Background:
I know two brothers, Franklin (Flash) and Ben (Boom) Lytnstryke, who are intrigued by lightning. They are really intrigued by lightning. They observe it and photograph it. They seek it out, chasing large thunderstorms. Lightning is to them what Tupperware in the woods is to me, and that's saying something! Recently we thought of a way to combine our mutual interests – we would place Geocaches where lightning had struck.
The plan was to record lightning strikes from two separated locations using fancy video gear Flash and Boom have for just such purposes. Information would be extracted from the recordings and used with mapping, trigonometry, and coordinate manipulations to locate the lightning strike sites. Finally, we would hike to the spots and leave caches.
The plan worked pretty well, although there would be some glitches. As a big storm approached Liberty Reservoir, the three of us hurried to get going. The video gear had already been packed in the van, so we just needed to grab something to stay dry. With the outside temperature a mild 68°F, rain slickers were enough. I drove and first dropped off Flash. He set up his camera at
N39 26.931 W76 52.665.
Next I took Boom to a spot several miles away where he set his camera up at
N39 22.697 W76 53.344.
I used my GPSr to measure the camera locations.
Flash and Boom were able to record during the entire storm, although clouds and rainfall sometimes limited visibility. The brothers risked their lives and got very wet, but had a great time. I stayed safe and dry in the van and had a great time.
The first lightning strike was clearly visible to Flash and Boom, but later strikes were obscured to one or both. The obscured strikes were experienced only as a flash of light and a crack of thunder. In spite of the problems with visibility, sufficient information was recorded for us to find four lightning strikes.
As part of the division of labor, I was given the job of calculating the locations. That was fine with me since I enjoy mapping and playing around with coordinates. I used Fizzycalc, a great free computer program, to do the coordinate math. My biggest problem was coming to understand how the angles and sides of general triangles are related. I really wasn’t sure there were relationships between them! But I vaguely remembered hearing about the Law of Sines and the Law of Cosines and wondered if they might apply. Well, as I learned after a bit of Wikipedia research (quicker than going back to the textbooks), those “Laws” were indeed for general triangles! With the Laws in hand, the rest of the figuring was similar to what I already knew, and not too hard.
We placed four Geocaches in total, all ammo boxes. The first three locations can be determined from Flash and Boom’s recorded data. For a change of pace, the fourth cache location is not related to that data but instead to the locations of the first three lighting strikes. One other difference is that the fourth cache container is locked, with pieces of the combination to be found in each of first three caches. So it’s necessary to find the first three caches before the fourth, even after the fourth’s location is known.
Video recording information for LS#1:
The storm hadn’t quite reached the brothers so they were both able to clearly see the first lightning strike. Using reference landmarks, the bearings to the strike from Flash and Boom’s locations were very accurately determined:
228.923° True (Flash),
352.599° True (Boom).
You can check your answer with Geocheck. More information regarding parking and cache hint will display with the correct answer.