Time is only linear in my corporal state, in my mind I really have no concept of time and use a watch just so I can keep track of it ~chuckles~. Yes, since the 60's and 70's time has been considered the next deminsion, however I would suspect that time is not the only Quantum Mechanic involved in this, just like Height, Width and Depth are all seemingly one deminsion or plane too us, so perhaps it would just be more than just a single component...
Space is the word given to the whole deminsion I think...sometimes called Real and Conceptual Space...Heighth, Width and Depth make up space, so we would have to find out what compenent and how many make up the compound of time. You have a good point as there is no way yet to dye or tag an electron to make sure it is the same one coming back and forth into dimensions ~chuckles~. I am assuming that they are part of the same molecular chain which causes the quantum assumption that it is the same one, but I would need to look some .edu stuff up to make sure ~smiles~. Think of it like a watch band with interlaced/linked sections, as it rolls it only appears to disappear because of the laws of light and reflection. In reality they could still be there but because of the light energy refraction causes a cloaking ability, so we think they disappear into another dimension but they are just invisble like a chameleon or an octopus ~smiles~.