From Fax to Forever: Unraveling the History and Science of Video, a Veritasium Perspective

Inspired by Veritasium, explore how the concept of scanning from the first fax machine evolved into the technology of moving electronic images we know as video, from early mechanical systems to the advent of the cathode ray tube and beyond.

Discover "How Was Video Invented?" Journey through the history of video, from its roots in facsimile technology and early mechanical scanning to the all-electronic era of television (tv) and the video camera. Learn about key innovations and the evolution of video, inspired by Veritasium......

The technology of film, involving the straightforward process of focusing a two-dimensional light image onto a two-dimensional strip, boasts a relatively linear history. However, video, which we understand as moving electronic images, possesses a far more intricate past, marked by numerous transformative changes. This exploration, drawing inspiration from the engaging science communication of Veritasium, delves into the fascinating journey of how video was invented, tracing its evolution from early concepts to the digital age.

The Precursors to Motion: Scanning and the First Fax

The fundamental challenge in creating video was converting a two-dimensional light image into a one-dimensional electrical signal. The solution to this seemingly complex problem surprisingly has roots in the first fax machine, an invention by the Scottish clockmaker Alexander Bain in 1843. While Bain's device only transmitted static images, its underlying principle of scanning – moving across an image line by line – proved foundational. His system used synchronized pendulums at a transmitter and receiver. At the transmitter, an electric "finger" would trace over a metal sheet with a non-conducting ink drawing. Where the finger encountered metal, it would conduct an electrical signal. This signal was then sent to the receiver, where it was applied to chemically treated paper that darkened upon receiving electricity, thus reproducing the original handwritten note. Although Alexander Bain only dealt with static images, his invention of scanning is why some consider him a true pioneer in the lineage leading to television.

To achieve moving images, a much faster rate of scanning was necessary. This brings us to 1884 and a 23-year-old German student, Paul Nipkow, who patented the Nipkow disk. This device was essentially a large disk with a spiral arrangement of pinholes. Light passed through the spinning disk, creating a moving spot of light that would scan across a subject. Reflected light from the subject would then be picked up by light sensors, generating an electrical signal. This signal could be transmitted to a receiver. At the receiving end, this electrical signal would modulate the brightness of a light source positioned behind another synchronized Nipkow disk, thus recreating the image from the transmitter. While rudimentary, the Nipkow disk system was used for experimental broadcasts for a couple of years in Britain and America, arguably producing the first-ever broadcast television image. However, it soon became evident that this mechanical approach was not the optimal path forward. By 1939, mechanical tv was largely replaced by all-electronic tv.

The All-Electronic Era: The Cathode Ray Tube

The all-electronic television era was ushered in by the cathode ray tube. This is a glass vacuum tube containing an electron gun at its rear. The electron gun would fire a beam of electrons towards the screen, which was coated with a phosphor, a chemical that emits light when struck by electrons. Magnetic fields were used to scan this electron beam across the screen from top to bottom and left to right. The brightness of the beam was controlled by varying the voltage on a control electrode, which determined the number of electrons hitting the screen at any given moment. A large number of electrons resulted in a bright spot, while fewer electrons created a darker spot, allowing for the creation of black-and-white images.

The journey to color video involved several experimental systems before the red-green-blue pixel system became the standard. One such attempt involved a tv with a spinning color wheel. Ultimately, the solution was to use red, green, and blue phosphors for each pixel on the screen, with three electron guns controlling their respective brightness. The electron beams would rapidly scan lines across the screen, typically 525 lines every thirtieth of a second, achieved by interlacing – scanning every other line each sixtieth of a second, requiring two scans to form one frame. Our persistence of vision allows us to perceive this rapid succession of lines as a continuous moving image, even though we are often looking at a blank screen. The resolution of these early tvs was around 480 lines, which is why 480p is still a video resolution option today. Interestingly, the "tube" in "YouTube" refers to this very component, the cathode ray tube.

