As a car enthusiast, I can think of a good one, the Ford Nucleon.
During the 1950s and 1960s, there was considerable interest in nuclear power and its potential applications. This led to the idea of using nuclear energy to propel cars. The concept behind a nuclear car was to utilize a small nuclear reactor to generate steam, which would then power the vehicle's engine.
Of course back in those days, this was extremely futurustic and some at the time thought this would be a game changer, but ultimately, the safety aspect was one of the biggest reasons why this idea was dropped, and I probably don't have to explain why it may not have considered to be safe, I mean, it was using nuclear power, so even if the engineers tried to make it as safe as possible, IF something went wrong, it would have been catastrophic.
Ever since then, the interests in the automotive sector has shifted to Electric and Hydrogen.
Still, a very intriguing concept car and idea.
Outside cars, you have blimps, and I personally believe if we tried to make something like a hindenburg today with existing technology, we might have been a lot more successful than back then (as it goes way back to 1930s), there are still some blimps used occasionally, I also don't believe those use hydrogen(?), but they are not the "game changer in air travel" it was once seen as, although we can't rule out a comeback.
What about you guys?
Wasn’t there a hubbub about the Segway?
Huge.
Only a few people saw it, mostly CEOs and billionaires. They said it could revolutionize cities, which is technically true, as part of a larger transportation shift. But the rest of the public just heard 'this will revolutionize the world'. And they didn't do any focus groups or beta testing or anything outside of their own company, so they didn't have anyone telling them 'I'm not gonna pay $5k for a fucking scooter'.
And then they launched, and people started telling them 'I'm not gonna pay $5k for a fucking scooter'. And then powered skateboards became the Next Big Thing, and then some Chinese companies realized nobody wants to learn to skate just to get around so they put a battery and a motor on a Razor scooter and suddenly Ninebot blew the fuck up.
Then Dean Kamen (inventor of Segway) got killed riding one, and Ninebot bought what was left of Segway.
fwiw looks like Dean Kamen is still alive; it was another owner - the one who bought the company from Kamen - died in the accident. someone named Jimi Heselden apparently.
Oh man, I remember the hype over Segway. "It'll change the world!" Along with the secrecy, like it was nuclear fusion or something.
Ninebot really showed them in the end, by making something nearly as good for like 1/8th the price.
Lol yeah the news kept saying stuff like a new transportation technology that will revolutionize how you get around. It doesn't use any gas or fuel. It was so mysterious and futuristic. Then ended up being an uncool scooter.
Back when they came out I checked the price on one, and it was closer to $12k. That was Harley-Davidson money at the time.
Holy crap. Gotta be smoking something serious to think people are gonna pay $12k for a scooter.
Til the dude who invented Segway died while riding a Segway. That tends to put an end to things quickly.