Fuzzballs become less dense as their mass increases due to "fractional tension". When matter or energy (strings) fall onto a fuzzball, more strings are not simply added to the fuzzball; strings "fuse together", and in doing so, all the quantum information of the infalling strings becomes part of larger, more complex strings. Due to fractional tension, string tension exponentially decreases as they become more complex with more modes of vibration, relaxing to considerable lengths. The "mathematical beauty" of the string theory formulas Mathur and Lunin employed lies in how the fractional tension values produce fuzzball radii that precisely equal Schwarzschild radii, which Karl Schwarzschild calculated using an entirely different mathematical technique 87 years earlier.