Interview with Ted Weimann, Author of “Paradox: Fascinating Anomalies of Science”

webTedTed Weimann is obsessed with science and shares what he learns generously in his recent book, Paradox: Fascinating Anomalies of Science from Quest Publications. If you want a crash course on the hottest topics in science today, I highly recommend this book, as you can tell from my recent review. Ted’s enthusiasm and love of learning comes through in his writing, thanks to his ability to synthesize the information and then explain it in a way a person of average intelligence can understand.

Ted was gracious enough to grant me an interview, which gives us further insights into his brilliant mind and his ongoing quest for knowledge, fueled by his “Question Everything” attitude.

MF: What motivated you to compile Paradox’s rich collection of modern research?

TW: The thrill of learning about these fascinating topics.  I so thoroughly enjoyed the dark energy / center of the universe enigma over the years, that I began noticing other paradoxes.  They’re interesting.  For instance, who would have thought that France will experience a higher sea level rise than Iceland when the Greenland Ice cap melts?  But with the reduced gravitational attraction upon the North Atlantic Ocean because all Greenland’s ice mass is gone, and with the resulting glacial rebound, France actually will.

Something else I didn’t include in that section because I didn’t think about it at the time, is when that part of the North American Plate glacially rebounds, Iceland’s continental rift will likely increase.  As you know, Iceland is practically split in half because it straddles two tectonic plates that are moving apart from each other.  Its western half will experience some glacial rebounding when Greenland does.  Since its eastern half is on the Eurasian plate, that part of Iceland likely won’t, or if it does, will to a far lesser degree.  An increase in Iceland earthquakes may be in their future, perhaps even their volcanic activity will increase. We could talk all night about this one topic and all its implications.  Scientists could research it for years.  I find that pretty cool.

MF: Which part of Paradox is your favorite section?

TW: It’s changed over time.  First it was the section on dark energy.  And then it was black holes.  When I calculated the compression of a neutron star down to a black hole, I made mistakes.  Catching those mistakes was fun, and humbling.  And then I realized that the neutron star would start rotating faster than the speed of light.  Since I knew that this could never happen, I started researching the ways in which this violation of physics was avoided.  One of those ways is the decoupling of the magnetic field-lines when they cross the light cylinder.  I had never heard of a light cylinder.  That was another cool concept I got to research.

Plate tectonics made a run for the number one spot, but I’d have to say the chapters on the evolution and devolution of the human brain are my favorites.  So many questions remain unanswered.  Like how will our intelligence change in the future?


MF: Tell us about the research/facts presented in your book that surprised you the most.

TW: Probably the agricultural paradox.  I knew farmers produced more calories, yet had poorer nutrition than hunter gatherers, but I didn’t realize how much poorer their diets were.  I had always been led to believe that hunter gatherers lead such difficult lives compared to farmers.  And that’s not necessarily the case.

I also didn’t know that farmers used to live with their livestock.  Living in these cramped, filthy conditions is how their diseases evolved and became our diseases.  That was interesting.

MF: Do you have a particular source you trust more than others?

TW: The source I use the most, not necessarily for writing books, but for medical research, is  I’ve been researching medical studies on their site since practically day 1.  But, as discussed in my chapter on the obesity paradox, the reliability of medical studies is far lower than it should be.  So, they’re not my answer to your question.

I’m sorry but, I don’t have any one source to hold up for you.  My thanks go to the majority of the experts that take the time to answer questions from me and I’m sure many other people.  Sometimes it was research for this book, but often I simply read about their research and had a question about it or its implications.  And most of these experts took the time to help me.  So, thank you to them.

MF: What do you think the next major technological breakthrough will be (that’s revealed to the public)?

TW: I might have to go with batteries.  I’ll be surprised if we don’t have vastly superior batteries 10 or 15 years from now.  And that simple advance will have profound changes upon the planet.  Think transportation, renewable energy, climate, and the lives of people around the world currently without power.  We’ll all benefit with that one, seemingly simple advance.

MF: If you were the one controlling the purse strings to a big chunk of grant money, which branch of science would you reward it to? Why?

TW: Renewable energy.  We’re making good progress and I believe we’ll get to where we need to be, but the sooner we get the cost of renewable energy lower than fossil fuels, the better off our climate, and everything tied to it, will be.

