The Entity of Time

When Einstein said we don’t feel the same speed of time and give the example of the feeling beside the fireplace, he did not want to give some examples to enrich psychological research. While, the main point is that the feeling of the speed of the passage of the time does not mean time is strictly limited to feelings or we can judge the entity of time only by our feelings of it. So, when we found that people moving in different speeds will lead to the different speeds of their aging speed, we can not object it only by different people’s probable similar feelings of the passage of the time.

So, maybe, it’s still necessary to clarify the usage of some most common concepts, such as time, space etc.