With all this white stuff falling from the sky and blanketing the ground, and the moon and Venus shining so brightly in the sky, I’m reminded of an interesting concept I learned about in graduate school: albedo. Astronomers use the term albedo to quantify how much visible light a surface or object diffusely reflects.

Consider snow, for example — plenty of that around to illustrate the point. The albedo of freshly fallen snow is very nearly 1, meaning that a surface of fresh snow reflects nearly 100% of the visible light that falls on it.

Note that a smooth, snowy surface reflects light differently than, for example, a nice clean mirror. A snowy surface on a sunny day reflects incident light rays every which way, making the surface appear bright no matter how you look at it. A mirror reflects incident light rays so that each ray goes out at the same angle, relative to the mirror’s surface, as it went in. The term albedo is usually used to quantify diffuse reflection (or scattering) off a relatively rough surface, like a snow hill or a dirt road, rather than what’s called specular reflection off a smooth, shiny surface, like a mirror.

The albedo of snow is among the highest of all naturally occurring materials; snow is very white and bright, even on a mostly cloudy day. And speaking of clouds, when illuminated by the sun, they are very bright too.

It’s interesting, but off topic, to wonder why clouds and snow — both composed of water, which is transparent to visible light — have such a high albedo. And why the foamy head on a nicely drawn mug of beer is bright white, when the beer itself is yellowish and transparent. That’s for another column.

Astronomers have long measured the albedo of solar system objects to learn what the planets might be made of. If you’ve seen Venus lately, you won’t be surprised to learn that Venus has the highest albedo of any planet in the solar system. Venus reflects between 60% and 70% of the sunlight that falls on it. You might also be surprised, given the recent famously bright full moons, to hear that the moon’s albedo is very low. The moon reflects only about 10% of the sunlight that falls on it.

Imagine if the moon’s albedo was as high as Venus’. A full-moon night here on earth would be six times brighter.

We can also consider what earth must look like from other planets. Earth’s albedo is about 0.35, about half way between that of the moon and Venus. Viewed from Venus, the earth, which is about the same size as Venus, would appear only half as bright as Venus does from earth.

What’s Venus got that earth doesn’t? Earth is one-third covered by dark landmasses and two-thirds covered by water. And although the albedo of water can be very high, like when water is in the form of tiny droplets or frozen flakes of snow, the albedo of liquid water — of the oceans — is in fact very low. Liquid water is mostly transparent, so sunlight goes right into the oceans and is eventually absorbed. In fact, if it weren’t for the clouds that always partially cover earth’s surface, earth’s albedo would be much lower than it actually is.

Venus is totally cloud covered, and that’s why its albedo is so high, and why it is now so bright in the evening sky.

This column originally appeared in the Grand Haven Tribune on 16 January 2009.

Through breaks in the clouds, Venus is living up to her name “The Evening Star” right now. Find a patch of clear sky about half way up in the sky to the southwest a bit after sunset and you can’t miss her. She is by far the brightest star-like object in the evening sky.

Next week Venus reaches what astronomers call greatest elongation. In this configuration, Venus stands as far from the sun — from our perspective — as she ever gets. And during the weeks on either side greatest elongation, Venus shines brilliantly and sets long after sunset.

Venus is racing to catch up with earth as both planets orbit the sun. The race is like an individual-pursuit cycling race. Did you catch any of those races during the 2008 summer Olympic games? In individual pursuit, two cyclists start on opposite sides of an oval track and race to try to catch up and pass each other.

The race between Venus and Earth started on 9 June 2008 when Venus was exactly opposite the sun from us, in a configuration astronomers call superior conjunction.

Venus has the edge, however, because she orbits on the inside track. Venus orbits closer to the sun than does earth, so she has to cover a shorter distance to get around once. And on top of that, the laws of celestial dynamics make it so Venus always moves faster than earth. So Venus is steadily catching up to us from the west. And boy can we see her coming.

