Gas Mileage, with a Side of British Units

In the United States we measure how much gasoline an automobile uses in units of “miles per gallon”, often referred to as the car’s “fuel economy”. Elsewhere in the world it is measured in “liters (litres) per 100 kilometers”.

Since both gallons and liters are volume measurements when we do a dimensional analysis of these quantities, we get for the United States L/(L^3) or L^{-2}, and for the rest of the world L^3/L or L^2. In both cases it comes out as an area measurement, inverted in the case of the United States.

For 25mpg in the US (which is 9.4 liters per 100 kilometers), we can calculate the area knowing that a US gallon is defined to be 231 cubic inches, and since a mile is 5,280 feet, or 63,360 inches, the area (un-inverted) in square inches is: 

    \[\frac{231}{25\times 63360} = 0.000145833\]

 or a square 0.0121 inches on a side or a circle that is 0.01363 inches in diameter. In metric units, given that a liter is 1,000 cubic centimeters, or 1,000,000 cubic millimeters, and a kilometer is 1,000,000 millimeters, the area is 0.094 square millimeters, which is a square 0.3066 millimeters on a side, or a circle 0.3460 millimeters in diameter.

So that’s the area. But what does it mean physically?  It is the volume of gasoline that it takes to drive 25 miles, or in the other units 100 kilometers, stretched out to that length. If we form it into a very long cylinder then the area is the cross section of the cylinder. So a 25mpg automobile has the contents of its gas tank stretched out over the whole length of its journey, into a cylinder of gasoline with diameter 0.346 millimeters, and the car is precisely eating that cylinder as it drives along!

Of course, having grown up in Australia back when we used Imperial British units for everything, I have always preferred expressing gas mileage in acres^{\big 1}. And 25mpg turns out to be 2.325 \times 10^{-11} acres.

A Boeing 747 burns about 5 gallons of fuel per mile, or 12 liters per kilometer, so it is eating up a cylinder with a cross sectional area of 12 square millimeters, which is a cylinder with a 3.9 millimeter diameter, roughly 100 times more than an automobile.

The first stage (S1-C) of the Saturn V moon rockets burned out at about 61 kilometers up, having consumed 770,000 liters of RP-1 kerosene. That means it consumed a cylinder of fuel with 12,623 square millimeters, i.e., a diameter of 126.8 millimeters, or just about exactly five inches.  Now that is a gas guzzler!

^{\big 1}What is an acre? It is derived from the amount of land tillable by a yoke of oxen in one day–and a long strip of land is more efficient to till than a more boxy area as you have to change direction less often. So an acre is defined as one “chain” wide, by 10 chains long. And a chain?  It is a 100 links, or exactly 22 yards (and also exactly four “rods” long, each of which is sixteen and a half feet long). So the standard tillable plot was 22 yards wide, and 220 yards long, which happens to be one eighth of a mile long, otherwise known to horse racing enthusiasts as a furlong, or “furrowlong”!

An acre plot was one eighth of a mile long and one eightieth of a mile wide, which is why there are 640 acres in a square mile. Of course once an acre is an area it can be any shape, and it is 4,840 square yards, or 43,560 square feet, which itself is precisely 99% of 44,000 square feet. Since a square rod is known as a perch, an acre is 160 perches. And BTW, the playing area of a standard US football field is roughly 0.9 acres.

Don’t even get me started on Imperial British units for weight, including a hundredweight (which is 112 pounds, of course), one 20th of an Imperial ton (2,240 pounds), and itself four quarters (28 pounds each), or 8 stone (14 pounds each). No, I won’t get started… and certainly not on money made up of pounds, shillings, and pence, with 20 shillings to a pound, and 21 shillings to a guinea for fancy stores, with 12 pence to a shilling, and a half crown was two shillings and six pence, or 2/6 (“two and six”, or 2s 6d). I won’t get started there, either…

Robot Is A Hijacked Word

The word “robot” has been hijacked. Twice. (Or thrice, if we want to be pedantic, but I won’t be.)


The word “robot” was introduced into the English language by the play R.U.R., written in Czech by Karel Capek, and first performed in Prague on January 25, 1921. R.U.R. stands for Rossumovi Univerzálni Roboti, though even in the first edition of the play, according to the play’s Wikipedia page, published by Aventium in Prague in 1920, the cover designed by Karel’s brother Josef Capek, had the English version as the title, Rossum’s Universal Robots, even though the play within was in Czech.