Where my passion lies however, is the likely extinction many large mammals will face, regardless of climate change.  Because of greed, religion and superstitions, the mega fauna that we all love are in serious danger.  I’d like to get Bill Gates, Ted Turner, Jeff Bezos and others together with the purpose of talking them into purchasing a huge track of land in the US and turning it into an African savanna.  I believe that’s the only chance elephants, giraffes, rhinos, cheetahs, and others, will have in the long term.  It might even turn a profit someday.

MF:  What percentage of critical medical knowledge do you think is being withheld from the public?

TW: Nearly 50% of all medical studies go unpublished.  To answer your question though, we’d have to define critical.  To me, all well conducted studies are critical, because they contain knowledge we need.

MF: Do you have any particular method for recognizing “fake science?”

TW: For me, I’d say it’s a combination of intuition and reason.  For example, I just had lunch with a friend who’s an avid hunter.  He was showing me photos and telling stories of his wild hog hunting trip, when he said the local experts he was hunting with told him that he should dodge a charging pig to the right, because they can’t turn to the left very well.  I told him I didn’t believe that.  Rationally, it didn’t make sense to me on an evolutionary basis.

If your gut feelings send you signals, or if the media headline seems a little too dramatic, question it.  Do your research.

MF:  What do you like to read in your spare time? Strictly nonfiction or do you ever take a break with fiction? If so, which genre?

TW: I was in my 30s when I read my 3rd fiction book, Jurassic Park.  The first two were The Little Engine that Could, and Bugs Bunny adventures, or something like that.  My 4th was Jurassic Park in Spanish, Parque Jurasico.  I started reading The Destroyer, a comedy/ adventure series during my recoveries from my spinal surgeries.  I’ve now read about 100 of them.  I also enjoy some comedies like The Hitch Hiker’s Guide to the Galaxy, and A Dirty Job.  In that book, the author has a hilarious comparison of an alpha male versus a beta male.  When I’m healthy though, it’s pretty much non-fiction for me.  I like to learn about the world around me.

MF: Do you have any other books planned or in-work at this time?

TW: I did have one I would love to write, but I knew I’d never pull it off.  I wrote all the living presidents, requesting interviews with them and their spouses, as well as access to the medical records of the presidents.  Of course, none granted me such access. My idea was to conduct a small sample study on the effects of the extreme stress of the presidency on health and aging.

Imagine how much I would have learned in the process.  That, would have been fun.

Yes, learning should be fun. I know it is for me, but far too many find it an unpleasant chore. Just think what the world would be like if we could find a panacea for this crippling attitude. Thanks to people like Ted, however, who shares these delicious brain candy tidbits so generously, hopefully others will find the intellectual stimulation as fun and interesting as the next computer game. -MF

You can pick up a copy of Paradox: Fascinating Anomalies of Science from Amazon or the publisher.



Is your inner Einstein looking for some brain candy?


This deliciously meaty and heavily researched book should be on everyone’s shelf. Of course, I’m prejudiced as a scientist myself. I thrive on nonfiction books like this, because they clear the dust from those remote corners of my brain, many of which haven’t been used in a long, long time.  In many ways, the content reminds me of the popular physics books Isaac Azimov wrote years ago, which I thrived upon, prior to actually obtaining a physics degree myself.

Probably what I liked most is its focus on the numerous paradoxes that exist in just about every field of study. The author includes sections on medicine, neurology, and psychology; astronomy, cosmology, and physics; and geosciences and math. He points out through a host of examples that there is still so much we don’t understand and thus so much to learn and explore. On the other hand, research is often subjective and highly biased, conducted to prove a point that financially benefits someone or, more likely, a corporation or industry.

So can you trust research results? Maybe, maybe not, making scientific findings paradoxes in and of themselves.  Science should represent facts, but does it? If someone you don’t trust tells you one thing, scientific data notwithstanding, do you automatically assume the opposite to be true? Do you trust everything the pharmaceutical industry tells you? The tobacco industry? Monsanto? The government? How many times has USDA’s official “food pyramid” changed? How many drugs or food additives have been declared “safe” by the FDA only to be proven otherwise at a later date? is it a paradox we can’t believe so much of what we’re told in the name of science?

You’ve probably heard the quote “Lies, damn lies, and statistics”. The section on mathematical manipulation was particularly fascinating, especially pointing out a statistical flaw (or method, depending on whom you ask) known as HARKing, “hypothesizing after the results are known.” Sometimes, remarkable discoveries are found that way; but, on the other hand, it can be used deceptively.

