Category Archives: Book Review

Book Review: The Knowledge by Lewis Dartnell


My website contains a review of the WikiReader. This little device set me back about $20. It’s apparently no longer available on Amazon, but there do seem to be examples available on eBay and elsewhere. It’s a small battery-operated device that contains in its internal memory (with some limitations) the full contents of the English language Wikipedia.

In other words, it contains what its manufacturer called “the Internet without the Internet.” If you’re transported back in time, if you get stranded on another planet or on Gilligan’s Island, or if the world suffers TEOTWAWKI (The End Of The World As We Know It), you’ll no longer have access to the Internet, but you’ll have a pretty good summary of just about any subject. The batteries of the WikiReader will eventually go dead, but before that happens, all you need to do is find the Wikipedia article on the history of the battery, take some good notes, and you’ll be able to whip yourself up a new one when the time comes. Once you’re settled in in your new era, you find an interesting article such as the one on the electrical telegraph, put together a prototype, and then make arrangements to demonstrate it to Julius Caesar or Louis XIV.

The WikiReader has a number of practical limitations, and I rarely use it. But it’s carefully put away just in case I’m involved in inadvertent time travel. In my pocket, I have the important knowledge of the 21st century. If I accidentally get stuck in a time warp, I’m going to make the best of the situation.

It appears that I’m not the only one who thinks that way. I recently got an e-mail from Amazon stating that customers who bought the WikiReader also bought a book with the intriguing title The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm by Lewis Dartnell. The book is available in the usual places, such as Amazon, in Canada, or your local library.

As the title suggests, the book is written for the benefit of some future inhabitant of Earth who needs to reconstruct (or “reboot” as  author Dartnell calls it) civilization after some sort of cataclysm.  The first chapter suggests some possible sources of the disaster, and the second chapter discusses the “grace period.”  After some types of disasters, such as a pandemic (such as happened in Earth Abides by George Stewart or in my own novel Caretaker), the survivors of the disaster have at their disposal the spoils of the earlier civilization.  It’s a relatively simple matter to eat canned food, set up generators, and take advantage of what was left behind.  In some cases, such as pandemic, that grace period might extend for generations.  In other cases, such as nuclear war, there will be fewer benefits available from the earlier civilization, and survivors will need to get to work right away tending to their immediate needs.

Dartnell doesn’t dwell a great deal on the grace period, since he correctly notes that numerous other survival manuals have been written.  What he spends most of his time talking about is rebuilding a technological civilization after the grace period has ended.  With a few exceptions (such as how to make soap), he doesn’t provide enough detail about any given technology in order to show exactly how they’re done.  But Dartnell does give enough clues in order to point survivors in the right direction.

For example, in the section on radio communication, he describes how to build a crystal radio, and he gives enough detail to allow the future archaeologist to recreate one.  He gives some of the theory, but no unnecessary theory.  In our current timeline, for example, it probably would have been impossible for society to come up with radio without first having an understanding of Maxwell’s Equations.  Instead, Dartnell gives only enough theory to make the thing work.  After building a few radios, the post-apocalyptic society would eventually come up with Maxwell’s Equations on its own.  So future history would follow the same general course, but in the opposite order from ours in some instances.

In addition to the plans for the receiver, Dartnell also gives enough detail so that someone could probably come up with a workable spark-gap transmitter.  I think the stumbling block for the future inventor would be coming up with an earphone sensitive enough to work with the receiver described.  Armed with theory in our own civilization, the telephone was created first, which gave the required prior technology.  Dartnell does qualitatively describe both a magnetic and piezoelectric earphone, but either one would require a great deal of trial and error.  In our own history, a skilled inventor would know enough theory to realize that sound would come out of a telephone receiver if hooked up properly.  If it didn’t work the first time, he would eventually figure out that he needed to make it more sensitive by adding more windings to the coil.  The post-apocalyptic inventor would have more trial and error.  But if he or she had enough faith in the book (perhaps because he knew that the soapmaking description was correct), that might provide the incentive to keep experimenting.  (Dartnell does provide the future inventor with Edison’s admonition that genius is 1% inspiration and 99% perspiration.)

