Teleporter
Teleportation is possible in the future. You would have to transfer the information separate from the particles of the actual person, but it is possible. If we were to do it now it would take forever to rearrange the particles back into a person.
In some Star Trek episodes on TV the transporter somehow duplicates a person. This is impossible if the Teleporter transfers the particles that the person is made from to beginning. The particles wouldn’t be able to duplicate. One person’s worth of particles can only make one person.