Bell Tower Henge

Twice each year, the setting sun will align with the west windows of the North Tower of the D H Hill library, and the east windows (passing through the library) and the NCSU Bell Tower. There's a tool here that shows when this is likely to occur. It looks like around April 20 or 21 or 22 or 23 or 24 or somewhere around there. There's another similar tool here. One evening I was in the D H Hill library on a cloudless day at sunset and the sun came in the west windows of the upper floors of the North tower of the library, shown straight down the aisle, and out the east windows. As I recall, it shown on the bell tower for an instant. In the fall, the sunset event will occur around August 9. There are sunrise events around Valentine's day and Halloween as well. But the sunrise event would just consist of the shadow of the bell tower falling on the library. That still might look neat if photographed from inside the library. These are some possible vantage points for time lapse photography of the sunset events.

• Inside the library. The April event is a poor choice for inside-the-library time lapse. Students are everywhere. The August event would find a much less crowded library. There are two vantage points that might be interesting inside the library. A time lapse taken near the west windows could follow the sweep of the sun beams as they align down the aisle of books and onto the east windows. It is unlikely that you could photograph any light hitting the bell tower from the west wall, though, due to glare. So a second vantage point would be the east windows looking out at the bell tower. At the moment of alignment, however, there is going to be a lot of glare off the inside of the window from the sun, but you could shade that with your body. Note that technically, you're supposed to submit a request (see rule 2.10 at http://policies.ncsu.edu/rule/rul-02-61-... ) to photograph inside the library. But they had a photo contest when the Hunt library opened, so I don't know.
• On the ground, east of the library, looking up at the North tower. You should see the east windows light up as the sun emerges from inside the library.
• On the ground, west of the bell tower looking up at the tower. You might be able to catch some illumination of the bell tower at the moment of the event. But I think the light makes a glancing blow rather than a direct hit. The April event might be subdued due to shadows of students sitting in study carrels.
• From insided the bell tower looking toward the library. Tom Stafford gives bell tower tours (thstaffo@ncsu.edu). As a pre-test, if you can peer out of the bell tower and see daylight through the windows of the library, then in theory there should be a day when you can see a sunset through them.
• From a drone hovering around the bell tower.
• From the US District Court building looking back to the west. As you look off in the distance from the library, there's a white building way off behind the bell tower. I *think* its the US District Court building.

April 2015 oberservation diary

See also

• Manhattanhenge