Kilometers vs Miles

[Hartful]

I'm sure that this topic has popped up on other occasions. I can't be the only person who has to go to a kilo to mi converter each time I read the explanation under the pictures posted at APOD, NASA, etc. It's apparent that scientists and others dealing in science love to use the metric system for distance and weight measurements. Is it because they want to show that they know them? It's very annoying. We all grew up learning US Standard units in schools here in the US. The metric system is not more accurate than US units. I'd rather read 1,203,303,304.922309724 miles than 1.61 kilometers. I'm sure most people in the US feel the same way.

Just call me an American.

[rstevenson]

Rob

[Ann]

I think it's a bit of a bother to convert miles into kilometers, myself.

(Let's see... the speed of light is 186 282.397 miles per second. One mile is 1.609 kilometers, so... oh, bother! The speed of light is almost 300,000 kilometers per second!)

Ann

[Nitpicker]

Yes, it's disgraceful that a scientific outreach program might encourage people to learn new things. I blame the French.

[Chris Peterson]

I'm sure that this topic has popped up on other occasions. I can't be the only person who has to go to a kilo to mi converter each time I read the explanation under the pictures posted at APOD, NASA, etc. It's apparent that scientists and others dealing in science love to use the metric system for distance and weight measurements. Is it because they want to show that they know them? It's very annoying. We all grew up learning US Standard units in schools here in the US. The metric system is not more accurate than US units. I'd rather read 1,203,303,304.922309724 miles than 1.61 kilometers. I'm sure most people in the US feel the same way.

Just call me an American.

I'm American, too.

And while metric units are no more accurate than English or U.S. units, they are certainly far easier to work with, and they are the accepted units of scientists and science. So they are also the best choice in any science discussion, even popular science.

The best way to get comfortable with a different unit system is to use it. If you enjoy APOD, why not see it as an opportunity rather than a problem? It shouldn't take long before the few units commonly used here seem natural, and you don't have to go to a calculator or conversion site for them to make sense.

[bystander]

The U.S. is one of only three nations that has not formally adopted the metric system; the other two being Myanmar and Liberia. It seems to me it would make far more sense for the U.S. to convert to the International Standard of Units (i.e. the metric system).

[Chris Peterson]

The U.S. is one of only three nations that has not formally adopted the metric system; the other two being Myanmar and Liberia. It seems to me it would make far more sense for the U.S. to convert to the International Standard of Units (i.e. the metric system).

Strictly speaking, the "metric system" isn't the same as the SI system (although for practical purposes they can usually be treated synonymously). Indeed, while scientists usually use unit systems based on SI, they are frequently variants (such as MKS), and occasionally use units not part of the SI system at all, such as the angstrom, liter, dyne, torr, calorie, gauss, and many others.

[geckzilla]

I'm sure most people in the US feel the same way.

[Citation needed]
This American would not mind switching to metric. The best argument against the switch is that it costs money to change. The rest of the arguments are laughable pleas of nationalism.

[Doum]

Some history on SI,

http://en.wikipedia.org/wiki/Metricatio ... ted_States

...In 1866, Congress authorized the use of the metric system[5] and supplied each state with a set of standard metric weights and measures. In 1875, the United States solidified its commitment to the development of the internationally recognized metric system by becoming one of the original seventeen signatory nations to the Metre Convention or the Treaty of the Metre...

...The 1895 Constitution of Utah, in Article X, Section 11, originally mandated that: "The Metric System shall be taught in the public schools of the State." This section was, however, later repealed...

and also

http://en.wikipedia.org/wiki/Mendenhall_Order

[owlice]

I'm sure most people in the US feel the same way.

[Citation needed]
This American would not mind switching to metric. The best argument against the switch is that it costs money to change. The rest of the arguments are laughable pleas of nationalism stupidity.

Fixed it.

[geckzilla]

Nationalism is just a concise type of stupidity.

[MargaritaMc]

I remember when the UK changed its money to decimal. When I was growing up we had this very simple system where:


Twelve pennies made one shilling
Two shillings made a florin
Two shillings and sixpence made one half crown
Five shillings made a crown
Twenty shillings or four crowns made a pound.

In place of that totally straightforward system the Government imposed a system of horrendous complexity in which:

100 NEW pennies made one pound.

Huh? How on earth were we going to get out heads round THAT??!

M

[Chris Peterson]

100 NEW pennies made one pound.

Nonsense, there are 16 ounces in one pound.

[Ron-Astro Pharmacist]

Unless it's a Troy pound.

It's all so confusing.

[rstevenson]

Are Imperial Measurements outdated?



Rob

[Nitpicker]

So much for the km versus miles debate ...

What about light-years versus parsecs? Technically, neither of them are accepted for use in the SI and they probably can't even be defined as metric. (The astronomical unit, AU, is officially accepted in the SI, and is a critical component of the parsec.)

[geckzilla]

I need a system which would allow me to measure the amount of chagrin I feel for not checking my facts before making a post. Is there something in the SI for that?

[Nitpicker]

I need a system which would allow me to measure the amount of chagrin I feel for not checking my facts before making a post. Is there something in the SI for that?

Surely the SI will eventually accept "derps".

[MargaritaMc]

Are Imperial Measurements outdated?



