What's Up With That Leap Second?

In case you hadn't heard, a leap second will be added to the calendar at midnight on December 31, 2008.  Modern timekeeping will hang in limbo for a whole second between the end of 2008 and the start of 2009.  Like most people, you won't even notice or give it a second thought.

For most of us, the leap second is something to laugh at -- a trivial bit of minutia of interest only to pedantic scientists and utterly irrelevant to everyone else.  How could anyone possible care whether or not we bother with a second at the end of the year? 

It turns out that such precision in timekeeping is extremely important to the modern world.  We live in an age of computers where a second is like a century worth of processor cycles.  Global telecommunications depend on precise timekeeping.  We all know how awkward it can be to have a dropout or a delay of one second when talking on the phone.  Timekeeping and navigation are interdependent, and the precision accuracy of GPS systems is a function of accurate time measurement.  Indeed, our modern world would have major problems without that leap second!

Atomic Time

We read that the LORD created the Sun, Moon and stars for time measurement (Genesis 1:14).  For millennia of human history, the luminaries were sufficient for man's timekeeping needs.  Down through history, the second was defined as 1/86,400 of a solar day.  This was more than enough for telling time from a sundial, or even a wind-up mechanical clock that corresponded to the solar day.

It's only in our breakneck, high-paced modern world that God's timekeepers have been deemed to be inadequate.  Perhaps the LORD never intended us to live as we do today.  On the other hand, the LORD did give us the minds to study His handiwork to learn the rules of His creation, and fashion devices to serve our needs.  As we all know, modern technology can be a blessing or a curse, depending on how it is used.  These are questions best discussed at home or with your pastor.

For better or worse, since the 1950s our modern world functions on a system of International Atomic Time (TAI) in which the second is defined as 9,192,631,770 oscillations of a certain electron orbital in a Cesium-133 atom.  TAI is periodically adjusted to result in Universal Coordinated Time (UTC) which is the basis of our standard system of civil timekeeping.  Atomic timekeeping is maintained through a time service of professional scientists working through the U.S. Naval Observatory and other agencies in the USA and abroad.

The Unruly Earth

Our modern method of atomic timekeeping does not exactly correspond to the rotation of the Earth.  Though our world spins around each day at more or less the same speed to complete a 24 hour day, it so happens that the Earth's rotation is slowing by a very tiny amount.  This amount is not in any way discernable to human perception, but factors in heavily with atomic time. 

To make matters worse, this slowing does not occur evenly.  Sometimes the Earth's rotation slows by a greater amount and sometimes by a lesser amount.  Scientists suspect that there are "inhomogenieties" within the Earth, that there might be magma or something "sloshing around" inside our planet, though there is no way to know anything with certainty.  In spite of everything that we have learned about our world, we only live on the thin skin of a sphere 8000 miles in diameter, and we actually know very little about what might lie thousands of miles under our feet.

Anyway, to account for the irregular slowing of the Earth's rotation, the professional time service inserts a leap second to TAI every couple years as needed, in order to bring the unruly Earth into the precise harmony of UTC-based civil time.  A leap second was added on December 31, 2005 and another for December 31, 2008.  

To accommodate the addition of the leap second, I've noticed over the years that the television broadcasts from Times Square in New York tend to start the countdown one second late, so that midnight arrives at the time everyone would expect!

At the present time, there is discussion as to whether our system of atomic time should be modified to eliminate the leap second.  Depending on the outcome of that, we may not hear about these leap seconds in years to come.     

The Slowing of the Earth Rotation

In addition to whatever internal "sloshing" that makes the Earth's spinning uneven, a smooth, regular, predictable slowing of the Earth's rate of rotation has been observed. This has been found to be the result of the tides raised by the Moon.  

The Moon's gravity acts upon the level of the oceans, and raises the tide along the coastlines of the Earth.  As the Earth rotates, the tide is like a wave continually moving west and colliding with the coast, resulting in a continual friction between land and sea.  It is this friction that slows down the Earth's rotation by a very small amount each day.

