The best viewing time of the glittering Summer Palace

The best time to watch the glittering in the Summer Palace is around 4 pm before and after the solar term of the winter solstice.

"Golden light piercing the hole" is a scene that the bridge opening of the 17-hole bridge in the Summer Palace is illuminated by the sunset every winter. The best time to watch "Golden Light Piercing the Hole" is around 4 pm before and after the solar term of the winter solstice, and the daily duration is only about 20 minutes.

The phenomenon of golden light piercing only exists around the winter solstice in a year. This angle of light comes from the angle of the earth's revolution around the sun and the earth's rotation. Around the winter solstice, the sun is closest to the tropic of Capricorn, with the smallest light angle and the southernmost position.

Cause of orange glow at bridge opening.

It turns out that the light with shorter wavelengths such as green, blue and purple in the sunlight produces a lot of scattering in the atmosphere, while the light with longer wavelengths such as red, orange and yellow reaches the bridge in large quantities. Therefore, near sunset, the mixed color of red, orange and yellow is golden yellow, shining in the bridge opening, showing a beautiful "golden light piercing the hole" effect.

And with the setting of the sun, the color of golden light is constantly changing. At sunset, the thickness of the atmosphere penetrated by sunlight increases, and monochromatic light such as orange and yellow will also be scattered. The sunlight on the bridge is mainly red light, and bridge opening presents the effect of "red light piercing holes".