Meditações - o presente não se mede

Present resembles the sharp point of a recording laser or needle, unlike the present, the past and future are measurable durations of time. Past historical events are in our memory just like recorded material is on tape, CD or DVD. This similarity suggests that past is just like a record in memory, while future is like an unrecorded tape. Future may just be a projection created by our mind from our past experiences stored in our memory. The fact that the most real feeling of time "the present" is not measurable while the past and the future which are not accessible can be measured strongly suggests that the way we perceive time is an illusion.

Internet Encyclopedia of Philosophy