Stanley Meyer was an inventor in who died in 1998, and he can be best remembered for one thing.
He claimed that he had invented a car - a dune buggy - that could run on water.
He was thought to have developed an engine that would run solely on water - which would have been a huge deal if it had worked out for him.
There are a few theories on how he said he's done this.
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One reportedly being that he'd created a fuel cell that used a principle of splitting water atoms into their constituent elements.
This one mean using hydrogen and oxygen - using hydrogen as a fuel, strictly speaking.
Meyer's claim was apparently that his engine was able to separate the two elements down, and burn the hydrogen which would create energy.
According to his engine plans, oxygen and some water residue would be the only emissions.
An invention like this would be game-changing, and would turn the oil industry upside down - So it's easy to see that not everybody would be pleased with a nifty, environmentally-friendly invention like Meyer's supposed water-fuelled engine.
When Meyer died in 1998, his chilling reported last words made headlines.
He'd apparently been out at a lunch, according to his brother, when he grabbed his throat, fell to the floor and uttered the words: 'They poisoned me'.
However, when a toxicology report was released following an inquest into his death, there was 'no poison known to American science' present.
It was then later reported that Meyer died as a result of an aneurysm and the coroner's conclusion was a death from 'natural causes'.
Naturally, people have their theories about the situation.
A Reddit thread, r/pics, has some interesting comments and explanations.
One person explains: "The 'car that runs on water" and the "100MPG carburetor" are myths that have persisted for a long time and gained a lot of traction in the 80s and 90s. I remember hearing about them all my life.
"Both are technically true, you can run a car on 'water' and you can get 100MPG out of a carb, but whats left out is that we don't do those things for a reason, there are huge drawbacks. With water, you're basically just using hydrogen which takes way more energy to produce than you can get by burning it, and you can get 100mpg out of a carb but it won't output enough horsepower to be actually useful (think car unable to maintain speed or even climb a gentle hill).
"These conspiracies persist because there's enough of an element of truth to be extremely enticing to people who don't fully understand the problem".