Welcome to my musings on whatever topic catches my eye, plus stories, recipes, handyman tips, welding, photography, and what have you. Oh, and analog/digital hardware design, and software. Please comment on the blog post so everyone who visits can see your comments.

Author: Phil (Page 19 of 51)

Hello. I'm a retired electronic hardware, software & mechanical engineer. My hobby is making metal art. My interests range across writing, economics, politics, history, photography, fountain pens, languages, ham radio, and music. I've been writing software since 1968.

The Paradox of Tolerance: If a society is tolerant without limit, its ability to be tolerant is eventually seized or destroyed by the intolerant. --Karl Popper

Mayan Calendar Doesn’t End on December 20, 2012

August 11, 3114 BC marks the beginning of the current calendric cycle of the Mayan Long Count calendar.  The Mayan calendar is comprised of repeating periods that result from the Mayan base-20 positional number system.

The Mayans were the first humans to invent a positional number system like our decimal system—a system based on powers of a number base plus the idea of a numeral that represents zero.  A positional number system must have some way to represent the value zero.  In contrast to our base-10 system, the Mayans chose base-20.  So instead of decimal places Mayan numbers have vigesimal places.  Instead of the decimal system of nine numerals plus zero, Mayan numbers are composed of 19 numerals, plus zero.  In the decimal system, each digit represents a power of ten.  In the Mayan system, each digit represents a power of 20.  A positional number system is a necessity for doing serious mathematics.  Imagine doing even simple addition with a non-positional system like Roman numerals.

Our Gregorian calendar uses decimal numbers for years and a messy system based on the arbitrary values 7, 28, 29, 30, and 31 for weeks and months.  We call the periods of our calendar days, weeks, months, years, decades, centuries, and millennia.

The Mayan Long Count system is much cleaner.  The periods correspond to vigesimal places of a Long Count date and are named k’in, uinal, tun, k’atun, baktun, piktun, etc., each representing a power of 20 except the the second place, the uinal, which is base-18. (This results in the 20×18 = 360 day count in the lowest two places to represent the 360 day Mayan year.) From the third place on up, the count is purely vigesimal.

Mayan Calendar

Mayan Calendar

The Mayans actually used three calendars side-by-side.  The Tzolkin and the Ha’ab calendars are designed to keep track of holidays and astronomical / planting cycles.  Those calendars restart every 52 years and don’t concern us here.  The third calendar, the Maya Long Count calendar, counts an unlimited number of days from a specified starting point using a modified base-20 system that accommodates the 360 day Mayan year. Because this calendar is unlimited, Long Count dates are inscribed in monuments intended to last for a long time.

Now let’s connect some of the Mayan Long Count periods with real numbers.  The first vigesimal place, the kin, counts 20 day cycles.  The second place, the uinal, counts base-18.  Together, the first and second places roll over every 360 days, which is the length of the Mayan year, and the count carries into the third digit.  The third digit, tun, counts 20 Mayan years.  The fourth digit, k’atun, counts 20 tuns, or 400 Mayan years, which is 394.25 years on our Gregorian calendar.  It is this 394 year cycle that is going to roll over in December 20, 2012, and the next vigesimal place, the baktun, will increase from 12 to 13.  We are now in the 13th baktun since the start of the Long Count calendar (like saying we’re in the 21st century in our calendar).  The next baktun begins on December 21, 2012.

A baktun is a period of 144,000 days or 394.25 Gregorian years. The Classic Period of Mayan history occurred during the 8th and 9th baktuns.  The last day of the 13th baktun occurs on Dec 20, 2012 in the Gregorian calendar, which is 12.19.19.17.19 on the Mayan Long Count calendar. The 14th baktun begins
on 13.0.0.0.0 (Long Count) or Dec 21, 2010 (Gregorian).

When 20 baktuns are completed (7,885 years from the starting point in 3114 BCE) a new piktun begins and the baktun starts counting again from zero.  The pictun isn’t normally written on Long Count dates because it’s assumed.  Just like we don’t write leading zeros on Gregorian years.  We don’t write 000002012, just 2012.  When 20 pictuns are completed, or 157,700 years, a new kalabtun begins. In fact there are two more digits defined beyond these in the Mayan Long Count Calendar, the k’inchiltun and the alautun.  The Mayan Long Count calendar has places already define and named that carry it another 1.2 billion years.  In our calendar we’re only named periods out to millennia.  The Mayans had a much longer view of time.  And even after 1.2 billion years have elapsed and the named periods of the Mayan calendar are filled, the calendar still doesn’t end.  You just keep adding more digits to the year, the same as we will do when our year passes 9999.

In light of this, the idea that the Mayan calendar ends is particularly ridiculous.  The Long Count calendar is defined, with named periods, 1.2 billion years out into the future.  It would make more sense to say that our calendar ends in 9999, since we haven’t named any periods beyond the millennium.  But the hoopla about the new baktun (similar to a century on our calendar) makes for lots of book and movie sales.

For a timeline of Guatemalan history, from 15,000 BC to the present, see Guatemala History Timeline. 

