The great Crichton is known for thoroughly researching his subject areas for each different book, evident from the extensive bibliography in the end and the checkable facts throughout the book. This contributes to a heightened sense of immersion.

Yet, the cutting-edge scientists he depicts, communicate exclusively in US Customary units. This not only contrasts modern science practices worldwide, but even turns suspense and horror into comedy, when some character tries to scale in their head 5 feet 9 inches by a factor of 10^-3.

Considering his works are worldwide bestsellers, why did he settle on this approach?

  • 47
    Even though science typically uses metric units, the average American reader would be more familiar with imperial. It's very likely Crichton was appealing to his American audience. Oct 4, 2017 at 16:46
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    This would be a better question/easier to answer if you provided examples. I just reread Congo, and he seems to use plenty of metric. Oct 4, 2017 at 18:06
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    As a scientist working in the USA, I would almost certainly use feet and inches to describe many things -- someone or something's height, for example. Just because scientists use metric to measure some things doesn't mean they carry it into every aspect of their lives.
    – iayork
    Oct 4, 2017 at 18:08
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    @Vorac I'm a biologist/molecular biologist, but I have friends who are astronomers, physicists, and mathematicians, and they do the same. If one of them was to refer to their child's height as "150 cm" I'd be taken aback (except for the European ones of course). You can also look at typical usage in Canada, which has been officially metric for decades; but Canadians still use Imperial units for some casual purposes. All in all, the phrasing you find strange seems perfectly normal American Scientistese to me.
    – iayork
    Oct 4, 2017 at 19:11
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    Considering that Scientific American and National Geographic continue to use US Imperial units, it's not surprising that a fiction writer would also do so
    – HorusKol
    Oct 4, 2017 at 20:20

5 Answers 5


Crichton used both imperial and metric, depending on the context.

In the course of one paragraph in The Sphere, he managed to use both!

"Pacific coral grows two-and-a-half centimeters a year, and the object-- whatever it is-- is covered in about five meters of coral. That's a lot of coral. Of course, coral doesn't grow at a depth of a thousand feet, which means that the present shelf collapsed to a lower depth at some point in the past."

When the character (Barnes, a Navy captain) is talking about precise measurements, he uses metric. When he's being more general, he uses imperial.

The main character Norman (a psychologist, not exactly the most mathematically intensive field) uses imperial when thinking to himself.

He climbed up through the submarine and into a round steel cylinder approximately eight feet in diameter.

But later, when the astrophysicist Ted is giving officialish measurements the titular sphere, he uses metric:

"This object is a burnished sphere approximately ten meters in a diameter, no solid, and composed of a dense metal alloy."

So the short answer is that Crichton is an American writing American characters for a predominantly American audience. He uses imperial units for clarity, but metric when it would realistically be used.

  • 14
    Isn't it also the case that naval depth measurements (as aeronautical heights) are always made in feet? In that case, the captain would not be colloquial, but in fact use his "professional" units. - Come to think of it, my GPS has several unit options to switch between - and IIRC one of them is such a mix between metric and imperial Oct 4, 2017 at 21:48
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    @HagenvonEitzen yes — in the USN, at least. I believe everybody else uses meters (there not being any equivalent to the international aviation standards that dictate use of feet).
    – hobbs
    Oct 5, 2017 at 0:44
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    What is your rationale for the claim that Crichton was writing for a primarily American audience? His books are published worldwide and most people on Earth are not American. Oct 5, 2017 at 9:24
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    @HagenvonEitzen As a subsea engineer I usually see American companies measure depth in feet while almost every one else use meter.
    – Ling
    Oct 5, 2017 at 9:45
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    Wow, this is actually a detail that has given me more respect for Crichton. I'm impressed that it makes that much sense. Oct 5, 2017 at 19:17

American scientist here. US Standard units are quite common here. Many of us tend to use Standard for casual things but use Metric for work. However, that is not always an option. Some fields, like electrical engineering, still use older units like mils (1/1,000th of an inch) and many who work for either government or industry are more or less required to work in Standard, whether they like it or not. Often hidden regulations only known by people dealing with them force the hands of government scientists, while industry scientists selling in the US will be used to having to sell and frame instructions using Standard.

