A point of the horizon and a circle extending to it from the zenith; or an arc of the horizon measured clockwise between the south-point of the horizon and a vertical circle passing through the center of any object. An azimuth is an angular measurement in a spherical coordinate system. The vector from an observer (origin) to a point of …

A branch of astronomy that deals with the identification of habitable regions in the universe, the search for extraterrestrial life and effects of outer space environments on living organisms. It is the study of the origin and distribution of life in the universe. Astrobiology makes use of physics, chemistry, astronomy, biology, molecular biology, ecology, planetary science, geography and geology to …

If you touch a hot metal object, you will yank your hand away immediately. When this happens to you the first time, the sequence of events and the result (the burning of your hand) gets stored in your brain. This is what we call an experience. When you see a hot metal object next time, you will not touch it. …

Artificial gravity is the varying of gravity using artificial means. It is used largely in space, but also on Earth. It can be achieved by the use of different forces, in particular centrifugal force and (for short periods) linear acceleration. The creation of artificial gravity is considered desirable for long-term space travel or habitation. It allows for ease of mobility, …

This is technique whereby a diseased or damaged section of artery is replaced with tubing prepared either from synthetic materials, or with a section of healthy artery from the patient or from another person.

Argemone oil is extracted from argemone seeds. It is mixed with sunflower oil and sesame oil to increase their quantity. Consumption of this oil leads to health disorders among children. To avoid this, we must check the contents of the cooking oil. Many oil brands mention ‘no argemone oil’ on their packs.

Apomixis is asexual reproduction without fertilization — developing or producing without sexual union. This is a botanical term (also known as apogomy) used with respect to many plants. Apomixis can occur in two ways: when the embryo arises from unfertilized egg produced without meiosis, called agamugenesis; a nucellar embryo is formed from surrounding nucellus tissues. The seeds produced are generally …

The apogee is the point at which a body is at its furthest orbit from the Earth. The opposite of the apogee, the point at which an orbiting body is nearest to the earth, is the perigee. Apogee is an Earth-specific term, and other terms exist for different celestial bodies. The apsis, for example, is a generic term used to …

The current geological epoch we live in is called Holocene, which began around 9600 BC. However, considering the way humans have altered the course of the Earth scientists suggest that the epoch be renamed anthropocene. Nobel-prize winning chemist Paul Crutzen coined this term in a casual remark in 2002, while talking about how the Earth was entering a new epoch …

The point of origin of an earthquake inside the Earth is called the focus, and the point on the surface directly above it is the epicenter. Severe earthquakes are usually shallow focus-that is, they occur within 60 km (37 miles) of the surface.