According to Science Friday, the word robot comes from an old Church Slavonic word, robota, meaning “servitude”, “forced labor”, or “drudgery”. And the more you look the more references indicate that it is not known whether Karel or Josef suggested the word.

But, in any case, in the play the robots were not electro-mechanical devices, in the way I have used the word robot all my life, in agreement with encyclopedias and Wikipedia. Instead they were “living flesh and blood creatures”, made from an artificial protoplasm. They “may be mistaken for humans and can think for themselves”. Both quotations here are from the Wikipedia page about the play, linked to above. According to Science Friday they “lack nothing but a soul”.

This is the common story, more or less, about where the word robot came from.


But, but, maybe not.  According to this report the word “robot” first appeared in English in 1839. 1839! It says that robot at that time referred not to an individual, neither machine, nor protoplasm, nor electro-mechanical , but rather to a system, a “central European system of serfdom, by which a tenant’s rent was paid in forced labour or service”. Ultimately that word came from the same Slavonic root.

So perhaps in English the word “robot” changed in meaning between 1839 and 1920. Though realistically perhaps no one who picked it up from the Capek brothers in 1920 had ever heard of it from the old 1839 meaning. And in any case it seems such a different use that I don’t think it really is a hijacking. Just as “field” was not “hijacked” in going from a field of wheat to a field of study.

I am not going to count this as a “robot” hijacking.


In 1920 “robot” referred to humans without souls, manufactured from protoplasm. But that meaning changed quickly.


By the time I was deciding what really interested me in life, the word “robot” had turned into meaning a machine, as given by the online English Oxford Living Dictionaries, where it defines the word as:

A machine capable of carrying out a complex series of actions automatically, especially one programmable by a computer.

Here is the cover of the January 1939 edition of Amazing Stories.

There is a robot, a machine, right on the cover, illustrating a story titled I, Robot. But for me the big news is that the author of that story is Eando Binder (a nom de plume for Earl and Otto Binder), rather than Isaac Asimov–we’ll get back to Dr. Asimov in just a minute. I have found one slightly earlier reference to mechanical robots, but it is only a passing reference. In this Wikipedia list of fictional robots there is a story titled Robots Return, by Robot Moore Williams, dated 1938. Unfortunately I do not have the text of either of the 1938 or 1939 stories, so can’t tell whether the authors assume that their readers implicitly understand to what the word “robot” refers.

However, in 1940, only twenty years after the R.U.R. play was first published with the English version of robot on its cover, Isaac Asimov published his story Strange Playfellow in Super Science Stories, an American pulp science fiction magazine (of the Binder story he said “It certainly caught my attention” and that he started work on his story two months later). Later, retitled as Robbie, the story was the first one that appeared in Asimov’s collection of stories published as the book I, Robot, on December 2, 1950.  I have a 1975 reprint of a republished version of that book from 1968. In that reprint, at the bottom of the third page, after describing a little girl, Gloria, playing with a mechanical humanoid Robbie, Asimov uses the word “robot” to refer to Robbie (note the alliteration) in a very casual way, as though the reader should know the word robot.  The word “robot” got hijacked in just 20 years, in the popular culture, or at least in the science fiction popular culture, from meaning a humanoid made of protoplasm in a Czech language play in Prague, to meaning a machine that could walk, play with, and communicate with humans. Note that 1940 was before programmable computers existed, so there was some more evolution to get to the definition involving computers as quoted above.

In the 1920’s such mechanical humanoids seem to have been referred to as “automatons”.

I have no idea what contributed to that transformation of the word “robot”, but I am eager to see any citations that might be offered in the comments section.

So now we have the first real hijacking of “robot”. But there has been a more recent one. I may not care deeply about the earlier hijacking, but I sure do care about this one. I am an old school roboticist in the sense of the definition in italics four paragraphs back. And my meaning has been hijacked!!


In the more recent hijacking, “robot” has come to mean some sort of mindless software program, that does things that are relentless, or sometimes even cruel, though sometimes amusing and helpful. This new use is getting so bad that it is often hard to tell from a headline with the word “robot” to which form of robot the story refers. And I think it is giving electromechanical robots, my life’s work, a bad name.