It's honestly less uncommon than you may think. Most of us have just become used to swapping back and forth without much difficulty. The difficulty usually comes when trying to combine the two systems.

Thinking about this a bit more, units like mm Hg are still very common, as are atm.

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    Now that I think of it, we Europe uses mils for PCBs, inches for various mountain bike measurements and there is probably more.
    – Vorac
    Oct 4, 2017 at 20:09
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    Europe doesn't use mills for PCBs, we use millimetres. Perhaps it's the abbreviation to mils that is confusing - it means millimetres, not thousandths of an inch. As an example, 0.1" pitch is 2.54mm in Europe.
    – user
    Oct 4, 2017 at 21:31
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    @user23235 When I had to buy some capacitors for lab work a few years ago, I asked about measurements and was told it was 200 mils. I thought that meant millimeters and said that was a lot larger than I had envisioned. The guy corrected me like I was an idiot and told me it was in thousandths of an inch. I had to mentally convert that to roughly a centimeter to understand it, but it was unquestionably a Standard measurement. However, this was in the States and not in Europe. As I recall, my comment at the time was that measuring something at 200 thousandths of an inch was incredibly stupid.
    – Broklynite
    Oct 5, 2017 at 9:52
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    Yes, in the US they use "mills" to mean "1/1000ths of an inch" (try saying that out loud). In Europe "mils" or "mills" means millimetres. Most of Europe doesn't even use imperial measures at all, it's only the UK where they get some use. In the UK 1/1000ths of an inch is rarely used for anything, e.g. the common 2.54mm pitch would be referred to as 0.1 inch.
    – user
    Oct 5, 2017 at 9:56
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    "Thou" (pronounced "thouw") would be used by an auto mechanic to describe a spark plug gap measured in "thousandths of an inch"
    – Criggie
    Oct 6, 2017 at 3:12

Likely, it's because Michael Critchton was born in the United States, a nation that has officially adopted both Metric units and United States customary units (not Imperial) but primarily operates in the US customary, and lived and wrote there. It's little different than how everyone in Star Trek speaks in English (and they occasionally dip into Imperial or Customary units).

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    Perhaps it is more important that his audience is the general reading audience of the US and those are the units that this audience thinks in. (The SF community may claim him as one of our own, but his books are market to the general public rather than locked in the notional ghetto.) Oct 4, 2017 at 17:34
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    +1 for knowing that US units aren't imperial. en.wikipedia.org/wiki/…. Oct 5, 2017 at 8:46
  • @dmckee: "Perhaps it is more important that his audience is the general reading audience of the US" What is your rationale for this claim, please? Crichton's books are published worldwide. Oct 5, 2017 at 9:27
  • @LightnessRacesinOrbit what says you don't adapt your units for the country of your publishing? in terms of English language countries, they all are familiar with inches, so there is no need to adapt. I have a Crichton book in Latvian, and as far as I remember, it is metric all the way.
    – Gnudiff
    Apr 7, 2020 at 16:16

As a Canadian, I can give a pretty good go at this as Crichton does a beautiful job of showing a mixed system at work. Canadians should be Metric, but we exist in a weird middle space. Ask a European traveler here, we are weird for this.

I am 6'6"...it's almost 2m exactly, but if I told a fellow Canadian 2 meters, they'd be confused until I said feet inches. Same with weight, we talk our bodies weight in pounds despite it being clearly written in KG on my driver license. My fruits and veggies are in grams and KG. Oddly, I know my car's weight in KG...if you asked me to tell you my combined weight when I'm in the car, I'd have to go through math in my head to convert my cars kilo's into my bodies pounds or vice versa.

Distances are meters and KM. I drive in KM. I buy litres of fuel. Ask me to tell you my cars fuel efficiency and I'll answer in Miles per galleon without blinking (and will readily say I bought 10 litres of fuel and go 33 mpg in the same sentence).

