The Liquid Rainbow is caused by a unique phenomena: a red plant – Macarenia clavigera – growing in the riverbed. Other colors come from black rocks, green algae, blue water and yellow sand, producing an iridescent effect. The river also features waterfalls, pools and caverns, making it even more dramatic.
Danxia Landforms, named after Mount Danxia in Guangdong province, are stunning geological formations that are unique to China. They were formed when red sandstone and other minerals were deposited by rivers over a period of about 24 million years.
Synesthesia is an anomalous blending of the senses in which the stimulation of one modality simultaneously produces sensation in a different modality. Synesthetes hear colors, feel sounds and taste shapes. What makes synesthesia different from drug-induced hallucinations is that synesthetic sensations are highly consistent: for particular synesthetes, the note F is always a reddish shade of rust, a 3 is always pink or truck is always blue.
These dancing celestial hues have been both feared and revered throughout history. Today, although we know their cause – charged particles ejected from the sun reacting with the earth’s atmosphere – they are no less awe-inspiring. Enormous curtains of bright green, red and blue sway among the stars. To see them, you must travel north to the Arctic circle, away from light pollution, on a clear, dark night when the solar winds are blowing. Wait, look up and you might just catch the greatest show on earth.
In psychology, the Stroop effect is the delay in reaction time between automatic and controlled processing of information, in which the names of words interfere with the ability to name the colour of ink used to print the words.