Similarly, Dartnell gives enough clues to invent the triode tube.  There isn’t nearly enough detail to make one, but he tells just enough about the Edison effect so that a gifted future scientist could verify it, and some hints as to how this effect could be harnessed to provide amplification.  Dartnell mentions in passing that oscillation is possible, although I hope the future scientist figures out that feedback is necessary in order to get the thing to produce radio signals.

In order to jump-start science, Dartnell provides a few simple experiments to prove non-intuitive concepts, such as the Earth spinning on its axis (Foucault’s Pendulum) and revolving around the sun (stars rising four minutes earlier each night).   In case the surviving society has lost track of time, he shows how to establish the year, either by the proper motion of Barnard’s Star or changes in the night sky due to the Earth’s axial precession.  The book contains convenient charts showing the reader the year (as well as a map and picture to locate the Svalbard Global Seed Vault).

In short, the future reader will get a lot of useful information from this book.  In most cases, the ideas contained in the book will need additional details, but Dartnell points the future inventor on the right path for either experimentation, or at least a clue as to which ancient texts he or she should try to recover.  (The book contains an extensive bibliography to help the future inventor in that quest.)

Chances are, nobody would read a book entitled, “The History of Science and Technology.”  But when you get to the end, you realize that’s exactly what you read.  In detailing the easiest course for future civilization, he necessarily recreates our own.  There will, of course, be some differences.  For example, most readily accessible deposits of fossil fuels will be gone for the next civilization.  But he offers a number of workarounds.  And since the current nitrate supplies of our early civilization (see The Guano Islands Act for an interesting discussion of a seemingly mundane commodity) are also depleted, he goes into more detail regarding the relatively simple chemistry required to fix nitrogen from the air.  On the other hand, aluminum requires a great deal of industry to refine.  But in the case of a future society, even hundreds of thousands of years in the future, our dumps will provide ample mines of high-grade ore that will need little more than melting down and re-casting.

In short, if you bought a WikiReader after reading my review, then, yes, Amazon was right.  You’ll want a copy of Dardnell’s book as well.

More information, including a discussion forum, is at the book’s website:

   Buy this Book on Amazon:
USA:                              Canada:

Click Here For Today’s Ripley’s Believe It Or Not Cartoon

Book Review: Radio Science for the Radio Amateur by Eric Nichols, KL7AJ

At the Sooland Amateur Radio Association hamfest, I was the winner of $50 worth of ARRL books.  After perusing the available options, and deciding that my 2010 Handbook was current enough for my needs, I decided to get Radio Science for the Radio Amateur
by Eric Nichols, KL7AJ.

The book bears the rather steep list price of $27.95, although it’s available at Amazon for a bit less. Overall, it was a good read, although I think I would have been somewhat disappointed if I had paid the list price. I suspect the price had something to do with the handful of one-star reviews on Amazon.

Nichols is a regular poster on the forums at, and the book’s writing style is a similar level of informality.  Some of the Amazon reviews point out that he seems to jump all over the place from topic to topic, and this is true.  However, the book isn’t intended to be a scientific treatise about any particular subject.  Nor does the book give many construction details.  What the book does do, and the scatterbrained style actually does well, is give the reader some ideas about real scientific experimentation that can be done by amateur radio operators.  It whets the appetite and lets the reader do some more research about what is possible.   The book doesn’t really teach you how to do anything, but it does teach you that a number of interesting activities can be done.

In no particular order, here are some of the insights that I got from the book:

1.  It’s possible to build a plasma chamber at home.  I’m not sure exactly what I would do with it once built, but he does suggest some ideas.

2. One can purchase data acquisition modules relatively inexpensively, and these allow you to interface a computer to an analog voltage source (such as a receiver S-meter, a photocell, or a thermocouple) so that the computer can easily collect data for later number crunching.

