Time Machine Safety Protocol

[rbandrews]

A time machine is the most dangerous device known to man. From the moment you turn on the box, absolutely anything can magically appear in it. Worse yet, if you're prepared for something bad to appear, that's almost a guarantee that that thing won't appear. That having been said, there are a few precautions you can take to ensure that you won't be killed after building one.

1. Time machines have increasing danger proportional to the length of time they've been running.
The longer the machine has been running, the longer the sender in the future has to prepare something to send through it. If you have a machine running in a lab for five minutes, chances are nothing more than a Weeble will pop out when you turn it on. Leave one running for a year, however, and your double has had a year to design the bomb to send back to kill you.

2. You can always know what's going to happen to your time machine, before it happens.
If you build a time machine that works in the lab, there is one thing you have to do before anything else: build a failsafe box and turn it on. Stand outside it with a gun. Wait for someone to come through, which will happen immediately after you turn it on. One of two types of people will come through: either yourself, with a message that something has gone horribly wrong, or someone else, which in and of itself is a message that something has gone horribly wrong. Listen to the story of whoever comes back, and then most likely walk away and never deal with time machines again.

3. The failsafe box is important. Keep it hidden, keep it safe.
The failsafe box is your way, your only way, to fix what you've broken in the timeline. You only get one real shot at this, and it only works if nobody else finds out about it. If it is revealed, then someone else can get in it and get back to earlier than you can, at which point you have no way to set things back to the way they were. You can't actually set everything back anyway (you'll always know how to make a time machine), but if someone else comes back in the failsafe instead of you, then the failsafe is worse than useless. Someone coming back to maliciously change your timeline is the single most dangerous thing that can happen to you. This possibility is the dangerous downside of the long-duration failsafe box.

4. Avoid paradoxes.
No matter what happens, you cannot interrupt a time box trip after you've found out about it. Any other type of paradox you can fix by doing another loop, but this one thing corrupts your own subjective timeline, and is thus irreversible. This is the cardinal sin of time travel. If someone has stolen one of your boxes, it is too late. This is not a possible avenue to prevent the theft; the only way out is to use your failsafe box, or other box that was activated earlier than the one they stole.