As Venus stands now, the angle between a line extending from earth to the sun and a line extending from earth to Venus is as large as possible. This angle is zero when Venus and the sun are lined up, like they were on 9 June 2008 when Venus was at superior conjunction, and will be zero again when Venus gets directly between earth and the sun in late May.

Venus, now at greatest elongation, is about 47 degrees away from the sun, and sets about four hours after sunset. But as Venus catches up, in the coming weeks, Venus will appear to get closer and closer to the sun and set sooner and sooner after sunset.

It is interesting that Venus will continue to brighten over the next few weeks, as she draws closer to earth, reaching maximum brightness about mid February

Venus’ brightness is affected by two things: how close Venus is to earth, and how much of Venus’ sun-lit half we can see. Right now, Venus is about 0.7 AU from earth (1 AU is the distance between the earth and sun) and appears through a small telescope like a half moon. By mid February, Venus will be about 0.4 AU from earth, but will appear like a tiny crescent moon.

Into the spring, Venus’ will rapidly dim, even though she will continue to get closer to earth. She dims as she draws nearest because as she slides eventually between the earth and sun we are able to see only a tiny sliver of her sun-lit half.

Venus will defeat earth in individual pursuit on 26 March 2009 when she slips between the earth and the sun, reaching what astronomers call inferior conjunction. At inferior conjunction Venus is not visible, even though she is less than 0.3 AU from earth — the closest any planet gets to earth — because then she rises and sets with the sun.

If you can find a patch of clear sky to the southwest in the next few weeks, Venus is brilliant.

This column originally appeared in the Grand Haven Tribune on 9 January 2009.

My family and I visited the Kennedy Space Center last week near the end of our Florida holiday vacation. While the visit and tours were interesting and comprehensive, the lasting impression it all made on me was one of nostalgia and honor of past accomplishment, with only a dimmest look to the future.

The Kennedy Space Center Visitor Center is located on Cape Canaveral, Florida, a short drive from the beaches and hotels of Cocoa Beach. Driving into the parking lot, a full-size mock space shuttle and the Rocket Garden — a standing collection of early NASA rockets — beckons visitors young and old. After standing in line (the first of many) to buy a $38 ticket, you’re in and facing the decision of what to do first.

Aside from the mock space shuttle and the rocket garden, the main part of the visitor center is built out something like the theme parks central Florida is so famous for. There are theatre attractions and “rides”, a restaurant and a huge gift shop, and here and there a few informative exhibits about NASA’s plans for the future.

The centerpiece of a tour of Kennedy Space Center is a three-stop bus ride onto the real estate of the complex. But the line is long — for us, more than an hour after lunch on a day when the center wasn’t very busy.

The first stop of the bus tour is an observation tower located some distance from the distinctive vertical assembly building and the two launch pads used to launch space shuttles. From this three-story tower, using the pay-per-view binoculars, one can sort of see the launch pads and some of the launch complex. Best for us here was the wildlife: wild pigs, alligators, raccoons and an armadillo. A line awaits to get back on a bus to move on.

The second stop of the bus tour, and the gem of the Kennedy Space Center, is a newly created museum of the Apollo moon-landing era. Inside the building, in addition to several other exhibit rooms and a theater (and another gift shop — it’s hard to get a five-year-old boy through a gift shop), are an Apollo capsule, a lunar lander and rover, and a mighty Saturn V rocket laid out on its side.

What an impressive vehicle. More than twice as tall as the space shuttle, the Saturn V is one of the most powerful machines ever made. The rocket was designed and built in the early 1960s under the direction of the famed German rocket scientist Wernher von Braun. Thirteen Saturn Vs were launched from Nov. 9, 1967 to May 14, 1973, taking men to the moon and establishing the United States first space station Skylab. That was more than thirty-five years ago now.

Nearing the end of our day, it just seemed like thirty-five years in line to get on a bus to push on to the third and final stop of the tour, a mini museum devoted to the International Space Station. Here, one can walk through several mock ups of ISS modules and have a look inside the large clean room where materials destined for the ISS are prepared for launch, and learn how badly NASA wants to “complete the space station.”

