If we specifically engineered a doomsday bunker to preserve technology and weaponry, what could we preserve and how long could we make it last? I'm looking at a timeline of circa 300 years.
You can assume that it has power (e.g. geothermal) and is completely undisturbed until it is opened. Any type of preservation we're currently capable of is on the table: airtight, vacuum sealed, submerged in oil, wrapped in your grandmother's couch cover, etc.
I'm looking for things that would work "out of the box", so a gun without working gunpowder isn't much help. Would any kind of explosives still work? Nuclear weapons? Computers or electronics? Motors (with fuel)?
EDIT: Sorry, first time on the site. Thanks for the responses. I did read the other posts, but they were all centered around how long our current technology would remain working. I didn't see anything about how long things could last if we specifically tried to preserve them.
I'll try to answer/clarify things here.
Say the human race knew that we were facing an extinction event like an asteroid collision and wanted to preserve ourselves. We built a number of bunkers to house and preserve the human race. One of these was a military bunker that did not contain people, but was designed to rearm them whenever they were able to come recover its contents. What would they put in it and how long could they make it last?
Our hero discovers one such bunker. What would he find it in it? Assuming he has all the knowledge necessary, what could he pick up and use more or less immediately?
Good point on the word "technology". I mean stuff. Maybe some specific example questions would help:
Assuming the bunker had a continual working geothermal power source, could they build electronics that still worked? Computers?
My current version of the bunker is protected by a large blast door that requires a motor to open it. Ideally, I'd like to have working electronics and motors so that a single person could open it. For example, a modern keypad and keycard. Could that still work? Is there another way?
I'd like our hero to be able to fight his way back out of the bunker with some kind of advantage. For the sake of this discussion, assume he can figure out any technology. It sounds like it would be possible to preserve guns and gunpowder for that long, so that would be an option for this.
There also needs to be a reason that the new nations of the world want to get into the bunker. Guns are a good motivator, but bombs are better if they would keep that long.
Hope that helps and thanks again.