Reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power, reflected at an interface; the reflectance spectrum or spectral reflectance curve is the plot of the reflectance as a function of wavelength. The hemispherical reflectance of a surface, denoted R, is defined as R = Φ e r Φ e i, where Φer is the radiant flux reflected by that surface; the spectral hemispherical reflectance in frequency and spectral hemispherical reflectance in wavelength of a surface, denoted Rν and Rλ are defined as R ν = Φ e, ν r Φ e, ν i, R λ = Φ e, λ r Φ e, λ i, where Φe,νr is the spectral radiant flux in frequency reflected by that surface. The directional reflectance of a surface, denoted RΩ, is defined as R Ω = L e, Ω r L e, Ω i, where Le,Ωr is the radiance reflected by that surface; the spectral directional reflectance in frequency and spectral directional reflectance in wavelength of a surface, denoted RΩ,ν and RΩ,λ are defined as R Ω, ν = L e, Ω, ν r L e, Ω, ν i, R Ω, λ = L e, Ω, λ r L e, Ω, λ i, where Le,Ω,νr is the spectral radiance in frequency reflected by that surface.

For homogeneous and semi-infinite materials, reflectivity is the same as reflectance. Reflectivity is the square of the magnitude of the Fresnel reflection coefficient, the ratio of the reflected to incident electric field. For layered and finite media, according to the CIE, reflectivity is distinguished from reflectance by the fact that reflectivity is a value that applies to thick reflecting objects; when reflection occurs from thin layers of material, internal reflection effects can cause the reflectance to vary with surface thickness. Reflectivity is the limit value of reflectance. Another way to interpret this is that the reflectance is the fraction of electromagnetic power reflected from a specific sample, while reflectivity is a property of the material itself, which would be measured on a perfect machine if the material filled half of all space. Given that reflectance is a directional property, most surfaces can be divided into those that give specular reflection and those that give diffuse reflection: for specular surfaces, such as glass or polished metal, reflectance will be nearly zero at all angles except at the appropriate reflected angle.

Such surfaces are said to be Lambertian. Most real objects have some mixture of specular reflective properties. Reflection occurs when light moves from a medium with one index of refraction into a second medium with a different index of refraction. Specular reflection from a body of water is calculated by the Fresnel equat

Adonis is an 1884 burlesque musical produced by Edward E. Rice who composed the music along with John Eller; the book was written by William Gill. After playing at Hooley's Opera House in Chicago in the summer of 1884, it debuted at the Bijou Theatre in New York on September 4, 1884, it there had a run of 603 consecutive performances, making it the longest-running show on Broadway during that period, the longest Broadway run of all time until 1893. After the show ran for 500 shows, a cocktail was created in its honor, it was co-written and directed by Henry E. Dixey who starred as the titular Adonis; the Adonis cocktail was named in honor of the musical's 500th showing. Adonis tells the story of a gorgeous male statue that comes to life and finds human ways so unpleasant that he chooses to turn back into stone – after spoofing several famous personalities; the company traveled to London. Adonis, an accomplished young gentleman of undeniably good family, insomuch as he can trace his ancestry back through the Genozoic and Paleozoic period, until he finds it resting on the Archaean time.

His family name, by the way, is Marble. Marquis de Baccarat, a polished villain, it is well enough to describe his character. Bunion Turke, father of Rosetta, an unblushing appropriator of the stock in trade of a well-known and worthy old histrionic miller. Talamea, a sculptor who, like most of her sex, is in love with her own creation. Artea, a Goddess, Patroness of the fine arts. Duchess of Area, aesthetic to the verge of eccentricity, rich to the verge of Millionairism, sentimental to the verge of gush. Lady Nattie, daughter of the Duchess, she and her sisters Hattie and Pattie are professional beauties. Lady Hattie, daughter of the Duchess, she and her sisters Nattie and Pattie are professional beauties. Lady Mattie, daughter of the Duchess, she and her sisters Nattie and Pattie are professional beauties. Lady Pattie, daughter of the Duchess, she and her sisters Nattie and Mattie are professional beauties. Rosetta, a simple village maiden, the happy possessor of a clear conscience and a strong will.

Gyles, Myles, & Byles, ordinary everyday rustics. Gills, Sills, & Tills, homely rustics; the Plumed Knights. Henry E. Dixey... Adonis George W. Howard... Bunion Turke Herbert Gresham... Marquis Ida Bell... Lady Nattie Lillie Grubb... Talamea Jennie Reiffarth... Duchess Louise Eissing... Artea Amelia Summerville... Rosetta History of the Musical Stage 1870s-1880s: Burlesques and Pantomimes Image of original cast program Adonis at the Internet Broadway Database

Saint Augustine Webster was an English Catholic martyr. He was the prior of Our Lady of Melwood, a Carthusian house at Epworth, on the Isle of Axholme, in north Lincolnshire, in 1531, his feast day is 4 May. At the outbreak of the English Reformation, England had ten of these hermitage-monasteries. In English they are called "Charterhouses," from the French name of the location of their first foundation, in the mountainous area of the "La Chartreuse"; the Carthusians were held in the highest esteem. The government was at first anxious to secure the public acquiescence of the monks of the London Charterhouse regarding royal supremacy in ecclesiastical matters, since for the austerity and sincerity of their mode of life they enjoyed great prestige; that is one reason why King Henry VIII set out to destroy them. Augustine Webster was educated at Cambridge University, became a monk at the Charterhouse of Sheen. In 1531 he became prior of Our Lady of Melwood, a Carthusian house at Epworth, on the Isle of Axholme.

In February 1535 he was on a visit to the London Charterhouse with his fellow prior, Robert Lawrence of Beauvale to consult the prior of London, John Houghton about the approach to be taken by the Carthusians with regard to the religious policies of Henry VIII. They resolved to go together to Cromwell, the King’s Vicar-General, to represent their sincere loyalty, but to petition to be exempted from a requirement that would violate their conscience. Cromwell was unsympathetic. Sometime around the middle of April 1535, fellow Carthusians and Lawrence were imprisoned in the Tower on the orders of Thomas Cromwell for refusing to take the Oath of Supremacy, they were soon joined by Bridgettine Richard Reynolds. All four were charged for their denial of the royal supremacy; the trial took place 28 April. They were led back to prison; the jury deliberated all day, when Cromwell sent to inquire the cause of the delay, it was intimated that they would find the men innocent. Despite threats, the jury refused to return a guilty verdict until Cromwell appeared before them in person.

All four were hanged and quartered at Tyburn on 4 May 1535. Augustine Webster was one of the Forty Martyrs of England and Wales canonized by Pope Paul VI. St. Augustine Webster Catholic Voluntary Academy in North Lincolnshire is named after him. Forty Martyrs of England and Wales Carthusian Martyrs of London Carthusian Martyrs