Then, another line to catch a final, sunset bus ride back to the visitor center.

If you visit the Kennedy Space Center, however, be sure to hit the Astronaut Hall of Fame. The Hall of Fame was established by astronauts and is located about six miles off the main complex. It is a wonderful museum with a great collection of space memorabilia and a variety hands-on exhibits for kids young and old.

This column originally appeared in the Grand Haven Tribune on 2 January 2009.

Like many others, my family and I traveled for the holidays. Let’s see if you can figure out where we are. I’ll give you a few hints.

This morning (I’m writing early Friday morning, hoping to make my deadline), I’m expecting a beautiful sunrise at 7:16 am, which I’ll be sure to get out to see. In the Grand Haven area, the sun will rise an hour later, at 8:16 am. Probably it will be cold and cloudy in Grand Haven (I’ve not looked up your weather forecast), so I don’t know if you’ll get out to catch the sunrise.

Later today, at precisely 12:29 pm my time, halfway between sunrise and sunset, the sun will reach it’s highest altitude. This is called solar noon. At solar noon here, the sun will be 40 degrees above the horizon.

Solar noon in the Grand Haven area today is a bit later, at 12:46 pm, and then the sun will be just 23 degrees above the horizon.

Tonight I’ll be sure to get out to see a nice sunset at 5:45 pm. In the Grand Haven area today, sunset is at 5:18 pm.

Today I’ll see the sun for most of the 10 hours and 29 minutes it will be above the horizon; you’ll have sunlight for just 9 hours and 2 minutes.

Have you figured out where my family and I are spending the holidays this year? Here is another hint: we’ve not seen a snowflake since the plane that flew us here was on its takeoff roll last Saturday. We got out in the nick of time.

Here’s how the numbers add up. Recall that our round earth is mapped out by lines of latitude and longitude. Pardon me if this is a review, but so we’re all on the same page, it goes like this. Lines of latitude run east-west parallel to the equator and map how far north (or south) of the equator a place is. Lines of longitude run north-south, wraping around earth, all passing through the north and south poles. Longitude maps how far west (or east) from Greenwich, England a place is. (Why Greenwich, England? I don’t know, off hand).

Notice that at solar noon where I am the sun is 17 degrees higher in the sky than it is at solar noon in the Grand Haven area. This betrays the fact that my family and I have travelled to a location that is 17 degrees of latitude south of Grand Haven. Grand Haven’s latitude is about 43 degrees (N).

Notice that solar noon occurs where I am about 15 minutes before it does in Grand Haven. The east-rising/west-setting of the sun is a consequence of earth’s daily west-to-east rotation. Earth spins 360 degrees in 24 hours, so at a rate of 15 degrees per hour. The quarter hour difference between my solar noon and yours betrays the fact that my family and I have travelled to a place that is about 4 degrees lof longitude east of Grand Haven. Grand Haven’s longitude is about 86 degrees (W).

Where are we? Latitude 26 degrees (N), longitude 82 degreees (W) – Punta Gorda, Florida.

It’s warm and sunny here. Warm and sunny because the sun is higher above the horizon all day long here compared to West MI. Very nice.

I hope you are enjoying the holidays. And as nice as it is here in Florida, our return to the land of snow and ice is surely going to be harsh.

This column originally appeared in the Grand Haven Tribune on 26 December 2008.

Winter sure didn’t sneak up on us this year. Astronomically, winter officially begins on Sunday Dec. 21 at 7:04 am EST, which is nice, because the beginning of winter is the beginning of the end. From Sunday on, the days will get longer, and West Michigan usually begins to see a bit more clear sky.

When it does clear up, the winter sky is always a wonder.

Astronomers have mapped the sky onto coordinate systems to help locate things. The simplest useful coordinate system is the altitude and azimuth system. Everyone has their own altitude and azimuth coordinate system. The center of your coordinate system is the point directly over your head, called the zenith. The altitude of the zenith is 90 degrees.

