The metric system (a.k.a. SI) does not have to be the only measurement system that people use. Various proponents of the metric system here in the U.S. complain that the U.S. needs to "go metric" or that it needs to "catch up to the rest of the world" by using the metric system. This page intends to show that it is fine to keep using the U.S. (or Imperial, or English) system. The metric system is not technologically superior to the U.S. system. The distance from London to Moscow can be measured in miles or meters (or metres for those out there who prefer (prefre?) that spelling), and they will each be correct.
Here is an outline of the contents of this page.
Why is There No Metric Time?
One of more noticeable uses of the U.S. system versus the metric system is with the speed limit postings on the roads. The U.S. uses MPH (miles per hour), and it seems that the other countries use KPH (kilometers per hour). Those so-called metric countries use KPH because it is supposedly metric. But the hour is not a metric unit. The second is one of the approved metric units, so anything that is metric should use units of seconds. An hour is, of course, 60 minutes, which is 3600 seconds. So if those countries truly want to be able to back up their claim of using the metric system, they should post their speed limits in meters-per-second (or, if they want to keep the same numbers, the speed would be in kilometers-per-36 hectoseconds). That would be a correct use of the metric system. Why do they still use hours? ...because it is an established and convenient measurement unit.
Astute readers will notice that the title of this section is not entirely correct. There is metric time, since the second is allowed in the metric system, but the title is asking why people still use minutes, hours, days, weeks, months, and years. Should they use kiloseconds, megaseconds, etc. instead of those old, outdated, useless units of hours, weeks, etc? For some reason, the metric community finds it abhorrent that people divide by 12 in order to convert from inches to feet (because the metric system of dividing by 10 is much simpler), even though they themselves continue to divide by 60 to convert seconds to minutes and minutes to hours, by 7 to convert from days to weeks, and by 12 (there is that evil number again) to convert from months to years. There are also the numbers of 52 and 365 as conversion factors, which are very non-metric, but the metric people still use them.
Also, metric people seem to enjoy asking how many ounces there are in a pound, because the answer depends on which system of ounces is being used. There are 2 or 3 different answers. They like to note that as one of the confusing points about the U.S. system that makes it bad. If they ever ask that, ask them how many days there are in a month. Then ask how many days are in the month of February. Then ask them why they keep using such a confusing system, where there is not even a consistent conversion factor.
Another thing to note is that it is often claimed that the scientific community uses the metric system. They use it for a lot of things, but it is interesting that they still continue to use light-years when dealing with measurements of astronomical proportions. Why do they use light-years instead of some multiple of exameters? ...because it is an established and convenient measurement unit. Also, a little while back, NASA lost a space probe that was headed to Mars. The problem was that one company provided information to NASA in U.S. units and the other company gave information in metric units. It was interesting to see that most people and most of the news reports seemed to blame the one company for using U.S. units. Why was the problem not that the other company used metric units? The problem was not that U.S. units were used, but that NASA did not convert all its information to the same system (whether SI, U.S., or it could make up its own special NASA system - it does not matter) before using it.
There are Multiple Languages
There are many different countries in this world, and many different languages used by those countries. Some countries even have several different languages and dialects within languages. The metric community seems to have no problem with this situation. But if a country tries to have its own measurement system language, for some reason that is a problem.
Because of various technological and political advances, it is easier for people and businesses to experience a wider range of countries, cultures, and languages. In order for those different people to communicate and understand each other, they must decide on which language they will use. A business venture between Germans and Russians may decide to use German, and a business that operates in both Germany and the U.S.A. may decide to conduct its business using English. The key is that the people involved decide on a language to use. The same should apply to measurement systems. If a business or industry decides that it wants to use the U.S. system for its products, then why should it not do that?
Many countries recognize English as the international language. Some countries (e.g. Japan) require students to learn English in school, as well as further instruction in the national language. Just because English is the international language, does that mean that non-English-speaking countries abandon their own langauges? No, it means that they recognize English and use it in international situations, but they keep their own language for domestic and other use. Likewise, just because the metric system (SI, for System International) is the international system, does that mean that English-unit countries abandon their measurement system? No, it means that they recognize the metric system and use it in appropriate situations. Languages are also significantly tied to a culture. Likewise, the U.S. system is tied to U.S. culture. Who in the U.S. would want to eat a meter-long coney dog? There are a number of sayings using the U.S. system that have cultural and historical value for the U.S., and totally converting to the metric system would change a lot of that.
As was the example at the top of the page, the distance from London to Moscow can be measured in miles or meters. It is just like languages. The Spanish language (or any other language) is neither superior than or inferior to the English language. The same things (food, geography, weather, etc.) can be described by either language, just as any system can describe measurements (length, mass/weight, etc.).
By the way, one of the differences that metric people like to note is that the gram is a unit of mass, but the pound is a measure of weight. So, on the moon, a gram is still a gram, but a pound is not a pound anymore. There are two problems with that. The first one is that the difference between mass and weight does not matter to the general population. The people that do need to know the difference are smart enough to be able to handle the math associated with the U.S. system. The second one is that a person feels weight, not mass. So for the people who do get to travel in space, they think "Wow, I feel lighter!", not "Hey, my mass hasn't changed..."
Why is it Good Not to do Math?
One of the main selling points of the metric system seems to be that a person does not have to be good at math to be able to convert from one unit to another, since all the units are defined in relationships of 10. So to convert from one unit to another, a person simply shifts the decimal point left or right by the appropriate number of places. There are are two problems with that: it reduces math skills and it puts people in the wrong mindset (actually that second point probably is not a full point, so make it one and a half or one and a quarter problems, not two problems).
