Nobel Prize-winning physicist Max Born once mused that, in science, humankind is “in a jungle and find our way by trial and error, building our road behind us as we proceed.” The process of discovery leaves behind a trail of ideas that didn’t pass muster, and the road to just about every breakthrough we’ve made is littered with alternate versions that got left behind. Here are just eight alternatives to popular technologies that didn't survive.

1. THE DYMAXION CAR

R. Buckminster Fuller’s “Dymaxion Car” is just one of many striking designs that the architect and inventor created in the first few decades of the 20th century (he also created the geodesic dome). Fuller designed the aerodynamic vehicle as part of his vision for a “Dymaxion World” (dymaxion was a portmanteau of “dynamic,” “maximum service,” and “ion”) in which efficiently designed vehicles, structures, and communities could go hand-in-hand with utopian living. The three-wheeled, roughly blimp-shaped car was designed to accommodate 11 passengers at speeds of up to 125 mph while getting 30 miles per gallon of gas (or, according to Fuller’s long-term vision, per gallon of alcohol-based fuel). The car drew interest and investment from a range of 1920s and ‘30s innovators, including magnate Henry Ford, who supplied parts to Fuller at a low cost, and famed flyer Amelia Earhart, who reportedly ordered one for herself around 1933. 

Sadly, the Dymaxion car’s future was cut short when a drive in the third prototype outside the 1933 Chicago World’s Fair ended in tragedy. Injured in the crash were passengers Colonel William Francis Forbes-Sempill and Charles Dollfuss, two famous aviators who had arrived on the Graf Zeppelin from Europe and were hurrying to the airport to fly back home. Fuller's prototype toppled over, and the accident injured the two aviators and killed the Dymaxion’s driver, Francis T. Turner. He was the second person to die in a Dymaxion accident. 

Another car’s aggressive rubbernecking of the strange vehicle, which ultimately forced the rear-driven Dymaxion car out of its lane, was likely more responsible for the crash than its design was; still, the incident sparked headlines around the world, and potential investment quickly dried up. Decades later, the Wall Street Journal also reflected that the experience of driving a reproduced version of the early car brought many safety concerns to mind.

2. THE PENNY-FARTHING BICYCLE

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The evolution of the modern bicycle began in the late 18th and early 19th centuries with new two-wheeled “hobby horses” that riders powered by pushing their feet along the ground (and without proper steering until Baron Karl von Drais de Sauerbronn's 1815 breakthrough). Through the 1830s, '40s, and '50s, bikes gained treadles, then rear wheel-powering cranks and rods, and finally even brakes. Still, riding these "velocipedes" and "bone shakers"—each fitted with approximately 110 pounds worth of wooden tires, iron wheels, and a big frame—was tricky business.

So, in the 1870s, the penny-farthing bicycle offered a solution to the “impractical gearing associated with directly pedaling at a conventional wheel axle,” according to Lay. Its large, powering front wheel—a big “penny” when compared to the tiny “farthing” that was the rear wheel—gave riders more traveled ground for each pedal rotation. 

Penny-farthing bikes provided a new, key kind of rapid transport good for covering long, flat distances. But the design’s very high seat meant that taking a header over the handlebars could cause serious injury, and general preference for the slower-but-surer “safety bicycle” and its more proportionate front wheel had penny-farthings mostly kicked to the curb in the 1880s. 

3. WOOD-PAVED STREETS

Popularized in the U.S. in the early-to-mid-19th century by Samuel Nicolson, wood block paving, or “Nicolson pavement,” offered a reprieve from the uneven cobblestones that filled most urban streets at the time. Fitted together in several different styles, the wooden blocks were also fairly easy to install, and cut down on street noise by being a gentler surface for horses’ hooves and rattling cart wheels. 

But wood’s propensity to rot and get slippery when wet, plus the fact that grooves from cart-wheels form much more quickly in wood than in stone, emerged as common downsides in cities that had embraced wood block paving; the creosote oil that was often used to preserve wood blocks and seal them together was extremely smelly, too. Historian Clay McClane has also pointed out that, during the Great Chicago Fire of 1871, the city’s creosote oil-soaked wooden streets—which mostly survived, themselves—“acted to spread the fire, rather than serving as a fire break” (the latter being something that asphalt and stone can do). Only a handful of U.S. cities still retain wood-paved street sections for posterity’s sake.  

4. PERSONAL RAPID TRANSIT

Automated, individualized transport may have always been one of the most enviable aspects of sci-fi stories, but efforts to put on-demand Personal Rapid Transit (PRT) vehicles on real-world roads—or, rather, on specially built real-world tracks—have also been underway for over half a century.

The idea of using networks of small on-rail, self-navigating pods to tackle urban congestion really started gaining speed and enthusiasm in the mid-1960s. Studies like Donn Fichter's 1964 "Individualized Automatic Transit and the City" and L.M. Cole’s "Tomorrow's Transportation: New Systems for the Urban Future" offered city planners several highly detailed visions of a simultaneously walkable, busable, drivable, and PRT-able modern metropolis. In cooperation with the Department of Housing and Urban Development (HUD), Cole presented “Tomorrow’s Transportation” to the U.S. House of Congress in 1968 as “a first major effort to formulate a comprehensive urban transportation research, development and demonstration program,” then-HUD Secretary Robert C. Weaver wrote in the study’s introduction.