The altitude of the horizon is 0 degrees. Anything between the horizon and the zenith has an altitude between 0 and 90 degrees. Halfway is 45 degrees.

Azimuth is the compass direction you need to face in order to see something in the sky most conveniently. Around the horizon, north is 0 degrees, east is 90 degrees, south is 180 degrees and west is 270 degrees.

Your sky is divided into an east half and a west half by an imaginary line that runs from the north point on the horizon, overhead through your zenith, to the south point on the horizon. This line is called the meridian. The meridian is useful because as celestial objects rise and set, they reach their greatest altitude, and thus are easiest to see, when they cross the meridian.

When the clouds take a break from casting gloom over West Michigan, look along the meridian to the south a couple of hours after sunset for some of the brightest, most conspicuous stars and constellations.

Canis Major and the brightest star in the sky Sirius are low in the southeast, Orion, with bright blue Rigel and glowing red Betelgeuse, is at an altitude of about 45 degrees on the meridian, and Taurus the Bull, with the star Aldeberan marking his glowing red eye, are higher and to the west. Also look for the Pleiades, the tight cluster of stars, sometimes called the seven sisters, riding on Taurus’ back.

Closer to home, look for Jupiter and Venus low in the west and southwest. Jupiter at an azimuth of about 200 degrees and an altitude of about 30 degrees; venus at an azimuth of about 250 degrees and at an altitude of about 20 degrees. Both planets are very bright.

Also, early in January, you may catch a glimpse of fleet-footed Mercury. The closest planet to the sun is best situated for viewing on Jan. 4 2009 when it is at it greatest eastern elongation. Look for Mercury then at an altitude of about 10 degrees above the west-southwest horizon as soon after sunset as the stars begin to shine.

In the morning, you may see Saturn drifting between Leo and Virgo across the meridian at an altitude of about 50 degrees. But don’t look for Saturn’s rings these days (you would need a telescope anyways); Saturn’s thin ring system is oriented just about edge-on toward earth. Saturn’s rings won’t be visible again for about a year.

Happy holidays, and enjoy the snow. It won’t be long until we see more of the sun and sky.

This column originally appeared in the Grand Haven Tribune on 19 December 2008.

In the news are reports that the December 2008 full moon was the biggest and brightest of the year. True enough. The moon’s orbit isn’t perfectly circular, so the moon is sometimes a bit closer to the earth and sometimes a bit further away. December’s full the moon was as close to the earth as it gets. The result: a big, bright full moon.

Coincidentally, I caught a glimpse of the moon — one of the most unusual nearly-full moon’s I’ve ever seen — Thursday morning, Dec. 11, while walking the dog along the lakeshore. I wish I had camera with me; I’m at a loss to describe it with words.

Strolling along Harbor Drive in the wind and cold before sunrise, I happened to see a long, thin red glow out in the lake. At first I thought it was a ship, but the color wasn’t right. As the minutes ticked by, I realized I was looking at the moon slipping out from behind the clouds through what must have been a narrow swath of clear sky at the horizon toward the northwest. As I made my way north, the big, red moon, misshapen by refraction in the thick atmosphere, set gently on top of the lighthouse.

And after seeing the sight, I was reminded of an experiment I conducted, or rather tried to conduct, as you’ll learn, some years ago when I was unencumbered by having a regular job.

The holiday season is a busy time of year. Have you ever wished there were more hours in a day to get things done? Sometimes just an extra hour would be so helpful.

The sun defines our sometimes-too-short twenty-four hour day. The sun rises, passes overhead, sets and rises again once every twenty-four hours, and we march to the beat of its drum.

The moon, however, drums a different beat. The moon rises and sets about fifty minutes later each day compared to the day before. This delay, a consequence of the fact that the moon makes its way around the earth once each month. A day by the moon is nearly twenty-five hours long — there’s that extra hour!

So one day in Y2K, I decided I would try to live on moon time. I would get up around moonrise and go to bed around moonset, following the moon around the month, living luxurious twenty-five-hour-long days.

