reveritt

I would call any container with a volume of less than a half liter "small", less than a deciliter "micro", less than a milliliter "nano". Just my opinion.

No solution was posted--only a general description of the method. That still leaves quite a bit of work to do.

7RXC and I have been conferring on this, and he was sharp enough to notice that I had entered one digit incorrectly in the spreadsheet that I have been using to solve this. My method (as described in post #37 above, but omitting step 6) was correct, and Evince now confirms my solution. I used Fizzycalc to convert my UTM solution to Lat/Lon, but I found that I had to round my UTM coordinates off to whole meters (no decimals) to get a correct conversion.

Hey TF102, I am running out of ideas. At this point, if I were trying to find this cache, I would ask the cache owner to review this thread and offer a hint. However, it is your thread, and you are the one looking to find the cache, so that is your decision. I am happy to keep working on the puzzle, but I would like to know if I am getting warm, or if I am completely out in left field. (hey--may that's where the cache is hidden--out in left field!)

I tried subtracting the assumed UTM offsets from the Cache coordinates (step 2 in my post above), which landed me in the middle of a cornfield with no joy.

GPSr, paper printouts, flashlight, first aid kit, knife, pruning shears, compass, DEET (in season), spare log books and pencils, TP, water bottle, hiking stick, cell phone, whistle, map (sometimes), spare gloves, yaktrax (in winter), orange hat (in hunting season), disposable poncho, and of course, swag. Some of this stuff is carried with me; the rest stays in the car.

Hey TF102, calm down; some of us are doing our best to help.

I have the solution as a UTM coordinate set, but when I use FizzyMagic's Fizzycalc utility to convert UTM to Lat/Lon, I get a bogus latitude. My steps: 1. divide each of the three datapoints given in the cache listing into two 5-digit numbers, which are assumed to be offsets (easting and northing, respectively) to the posted cache UTM coordinates. 2. Add the offsets to the cache UTM coordinates to get UTM coordinates for 3 new points, which are assumed to be equidistant from the actual cache location. 3. Using the UTM coordinates, solve for the circumcenter of the triangle formed by the 3 points. I used the formula in this Wikipedia article (the Cartesian coordinates solution) 4. Check the distances between the solution point and each of the three triangle points, using Pythagorean theorem. The three distances are all 18227.31 meters (about 11.3 miles). 5. Check solution with Evince, using link on cache listing. Solution is incorrect. 6. Jump off tall building.

I don't do caches like that unless the cache owner has made it clear in the cache listing that everything is cool.

Perhaps they are UTM offsets to be applied to the posted coordinates. This problem would be much easier to solve with UTM coordinates and plane geometry ("Earth is flat", says the hint). Perhaps Point A (3880271709) is two offsets, 38802 and 71709. Yeah--I like that approach.

Quite right. Perhaps I should have another coffee. I'm still looking for some suggestions on how to interpret the coordinates in the cache listing. If my initial idea was incorrect, then what do the numbers mean? They don't seem to be UTM, or MGS

I try to check all my caches twice annually, but I don't always make it. When I do maintenance, I dump everything out, wipe out the container to remove dirt or moisture, replace container, if necessary, replace log book if necessary, remove all crappy swag and replace with new swag, replace pen or pencil.

Both longitude and latitude coordinates can be up to 90 degrees. I personally live at 71 degrees, 18.5 minutes west longitude, and you apparently live well west of that. That said, however, Fizzymagic pointed out above that my interpretation of the data is probably incorrect.

Yeah, that was my impression, as well. Well, I'm not going to bust my brain any more trying to figure out how to interpret what is posted in the cache listing. The math is the fun part.

OK, the solution to the puzzle is the CIRCUMCENTER of the triangle formed by the three points, A, B, and C. For any 3 points that are not all on the same line, there is exactly one circle that passes through all the points. The center of that circle will, by definition, be equidistant from each of the 3 points. That center point is the circumcenter of the triangle formed by the 3 points. I will try to look at this some more in the near future. I suggest you look for methods for finding the circumcenter of a triangle, given the coordinates of the 3 vertices.

If you are running a Windows machine, you might want to grab a free copy of FizzyCalc, which is a neat little utility that might be helpful in solving problems like this.

Even over short distances, this will not work, because the scale (miles per degree) of longitude depends on the latitude. Here is a formula for distance that gives a very good approximation over hundreds or even thousands of miles: Distance (in NM) between points A and B: 1) average LatA andLatB; and call the result Q. 2) D = 60* SQRT((LatA - LatB)^2 + (cos(Q)*((LongA - LongB)^2))) But knowing how to figure the distance is not much help in solving for the single point that is equidistant from three other points.

I use them to help maintain my own caches, which sometimes get overgrown, as well as when bushwhacking into someone else's cache. I'm talking about a small one-handed pair of shears, not big loppers.

A graphical method like that would be easy if the points were closer together, but these are quite far apart, and the distortion of any map projection is bound to introduce error. I think a mathematical method is needed. I sure would like to read the cache listing for myself.

You're quite right--I didn't notice the inherent contradiction in the original post, which mentions "center".

I keep a mini maglight, a small folding knife, and a small pair of pruning shears in my caching bag.

Well, first you need to interpret the coordinates. I would start by assuming that each point contains both longitude and latitude in degrees, as follows: A: N38.802 W71.709 Then I would average the three longitudes to get a resulting longitude, and do the same with the latitudes. If you have transcribed the coordinates correctly, and I didn't make a mistake (big assumption there), and my assumptions about format and N/W are correct, then the cache is somewhere in the northern Ungava peninsula, not far south of the Arctic Circle. If that sounds like an unlikely location, then reexamine my assumptions and your data.

I have passed up quite a few caches because I thought I would be too conspicuous when searching. I often cache with my granddaughter, and let her do the searching. Kids look a lot less suspicious snooping around in the bushes.

Among the paraphernalia that bookcrosser can order is large ziplock bags with explanatory text on the outside. These are good for bookcrossers who also geocache.

Our island was named for your island.