(a) Sixteen hours later
(b) Six days later
(c) Seven days later
Figure 3: Measurement of ultra-weak photon emission with a photomultiplier tube. The blue line (DW), red line (SiO2), and the green line (QE powder) indicate the number of photons from deionized water only, deionized water mixed with silica powder, and deionized water mixed with the QELBY powder, respectively. The number of photons per one second was measured for eight minutes. The vertical axis depicts the number of photons, and the horizontal axis represents seconds elapsed.