People will pay for a 5-digit ID?!

Hydrogen peroxide powered rocket packs fly for around 30 seconds, because they have a specific impulse of around 125, meaning that one pound of propellant can make 125 pound-seconds of thrust, meaning that it takes about two pounds of propellant for every second you are in the air. Mass ratios are low for anything strapped to a human, so the exponential nature of the rocket equation can be safely ignored.

A pretty hot (both literally and figuratively) bipropellant rocket could manage about twice the specific impulse, and you could carry somewhat heavier tanks, but two minutes of flight on a rocket pack is probably about the upper limit with conventional propellants.

However, an actual jet pack that used atmospheric oxygen could have an Isp ten times higher, allowing theoretical flights of fifteen minutes or so. Here, it really is a matter of technical development, since jet engines have thrust to weight ratios too low to make it practical. There is movement on this technical front, but it will still take a while.

John Carmack

Google has earned a lot of respect from web users. I genuinely believe them when they say "Don't Be Evil." I always laughed at anyone who complained that Google would misuse any data they collect about their users.

Google is trustworthy but secretly listening to a user's microphone sets a dangerous precedent. If other software firms see this and think it's acceptable and legal they will start doing it too. Oh, terrific, I'd love to have Microsoft listening to my microphone...