Total internal reflectionIn physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium. It occurs when the second medium has a higher wave speed (i.e., lower refractive index) than the first, and the waves are incident at a sufficiently oblique angle on the interface.
Specular reflectionSpecular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. This behavior was first described by Hero of Alexandria (AD c. 10–70). Later, Alhazen gave a complete statement of the law of reflection.
Reflection (physics)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 (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves.
Born-digitalThe term born-digital refers to materials that originate in a digital form. This is in contrast to digital reformatting, through which analog materials become digital, as in the case of files created by scanning physical paper records. It is most often used in relation to digital libraries and the issues that go along with said organizations, such as digital preservation and intellectual property. However, as technologies have advanced and spread, the concept of being born-digital has also been discussed in relation to personal consumer-based sectors, with the rise of e-books and evolving digital music.
CoffeeCoffee is a beverage prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It has the highest sales in the world market for hot drinks. The seeds of the Coffea plant's fruits are separated to produce unroasted green coffee beans. The beans are roasted and then ground into fine particles that are typically steeped in hot water before being filtered out, producing a cup of coffee.