I think it starts with this secondary definition which also appears with the English Oxford Living Dictionaries definition from above.

Used to refer to a person who behaves in a mechanical or unemotional manner.

And then it includes an example of usage: ‘public servants are not expected to be mindless robots’.

Now Asimov’s robots have not been mindless, and none of mine have ever been mindless (well, perhaps my insect-based robots were a little mindless, certainly not conscious in any way). But the first industrial robots introduced into a GM automobile plant in 1961 certainly were mindless. They did the same thing over and over, without sensing the world, and did not care whether or not the parts or sheet metal they were operating on was even there. And woe be a person who got in their way.  They had no idea there was someone there, and even had no idea that someone, or anyone for that matter, existed, or even could exist. They did not have computers controlling them.

I may be wrong, but I trace the hijacking of the word “robot” to two things that happened in 1994. I am guessing that there is some earlier history, but that I am just not aware of it. Ultimately it is all the fault of the World Wide Web…

Tim Berners-Lee invented the World Wide Web and put up the first Web page in 1991. Explosive growth in the Web started soon after, and by 1994 there were multiple attempts to automatically index the whole Web. Today we use Google or Bing, but 1994 was well before either of those existed. The way today’s search engines, and those of 1994, know what is out on the Web is that they work in the background building a constantly updated index. Whenever someone searches for something it is compared to the current state of the index, and that is what is actually searched right then and there–not all the Web pages spread all over the world. But the program that does search all those pages in the background is known as a Web Crawler.

By 1994 some people wanted to stop Web Crawlers from indexing their site, and a convention came about to put a file named robots.txt in the root directory of a web site. That file would never be noticed by Web browsers, but a politely written Web Crawler would read it and see if it was forbidden from indexing the site, or if it was to stay away from particular parts of the site, or how often the owner of the site thought it reasonable to be crawled. The contents of such a file follow the robots exclusion standard of which an early version was established in February 1994.

You can see a list of 302 known Web Crawlers (listed as a “Robots Database”!) currently active (I was surprised that there are so many!).  Of the 302 Web Crawlers, 29 include “robot” in their name (including “Robbie the Robot”), 18 include “bot” (including “Googlebot”), three have “robo”, and one has “robi”.  Web Crawlers, which are not physical robots, have certainly taken on “robot” as part of their identity. Web Crawlers became “robots”, I guess, for their mindless search of the Web, indexing it all, and following every link without understanding what was there.

That same year there was another innovation. There had been programs, all the way back to the sixties, that could engage in forms of back and forth typed language with humans. In 1994 they got a new name, chatterbots, or chat bots, and some of them had a more or less permanent existence on particular Web pages. Probably they attracted the suffix “bot”, as they could seem rather mindless and repetitive, again harking back to the dictionary example above of mindlessness of robots.

Now we had both Web Crawlers and programs that could converse (mostly badly) in English that had taken parts of their class names from the word “robot”. Neither were independent machines. They were just software. Robots had gone from protoplasm, to electromechanical, to purely software.  While no one is really building machines from protoplasm, some of us are building electromechanical devices that are quite useful in the world. Our robots are not just programs.

Since 1994 the situation has only gotten worse! “Robo”, “bot” and “robot” have been used for more and more sorts of programs.  In a 2011 article, Erin McKean pointed out that there were “robo” prefixes, and “bot” suffixes, and that at that time, in general, robo has a slightly more sinister meaning than bot. There was “Robocop”, definitely sinister, and there were annoying “robocalls” to our phones, “robo-trading” in stocks caused the 2010 “Flash Crash” of the markets, and “robo-signers” were people signing foreclosure documents in the mortgage crisis. Chat bots, twitter bots, etc., could be annoying, but were not sinister.

Now both sides are bad. We see malicious chat bots filling chat rooms intended for humans, we see “botnets” of zombie computers, taken over by hackers to launch massive denials of service on people or companies or governments all over the world.

Here is a list of varieties of bots, all software entities. Some good, some bad.

At some web sites, such as, it seems to be all about “bots”, but it is hard to tell which ones are software or if any have a hardware component at all. Now “bots” seems to have become a generalized word for all aspects of A.I., deep learning, big data, and IoT. It is sucking all up before it.

The word “robot” and its components have been taken to new meanings in the last twenty or so years.


