(1) Where P (watts) is the radiated power from a body of area A (m2) at temperature T (K). Îµ is emissivity, a dimensionless number between 0 and 1 that determines the. efficiency of a body to radiate and absorb energy. A perfect radiator and absorber has an emissivity of 1. Soil, ice, rock, asphalt and human skin have emissivities slightly less than 1. Ï -8is the Stefan-Boltzmann constant, 5.67 x10 Wm-2T-4 T is the body temperature in Kelvin. So if absolute temperature (in Kelvin degrees) doubles, radiated power increases by a factor of sixteen. Also, changes in temperature alter radiation peak wavelengths. Temperature increases move peak radiation to smaller wavelengths and vice-versa. Equilibrium and Solid Angles
Martin Luther King was often seen wearing a gold Rolex DayDate at many of his speaking functions. Musician John Mayer is seen here wearing his Rolex Daytona. Talk show host Ellen DeGeneres also wears a Rolex Daytona. Actor Brad Pitt is often seen wearing a Rolex Explorer.
About Ellen DeGeneres. Emmy award winner Ellen DeGeneres is probably one of the most popular TV talk show hosts in the world today. This American actress, talk show host and stand-up comedian is known to host the 10-year running The Ellen DeGeneres Show. Her net worth is estimated to be $345 million in 2015.Ellen DeGeneres was born on January 26, 1958 in Metairie, Louisiana, U.S. She is of Irish, German, English and French descent. Ellen is a self-proclaimed lesbian. She is a recipient of 13 Grammy Awards for her impressive hosting abilities.his American actress, talk show host and stand-up comedian is known to host the 10-year running The Ellen DeGeneres Show. Her net worth is estimated to be $345 million in 2015. Ellen DeGeneres was born on January 26, 1958 in Metairie, Louisiana, U.S. She is of Irish, German, English and French descent.