"But 'the sun and moon together'..." He looked up at the sky. "Today is the sixteenth of the lunar month, when the moon is at its fullest. At high noon, the sun will be due south and the moon due west. If this groove is ingeniously designed, it should be able to receive both sunlight and moonlight simultaneously."
Qin Yue checked the astronomy software on her phone. "At 12:17 p.m. today, the moon will be at an azimuth of 285 degrees, and the sun at 180 degrees. If this groove is double-layered..."
Mu Feng had already taken out the jade seal, his Mystic Pupil fully active as he studied the structure of the groove. "You're right! Inside this groove are two reflecting surfaces at different angles—one aimed at the midday sun, the other at the moon at the same time. It requires both beams of light, plus the jade seal as a triggering medium, to activate the mechanism."
Chapter 61