Among other things, the study imagined a system of pods traveling with average speeds of between 50 and 70 miles per hour. At a capacity of 6000 riders per hour or higher, it suggested, the system's pods would cost less than 10 cents per mile each. It proposed demand-based group transit services like “dial-a-bus,” too, but also dual-mode vehicles that could run on both roads and tracks. Overall, its vision for efficiently transporting city residents from across the economic spectrum has remained mostly unchanged in more recent proposals for PRT systems, despite various technological and design upgrades. 

In the past few decades, just a handful of smaller-scale PRT systems have been built, including still-functioning lines in Morgantown, West Virginia and Suncheon, South Korea. As to whether or not PRT systems have what it takes to finally catch on, The Atlantic’s CityLab concluded in 2014 that, “At least as they're currently conceived, they probably don't.”

But don't count them out just yet: Researchers have recently suggested that a sort of hybrid PRT system—one using the kind of dual mode vehicles that were first suggested in the ‘60s—could be a more feasible answer to traffic congestion; in 2003, a Ford Research and Advanced Engineering team outlined their PRISM system [PDF] (or Program for Individual Sustainable Mobility) of “privately owned small, dual mode vehicles that can run on both conventional streets and a dedicated guideway" in urban zones, as well as the possibility of using various guideways for quicker, safer transport of different vehicle types.

5. SEGA’S HOLOGRAPHIC ARCADE GAMES

According to The Verge, Sega’s “holographic” game Time Traveler “looked like it was going to revolutionize the face of arcades” when it landed in 1991, with its built-in CRT TV and special curved mirror bringing characters from the game’s stereographic Laserdisc into (seemingly) three glorious dimensions in front of players’ eyes. But when Capcom’s record-breaking Street Fighter II consoles hit arcades shortly thereafter and established a new, higher standard for combat detail and options, Time Traveler’s innovative graphics couldn’t make up for its more simplistic gameplay in the eyes of young gamers, and the flow of quarters dried up almost as quickly as it had come.

6. BUBBLE MEMORY

The humble bubble often gets a bad rap for its seeming whimsy and impermanence, but bubbles were taken very seriously in the late 1960s and ‘70s as the potential future of data storage and processing in computing. Composed of parallel tracks of moveable, one-bit storage domains (or “bubbles”), the system used magnetic fields and pick-up to write, access, and read information stored therein, making it more durable than competitor systems—and potentially able to store much more data. In 1974—the same year that IBM research developed Bubble Lattice Storage [PDF] for circuits with even greater power and storage—Texas Instruments’ annual stockholder meeting even predicted that bubble memory systems “[had] the potential of replacing the mechanical disk and drum storage systems,” according to The New York Times.

By 1980, though, the innovative system’s bubble had burst as cheaper, easier-to-test semiconductor memories and magnetic-disk memories started taking over the marketplace, consistently getting better, faster, and more inexpensive as they did so.

7. THE AT&T “PERSONAL TERMINAL” TOUCH-SCREEN

Decades before the digital touch-screen became standard equipment on smartphones and tablets, AT&T’s research team was developing a much earlier version of the technology for use with their Personal Terminal 510 machines. According to a 1986 report by AT&T Information Systems engineer Thomas A. Schwartz, the screen consisted of a “soft, transparent membrane” covering the faceplate of a cathode-ray tube. The membrane registered a finger’s firm touch via photosensors surrounding the screen that detected interruptions in the screen’s trapped light.

As for the content behind the screen, the 510 functioned mostly as a very fancy phone: It let users directly dial any of 100 contacts, utilize a “time manager” program, and even crunch some numbers with an on-screen calculator. Thanks to its touch screen, Schwartz said the 510 could help with “drawing the computer-leery into the realm of data bases and computer applications.”

Schwartz describes the 510’s soft touch screen as “ideal for applications involving menu selection, [such as] one-touch dialing from shared-access corporate directories, automatic teller machines, airline seat selection, on-board automotive environmental control, and on-line factory process control systems.” But its high price, somewhat niche usefulness, and ultimately rather unwieldy screen kept AT&T’s phone from becoming a bestseller, and it would be years before the rather sophisticated technology behind it would start enjoying (and processing) human touch again. 

8. MECHANICAL, ACOUSTIC, AND PULSION TELEPHONES

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As competition surrounding the first wave of patented, functional telephones gained speed in the last few decades of the 19th century, a number of mechanical or acoustic models appeared that challenged the electromagnetic and liquid transmitter version developed by Elisha Gray, Alexander Graham Bell, Thomas Edison, and other inventors (though the latter would finally dominate the market and lead to the evolution of more modern phones). 

Thanks to the late-17th century inventor Robert Hooke, designs for a working acoustic telephone had already been around for about 200 years, and short-range versions of these mechanical, so-called "tin can" or "lovers" telephones were reasonably popular alternatives to Bell’s patented phone up through the turn of the 20th century. The Pulsion telephone, too (courtesy the Pulsion Telephone Supply Company), offered easier communication without needing any electricity to function, making it desirable in areas that didn’t yet have access to electric juice. 

Ultimately, though, the electromagnetic telephone’s ever-further service capabilities made it a tough act to follow, and the device’s proliferation after Bell’s patent on it expired meant that the 20th century would decidedly be a time for electromagnetic phones, and not lovers’.