Weimann notes how correlations are often implicated as causes, when there’s no solid evidence to substantiate it. Along similar lines, in some cases, I would have liked to have seen a specific source as opposed to the massive bibliography at the end. While I understand that footnoting every fact would have been a Herculean task, I definitely raised a eyebrow from time to time wondering, and would have appreciated more substantiation. Ironically, the author himself points out how so much of published scientific findings are suspect, yet other times presents them as gospel. I find this somewhat ironic, perhaps a subtle play on the title, perceivable only at the subconscious level, or maybe it’s the author’s way of messing with us.

What can we believe these days? Sometimes, it’s hard to tell. In some ways, the entire book is a paradox, where facts are provided on one hand, yet the overall theme is that contradictions lie all around us. It’s as if it the book’s underlying message is something like, “This is all the cool stuff science is discovering these days, but don’t believe everything you hear.”

Maybe you need to be a scientist to see the humor in that. We nerds do tend to have a weird sense of humor, a trait that’s occasionally, but not always, captured on the popular TV show, “The Big Bang Theory.” It’s a matter of laughing with versus at someone and, more often than not, the humor in that show is directed at mocking those who are different. Personally, as a physics major myself, I find it marginally offensive, and if I were of certain political persuasions, I’d be out there protesting and demanding it be removed from the airwaves. Not that scientists can’t laugh at themselves. They just do it at a level the average person doesn’t grok.

Digression aside, Paradox contains a wealth of science, much of it unknown or cutting edge; the beauty of it lies in pointing out–sometimes clearly, sometimes, not–the various contradictions afoot. A favorite saying among physicists and mathematicians is that something is “intuitively obvious.” That tends to show our arrogant side, since so much isn’t, such as his expose of the number one in the math section.

One human behavior paradox I particularly enjoyed in Weimann’s book was in the section that addresses psychology. As humans, we want choices, even demand them, but too many options are overwhelming and tend to result in a person not selecting any of them. I know I’ve experienced this in the grocery store, where there is so much to choose from (especially in the ice cream cooler) that walking away and thus doing without is a far simpler decision, and probably healthier. Another example would be the plethora of political ideologies (some of which are idiotologies) where people scream for freedom to express their own views, then want the entire world to conform to their beliefs, a primary reason why democracies fail.

Some sections are more controversial than others, including the age of the Earth, as well as whether global warming is attributable to a natural climate cycle, which the Earth has endured for millennia, or being contributed to by fossil fuels. I must say, that section tended to convince me of the latter, though I previously leaned toward natural cycles. I found the section fascinating that addresses how our brains have evolved and actually become smaller. The author states that scientific evidence indicates that once daily environmental threats are removed by a “civilized” society, brains shrink, while disease increases. Apparently, “Survival of the fittest” conditions refine a species to top efficiency, whereas survival for everyone, including the drones, downgrades the species, generally. Who woulda thunk it?

The contradictions paradoxes represent keep us honest and humble. They remind us that all may not be as it seems, that our sense of reason may be flawed, implying we’re not as smart as we’d like to think we are. What we believe is impossible is limited only by our knowledge of natural law. Perhaps the only individuals from centuries past who wouldn’t be surprised by what we’ve achieved would be Nostradamus and other visionaries who were considered crazy in their own time.

While this book serves as brain candy if you’re a scientist, you don’t have to have a physics degree to appreciate or understand this information. Rest assured, it’s presented for a lay audience, but won’t be palatable for everyone. For those who find science boring, it’ll serve best as bedtime reading for insomniacs.

On the other hand, this is a must read if you’re a science aficionado or entirely immersed in it by degree or profession. Stretch your synapses to fields outside your own! If you love science, yet aren’t formally educated in its tenets, Paradox is a wonderful primer that will keep you informed of some of the most interesting subjects under investigation today. If you’re surrounded by scientists or engineers, but aren’t one yourself, yet want to participate in conversations at work or social gatherings and show you’re smarter than they think you are, this handy volume will provide a wealth of the latest information on what’s going on out there in the world of research, both in the cosmos and on planet Earth.

Those heading for college to obtain a technical degree can benefit greatly as well. If you’re not sure which field you want to go into, you may find something that grabs you. Furthermore, this material will help grease the skids, so to speak, introducing concepts that will make them easier to understand later. Our brains require synaptic connections to work properly, and if a concept is entirely new, it’s harder to grasp than one with some level of familiarity where a niche has already been prepared in your grey matter, if you will. Anyone home schooling their kids will also find this an excellent resource. If you’re a science fiction author, you definitely need this book, not only to keep your writing credible, but to likewise trigger a wealth of new ideas.