As shown by Isaac Newton in A.D. 1687, for every action there is an equal and opposite reaction, and this is also true in the case of the Earth's slowing rotation.  Remarkably, as a result of this tidal interaction, the Moon is actually moving farther away from the Earth!  As the Earth's rotation slows down, the orbit of the Moon grows larger.  This is a result of conservation of angular momentum, since the momentum lost from the Earth's rotation appears in the Moon's motion in its orbit. 

This is similar to a skater who twirls faster as her arms are drawn closer, and twirls slower again as her arms are extended.  It seems strange to me that energy can be transferred from the Earth to the Moon without any direct physical contact, yet this energy is in fact transferred through the gravitational field that connects our world with its satellite.

The Receding Moon

This Earth-Moon tidal interaction was known theoretically since the 1870s.  It was finally proved by Apollo 11 in 1969.  Astronauts Neil Armstrong and Buzz Aldrin set up a laser ranging reflector on the Moon.  A laser beam is fired from the Earth and reflected back to the Earth.  This ranging reflector is a corner-cube reflector similar to our traffic signs that return light beams back in the same direction down the same path.  In this way, a measurement can be made from the Earth to the Moon a quarter-million miles away.

By precisely measuring the travel time to the reflector, the exact distance from the Earth to the Moon can be measured.  From this, it has been found that the Moon is moving away from the Earth by about three centimeters a year, about an inch and a half!  The last I heard, the Apollo 11 lunar ranger reflector was still functioning and this measurement is continually being maintained nearly 40 years later. 

The Other Darwin's Theory

The tidal interaction between the Earth and Moon was theoretically deduced in  1878 by George Darwin, the son of proto-evolutionist Charles Darwin.  Like father like son, the younger Darwin following in the family tradition of making long inferential leaps from skimpy scientific evidence.  George Darwin proposed the "fission theory" of the Earth-Moon system. 

Upon realizing that the Moon was receding from the Earth, Darwin taught that, once upon a time, the Earth and Moon must have been part of the same ball of glop.  Darwin figured that the mass of the Moon mst have flown off away from the Earth to form its own body in space.  Darwin proposed that the crater formed by the escaping Moon resulted in the Pacific Ocean, which happens to be just about the right size to fit the Moon. 

The fission theory was contended during Darwin's lifetime.  Basically, if the Earth was spinning fast enough to throw off the Moon, how would it have formed as a single mass in the first place?  There is too much angular momentum in the Earth-Moon system to form a single stable body.  Darwin's theory was ultimately debunked by Apollo 11 and the other Apollo missions which brought back lunar samples that proved that the Earth and Moon were not made of the same stuff and thus could not have arisen from the same body. 

The "fission" or "ejection" theory and other secular creation myths is touched on in this Update article, The Face on the Moon.  If nothing else, the failed theory of Darwin, Jr. encapsulates the whole problem with his father's methodological approach to science -- that small, isolated observations can be extrapolated to produce a grand, all-encompassing universal theory of science.  It's unfortunate that the science mainstream refuses to acknowledge this simple point as continually made by creation scientists.     

Leap Second article

10:13 PM, Wednesday, February 4, 2009
Posted by Anonymous

This is very interesting. I am especially excited to hear the details of how we know the moon is getting farther away. I first heard the concept on a creation astronomy DVD, but the speaker didn't explain how we knew. Thanks!

Untitled Comment

10:26 PM, Wednesday, February 4, 2009
Posted by jay

Gimme a break, that was a long-winded explanation! Did you read the article? As mentioned, the Apollo missions verified that the Moon is receding by a small amount. Don,t know what else you need to know!

Siblings

7:12 AM, Thursday, April 9, 2009
Posted by Anonymous

I'm guessing that Jay is Anon's brother! I agree with Anon. Very interesting!

Here's an application: We are the light of the world, like the moon (without our own light, we reflect the Son's light--Ps 27.1). Sometimes the world comes between the moon and the sun, causing "no moon" in the night sky. Same thing happens with God's "light bearers." Like the moon, we should be moving farther away from the world, closer to heaven, every year.