The direction of the ray may also change. This property of waves is called refraction and commonly occurs with light rays. A normal is a dotted line drawn perpendicular to the surface of the ...

Ultrasound close ultrasoundSound with a frequency greater than 20,000 Hz (20 kHz). is sound with a frequency greater than 20,000 Hz. Humans cannot hear ultrasound but many other animals can, such ...

The Berkshires museum is getting a transformative gift: 331 artworks from the Renaissance on, worth several hundred million dollars, and money to build a new wing. By Ted Loos The museum will ...

A new exhibition at the British Library explores the public, private and spiritual lives of such figures as Joan of Arc, Christine de Pizan and Hildegard of Bingen Meilan Solly A new exhibition in ...

October 26, 2024 • College students often use posters to help spruce up their dorm. At the University of Chicago, they get a chance to borrow works by prominent artists for a year.