I started to march with the moon one day when the moon was new. The new moon rises and sets with the sun. Then each day I stayed up an extra hour or so and tried to sleep in an extra hour.

I was encouraged that I could adapt to the moon’s slow swing-shift by something I read about our natural sleep-wake cycle. It seems that physiological cycles combine with environmental signals, like the onset of darkness, to send us to bed at the end of each day. Absent the environmental clues — like when a sleep-research subject is asked to live in a cave for several months — it turns out our natural sleep-wake cycle runs more like twenty-five hours long. A moon day!

But I learned that the environmental clues are very powerful. After about ten days, when I was supposed to stay up to 7 am and sleep in until 3 pm, I was a zombie. I switched back to sun time and gave up the quest to put an extra hour in my day.

I’m interested to hear if anyone else has ever tried this.

This column originally appeared in the Grand Haven Tribune on 12 December 2008.

We’re in the midst of a particularly cloudy spell here in West Michigan. With all the clouds and snow, we’ve not been able to see the sky much. But it isn’t cloudy everywhere and professional and amateur astronomers around the world remain hard at work.

Professional astronomers report their advances in many high-brow journals, including The Astronomical Journal, the Astrophysical Journal, and Astronomy and Astrophysics. I don’t suppose many of you subscribe to these publications; they aren’t easy reads and don’t make good coffee-table books.

But if you’re ever interested to see what collectively the professional astronomical community does with its time, have a look at arXiv.org. This website is a document server where authors post their work before they submit to the major research journals. ArXiv.org is hosted by the Cornell University Library, with partial financial support from the National Science Foundation.

Here are a few of the astrophysics papers recently submitted to the archive.

How about having a look at “The Elliptical-Spheroidal and Elliptical-Elliptical Galaxy Dichotomies,” by John Kormendy at the University of Texas, Austin. Professor Kormendy analyzed a large amount of existing data on galaxies to conclude that galaxies known as spheroidals are not dwarf elliptical galaxies, but defunct late-type galaxies. This solves a long-standing problem in galaxy structure and evolution, believe it or not.

Check out “Discovery of Very High-Energy Gamma-Ray Radiation from the BL Lac 1ES 0806+524,” by a team of no fewer than 92 authors from around the world, literally. You might wonder how so many scientists can write a twelve-page paper (double spaced, with a few figures). The truth is that the paper was likely written by just one or two authors, who included the other collaborating scientists in the author list.

This work is based on data collected by an instrument called The Very Energetic Radiation Imaging Telescope Array System (VERITAS, another clever acronym). VERITAS is a new, major ground-based gamma-ray observatory. The observatory consists of an array of twelve-meter-diameter (almost forty feet) telescopes located in Amado, Arizona.

Or you could read “Revisiting the Confrontation of the Energy Conditions with Supernovae Data,” which will soon appear the Journal of Modern Physics D. The authors (M.P. Lima, S.D.P. Vitenti and M.J. Reboucas) write: “In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to model the Universe the violation of the so-called energy conditions is related to some important properties of the Universe as, for example, the current and the inflationary accelerating expansion phases.” And it gets worse from there.

Anyway, these are just three of the sixty-six astrophysics papers that were submitted to arXiv.org by 5 am EST today. Presently, about 5,000 papers are submitted to arXiv.org each month, across the disciplines it hosts: astrophysics, physics, mathematics, computer science, quantitative biology, and statistics.

The average montly upload rate to arxiv.org (click the image to hit the arxiv.org statistics page).

In the seventeen-some years arXiv.org has been collecting submissions, it has amassed more than half a million works.

One of the many, an oldie but goodie, is “The Ammount of Interstellar Carbon Locked in Solid Hydrogenated Amorphous Carbon,” by D.G. Furton, J.W. Laiho and A.N. Witt, from 1999. Complete with the misspelling in the title. I’ve always needed a good editor.

And all of these works are there for you to browse — for free — when the clouds in West Michigan keep you from gazing at the stars.

This column originally appeared in the Grand Haven Tribune on 5 December 2008.

