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What Is a Periscope

What Is a Periscope?

A periscope is an optical instrument designed to provide a view of objects or areas that are otherwise obstructed from direct line of sight. It consists of a series of prisms or mirrors, which enable light to change direction within the periscope, allowing users to observe objects from a concealed position. The term “periscope” originates from the Greek words “peri” (around) and “skopein” (to look), accurately describing its purpose: to see around obstacles.

Read: What is Magnetism

The History of Periscopes

Periscopes have a fascinating history, dating back to the ancient civilizations. However, their most significant impact on modern technology can be traced to the 19th and 20th centuries. Let’s take a captivating journey through time to understand the evolution of periscopes:

Early Instances of Optical Devices

In ancient times, simple periscope-like devices were used for various purposes, including spying, military reconnaissance, and navigation. The Chinese philosopher Mozi is credited with inventing the first known optical periscope around the 4th century BCE.

Submarine Periscopes: A Revolutionary Invention

During the 19th century, the need for concealed observation arose in the realm of naval warfare. Submarine periscopes emerged as a groundbreaking invention, allowing submarines to observe the surface while remaining submerged underwater. This innovation marked a turning point in naval tactics and warfare strategies.

Periscopes in the Modern Era

Advancements in optics and engineering led to the integration of periscopes into various applications beyond submarines. Today, periscopes are utilized in military vehicles, armored tanks, aerospace technology, and even consumer devices such as smartphones.

How Does a Periscope Work?

To truly appreciate the brilliance of a periscope, let’s dive into the inner workings of this optical marvel:

Understanding the Prism System

The core component of a periscope is its prism system. These prisms play a crucial role in redirecting light, enabling users to see objects from a different vantage point. Periscopes generally consist of two prisms: the main prism and the reflecting prism.

Light Reflection: A Clever Maneuver

When light enters the periscope, it reaches the main prism, where it undergoes total internal reflection. This reflection ensures that the light remains within the periscope rather than escaping. The light then encounters the reflecting prism, which directs it towards the eyepiece, providing the observer with a clear view of the otherwise hidden object.

Periscopes in Different Industries

The versatile nature of periscopes makes them indispensable in various industries:

Military and Defense

Periscopes play a critical role in military reconnaissance and armored vehicles, allowing soldiers and tank operators to survey their surroundings safely.

Submarines and Naval Applications

Submarine periscopes continue to be vital for submerged vessels, helping them navigate and gather crucial information about surface conditions.

Aerospace Engineering

Periscopes are employed in aerospace applications, aiding pilots in maintaining situational awareness during aerial maneuvers.

Consumer Devices

Periscope technology has found its way into consumer products, such as smartphones, enhancing photography and video capabilities.

Applications of Periscopes: From Adventure to Science

Periscopes have found diverse applications across multiple fields, and some of them might surprise you:

Underwater Exploration and Adventure

Periscopes are essential tools for underwater explorations, offering divers a means to observe marine life and shipwrecks without getting too close.

Architecture and Construction

In the construction industry, periscopes are utilized to inspect hard-to-reach areas of buildings and bridges, ensuring structural integrity and safety.

Medical Procedures

Periscopes are used in minimally invasive surgeries, enabling surgeons to see inside the body without making large incisions, thus reducing patient trauma and recovery time.

Astronomy and Observatories

Periscopes are incorporated into some telescopes and observatories to redirect light and facilitate celestial observations.

Periscopes in Entertainment and Photography

In the entertainment industry, periscopes have been adapted for use in some cameras and smartphones, allowing users to capture images and videos from unique angles.


Q: What is the difference between a periscope and a telescope?

A: While both optical devices serve different purposes, telescopes are primarily used for distant observation of celestial bodies, whereas periscopes are designed for viewing objects from concealed positions.

Q: Can I make a homemade periscope?

A: Yes, crafting a simple periscope is an enjoyable DIY project. By using mirrors, cardboard tubes, and some creativity, you can create your very own periscope.

Q: Are periscopes only used in military applications?

A: No, modern periscopes find applications beyond the military, such as in submarines, aerospace engineering, construction, and photography.

Q: How long have periscopes been in use?

A: Periscopes have a long history, dating back to ancient times. However, their significant impact on modern technology began during the 19th century with the advent of submarine periscopes.

Q: Do smartphones really use periscope lenses?

A: Yes, some high-end smartphones utilize periscope lenses to enhance their zoom capabilities, providing users with more versatile photography options.

Q: Are periscopes used in space exploration?

A: While periscopes are not commonly used in space exploration, some observatories and telescopes incorporate periscope-like components to redirect light for specific purposes.