Orange (colour) and absorb mostly greenish-blue light. (See also shades of orange). Other orange pigments include: The orange colour of carrots, pumpkins, sweet potatoes, oranges, and many other fruits and vegetables comes from carotenes, a type of photosynthetic pigment. These pigments convert the light energy that the plants absorb from the sun into chemical energy for the plants' growth. The carotenes themselves take their name from the carrot. Autumn leaves also get their orange colour from carotenes. When the weather turns cold and production of green chlorophyll stops, the orange colour remains. Before the 18th century, carrots from Asia were usually purple,
Photon energy to date, very-high-energy gamma rays, have photon energies of 100 GeV to 100 TeV (10 to 10 electronvolts) or 0.016 microjoules to 0.016 millijoules. This corresponds to frequencies of 2.42 × 10 to 2.42 × 10 Hz. A photon with a wavelength equal to the Planck length would have an energy of about 7.671 × 10 eV or 1.229 × 10 joules (12.29 gigajoules). This is roughly the amount of energy produced by the world's most powerful coal-fired power station, the Taichung Power Plant, during a period of 2.25 seconds. During photosynthesis, specific chlorophyll molecules absorb red-light photons at a