Look to the west after sunset tonight to see Venus, Jupiter and the moon converge on a tiny patch of sky. The three objects, now easily the brightest things in the sky (other than the sun, of course), will be closest together on the evening of Monday, Dec. 1.

November and December, West Michigan’s two cloudiest months, are not the best times for stargazing. You might have to steal a glance through gaps in the clouds. But you only need a partly clear sky to see part of the sky, so don’t give up hope.

Presently, the sun is setting in Grand Haven at 5:11 pm, according to data provided by the US Naval Observatory. On Monday, Venus, Jupiter and the thin, crescent moon will set at about 8:30 pm, giving a three-hour window to catch a glimpse of their alignment.

It is worthwhile to note at this time of year that while meteorologically, winter is just beginning, astronomically, we’ve just about reached winter’s greatest depth. The shortest day of the year is in just a few more weeks, on Dec. 21, the winter solstice. So if you’re a sun-loving person, you can look forward to longer days and more sun.

But we don’t even have to wait until the winter solstice to see more of the sun. In early December, about two weeks before the first day of winter, we reach the date of the earliest sunset. The earliest sunset in Grand Haven is shortly after 5:10 pm on or about Dec. 8. The sunset time will steadily march later and later, after that, reaching 5:20 pm by the end of December, almost 6 pm by the end of January, and about 6:30 pm by the end of February.

In case you’re wondering why the date of earliest sunset doesn’t coincide with the winter solstice, the shortest day of the year, I can only point you to the best explanation I’ve found (from the US Naval Observatory FAQ): http://tinyurl.com/5q5odz. It’s pretty complicated, but interesting.

There is another thing you might want to keep an eye out for next week. Did you hear about the small tool kit that was dropped accidentally from the International Space Station? Observers from around the world are reporting seeing this tool kit from the ground with nothing more than a pair of binoculars.

The flyaway toolkit near ISS (image courtesy NASA).

You can read more about the flyaway tool kit, and get predictions concerning when and where to look to see it, and the ISS, at http://spaceweather.com.

The tool kit is spiraling downward into thicker and thicker atmosphere, and is expected to crash and burn in a year or so. The lower something orbits earth, the faster it moves, so for now, the tool kit is visible as a pinpoint of light flying a few minutes ahead of the ISS. The ISS and tool kit make several favorable passes over West Michigan beginning on Dec. 5. For ISS and the toolkit sighting opportunities from Grand Haven visit http://spaceweather.com/flybys/) and enter our zip code.

This column originally appeared in the Grand Haven Tribune on 28 November 2008.

Watching the latest space shuttle launch and reading the news about the astronauts space walking to repair the International Space Station (ISS), I was reminded of some of the oddities of low-earth orbit.

The ISS and space shuttle orbit earth little more than two hundred miles up. At this altitude, in what is called low-earth orbit, objects coast with little resistance just above the upper reaches of earth’s atmosphere.

Two hundred miles is not very high. Consider that the earth itself is about four thousand miles in radius. Two hundred miles on top of four thousand miles amounts to just five percent. The fuzz on a Michigan peach stands out in about the same relief as does the ISS orbit above earth.

It is a common misconception that there is no gravity in space. While this is true, to some extent, in the deepest reaches of outer space, it is decidedly not true just two hundred miles above earth’s surface. The force of gravity exerted by earth on an astronaut in low-earth orbit is about ninety percent as strong as it is when the astronaut is back home.

What explains all the floating around?

Spacewalking astronauts, and everything else in orbit around the earth, are “weightless” because they are freely falling toward the center of the earth. You can be weightless right now, for a brief period of time, in exactly the same way if you jump. The higher you jump, the longer you can be weightless.

Us earthbound folks, who experiment with weightlessness when we jump, have to face the abrupt end of our orbits when we hit the ground. As the saying goes: “it’s not the fall that kills you, it’s the sudden stop at the end.”

Weightless astronauts don’t eminently face the sudden stop because they are zipping along in orbit around the round earth in just such a way that they can fall forever and never get any closer to earth’s center or surface. In orbit, astronauts move horizontally at a speed the matches the distance they fall in any interval of time to the distance earth’s surface curves away below.

