Let's assume that there is easy and very cheap method for someone to enter 'separate dimension' in one place, walk and exit in another. For an external observer it would look like instant teleportation. The person using would literary have to walk given distance and in their frame it would take time.
- It's widely known technology
- Users doesn't need any special equipment to enter/exit or to survive that place
- It takes no time for external observer, but the same time as walking give distance for user (User would exit older by time that he spend inside)
Momentum is preserved therefore moving to/from moving vehicles would be a rather bad idea
It ignores any physical barriers that would be in 'normal' world (e.g. walls or ravines).
- It is impossible to exit in place that is occupied. (You are safe from appearing inside wall or someone), small objects (gases,dust, small insects etc.) are pushed away.
- One can easily protect any place from being accessible to/from there (So no entering vaults or escaping prisons)
- It's impossible/very impractical to bring any vehicle with you ('roads' inside dimension while nice to walk on would be uncrossable even by cycling or skating, cars and bigger objects would be too big to be transported (point below)).
- User can take with himself anything he can carry. Anything that touches ground (boards of flying/floating vehicles also counts) (also via any other proxy (except air))) will stay at one side. (Boots are fine for some reason).
- There is no way to meet anyone in that 'dimension' (Two users would have to enter exactly at the same time, we can assume it would be impossible), except for using previous method to carry a second person.
When there are more than one person inside each of them can separately decide to exit, they would exit together only if (see above).
Anything left inside while there is no one would decay to dust, same happens to anyone who dies inside.
transfer happens when one decides they want to enter and is instant, even two tp would be too big difference for multiple users to be there at the same time.
It can't be limited who is allowed to use it, except for placing that person inside protected zone.
- You are unable to see how current situation outside is, (it would be wise checking live feed of place where you plan exit just before you enter) You can only check if place corresponding to your current is empty enough.
- Light inside is comparable to one in very cloudy day.
- Terrain is monotone and gray.
My first ideas
It would make escapes much easier, while it wouldn't help in actual escape from protected place it would help fugitive to hide immediately after they would be outside protected zone.
Smuggling, that one is obvious
Crossing difficult and/or dangerous terrain, although riding around or flying above would be probably often better choice. Still there would be place where direct (via this method) route would be much more accessible than normal, but probably wouldn't be common
Ideas mainly from comments
- Using it for calculations, you can bring computer with yourself and use it as long as you have power.
- Using it for learning/work: similar to above.
One of answers made me think about one thing. Store owners wouldn't want people disappearing from they shops, most people wouldn't want possibility for others to appear in their houses. It would probably soon end in situation where almost everywhere in cities is restricted area, except for places specially designated for this purpose. It could be necessary in busy places to avoid constant accidents, while you can't appear inside someone, you can appear just in front of them.