Your Brain is a Time Machine: The Neuroscience and Physics of Time

by Dean Buonomano

All that really belongs to us is time; even he who has nothing else has that. —BALTASAR GRACIÁN

time person year way day What do the words in the above list have in common? One would certainly be forgiven for not recognizing them as the five most commonly used nouns in the English language.1 That the word time sits atop the list, along with two others that are units of time, is a consequence of the overwhelming importance time plays in our lives. When we are not asking for the time, we are speaking of saving time, killing time, serving time, keeping time, not having time, tracking time, bedtime, time outs, buying time, good times, time travel, overtime, free time, and my personal favorite, lunchtime.

For their part, scientists and philosophers talk about subjective time, objective time, proper time, coordinate time, sidereal time, emergent time, time perception, encoding time, relativistic time, time cells, time dilation, reaction time, ...

And time is at the heart of the question of free will: is the future an open path, or preordained by the past?