As you can tell, if nothing else, this book made me think and possibly stimulated my neurons a bit too much. All that aside, even if you’re not interested yourself, pick up a copy of this five-star book and give it to your favorite nerd. They’ll be forever grateful.

You can pick up your copy on Amazon here.

Don’t miss “The Great American Eclipse” 21 August 2017


Path of Totality for August 21, 2017 Eclipse

A special event is coming up August 21, the scope of which hasn’t occurred for 99 years! If you had grandparents at that time in Portland, Oregon; Denver, Colorado; Oklahoma City, Oklahoma; or Orlando, Florida, to name a few, they would have most likely seen it, or at least heard about it.

As you’ve probably figured out, I’m talking about the Great American Eclipse, so called because it crosses the entire USA from Oregon to South Carolina, and is only visible in the Continental USA. Last time we had one that stretched from “sea to shining sea” was June 8, 1918. That one started in Washington State and struck a diagonal path across the US, clear down to Florida and slightly beyond.  When I gave this talk at my Toastmasters meeting recently, one of the members recalled her mother, who lived in Oklahoma, seeing it, and being amused when the chickens were confused and went to roost when it got dark.

Eclipse 101

Total solar eclipses are relatively rare. First of all, they only occur with a New Moon. Why? Because that’s when the Moon is between Earth and the Sun, allowing its shadow under the right conditions to reach the ground. But we have a New Moon every month! Why don’t we have a solar eclipse every month?

Easy–it’s a matter of alignment. Remember, both the Sun and Moon are moving! More correctly, the Earth is rotating, making the Sun appear to move across the sky in a path called the ecliptic, which changes as far as its elevation above the horizon is concerned, based on the seasons, which are caused by the Earth’s axial tilt. The ecliptic is highest for the summer solstice. This maximizes the Sun’s path and explains why the days are longer. The opposite is true in winter. So, the Sun is not only “moving” across the sky, but changing it’s elevation above the horizon. I knew someone once who loved to describe unpredictable people by saying that for them “The Sun always comes up in a different place.” Ironically, this is true. If you’ve never noticed, it’s never too late to start.

The Moon orbits the Earth, but where its orbit crosses the ecliptic is not static, but moves a few degrees each month. Thus, the Moon’s location is also constantly changing, though it does so in a predictable manner. For an eclipse to happen, both the Sun and Moon need to be in the location where their paths cross, placing the Moon exactly between Earth and the Sun, casting its shadow on the ground directly below. You can see how predicting when and where eclipses will occur is not a simple matter. Nonetheless, the antikythera device was able to predict eclipses and so were the Mayans, because as their precise calendar indicates, they understood solar and lunar cycles.

You may be surprised to find out that there are two solar eclipses every year, but they’ll be visible in different locations. With two-thirds of the Earth’s surface oceans, many occur there and go unnoticed, save for physicists dedicated to solar research, especially those trying to determine why the Sun’s corona is several millions of degrees, while its surface, known as the photosphere, is a mere 10,000 degrees Fahrenheit. A total eclipse is the only time when the magnificent corona is visible. Researchers suspect the corona’s temperature is related to the Sun’s magnetic field, but they’re still trying to figure out why.

Types of Eclipses

Not all eclipses are total. There are also partial and annular. Partial is when the Sun and Moon don’t line up exactly, so only a portion of the Sun is obscured. In this case, a total eclipse is not seen anywhere. However, note that a partial eclipse is also what those located outside the narrow band of totality will see on August 21, again because the alignment is not perfect.


Annular Eclipse

An annular eclipse occurs when the Moon is farther away from the Earth and therefore smaller, such that it doesn’t entirely cover the Sun. Then, instead of the magnificent corona visible during a Total Eclipse, you see a ring. In some of these less than ideal cases, the Moon’s shadow doesn’t even reach the Earth.

Eclipse Path of Totality

To see the upcoming event as a total eclipse, you’ll have to be somewhere along the red stripe shown on the map. The location where totality will be longest (2 minutes 41.6 seconds) is in the vicinity of Carbondale, Illinois. Oddly enough, another total eclipse in 2024 also crosses that location.  It’s very unusual for this to happen; often centuries pass before a total eclipse is visible again from the same place.


Paths of 2017 and 2024 Eclipses. “X marks the spot” over Carbondale, Illinois.

Unfortunately, the eclipse will not be total where I live, here in Texas. Rather, it will be a partial eclipse that covers 65-70% of the Sun. It will start here around 11:35 am, be at its maximum around 1:10 pm, and end around 2:40 pm. However, space cadet that I am, I’ll be traveling somewhere that it’s total.

