optical effects

Lasers discovered to block light, creating darkness
Strange optical effect found could change science's concept of darkness.
Appeared with the strange 'Bright Ring' in Moscow's sky
A bright cloud shaped like a ring that appeared in Moscow's sky on Wednesday made many people surprised.
Learn how to counter fake money from butterfly wings
Strange optical effects on butterfly wings can help people encrypt information on banknotes or other precious objects to prevent counterfeiting.