At what horizontal speed does something need to move in order to stay in orbit two hundred miles above earth’s surface? Really fast. Relative to earth’s center, things in low-earth orbit have to move about eighteen thousand miles per hour! At that speed, they scoot around earth in just ninety minutes.

All the fire and fury of a space shuttle liftoff is aimed at one thing: to get the shuttle and everything inside moving at eighteen thousand miles per hour. The energy required to reach an altitude of two hundred miles is tiny compared to the energy required to accelerate to the proper orbital speed.

You may have heard that one of the astronauts let a tool kit slip from her hands on a recent ISS spacewalk. Ultimately, like everything else in low-earth orbit, the tool kit will come back down.

For something to return to earth gracefully, however, it must shed the tremendous amount of energy it gained during launch and slow back down to a stop. That little tool kit, for example, has now as much energy as the average US home uses in two days. Before too long, after maybe a couple of years, the air molecules in the upper atmosphere will begin to tear at the toolkit, sapping its energy ever faster. When the kit falls into the thicker parts of the atmosphere, in a brief flash, it will be vaporized.

Let’s wish the astronauts a safe return.

This column originally appeared in the Grand Haven Tribune on 21 November 2008.

Have you ever had one of those days were suddenly you see your Universe in a whole new light? A day when it happens like in a work of fiction where the protagonist receives an electric shock or a blow to the head and instantly sees his place in the world, his relationships with other people and the vastness of the Universe for what they “really” are? A day when you perceive everything inside out and sideways?

Some say that perception is everything. Some say that the only reality is the one each and every one of us individually constructs in our minds, formed from our accumulated experience. You may find believing along these lines has some merit, especially if you’ve ever had one of those days when everything changes.

These reasoners contend that Science, for example, explains nothing; that Science is only a framework which allows us to come to grips with how the Universe behaves. Science allows us to make testable predictions about the Universe, and all is good when we perceive the Universe to behave as we predicted.

A leading ancient Roman science/math/astronomer/philosopher man named Ptolemy went to great lengths to write up his Science of the Universe in the second century AD. His volume on astronomy, entitled “Almagast”, described his view of the Universe — the sun, moon, stars and the planets Mercury, Venus, Earth, Mars, Jupiter and Saturn. Ptolemy’s model so accurately predicted the positions and complicated motions of everything that it worked nearly flawlessly for about 1,400 years.

The most notable attributes of Ptolemy’s model of the Universe are that it was earth-centered, and that the Earth was totally motionless, the absolute center of everything.

But then one day (figuratively), in the early part of the fifteenth century, it all changed. A polish astronomer named Nicolaus Copernicus saw the solar system in a whole new light. While not the first to have this idea, Copernicus was the first to lay out formally, for other scientists to ponder, the Science of a sun-centered Universe.

Copernicus’ best seller was entitled “De revolutionibus orbium coelestium”, which, in case your Latin is rusty, means something like “On the Revolutions of the Heavenly Spheres.”

The most notable attributes of Copernicus’ model of the Universe are that it was sun-centered, and that the Earth spun and orbited the sun with the other planets, no special place at all, except that we are here.

So Ptolemy had it all wrong. Or did he? The facts are that even after the Copernican Revolution, Ptolemy’s model predicted more accurately the positions of the sun, moon, stars and planets. It was only after being tweaked by scientists down the road that the notion of a sun-centered Universe — the Universe that is now our reality — prevailed.

With this little story (told briefly and probably inaccurately) in mind, next time you have a chance, step out of yourself and try to have a look at your Universe from the side. I’ve found that it helps to have your mind uncluttered by your everyday perceptions, and to have a star-filled sky overhead.

You may also want to have nearby some Tylenol. If you’ve ever had one of those days where you suddenly see the Universe in a whole new light, you know how bad of a headache you get.

This column originally appeared in the Grand Haven Tribune on 14 November 2008.