In July 2002, Appled filed a patent for a “Breathing Status LED Indicator” (No. US 6,658,577 B2). They described it as a “blinking effect of the sleep-mode indicator in accordance with the present invention mimics the rhythm of breathing which is psychologically appealing.”

The average…

Not to mention, the Ambient Light Sensor adjusts the brightness of the pulsing LED depending on surrounding lighting too!