Rob

Totally sensible and logical. I use barley seeds and poppy seeds all the time...
M

[rstevenson]

Are Imperial Measurements outdated?



Rob

Totally sensible and logical. I use barley seeds and poppy seeds all the time...
M

Of course you do. I have a hogshead of poppy seeds for measuring larger distances. And I have a chain around here somewhere, which I'm sure I could drag behind my car to determine my "mileage", whatever that is.

Rob

[Hartful]

the speed of light is 186 282.397 miles per second. One mile is 1.609 kilometers, so... oh, bother! The speed of light is almost 300,000 kilometers per second!

If you were born in the US, try doing this in your head . . . 367,293,229 k = ? miles. 10 seconds later into the documentary, 253 liters = ? gallons. Although I know what a 2 liter bottle of soda looks like and could picture what 253 2-liter bottles would look like, I would have to go to a conversion calculator to know what that equals in gallons. Since 0.2642 gallons = 1 liter, I would need to multiply .2642 x 253. Since the answer is 66.84 gallons, I now have a reference as to how much it really is. If I want to know how many quarts it is, my mind can multiply 66 or 67 by 4 and get a general feeling as to how much that is, but if I want to know how many deciliters it is, I wouldn't know how to figure it out in my mind and would therefore have to use a conversion chart. Since the US does not use, nor are children taught in schools, the metric system, most of America (over 7 billion people) would have no idea how many deciliters it is. That is what doesn't make sense.

[geckzilla]

We are taught the metric system in school. I went to a podunk public school in a podunk city and even I learned about SI units and the metric system in various science classes. If we converted to it then we would have no problem visualizing various units because we would be more accustomed to using them. Who would give a rat's ass what a mile is then? I certainly don't agonize over what my height in chains or cubits is. And I think you are confusing the estimated world population of 7 billion people with the United States population of around 300 million people.

[Chris Peterson]

If you were born in the US, try doing this in your head . . . 367,293,229 k = ? miles. 10 seconds later into the documentary, 253 liters = ? gallons. Although I know what a 2 liter bottle of soda looks like and could picture what 253 2-liter bottles would look like, I would have to go to a conversion calculator to know what that equals in gallons. Since 0.2642 gallons = 1 liter, I would need to multiply .2642 x 253. Since the answer is 66.84 gallons, I now have a reference as to how much it really is. If I want to know how many quarts it is, my mind can multiply 66 or 67 by 4 and get a general feeling as to how much that is, but if I want to know how many deciliters it is, I wouldn't know how to figure it out in my mind and would therefore have to use a conversion chart. Since the US does not use, nor are children taught in schools, the metric system, most of America (over 7 billion people) would have no idea how many deciliters it is. That is what doesn't make sense.

If you're only going for sense of dimension (which is usually the case), one mile is 1.5 km (or 1 km is a half mile). 1 liter is a quarter gallon. One meter is a yard. These are trivial calculations in the head.

And students in the U.S. have been routinely taught the decimal multipliers (milli, kilo, etc) for decades.

This doesn't have to be very difficult.

[Nitpicker]

If you were born in the US, try doing this in your head . . . 367,293,229 k = ? miles. 10 seconds later into the documentary, 253 liters = ? gallons. Although I know what a 2 liter bottle of soda looks like and could picture what 253 2-liter bottles would look like, I would have to go to a conversion calculator to know what that equals in gallons. Since 0.2642 gallons = 1 liter, I would need to multiply .2642 x 253. Since the answer is 66.84 gallons, I now have a reference as to how much it really is. If I want to know how many quarts it is, my mind can multiply 66 or 67 by 4 and get a general feeling as to how much that is, but if I want to know how many deciliters it is, I wouldn't know how to figure it out in my mind and would therefore have to use a conversion chart. Since the US does not use, nor are children taught in schools, the metric system, most of America (over 7 billion people) would have no idea how many deciliters it is. That is what doesn't make sense.

If you're only going for sense of dimension (which is usually the case), one mile is 1.5 km (or 1 km is a half mile). 1 liter is a quarter gallon. One meter is a yard. These are trivial calculations in the head.

And students in the U.S. have been routinely taught the decimal multipliers (milli, kilo, etc) for decades.

This doesn't have to be very difficult.

In addition to what Chris has said ...

A big, ugly number like 367,293,229 is a little difficult to grasp in km or miles. My inclination would be to convert 367 million km to about 2.5 AU. This conversion is no more difficult than miles to AU.

Regarding liters (or litres) compared with gallons, this can be a bit awkward since 1 imperial gallon is about 1.2 US gallons. But in the case of a volume like 253 litres, one could note that 1000 litres is 1 cubic metre, and using Chris's notion of "sense of dimension", a volume of 1 yard x 1 yard x 1 foot is pretty darn close to 253 litres (actually about 254.9 litres). Or, you could say there are roughly 4 litres in a gallon (and 1 litre is about 1 quart) so it is about 65 gallons, say, in anyone's language.

[MargaritaMc]

But be careful with quarts if cooking!

http://dictionary.cambridge.org/diction ... tish/quart
Quart: a unit of measurement for liquids, equal to approximately 1.14 litres in the UK, or 0.95 litres in the US:
A quart is so called because it is a quarter of a gallon.
(Definition of quart from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)

And Pints

I learnt this the hard way through some interesting cooking fiascos....