Light - UV - 11-14

This collection explores Ultraviolet light, suitable for ages 11-14.

About ultraviolet light: Ultraviolet (UV) light is an electromagnetic radiation with a wavelength from 400 nm to 100 nm, shorter than that of visible light but longer than X-rays. Though usually invisible, under some conditions children and young adults can see ultraviolet down to wavelengths of about 310 nm, and people with aphakia (missing lens) can also see some UV wavelengths. Near-UV is visible to a number of insects and birds. UV radiation is present in sunlight, and is produced by electric arcs and specialized lights such as mercury-vapor lamps, tanning lamps, and black lights. Although lacking the energy to ionize atoms, long-wavelength ultraviolet radiation can cause chemical reactions, and causes many substances to glow or fluoresce. Consequently, biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules.

Resources in this collection:

• Blu-Ray DVD Player: A National Science Learning Network Engineering Case Studies resource investigating the evolution of the Blu-Ray DVD player, starting with the invention of the laser in 1958.
  
  This is a science enquiry story of how these devices have evolved from the invention of the laser in 1958 to the high-tech blue laser Playstations that have greater capacity and definition then ever before. Reflection of light is the basis of how CD and DVD players work.