Time, a familiar yet elusive concept, continues to be a captivating mystery that has sparked human curiosity across a myriad of fields. From science to philosophy, religion to the arts, all have embarked on a quest to unravel time's true nature, yet it remains enigmatic. However, amidst this mystery, one aspect stands resolute in the measuring system we use to quantify time.

The modern international unit of time, the second, is a testament to our technological prowess. It is defined by the electronic transition of the cesium atom, a feat that showcases the remarkable advancements we have made. 

Time, as defined by physicists, is the intricate progression of events from the past to the present into the future. It's a fundamental aspect of reality, often called the fourth dimension, used to describe events in three-dimensional space. In other words, just as we can move up and down, left and right, and forward and backward in three-dimensional space, we also move through time, the fourth dimension. We cannot see, touch, or taste it, but we can measure its passage. 

Time slows down during emergencies or danger. The brain doesn't speed up, but the amygdala becomes more active. The amygdala, a small almond-shaped structure deep within the brain, is the region that makes memories. As more memories form, time seems drawn out. This suggests that our perception of time is influenced by the amount of information our brain processes during a given period.

The same phenomenon explains why older people perceive time as moving faster than when they were younger. Psychologists believe the brain forms more memories of new experiences than familiar ones. Since fewer new memories are built later in life, time seems to pass more quickly.

Hopefully, your time slows down as you work on this new puzzle!