It reduces math skills by having people do less and less mental arithmetic. It may be mentally fatiguing for some people to multiply or divide by 12, but exercise produces strength and endurance. If people get in the mindset that all they have to do is shift the decimal point, then they do not get much mental exercise from that. Of course, people will say that they just want to be able to function in society and not have to perform a set of calculations just to buy something or figure out measures. A vast majority of everyday, real-world things are not based on 10, and simple math is needed for those things anyway. If gasoline is 85 cents per liter, how many liters does 5 dollars buy? The math required for that is more than just shifting a decimal point; it requires division.
If a truck with a bed of length 2.4 meters is to be carrying items of length 20 centimeters, how many of those items can it carry?
Let's see, take the 2.4 and shift the decimal place to the left... that makes 240 centimeters. 20 centimeters goes into 240 centimeters how many times?The answer is simple, but it is not a power of 10. Does the all-you-need-to-do-is-shift-decimal-places philosophy work in real world situations? ...not usually. For the previous example, the answer would be 12. The metric people would like you to think that if you use the metric system, you do not have to divide by 12 anymore, but that is not always the case. On the other hand, a truck bed of length 2.4 yards can carry how many items of length 20 inches?
That's 2.4 times 3 equals 7.2 feet times 12 equals 86.4 inches divided by 20 equals 4, rounded off since only whole items are going in the truck bed.The example was done in the U.S. units in order to prevent the argument that the numbers were chosen to make the metric conversion seem hard and the U.S. conversion seem simple. The point of this section is not that U.S. conversions are easier than metric conversions, because they are not, but that division and multiplication appear in everyday life.
Teaching students the U.S. system in schools helps children learn basic math skills, and using the U.S. system exercises their brains. One of the complaints about the U.S. children these days is the lack of basic math skills. Teaching the U.S. system would help them learn multiplication and division better than metric-only curricula. Granted, metric problems can be made to have math (see example above), but it is easier to incorporate more math in a problem using the U.S. system than it is with the metric system.
For those people who cannot do the necessary math, there are calculators that they can buy. Likewise, for people doing a lot of calculations, they probably are using computers to do the math for them. For example, the contract companies doing work for NASA to build the Mars thingy did not do the calculations by hand or in their heads. They have the equations and the data for the computers to use. For a computer, dividing by 10 is no easier or no more difficult than dividing by 12. So for a lot of jobs, it really would not matter to the people involved what the system or its base units are, since the people are not going to be doing the math anyway.
So, if people have math skills, they should be able to handle the U.S. system. And if people do not have math skills (or they are using calculators/computers for efficiency reasons), then the U.S. system is fine since it does not matter, math-wise, what system they use.
Fahrenheit versus Celsius
Fahrenheit is a centigrade scale. Many people think that Celsius and centigrade are interchangeable when referring to thermometers. The word "centigrade" refers to the fact that a scale has 100 divisions. Since Celsius has 100 divisions (degrees) between the freezing and boiling points of water, it is a centigrade scale. But why is water the standard for temperature? Since humans are doing the measuring, why not make human comfort the standard? By that standard, Fahrenheit is also centigrade. Zero is the minimum temperature that most humans can stand, and 100 is the maximum temperature that most humans can stand. Anything outside those ranges can be dangerous.
The Celsius scale is tied to the freezing and boiling points of water. That can be very handy for dealing with water. However, most people are going to want the temperature in relation to themselves, and the Fahrenheit scale is better suited for relating temperature to people. What is the most commonly measured item regarding temperature? Would it not be the weather? So this discussion relates particularly to weather, which is in keeping with the overall theme of this page, which is that the English system is useable in everyday life.
People naturally rate things on a scale of 1 to 10 or 10 to 100. So a thermometer should read 1 or 0 for something that is really cold to a person, and it should read 10 or 100 for something that is really hot to a person. The Celsius scale is not easily felt. It is easily understood - 0 is freezing and 100 is boiling. But humans never experience boiling, so there is no reference. Humans do experience freezing, but it is tolerable for a short duration, so the Fahrenheit scale is better here since its 0 is below freezing. Those people who live in colder climates and go through winter every year know that if the temperature is around freezing, that is not very dramatic or drastic. One can even be outside for a stretch with a shirt but no coat. But go significantly below that, and that causes trouble for the human body, as well as cars and other mechanical items.
How do the cold and hot range of temperature work in Celsius? Why is a 40-degree day really hot? Doesn't a 100-degree day make more sense? Obviously not to someone who has Celsius as his first language. (But if the argument were that people should just use what they learned as children, then no one would be trying to convert the U.S. to metric.) So if you were creating a new weather thermometer scale, wouldn't you want 100 to be a really hot day? Hot and cold on the Fahrentheit scale are somewhat subjective: what's hot for one person might be just warm for another. But Celsius has the same problem: a 10-degree day might be too cold for one person but just mild for another. Celsius is fine if all you are doing is calculating the freezing and boiling points of water. But shouldn't people use temperature scale that was made for humans?
One may think that this section just made the case for metric -
"look, it says that humans like things on scales of 1 to 10 or 1 to 100."
However, scales of 1 to 10 is not the same as keeping multiples of 10,
and temperature is the only category which has a scale like that (effective min to max for humans).
Why is the boiling temperature of water always described as 100 degrees C? Shouldn't it be 1 hectodegree?