3. Amateur radio offers some real possibilities for distributed science. My own short story, Clint’s Best DX, concludes with an author’s note saying that the story was impossible. In the story, the hero discovers extraterrestrial life with his 6-meter beam. I explain that this is impossible, because the signal strength is just too weak for earthbound antennas.  (For an explanation of why, see this interesting NASA article, which also explains whether there are aliens watching reruns of I Love Lucy.)  The book got me re-thinking that conclusion.  If properly synchronized, it’s possible to distribute an antenna over widely separated points on earth.  If Clint were to use such a distributed antenna instead of his 6-meter Yagi, then perhaps he could listen to the farm reports from Canis Minor after all.

4.  Even the lone ham can do quite a bit of ionospheric research in his own back yard, and can probably do much more with some sort of distributed data collection.

The conspiracy buffs will be disappointed by this book, because it turns out that HAARP (the High Frequency Active Auroral Research Program) has a pretty mundane purpose, but makes use of some pretty interesting science.  It turns out that a lot of mixing of radio signals can take place in the ionosphere.  This is due to something called the “Luxembourg Effect”, which is explained pretty well in this 1935 article.  The powerful longwave transmitters of Radio Luxembourg (and Gorky, Russia) were found to cross-modulate the signals of stations on a higher frequency located further away along the same path.  The strong longwave signals were modulating the signal of the higher frequency station in the ionosphere as it passed over the longwave transmitter.

HAARP, as it turns out, was mostly involved in using this phenomenon as a cheap (by military standards) method of generating low-frequency signals.  It can be quite a task to generate a strong low frequency signal in order to communicate with submarines.  But if you want to generate a 20 kHz radio signal, one way to do it is to generate two HF signals 20 kHz apart.  The ionosphere will serve as the mixing stage, and the result is a 20 kHz signal being transmitted from the edge of space.  Since this signal penetrates sea water, the submarines can copy it.  Unfortunately for the conspiracy buffs, I can’t think of any easy way to use this phenomenon to generate earthquakes, hurricanes, or any of the other phenomena that are associated with HAARP in the minds of some.

I think the best use of this book is to inspire aspiring young mad scientists.  While not disclosing too many details, I think this book suggests a number of science projects that are well within the capabilities of a bright high school student.  So if you are a bright high school student looking for an interesting science fair project, I think you’ll get some good ideas from this book.  While your classmates are busy building their potato battery clocks or making a volcano out of vinegar and baking soda, you can be doing some actual science.  What do you think your teacher will find more interesting, a homemade model of a volcano, or your measurements of the motion of the ionosphere?  If you need to build some tangible device, then I suggest that a homemade plasma chamber, made out of a plexiglass tube, nails, and a pump from an old refrigerator, will probably be a bit more impressive than the potato clock that your classmate offers.

The price of the book is indeed a bit steep for the impoverished student.  If you can’t find a used copy on Amazon, you can speak to your friendly librarian and ask them to order a copy.  If your local library is also too impoverished to buy it, you’ll impress your local librarian to no end if you walk up to the reference desk and ask them to get a copy through “interlibrary loan”.  You simply print out the listing from WORLDCAT, which shows the closest library with a copy.  Your local librarian will request a copy from that library, and in a couple of weeks, it will be delivered for you to check out.  Librarians thrive on doing this sort of thing, and they will be absolutely thrilled to learn that a student actually knows what interlibrary loan is, and actually gives the librarian the excuse to engage in the process.

For now, I glossed over the chapters on Smith Charts and wave polarization.  There appears to be a lot of good material there, but it will require a bit more study than the quick read I was able to give most of the other chapters.  For once, however, I do have some understanding of what is meant by the “characteristic impedance” of a feedline.  A feedline is nothing more than in infinite number of tiny inductors in series, along with an infinite number of capactiors in parallel.  This tiny components have both an inductance and a capacitance.  And, of course, any time you have an inductance or capacitance, you also have an inductive reactance and capacitive reactance.   And when I re-read that chapter, I have no doubt that I’ll have some understanding of how those give the characteristic impedance of the feedline.

Perhaps I would have been a bit disappointed if I had shelled out $27.95 for the book.  But overall, I got some good ideas from the book and I’m pleased that I selected it as my hamfest door prize.