The desktop computer as a gaming rig will never die until I can write game code for consoles or cell phones without a desktop computer being somewhere in the pipeline, as it is ground zero for any game development effort.

Its easier to get set up and develop games on the PC than it is any other platform. As such, it has a much larger independent development community and has more choices when picking games.

Don't even get me started on the cost of indy development on consoles either. Its gotten better in recent years, but you usually still have to buy a platform development kit, which usually isn't cheap.

Simple: we don't. Future generations of 10.000 years will probably have the means to detect radioactive sites from the other end of the galaxy. And mabye they'll even have the means to dispose of them quickly and safely. So why warn them? We should be more concerned about how to warn people in the more near future, like 200-500 years...

Try answering the question without assuming that we managed to avoid having to go back to the stone age due to war, plague, famine, etc.

Better to have it and not need it than to need it and not have it.

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