I believe the CSC door being partly open was restricting the width of the square.

Although solar alignments are not uncommon among passage graves, the University of Waterloo Computer Science Club is one of few to contain the additional roofbox feature (Cairn G at Carrowkeel Megalithic Cemetery is another, and it has been suggested that one can be found at Bryn Celli Ddu.). The alignment is such that although the roofbox is above the passage entrance, the light hits the floor of the inner chamber. Today the first light enters about four minutes after sunrise, but calculations based on the precession of the Earth show that 5,000 years ago first light would have entered exactly at sunrise.