Diffuse reflection is the reflection of light or other waves or particles from a surface such that a ray incident on the surface is scattered at many angles rather than at just one angle as in the case of specular reflection.
 An "ideal" diffuse reflecting surface is said to exhibit Lambertian reflection, meaning that there is equal luminance when viewed from all directions lying in the half-space adjacent to the surface.
Specular reflection, also known as regular reflection, is the mirror-like reflection of waves, such as light, from a surface.
 In this process, each incident ray is reflected, with the reflected ray having the same angle to the surface normal as the incident ray.
 The result is that an image reflected by the surface is reproduced in mirror-like ("specular") fashion.
 The law of reflection states that for each incident ray the angle of incidence equals the angle of reflection, and the incident, normal, and reflected directions are coplanar.
 This behavior was first described by Hero of Alexandria (AD c. 10–70).
 It may be contrasted with diffuse reflection, in which light is scattered away from the surface in a range of directions rather than just one.
Polishing is the process of creating a smooth and shiny surface by rubbing it or using a chemical action, leaving a surface with a significant specular reflection (still limited by the index of refraction of the material according to the Fresnel equations.)
 In some materials (such as metals, glasses, black or transparent stones), polishing is also able to reduce diffuse reflection to minimal values.
 When an unpolished surface is magnified thousands of times, it usually looks like mountains and valleys.
 By repeated abrasion, those "mountains" are worn down until they are flat or just small "hills."
 The process of polishing with abrasives starts with coarse ones and graduates to fine ones.
In photography, a copy stand is a device used to copy images and/or text with a camera.
 The stand consists of a board onto which the media is placed and a tripod-mount parallel to it, usually with an adjustable height.
 Light is provided by bright lamps mounted on either side of the media at 45° angles.
 This provides uniform lighting and reduces specular reflection, keeping glare low.
A glossmeter (also gloss meter) is an instrument which is used to measure specular reflection gloss of a surface.
 Gloss is determined by projecting a beam of light at a fixed intensity and angle onto a surface and measuring the amount of reflected light at an equal but opposite angle.
In physics, backscatter (or backscattering) is the reflection of waves, particles, or signals back to the direction from which they came.
 It is a diffuse reflection due to scattering, as opposed to specular reflection like a mirror.
 Backscattering has important applications in astronomy, photography and medical ultrasonography.
In 3D computer graphics, Schlick's approximation, named after Christophe Schlick, is a formula for approximating the contribution of the Fresnel factor in the specular reflection of light from a non-conducting interface (surface) between two media.
Hero of Alexandria ( ; Greek: Ἥρων ὁ Ἀλεξανδρεύς , "Heron ho Alexandreus"; also known as Heron of Alexandria ; c. 10 AD – c. 70 AD) was a mathematician and engineer who was active in his native city of Alexandria, Roman Egypt.
 He is considered the greatest experimenter of antiquity and his work is representative of the Hellenistic scientific tradition.
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated.
 Common examples include the reflection of light, sound and water waves.
 The "law of reflection" says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected.
 Mirrors exhibit specular reflection.
In atomic physics, a ridged mirror (or ridged atomic mirror, or Fresnel diffraction mirror) is a kind of atomic mirror, designed for the specular reflection of neutral particles (atoms) coming at the grazing incidence angle, characterised in the following: "in order to reduce the mean attraction of particles to the surface and increase the reflectivity, this surface has narrow ridges".

Question: Who was considered the greatest experimenter of antiquity, and was one the first to describe specular reflection?
Answer: Hero of Alexandria