Safe Viewing Tips

To safely view the eclipse, you need to protect your eyes with special glasses or some other sort of filter. Ordinarily sunglasses are insufficient, so don’t even think about using them alone if you value your eyes. A pinhole camera will show it, too, or look at the shadows of leaves beneath a tree to see thousands of tiny Sun crescents.

You can get special ISO Certified glasses, but hurry since they’re selling out fast. Sources are listed below. Note that glasses suitable for you to watch the eclipse are NOT sufficient if you’re using a camera or telescope! In that case you need a solar filter for the lens!  Solar filters are available for most regular cameras. If you value your cell phone, don’t plan on taking pictures of the eclipse with it because it’ll burn it up. Remember starting a fire with a magnifying glass when you were a kid? Same idea. Another option to special eclipse glasses is #14 welder’s glass, which could also work to protect your cell phone.

The only time it’s safe to look at a solar eclipse without eye protection (for you or your camera) is during totality, i.e. when the Sun is entirely covered by the Moon. That is preceded by a final glint from the Sun they call the “Diamond Ring”, which also occurs as the eclipse ends, but that flare could be enough to zap your camera or cell phone, so bear that in mind. Totality doesn’t last long, usually between 1 – 2 minutes. Nonetheless, you should enjoy it with your natural eyes while it lasts to enjoy it’s full impact and beauty.

Many people go throughout their lives without ever witnessing a total eclipse. I’ve seen partials, but never a total, so I’m flying to Utah to visit my daughter and her family, then we’ll drive into Idaho to the band of totality. I’m sure it will be a get-together we’ll never forget. It’ll be worth watching, even from here in Texas. If nothing else, you can see firsthand why the ancients were frightened when it appeared something was consuming their life-giving Sun.

Another Eclipse is coming!

If you live somewhere outside the band of totality and can’t travel to see the total eclipse this time, then you can look forward to the one in 2024, when there will be another one.  (You can see the path as the second band that forms the “X” in the map above.) For me, here in Central Texas, it will be right on our doorstep! In fact, the center of the path of totality goes right over Lake Buchanan, northwest of Austin, meaning I’ll be able to watch it from my front yard! Come April 2024, there will be a lot of people around here praying for clear weather.



Eclipse Information (my astrology website)

Eye Protection (bulk orders)

Photo Tips


Geeks Make the World Go-Round

albertIf you’re a fan of the popular TV show, “The Big Bang Theory” you probably think you know what constitutes a geek. However, like most depictions of stereotypes, they’re often inaccurate. As a physics major, I’m qualified to define geekism. I can relate to what they’re trying to say, but it’s not on my favorites list. We had moments in college that were similar, but in most cases, like they say, you had to be there. True geeks aren’t impressed by “The Big Bang Theory.” They live it. I, personally, think it’s boring. I much rather watch “Ancient Aliens” or something on PBS.

Here’s what being a geek is really like. In college we had rituals at the end of every quarter, like having a pizza party and watching Monty Python’s “Quest for the Holy Grail”. We’d memorized the dialog and would quote key phrases at random times. Now that was funny. Or there was the time when four or five of us were holed up in our niche in the Utah State engineering building studying for finals in the wee hours. We were hungry so ordered pizza. Since we had a large variety of appetites and were all on a budget, we attempted to figure out how much everyone owed based on consumption. And there we were, deep into multi-variable calculus and orbital mechanics, but had a hard time dividing up the tab. And yes, we saw the irony and were laughing pretty hard, perhaps even bordering on hysteria.

sictrustatomWe had a professor who was so nervous lecturing that he not only would be visibly sweating, but he had a nervous habit of clearing his throat, after which he would always say “Pardon me.” This particular prof was a perfect fit for the very intelligent yet introverted nerd. So what did I do one quarter? Kept a tally, day by day, for an entire quarter, of how many times he said “Pardon me”. Then I graphed it by magnitude versus date, then analyzed the data with my fellow students. We discovered the rate went up right after he returned an exam, perhaps anticipating grading arguments. I still have the file labeled “Pardon Me Curves” in my file cabinet. I kid you not. It’s a college memory from the 80s that still makes me laugh.

Yes, I’m a geek. Always was, always will be.

