29 November 2013

Perceptions of Time

Watching the Doctor Who 50th Anniversary Special, The Day of the Doctor, got me thinking a lot about time. Time is a difficult thing to define and describe. Think about it for a second, which is, of course, just a bit of time. How would you define "time?" We know that different people, and indeed whole peoples, perceive time differently. Here is what Dictionary.com says about time:

1. the system of those sequential relations that any event has to any other, as past, present, or future; indefinite and continuous duration regarded as that in which events succeed one another.

In the U.S. we see time as a commodity. Time is money. This is particularly true in certain places in the U.S., mostly urban areas in the Northeastern part of the country. Researchers were able to determine that the 3 fastest cities in the U.S. are Boston, Buffalo, and New York City. They did this through observations of pedestrians, bank tellers, and postal clerks. Coincidentally, the three slowest-paced cities are Shreveport, Sacramento, and L.A. While the three slowest cities are highly urbanized areas, especially L.A., the pace of life in the South and West are probably influenced by factors that include urban sprawl, less people per square mile, and a higher percentage of non-European ethnic groups.

Psychologists have also noted that people who act as though they have more time to accomplish particular task do actually have more time. How is this possible? Are ordinary people influencing the bending and twisting of time? Of course not. Instead, they are dealing with the stresses of time differently than those who feel the mental pressures that come with being hurried.

So, time is perception. Or, rather, time is relative. This is easily explained in the old adage, "Time flies when you're having fun."* It is common for people to think time passes quickly when they are enjoying themselves and that time drags when they're watching the clock. Indeed, watching a clock tick can actually cause the brain to perceive time moving backward. The eyes move back and forth rapidly and send electric messages to the back of the brain for interpretation. Because the eyes are constantly moving, the part of the brain that interprets sight is far away from the organ that sees, and the brain must flip and process the information it gets (all while performing other functions), the brain has to fill in the gaps in data. For this reason, the second hand appears to move more slowly, or even move backwards when being ogled.

Time is an abstract concept and we tend to think of it in abstract ways. For example, many of us, Young Earth Creationists excluded, have a vague idea of when dinosaurs roamed the Earth. And when we think of dinosaurs, we often think of them existing together. But the actuality is that the Mesozoic Era was about 186 millions years long and while dinosaurs existed for roughly that period of time, no one individual species did. Rather, there were huge gaps in time between various species. In fact, according to the Smithsonian National Museum of Natural History, "The distance in time between Tyrannosaurus and Apatosaurus (formerly called Brontosaurus) is more than the time between Tyrannosaurus and your parents, about 65 million years." Imagine that: we live in time closer to the T. Rex than the T. Rex lived to some other dinosaurs!

Even scaling back to the last few thousand years, similar time perceptions abound. The last Pharaoh of Egypt was Cleopatra, who lived from 69 BCE to 30 BCE. The Great Pyramid of Giza was built during Pharaoh Khufu's reign between 2589–2566 BCE. Thus, Cleopatra lived closer to the Industrial Revolution, the first airplane, the moon landing, the invention of the Internet, and everything else that happens for the next 475+ years than she lived to the building of that pyramid. To confuse things a little more, the boy king, Tutankhamun, reigned over Egypt about halfway between the two.

Speaking of the Industrial Revolution and the moon landing, it is no surprise that technological advances result in the quicker passage of time before the next technological advancement. Homo habilis, also known as the Handy Man, was the first species in the genus Homo and lived approximately 2 million years ago. Handy Man is the earliest known tool-maker. While Homo habilis is much more ape-like than modern human-like, we can say that human, or Homo, technology began with him and his Olduwan stone tools. It took about 900 thousand years to get from simple bangers and scrapers to a stone axe and another 100 thousand to control fire.

Around 200 thousand years ago, Homo sapiens burst onto the scene and technology begins to pick up the pace. About 100 thousand years ago, a wide array of stone stools are used by ancient humans. By 15,000 BCE, humans have domesticated animals, made clothing from a wide range of materials, been storing food and other items in ceramic pots, and crafted all sorts of ideological art, mostly out of clay, wood, and stone. Between 8000 BCE and 0 BCE, copper, bronze, and iron tools and weapons are smelted, the wheel and writing systems are invented, vast cities with enormous buildings rise up, and geographically dispersed bartering systems are adopted. In the next 1900 years, the world goes from isolated pockets of people to a true global society with major advances in science and the invention of large ships, the steam engine, railway systems, the printing press, and the telephone.

Over the last 113 years, technology has increased exponentially, from the first automobiles and airplanes to space flight, nuclear weapons, the internet and mobile technology, and large hadron colliders that allow us to smash subatomic particles together to study particle physics and quantum mechanics. All of this has happened since the first ancient humans walked the Earth, between 2.4 and 1.4 million years ago. And the Earth is 4.54 billion years old! To put it into perspective, if all of Earth's history were compressed into a 24 hour period, modern humans wouldn't show up until about 40 seconds before midnight.

I could keep waxing philosophical about time, and I likely will in future posts, but for now I will share some interesting time-related facts that I found while Google surfing the last few days. But before I do, I would like to pose the question, does time have a direction?

Fun facts about time:

Will Smith is now older than Uncle Phil was when Fresh Prince of Bel Air started.

All of the blinking in one day equates to having your eyes closed for 30 minutes.

The average person will spend 25 years asleep.

Rock beneath Niagara Falls is worn away at a rate of about a metre a year by the flow of water from Lake Erie 165ft above.

Bristlecone pines are the oldest single organisms on Earth, some having lived more than 5,000 years.

The average U.S. city commuter loses 38 hours a year to traffic delays.

Time changes over time. Because the Earth’s rotation isn’t perfectly reliable for how we define a second and tidal friction from the sun and moon slows our planet's rotation, the length of a day actually grows by 3 milli­seconds per century. This means that in the Mesozoic Era, each day only lasted 23 hours.

Because time slows with Earth’s slowing rotation, a “leap second” must be added every few years, most recently this past New Year’s Eve.

The world’s most accurate clock, at the National Institute of Standards and Technology in Colorado, measures vibrations of a single atom of mercury. In a billion years it will not lose one second.

Einstein was able to show that gravity affects time. Gravity actually slows time. As a side effect, airplane passengers, age a few extra nano­seconds each flight because they are further away from the gravitational pull of the Earth's core.

According to quantum theory, the shortest moment of time that can exist is known as Planck time, or 0.0000000000000000000000000000000000000000001 second.

Time has not always existed. Many scientists believe it was created at the same time (pun intended) as the rest of the universe during the Big Bang, 13.7 billion years ago.

As there is a beginning, there shall also be an end. But don't worry, most scientists believe it is about 4 billion years away, judging by the currently observable expansion of the universe. Many guess that humans will be long gone by the time time stops.

And this is one for the faithful: According to 17th Century Archbishop of Armagh James Usher, the Earth was created on the evening of Saturday, October 22, 4004BC. He determined this by adding up the family histories mentioned in the Bible going all the way back to the creation of Adam and Eve. (I know, I know - it's not a fact!)


* It is important to note that one study shows that time seems to go more slowly for study participants when they listened to music they enjoyed.

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