The Maya Paradise home page displays today’s date in all three Mayan calendars: Tzolkin, Ha’ab, and Long Count.  Maya Paradise

Here Comes 3-D Printing

Engineering, software, and the Internet have made it easy for people to share documents, music, photographs, and videos on a worldwide basis. It’s obvious to anyone skilled in the art that, short of shutting down the Internet entirely, sharing cannot be controlled by governments or by anyone else. There are a lot of smart people in the world and any attempt to block sharing will be quickly circumvented. No matter how clever a blocking scheme you come up with, there’s always another guy on the other side of the world smarter than you who will break it. Recent history has shown over and over that this is true. Blocking and security schemes are usually broken before they are even introduced. So we’re not going to be able to control the sharing of music, videos, etc. Get over it.

Now imagine a world where the sharing of physical objects and mechanical devices becomes just as easy as sharing music or videos. That world is nearly upon us. 3-D printer technology is available and when people discover how useful it is, the technology will quickly mature. Today, consumer 3-D printers work mainly with plastics but 3-D printing with metals has existed for many years in industry and home printers will soon be able to work with a wide variety of materials including high-strength steels. Want a 9mm pistol? Just download the print file for the particular brand and model you want and send it to your 3-D printer. When the parts are done, assemble them and go shooting.

This technology has all sorts of implications. Intellectual property problems will not be limited to businesses producing music, photos, and videos. These problems will become real for manufacturers of all products that could be fabricated by a 3-D printer. A pistol is just one example.

And if that’s not exciting enough, work is already underway to develop bio-printers and chem-printers. These are devices that are miniature chemistry labs that will be able to generate a wide variety of chemical substances, including drugs. Need an antibiotic for an infection? No problem. Just download the chem file and generate it on your desktop. We’ll have this technology on our desktops in a few years. Imagine the implications this will have for pharma companies.

The Mystery of the Non-Waterproof Hot Glue Solved

Six years ago I had a bad experience with hot glue.  I expected it to be waterproof and it wasn’t.  I did an immersion test and within 3 days the glue turned into a whitish gelatin and fell off.  That’s barely water resistant and certainly not waterproof.

For waterproofing I usually lean towards silicone (RTV, silastic, aquarium cement).  It works well in every application I’ve ever used it on.  But hot glue is so convenient and sets so fast that I kept thinking about it and wishing I could use it.  A few weeks ago I decided to learn more about hot glue.

There are many different kinds of hot glues used in industry and most of them are available in standard 11mm sticks, but I would much prefer to use the common household clear bluish or yellowish stuff if possible.  The standard home-use glue is made from EVA (ethylene vinyl acetate) plus various additives to adjust its characteristics.  Nearly every article I read says that “hobby” hot glue is waterproof, and indeed, EVA is a waterproof thermoplastic.  This disagreement with my experience really got me studying.  Something is not adding up here.  I learned about all kinds of hot glues and their characteristics and just as I was getting ready to compose emails with specific questions to hot glue manufacturers, I ran across the answer.

What happened to me six years ago was a “materials compatibility problem”.  Six years ago, what I had done was to waterproof some electronics by building it inside of sealed PVC pipe.  The plan was to bring a couple of small insulated wires out through a small hole in the pipe and then seal it up by pumping hot glue into it.  This is the application that failed the immersion test.  Naturally I assumed it was the water that caused the failure, but it was not the water.  It was the PVC pipe material and especially the PVC insulation of the wires.  Actually, it was not the PVC itself but the pthallate plasticizer that’s mixed with the PVC to make it flexible and not brittle.  PVC wire insulation has an especially high amount of pthallate.  Pthallate attacks EVA and causes it to decompose, and that’s why my test failed.

Recently I’ve done more experiments with EVA hot glue.  Yes the material is waterproof.  I’ve had a glob of hot glue immersed in water for weeks and it’s  unaffected.  I did another experiment where I used EVA to hot glue polyurethane to painted ABS.  It sticks like a weld.  You have to destroy the pieces to get them apart and it’s unaffected by water.  So it all depends on materials compatibility.  I just wish I had known this sooner.

The IEC Power Cord Mystery

IEC Power Cord

The ubiquitous IEC power cord has been a part of everyone’s life for almost 30 years.  Nearly every device capable of running on different mains voltages and frequencies has one so the manufacturer can ship to different countries by simply changing the power cord to match the plug type used in that country.  Great idea.

Every device that needs an IEC cord comes with one from the manufacturer.  When a device is no longer wanted and we dispose of it, we always keep the cord “because it might come in handy”.  Thus, there should be an ever-increasing number of IEC power cords in the world.  There should be billions of them in existence.  After 30 years of this, even the most non-technical person should have at least 20 cords stashed in their closet.  Yet this is not the case.  When you need one, there’s none to be found.  Search the entire premises and there’s not one unused IEC cord.

How can this be?  I’ve never thrown one away in my life.  Do unused cords simply vanish?  Do they automatically return to the manufacturer to be shipped to someone else?  Do little gnomes steal them at night?  Where are all my cords?

😉

« Older posts Newer posts »

© 2025 Shuttersparks

Theme by Anders NorenUp ↑

Find me on Mastodon