A classic geek activity is astronomy. Not long ago I joined the Austin Astronomical Society, which conducts star parties a few miles from where I live. The vast majority of members live 50 – 90 miles away (in Austin, of course) so it’s a bit of an excursion for them to come up to the observatory, but I’m just a hop, skip and a jump away. While I had several quarters of astronomy and astrophysics classes in college, I never had any hands-on experience with telescopes before. So I’m a newbie with a lot to learn but it’s somehow very satisfying to stand around discussing the theory behind German equatorial mounts (no, they has nothing to do with sex) and remembering to select the solar, lunar or sidereal tracker during observation.

scithrillStar parties typically start while the Sun is still up so, with a proper solar filter, you can look at the Sun and its various sunspots. While it’s still daylight the geeks are pretty quiet, compared to the hobbyists. Unless they know you, they probably won’t say a word, preferring to busy themselves setting up their equipment or perhaps talking to someone they already know. Then it gets dark.

Obviously. It’s pretty hard to see the stars otherwise.

By the time your night vision peaks, they come to life, almost like vampires. It’s the original nightclub, fresh air under the stars and planets. Inhibitions evaporate. In a sense you’re invisible. No one knows who or what you are. They don’t know if you’re old or young, skinny or fat, only that you have the same passion for the night sky. I remember sitting in silence at one star party until it got dark, then finding two fellow physics majors, one around my age, the other a recent graduate, and sitting in the observatory swapping tales of school and work for hours. I hadn’t done so in years and can’t begin to describe how soul-satisfying it was. Like being with close family you’ve been away from for years. If I ran into them in the grocery store I wouldn’t recognize them. But that night we were soul mates, entangled by our love of what makes the world go round. Literally.

scigooutsideWhich brings me to what this blog is really all about. At last night’s star party I met a young woman whom I believe was still in high school. She had her niece with her, a young girl, probably around ten. She’d driven an hour to pick up her niece, then drove another three hours (for a total of four) to come to a star party. Her telescope, which she’d purchased herself with money she’d earned babysitting, was twice the size of the borrowed one I was using. She got it on sale for just under $1000. That’s a lot of babysitting.

It was not a good night for observing, lots of clouds and a Full Moon, with about the only thing visible Jupiter with his Galilean satellites high above our heads on the meridian. So after all that effort, that was all they saw, then turned around and drove back home. Eight hours of driving for a single star party.

If you’re not impressed, you should be.

knowledgegiftI would like to nominate that young woman as “Geek of the Year.” Someone who is enamored with our Universe, so much so, that she spent her hard-earned money on an eight-inch telescope instead of designer clothes or, heaven forbid, tattoos, then shares her passion with a younger family member; I think I was about ten when I discovered the stars. I would have given blood and paid money for an auntie like that. Maybe you find that behavior laughable; I find it admirable. And you know what? The world needs more people like that.

We didn’t talk long enough for me to get her name, much less find out her future plans. But she touched my heart. I hope our paths cross again. I would easily bet dollars to donuts she’s a future astronaut, astrophysicist or rocket scientist. She will obtain a good education, work for a living, and contribute to society.

Hail to geeks. Nerds, too, since I’m not sure of the difference between us. May you be lucky enough to have a geek or nerd or two in your life. They’re the glue that holds what’s left of our society together. Maybe instead of nerds they should be called gluons.

(Get it? Gluons? Never mind. It’s probably something only a geek would understand…)


The Astrolabe: Ancient Analog Computer with 1K Apps


Figure 1. Planispherical astrolabe. Marocco, 16th century. Engraved brass. On display at Paris naval Museum.

Whether you’re an astronomer, astrologer or steampunk fan, you’re bound to fall in love with this ancient analog computer.  Even better, you can make one for yourself by downloading the directions from the Resources section below.

The astrolabe is an ingenius device used for nearly two thousands years, from the time of Hipparchus (c. 190 – 120 BCE) until the turn of the 17th century.  It’s typically a disc constructed from wood or brass, about 10 – 20 centimeters in diameter, and a few millimeters thick.  In 1391, medieval writer and poet, Geoffrey Chaucer, wrote a treatise on the subject for his son, describing how to build one as well as its use.  Astrolabes had over a thousand uses, including timekeeping, navigation, surveying, solving equations, and so forth.  Mastering them all required an entire university level course.

While at first appearance an astrolabe is intimidating, breaking it down into its components, combined with the information contained on each one, brings a strong sense of familiarity if you’re an astronomer.  Appreciation for the knowledge ancient civilizations acquired of the stars and their relationship to the Earth quickly follows at the thought of designing, much less crafting, such a clever precision instrument.

