david williams

Is color a property of matter or is it created in the brain?
Colors are both real and fictional. Light consists of different wavelengths of light.
Is this bag white or blue?
Social network users around the world are debating the true color of a bag that is photographed and posted on Twitter.
NASA expert answers a 4-year-old girl's letter about satellite Europa
Dr. David Williams from NASA responded with her letter and included a photo with pictures of the Europa Clipper and the satellites Europa and Jupiter in the back.