i think your comment isn't just toward the guy. Lets put that into perspective
>they allow the balloonist to control buoyancy without dropping ballast or carrying enough fuel to maintain lift sufficient for the entire craft.
1. Rozier invented that 2 chamber balloon.
2. helium was discovered only more than half a century later.
If anything, i think the guy deserve the respect for what he did directly risking his life in the face of the known and unknown dangers and limited knowledge and technology of the time.
The combustibility of hydrogen was no secret; de Rozier was a chemist, and in fact famously demonstrated that feature of hydrogen by inhaling it and blowing it out across an open flame. There are risks to be bravely taken, and then there's foolhardy disregard for the dangers one knows. I think de Rozier fell into the second class of risk-takers.
The first class? Try Lilienthal, Percy Pilcher, Geoffrey de Havilland, the X-15 pilot whose name I can't recall — all these died testing something they couldn't have known would kill them, and the world gained from their sacrifice.
De Rozier had an idea that he knew he couldn't safely implement, but went ahead and did it anyway, and died. What did we learn from it? We knew hydrogen was flammable — de Rozier himself demonstrated it safely, except for his eyebrows. The balloon was only flown the once, and there's no evidence he grasped its potential, having little understanding of piloting a balloon. Useless sacrifice, in my opinion.
>Let's be very clear about how bad an idea this was: it was a balloon filled with hydrogen, with a chamber beneath it filled with hot air warmed by an open fire. An open fire. Beneath a container of hydrogen.
(I'll spare you argument about your facile comparison between a strong aluminum tank covered with 5000 pounds of thermal-protective material and a thin silk balloon.)
The Challenger astronauts didn't have all the knowledge they needed to be aware of the certainty of their own deaths — I'd hold that there was no such certainty. The explosion was due to a confluence of events beyond their control, even beyond their knowledge. De Rozier had all the knowledge he needed to avoid dying, and no new information was gained by his death. There's not just a line between the two, there's a broad gulf, dividing reasonable reliance on systems that one knows could fail, and unreasonable trust in a device one knows to be misconceived from the start.
>they allow the balloonist to control buoyancy without dropping ballast or carrying enough fuel to maintain lift sufficient for the entire craft.
1. Rozier invented that 2 chamber balloon.
2. helium was discovered only more than half a century later.
If anything, i think the guy deserve the respect for what he did directly risking his life in the face of the known and unknown dangers and limited knowledge and technology of the time.