Here’s the bottom line. My version of the word “robot” has been hijacked. And since that is how I define myself, a guy who builds robots (according to my definition) this is of great concern. I don’t think we can ever reclaim the word robot (no more so than reclaim the word “hacker”, which used to be only pristine goodness forty years ago, and I was honored when anyone ever referred to me as a hacker, even more so as a “robot hacker”). I think the only thing to do is to replace it.

How about a new word? What should we call good old fashioned robots? GOFR perhaps?

One that comes to mind is “droid”, a shortened version of “android”, which before it was a phone software system meant a robot with a human appearance. Droid distinguishes itself from the hijacked version of android which refers to phone software, and is generally understood by people to mean an electromechanical entity, an old style robot. Star Wars is largely responsible for that general perception. But that is also the problem in trying to use the word more generally. The Star Wars franchise has the word “droid” completely bottled up and copyrighted. I know of three robot start up companies that wanted to use the word “droid”, and all three gave up in the face of legal problems in trying to do that.

No droids. Unfortunately.

So…what should the new word be? Put your suggestions in the comment section^{\big 1}, and let’s see what we can come up with!

^{\big 1}I manually filter all comments, as the majority of comments posted are actually advertisements for male erectile dysfunction drugs…

A Fair Fight?

In all science fiction movies and TV shows when there are aliens and the humans have to fight them it turns out to be close to a fair fight.  Of course the humans always win in the end, but there is plenty of drama as the fight is balanced and there is room for the pendulum to swing back and forth.

But what if we met aliens for real, and what if for some stupid reason they or we wanted to fight each other instead of study each other and perhaps revel in the wonderful idea that two different life forms who could communicate with each other had somehow found each other in this very empty Solar System/Galaxy/Universe that we occupy?

Would it possibly be a fair fight?

The Universe is 13.8 billion years old, and our galaxy is almost as old at 13.2 billion years. But the Earth is relative newcomer at 4.6 billion years old–there are many planets in our galaxy much older than ours and many much younger. Life arose on Earth about 4.1 billion years ago.  Mostly it has been single cell life ever since–it would usually lose in a fight with blasters. Animals, weird ones, but recognizable as animals, showed up about around 500 or 600 million years ago, or about 96\% into the life of the Universe. Humans first appeared about 5 million years ago, or just in the last 1\% of the 4\% of the age of the Universe, or about the last 0.04\% of the history of time.  Humans only figured out how to organize into armies no more that 10,000 years ago, or the last 0.2\% of human history or 0.00008\% of the age of the Universe. And we only got anything like guns in the last 400 years, or the last 4\% of that so then the last 0.0000032\% of the age of the Universe.  And we won’t get blasters, according to most science fiction, for another 200 years.

So, if another species that arose somewhere else in our Galaxy, and who has interstellar travel, and shows up here on Earth, and turns out to be nasty and wants to fight us (oh, wait, maybe that is us who wants to do the fighting), what is the chance that they will be anywhere near to the 600 year period of our history of guns turning into blasters, and not way beyond? What is the chance that we and they will have anywhere close to the same technological level so that a fight even makes sense?  Does even one single scene in any movie or TV show about humans fighting aliens have even the slightest chance of being technologically plausible?

Or let’s put it another way.  The lion is the apex predator in Africa.  But when it comes to an encounter with an American dentist the lion always ends up dead, and the dentist walks away unscathed. Every time.

Humanoids of Star Trek

I am a big Star Trek fan.  But there is one little problem…

How come all the races they meet are essentially humanoid, apart from the occasional pool of tar which both speaks and absorbs well loved security officers? Why is the whole Universe, well at least the whole of Alpha Quadrant of our Galaxy, full of aliens who are remarkably human like in size and form, even though the may have extra organs, always unseen except by the various “Doctors” in weird places in their torsos? Oh, and despite that, they all happen to be wonderfully sexually compatible with each other….

It all goes back to the sixties when The Original Series (TOS) was made. That was before computer graphics were anywhere good enough to be used on film, and so all the aliens had to be played by human actors.  If it could be arranged that only the voice of the human had to be “seen” by everyone then the form of the body could be as weird as a pool of tar. But if there needed to be visible interaction then the aliens had to have human form, because that is what the available actors had.

And we won’t go into how the universal translators (nice dodge!) know how to communicate in English with any alien race before anyone has heard them first speak a word, or a paragraph, in order to learn their language…