To Chen Chen, who was used to international metropolises, Windhoek seemed like some backwater town. Everywhere he looked, there were two- or three-story buildings, with only a few high-rises worthy of the international stage several hundred meters away.
That glint came from the top of the tallest commercial building among them.
At that moment, the glint kept flashing, like a cold, murderous star in broad daylight.
Chen Chen remembered an analogy one of his middle school teachers had once used: if you stood beside a lake and looked down at the water beneath your feet, you would find it transparent, and the sun's reflection overhead wouldn't be very bright.
But if you looked at the lake from a distance, you would find that the water wasn't transparent, and its reflection would be extremely strong—so strong it could make you squint.
This was the Fresnel effect.
The so-called Fresnel effect described the relationship between reflection and the angle of view. Apart from metals, all materials in the world exhibited the effect to varying degrees.
Chen Chen had used this effect, along with a location and angle he had carefully chosen in advance, to make the sniper trying to kill him impossible to miss.
[The other person is 15° above my line of sight. If we treat our positions as two points on a right triangle, its interior angles are 15°, 75°, and 90°.]
[In other words, the straight-line distance between me and the other person is 580 meters.]
[There's a parapet on the building's top floor, which means the other person has rested the sniper rifle on it. The recoil when they fire will make the scope's reflection disappear. So the moment the reflection vanishes is the moment the other person's bullet leaves the barrel.]
[The wind is coming from the