It's spring already? Physics explains why time flies as we age

Credit: CC0 Public Domain

A Duke University researcher has a new explanation for why those endless days of childhood seemed to last so much longer than they do now—physics.

According to Adrian Bejan, the J.A. Jones Professor of Mechanical Engineering at Duke, this apparent temporal discrepancy can be blamed on the ever-slowing speed at which images are obtained and processed by the as the body ages.

The theory was published online on March 18 in the journal European Review.

"People are often amazed at how much they remember from days that seemed to last forever in their youth," said Bejan. "It's not that their experiences were much deeper or more meaningful, it's just that they were being processed in rapid fire."

Bejan attributes this phenomenon to in the aging human body. As tangled webs of nerves and neurons mature, they grow in size and complexity, leading to longer paths for signals to traverse. As those paths then begin to age, they also degrade, giving more resistance to the flow of electrical signals.

These phenomena cause the rate at which new mental images are acquired and processed to decrease with age. This is evidenced by how often the eyes of infants move compared to adults, noted Bejan—because infants process images faster than adults, their eyes move more often, acquiring and integrating more information.

The end result is that, because are viewing fewer new images in the same amount of actual time, it seems to them as though time is passing more quickly.

It's spring already? Physics explains why time flies as we age
Adrian Bejan, the J.A. Jones Professor of Mechanical Engineering at Duke University Credit: Duke University

"The human mind senses time changing when the perceived images change," said Bejan. "The present is different from the past because the mental viewing has changed, not because somebody's clock rings. Days seemed to last longer in your youth because the young mind receives more images during one day than the same in old age."

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More information: Adrian Bejan, Why the Days Seem Shorter as We Get Older, European Review (2019). DOI: 10.1017/S1062798718000741
Provided by Duke University
Citation: It's spring already? Physics explains why time flies as we age (2019, March 20) retrieved 24 August 2019 from
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Mar 20, 2019
I'll have to go with Bleibtreu's Parable of the Beast. During my childhood, the proportion of events that are new or never before experienced is far greater than for me as a teenager. Although as a 70 year old I still experience new events, much of my daily life is notably similar to previous events. If a "new event" is a metric of time in my brain, then there are just fewer ticks of the event clock per day or month or year. Calendar time seems to pass more quickly.

Mar 20, 2019
Rgoff, i agree, as well, a three month summer break for a 10 year old is a huge proportion of their life versus 3 months for a 49 year old

Mar 20, 2019
waste of taxpayer money

Mar 20, 2019
65+ adult's day is 20~21% longer than a child 6~13, the range in which the greatest time dilation effect is noticed. So the brain would have to slow by more than 20% before any effect would register. At 20% slower an individual would be unable to catch a ball or even walk unassisted.

Yet most 65 year olds are perfectly normal...a little slower in remembering and thinking certain things but nowhere near enough for the suggested effect to have a noticeable impact.

Time dilation becomes noticeable by late 20s when the brain is still in peak performance, having only finished maturing in mid 20s...

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