Capturing the Image: The Camera Tube

Before the advent of light-sensitive chips used in modern cameras, the creation of the image to display on a television relied on vacuum tube designs. One common type was the image orthicon tube, sometimes simply called "Emmy," which is where the name for the Emmy Awards originates. In this camera tube, a lens would focus an image onto the front of the tube, which was coated with a photoelectric substance. This substance would release electrons in proportion to the incident light. These electrons were then directed back towards a thin glass target. Where more electrons struck the target, a more negative charge would accumulate. An electron beam from the back of the tube would then scan across this target. The more negative the charge at a particular spot, the more the scanning beam would be reflected back towards an amplifier within the tube. This reflected beam served as the signal that determined the brightness of that corresponding part of the displayed image. This technology was fundamental to how television images were created and displayed for decades.

The Missing Link: Recording Moving Images

Remarkably, video cameras existed for a couple of decades before the invention of workable video tape recording. This meant that initially, the purpose of video, or electronic images, was primarily for transmission – "television" literally meaning "seeing at a distance" – rather than recording for later playback, as was the case with film and motion picture technology. This reliance on live broadcasting presented challenges, particularly for time-delaying programs for different time zones across the United States. The rather ingenious, albeit cumbersome, solution was to point a film camera, a cinema camera, at a television screen and film the displayed image. This film would then be rapidly developed and broadcast a few hours later as if it were live. However, this method often resulted in picture quality issues due to the mismatch between the scanning lines of the television and the film. By 1954, the demand for time-delayed programming meant that television networks were using more film than all of Hollywood's film studios combined – an inefficient and costly situation.

The breakthrough came in 1956 with the introduction of the first practical video tape recorder. These early machines were the size of large desks and incredibly expensive, utilizing two-inch magnetic tape and spinning video heads operating at speeds comparable to a jet engine. This marked a significant shift, transforming video into a medium for recording and storing images, not just transmitting them. Since then, video technology has advanced rapidly, with miniaturization leading to formats like VHS, Beta, DV, and Mini DV, eventually culminating in today's solid-state storage. Today, video technology has arguably surpassed film in many aspects, as evidenced by the shift in the early 2010s towards digital cameras for shooting top-grossing movies. This has empowered individuals to create high-quality videos more easily than ever before.

This exploration into the history of video reveals a fascinating journey from the mechanical ingenuity of the first fax and the Nipkow disk to the electronic sophistication of the cathode ray tube and the video camera, ultimately leading to the ubiquitous videos we consume today.

Frequently Asked Questions: The Invention and History of Video

Q: How was video invented? 

A: Video's invention was a gradual process evolving from 19th-century facsimile systems. Early mechanical scanning devices like the Nipkow disk (patented in 1884) laid groundwork, but practical video systems took decades to develop, utilizing principles from the first fax machine.

Q: Who made the first videos?

A: The "first videos" in the sense of moving electronic images weren't made by a single person. Early experimental broadcasts using mechanical television systems, like those based on the Nipkow disk, could be considered some of the earliest moving electronic images transmitted.

Q: When was video recording invented? 

A: The first workable video tape recorder was invented in 1956. Before this, video technology was primarily used for live broadcasting (television).

Q: What was the role of the Nipkow disk in the history of video? 

A: The Nipkow disk, patented in 1884, was an early mechanical video scanner. It used a spinning disk with a spiral of holes to scan an image and convert it into an electrical signal for transmission. It's considered a crucial step in the history of video.

Q: What is a cathode ray tube, and why was it important for video? 

A: The cathode ray tube was a glass vacuum tube that became the foundation of all-electronic television. It used an electron beam to scan and create images on a phosphor-coated screen, replacing earlier mechanical systems and enabling higher quality video.

Q: How did the "first fax" machine contribute to the invention of video? 

A: The first fax machine, invented by Alexander Bain, utilized the principle of scanning an image line by line to transmit it. This concept of scanning was fundamental to the early development of video and television.

Q: When did video cameras become popular? 

A: Video cameras gained popularity gradually after the advent of video tape recording in 1956, which made it possible for non-broadcast use. Their widespread adoption increased with the miniaturization of recording technology into formats like VHS and later digital formats.

Q: What is digital video? 

A: Digital video is a system of representing moving images as digital data, as opposed to analog signals used in earlier video technologies like those based on cathode ray tubes and magnetic tape. Modern video recording and playback overwhelmingly use digital formats.