Main Article  Theories about Blast door map equations  Main Discussion 
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The two differential equations shown on the right side of the map are standard engineering/physics equations: B vector, on the far right of the map, and H vector, immediately to the left of "C3?" on the map. B is magnetic flux density. H is magnetic field strength (or intensity).
There is also third equation, a trigonometric problem, in the top left corner of the map.
Coordinates
x4, y8, z15
 This would indicate an object that is not located on or under ground. The fact that the z coordinate is positive means whatever the object it is, it would be 15 units of measurement above the origin, which would most likely be a point on the ground.
 Origin could be a location underground as well, which would mean that object could be found at a height of zero.
Trig equation
 The equation B = 2 r*cos(θ) is used to determine the length of the base of an isosceles triangle in which θ represents the matching angles. So 2r*cos(72) would be used to find the base length of a 727236 triangle with the two matching side length’s known to be r.
 This equation is used recursively on the blast door meaning that author was analyzing a 727236 triangle inside of another 727236 triangle.
What does this mean? Perhaps the reason the artist wanted to find this length was so that he could find the exact location where the lines cross. If he knew that there were five objects located in a perfect pentagon shape but only knew the location of two of them, this equation would allow him to find the exact place where the unknown lines crossed the known line, r (connecting the two known points). After computing w he would simply follow r for a length of w from either direction and arrive at the crossing point.
B vector
H vector
 In the H equation there is a constant term (mu/G(p) then a partial with respect to k of a vector g. This is one of the steps involved in finding a magnetic field in the k directionthat is, in the Z direction, or up. There is no indication of the value of the g vector or of the constant. Why would someone write down just an intermediate step in an equation?
 In the H equation, the g vector is probably a pointing vector (a cross product of a magnetic and electric field) like a electromagnetic momentum density, and the partial derivative (the lower case delta / delta k) is with respect to k, which is likely the wave number (related to the wavelength of the EM field).
 If the calculator of the H equation was looking for magnetic field in the k direction (that is the Z direction, or up) they would have written partial d/dz. (It's very rare to see vector k as a derivative operator). k here probably represents wavenumber (2p/?).
 If k was a wavenumber, why are they taking a partial with respect to it?
 The H equation might be Hubble's constant, which gives the rate of recession of distant astronomical objects per unit distance away, it was the main observation which led to the Big Bang theory and gives a rough estimate of the age of the universe.
 The H equation might not be Hubble's constant (partly because it's a vector and not a scalar constant!). Although if H is a magnetic field vector, it's not clear what the other constants could be, apart from k which could be wavenumber, so in that respect would fit cosmology more.
Magnitude of B

 and could stand for internal and external.
 Another intepretation is that these are some kind of energy equations: and