I can go through many of these (some of them to the point of complete absurdity to be honest), but to generalize...anything that is exacting or that I need to pay for is in Metric. Anything that is relative or conversational tends to be in Imperial. Crichton does an amazing representation with the quote in the accepted answer:

"Pacific coral grows two-and-a-half centimeters a year, and the object-- whatever it is-- is covered in about five meters of coral. That's a lot of coral. Of course, coral doesn't grow at a depth of a thousand feet, which means that the present shelf collapsed to a lower depth at some point in the past."

I have actually said the following line and been completely understood myself... "We've been driving for hundreds miles, but down to 22km to our turn off".

Temperatures are even weirder...I don't know how hot 65 degrees Fahrenheit is and translate it to Celsius, however if you asked me what temp to start the oven at to bake a pie, I'll list Fahrenheit without question. When I tried baking at 220 Fahrenheit and messed up cause that number was supposed to be 220 Celsius, me and my friends all echo'd the same sentiment...what nut jobs cook in Celsius?, err but it's cold in here, turn the thermostat up to 21 fo me.

I give Crichton full marks in accurately portraying the use of a mix measuring system very accurately.


I'd like to add to Broklynite's answer (and I might add I'm a scientist in a land where the SI unit system is standard in commerce and most people under 40 have little appreciation for US customary units).

You are in many ways wrong that modern science worldwide uses the SI system exclusively. All kinds of unit systems are used by different branches of science to dovetail into the field's needs. My own field of physics/ geometry uses natural units extensively; these choose the base units to set the fundamental constants of nature to unity. Thus, for example, the speed of light $c=1$ is unity, the reduced Planck quantum of action $\hbar=1$ is unity, the universal gravitation constant $G=1$ is unity and time and distance have the same dimension. There are several variations on natural units with these attributes; these variations are mostly to do with electromagnetism and the form of Maxwell's equations.

It is interesting to note that the next revision of SI takes its cues from this and will concentrate on fixing values of the fundamental constants rather than defining "base units".

In astronomy, it makes next to no sense to use anything but astronomical units, parsecs, light years or $z$-values (redshift ratios) to measure distance.

The US fps system is perfectly acceptable as a scientific unit system; modern definitions link it to the same definitions as the SI system, i.e. to wavelengths of light of a certain atomic transition and a fixing of the value of $c$. So, although these units are awkward and unwonted to me, I disagree that they are in principle any way inferior for scientific purposes. They get a bit awkward when we introduce electromagnetism, as the volt is linked to the SI unit of energy.

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    Although an interesting answer and piece of information, we generally look for answers where the author has mentioned something in an interview or discussed it in his works. Rather than "you're wrong because in real life scientists don't do XYZ". Also, Latex markup is exclusive to certain stacks.
    – Edlothiad
    Oct 6, 2017 at 7:43
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    @Edlothiad Well, if a question is predicated on a completely false assumption, I fail to see how that cannot be relevant. Your assertion seems arbitrary and artificial - particularly as it applies equally well to other answers. I should have thought writing is about the author's relationship with the surrounding culture. Oct 6, 2017 at 9:30
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    I find this a good answer. Whoever downvoted it should have downvoted my question instead for being based on dubious assumptions.
    – Vorac
    Oct 6, 2017 at 9:54
  • This site primarily focus on discussion related to the work in question, and although your answer is relevant to the question asked, it fails to address the question of Michael Crichton, which is the primary focus of the question (or so it is assumed to be for it to be on-topic for the stack). As I'd said, your answer is not bad, merely that it is not as preferred, as the voting suggests. I'm aware now that this applies to other answer, but I was not following this post closely, I merely reviewed your posts in the queues.
    – Edlothiad
    Oct 6, 2017 at 10:29
  • You are correct, writing does have to do with the author's relationship with the surrounding culture. However, your answer simply discuses the use of non-SI units in science, and while your answer is correct the intention seems to be less focused on Crichton's use of the units rather that the OP's assumption for the question was wrong, and that scientist all round use every so what units that are not all SI. Again I didn't say your answer was wrong or bad, I'm merely stating the site generally looks for answers based on the works in question. If you disagree with our policies, we have a meta.
    – Edlothiad
    Oct 6, 2017 at 10:33

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