The main components of a planetspheric astrolabe are the mater, climate plate or tympan, and rete, which all function together, demonstrating how Earth’s place in the cosmos provides the ultimate reference frame.

Astrolabe (Front)

scan-astrolabe-front copy

Figure 2. Astrolabe Front: The Mater

The front of the astrolabe, called the mater, (which means mother and is sometimes referred to as such) looks mind-boggling, until you break it down into its components.

Starting from the outside, you see most of the letters of the alphabet around the circumference.  These represent the twenty-four hours of the day, more specifically, the equal hours system, which is what we use now, i.e. each hour is 60 minutes long.  However, at one time, there were twelve hours of daylight and twelve hours of darkness.  Needless to say, unless you live on the equator, the days and nights are NOT of equal length except at the equinoxes.  Thus, the unequal hours system meant that the duration of hours were adjusted, according to the time of year.  The astrolabe thus accounted for them as well, as shown by the designated lines in Figure 1.

The numbers just inside the letters represent degrees from the horizon, where’s it’s zero, to a maximum of 90 degrees at the zenith (Noon) or nadir (Midnight).

The horizon is represented by an oblique line. Unlike most of the maps we see these days, East is on the left, West on the right, North at the top, South at the bottom. ( If you’re familiar with astrology, you should not be surprised that these are the same as a horoscope with the ascendant on the left, Midheaven (Noon) on the top, descendant on the right and Imum Coeli (Midnight) on the bottom.) Just below the horizon is a dotted one, which is somewhat difficult to see at this scale, but represents the period known as Civil Twilight, or the time in the morning or evening when the Sun isn’t above the horzon, yet there’s a certain level of light.

So, to recap, so far we have 24 hours around the outer edge, perpendicular lines representing the cardinal directions, and an arc indicating the horizon.

Due North, represented so conveniently by Polaris, a.k.a. the North Star, is located dead-center.  Its position in the sky varies with latitude, indicated numerically on the vertical line extending upward from the climate’s center.

The climate, sometimes referred to as the tympan, comprises the section that looks like a spider web with a center just North of Polaris, which represents the zenith, or portion of sky directly overhead. The curved lines mark azimuth readings, while the concentric rings are lines of constant altitude or almucantars. These vary with latitude, like the view of the night sky, so astrolabes used in multiple locations required suitable climate plates, which fit into this area. Note the degree markings along the edge of the azimuth lines, which you’ll use later.

A rotating ruler with degree markings which represent declination, the altitude above the celestial equator, is attached to the center of the mater. It’s also used as a convenient pointer in the process of telling time, as explained further below. [NOTE:–The concentric rings, which are unlabeled in Figure 1, are duplicated on the rete and therefore explained in that section as well as defined in Figure 3.]

Astrolabe (Back)

Astrolabe-Back-Labels copy

Figure 3. Astrolabe Back: Calendars and Shadow Scale.

The back of the astrolabe is equally daunting at first sight, until you break it down. However, it’s this complexity that allowed this ancient instrument to provide so many functions. For example, the box labeled “Shadow Scale for surveyors” gives a hint of one of its many uses.

The top, called the throne, was used to hang the instrument or hold it in the proper position.

The outer ring has degrees from the horizon, like the front, with zero on the horizontal axis and 90 degrees on the vertical. Just inside the degrees are another ring of numbers, this time corresponding to the degrees of the tropical zodiac signs named in the next ring.

There are two calendars represented, one from Geoffrey Chaucer’s time (1394), which is included since Chaucer wrote a popular treatise on the astrolabe for his son, a copy of which you can find online. The modern calendar, closer in toward the center, is based on 1974, but this is close enough since it takes centuries for precession to change enough to worry about.

Near the center, several Saints’ Days are noted.

Thus, there’s a lot of information, but most of it’s familiar. Another pointing device called the alidade is placed on the back, which is similar to the ruler on the front except it has either pinholes or notches used to sight in the altitude of the chosen star or landmark, if being used for surveying.

The Rete

scan-astrolabe-rete-Labels copy

Figure 4. The Rete

The rete comprises the main component of a planisphere, i.e., a stereographic projection of the celestial sphere on a flat surface. Polaris is at the center with several constellations included with the brighter stars emphasized.

The outer ring represents the Tropic of Capricorn, the one in the center, the Equator, and the innermost ring, the Tropic of Cancer. The hours of Right Ascension are shown along the circumference as well.

A diagram of the annual path of the Sun, a.k.a. ecliptic, is offset from the center and includes markings for the signs and degrees of the tropical zodiac.

