1. Lock them in a room with a rotary dial phone.
2. an analog watch
3. a TV with no remote...
4. then leave directions for them on how to use, written in cursive...
And just where do you plan to find these terror weapons; dig up a time capsule?
There are available at my house Pappy....
don't use the rotary phone since i don't have land lines anymore, but I also don't have a smart phone.. a flip phone serves my needs just fine... I don't text, I talk to people..
i use an analog watch...
I have several TVs with no remotes.. which have lasted longer than a couple of smart TVs my wife has wanted..
and my 25 year old son is shocked at how good my hand writing is...
he was a 4.0 GPS student thru High School and College, yet he thinks I am a mathematical genius, because I can do math in my head.. and doesn't believe that we had to remember multiplication and division tables in grade school....