But I know they say some sub-atomic particles can travel through time.

The particles travel at near the speed of light.

The smaller particles on the other hand can travel all the way to the lungs from which they cannot be expelled.

In other words, particles can travel through walls, doors, etc. if the door or wall is thin enough.

The distance a particle can travel before reaching its initial position is said to be the size of the dimension.

As a particle travels through the silicon, its position will be recorded in 3 dimensions.

The particles travel near but not exactly at light-speed, so the devices are need to slow down the light.

Cosmic rays are particles traveling through space with high energies.

In quantum mechanics the same particle can travel between two points by a variety of paths.

Thinning the blood helps to ensure that small particles do not form and travel to the brain.