Day of Science (Algeria 2019)

Souvenir Sheet Day of Science it reflects the thematic directions:

A book is a medium for recording information in the form of writing or images. Books are typically composed of many pages, bound together and protected by a cover. Modern bound books were preceded by many other written mediums, such as the codex and the scroll. The book publishing process is the series of steps involved in their creation and dissemination.

Famous People refers to the fame and public attention accorded by the mass media to individuals or groups or, occasionally, animals, but is usually applied to the persons or groups of people (celebrity couples, families, etc.) themselves who receive such a status of fame and attention. Celebrity status is often associated with wealth (commonly referred to as fame and fortune), while fame often provides opportunities to make money.

A microscope (from Ancient Greek μικρός (mikrós) 'small', and σκοπέω (skopéō) 'to look (at); examine, inspect') is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope.

Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe.Modern science is typically divided into two or three major branches: the natural sciences (e.g., physics, chemistry, and biology), which study the physical world; and the behavioural sciences (e.g., economics, psychology, and sociology), which study individuals and societies.The formal sciences (e.g., logic, mathematics, and theoretical computer science), which study formal systems governed by axioms and rules, are sometimes described as being sciences as well; however, they are often regarded as a separate field because they rely on deductive reasoning instead of the scientific method or empirical evidence as their main methodology. Applied sciences are disciplines that use scientific knowledge for practical purposes, such as engineering and medicine