For a homemade astrolabe, the rete is printed on a sheet of clear transparency which allows the stars to be superimposed on the mater. Obviously, in ancient times, that wasn’t available, their solution not only innovative but artistic as well. The rete, like most of the other components, would be constructed of brass, but numerous areas cut away so you could see the mater underneath.

Most astrolabes were carefully crafted precision instruments which were much larger than the homemade version, allowing for a more accurate position determination, but nonetheless, a relatively accurate reading is possible with a homemade version, a source of which is included in the resource listing.  The ancient Turkish astrolabe in Figure 5 shows the mater and rete on the front and calendar and alidade on the back.  Note the incredible artistry and workmanship of this 17th Century device.

Planetary Position

To determine the position of a planet, use its relationship to the Fixed Stars on the rete.  By rotating the rete so that the position of the planet is on the horizontal axis, i.e., zero degrees, then following that line to the tropical zodiac on the ecliptic circle, to determine its position. The ruler provides its declination.

Telling Time

This process is relatively simple and shows the genius of using Earth’s position combined with celestial alignments to determine the time of day.

  1. First, using the back of the astrolabe, find the current date and note the corresponding zodiacal degree of the Sun.
  2. Next, select a specific star visible in the night sky that’s represented on the rete.
  3. Using the back of the astrolabe, align the device’s horizon line with the visible horizon and use the alidade to measure its altitude. (Warning: This could be the most

    Figure 6. Sighting in the altitude with the alidade.

    difficult part of the process. Furthermore, in many cases the visible horizon is not the actual horizon due to elevation, buildings, trees, mountains, and so forth. If nothing else, consider that the Moon appears to be, on average, a half-degree across, or approximately the width of your thumb, which you can use to approximate the altitude.)

  4. Identify the star on the front of the astrolabe (rete).
  5. Move the rete so the altitude you measured of the star matches the azimuth scale behind it.
  6. Align the rule on the rete with the zodiacal position for the Sun for that day.
  7. The rule will point to the time represented on the outer rim of the mater, indicated by a letter. (Don’t forget to adjust for Daylight Savings Time.)

If you know any two of the variables (date, time, rete star position), you can always solve for the third.


The innovative talents of the ancients who invented this device provide a new appreciation for their knowledge of the heavens, Earth, and their celestial relationships.

Even more astounding, and perhaps even a progenitor or technological cousin of the astrolabe, is the antikythera mechanism, an invention attributed by researchers to Aristotle.  It included the positions of the Moon and planets using a complex system of gears and pins that compensated for their elliptical orbits, plus had the ability to predict when eclipses would occur.  Researchers believe it was lost when General Marcellus sacked Syracuse, then surfaced later via the Byzantine Empire (500 A.D.) where it was most likely the inspiration for Persian astrologers to reinvent the astrolabe, then bring it to Spain in the 13th century via the Moors.

During the 14th century Renaissance, sophisticated gear trains came back to drive astronomical clocks found in various European cities such as Strasbourg, France and Prague, Czech Republic.  The sophistication of these devices demonstrates the knowledge of celestial mechanics and engineering possessed by past civilizations, tangible testimonials to man’s ingenuity, long before such calculations became the domain of application programmers creating smartphone apps.


Directions for Making an Astrolabe

Some Places to Buy Astrolabes

Video on How to Use an Astrolabe

Additional Information (Includes the TED video plus additional resource information)



“Building a Model Astrolabe” by Dominic Ford, Journal of the British Astronomical Association, 122, 1, 2012,

“Western Astrolabes” by Roderick and Marjorie Webster, Copyright 1998, Adler Planetarium & Astronomy Museum, 1300 South lake Shore Drive, Chicago, Illinois 60605

Picture Credits

Figure 1: Creative Commons Attribution Share Alike License, By Rama – Own work, CC BY-SA 2.0 fr,

Figures 2 – 4:  (c) Dominic Ford, 2013,

Figures 5a & b: Creative Commons Attribution Share Alike License, By Pom² – Own work, CC BY-SA 3.0, Description: Astrolabe planisférique Mère et tympan : Turquie ottomane, 1098 H / 1686-1687 Araignée: maghreb, vers 1850 Laiton à décor gravé et incisé D. 10,2cm Paris, musée de l’Institut du monde arabe, AI 86-45 Legs Destombes

Figure 6: Wikimedia Commons, Public Domain,

Copyright (c) 2016 by Marcha Fox, All Rights Reserved