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I think I figured out the real differences there. It's not the "power of
ten" stuff. After having to decide between 0.2 liters of beer or 0.3 liters
of beer, I realized it's something different.
Imperial measurements are generally based on humans, so it's pretty
convenient for everyday usage.
Temperature: 0 is about as cold as you're likely to run into in most places,
100 is uncomfortably hot and basically body temperature. 50-75 is
comfortable for the most part.
Distance: As big as your finger (inch), your foot (foot), your arms (yard),
how far you can conveniently walk (mile).
Volume: A sip (spoonful), a mouthful (ounce), a mug full (pint), a bottle
full (quart), a bucket full (gallon), and about as much as you can
conveniently move by yourself (a barrel).
Weight: Again, a little bit almost unnoticeable size of a coin (ounce),
convenient to carry in one hand (pound), convenient for weighing people or
animals (stone, which nobody seems to actually use any more), about as much
as you can reasonably ship someplace (a ton).
All very convenient for human scales.
But metric wins for science.
The difference with metric is that it's easy to calculate big numbers. In
imperial measurements, the next thing up from a mile is an AU, or a
light-year, or a parsec (assuming you want to call these "imperial" at all).
There's really nothing smaller than an inch, except fractions of an inch,
and nobody goes below a 64'th of an inch. There's nothing lighter than an
ounce, or heavier than a ton - no way to express the weight of an atom or a
planet.
Metric has the advantage that you don't get into weird problems with units
when you do science. I don't think it really matters that things are
specifically multiples of 10 until you start getting into figuring out
ranges of numbers where exponents come into play. I'm not sure how the
interrelatedness of the numbers matters at all: is it really useful that
grams are defined in terms of the weight of a certain substance? I can't
imagine how that would be useful in science, especially when things like
"moles" and "c" are defined in terms of natural units.
In practice (for those of you who are used to metric), in every-day usage,
imperial weird units don't really cause the sort of problem that people seem
to think it causes. I no more have to frequently convert inches to miles
than you frequently need to figure out the number of minutes in a year. Once
you're talking miles, the number of inches is as immaterial as asking how
many miles are in an inch when you're measuring to construct a chair or
something. The worst stuff is measuring your room to be 12 3/4 feet, and
finding out carpet is sold by the inch or something.
--
Darren New, San Diego CA, USA (PST)
Quoth the raven:
Need S'Mores!
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Darren New <dne### [at] san rrcom> wrote:
> I don't think it really matters that things are
> specifically multiples of 10 until you start getting into figuring out
> ranges of numbers where exponents come into play.
I don't really agree with that. The metric system makes it trivial to
switch between units as needed without the need of any calculations
whatsoever.
For example, a person can be 180 cm tall, or 1.8 meters tall, or 1 meter
80 cm tall. All three of these are completely and trivially exchangeable
with each other without the need to do any kind of mental calculations
whatsoever.
This makes it much more intuitive and easy to quickly get a grip on
everyday measurements, as compared to familiar measurements (such as
your own height). For example, if someone tells you "the stick is 160 cm
long", then you immediately get a mental image of how long it is if you
yourself are 180 cm tall: It's something like a head less than you.
If someone told something like "it's 2 meters tall", then once again
you can immediately grasp how much it is, compared to yourself: You know
that you are 1.8 meters tall, so 2 meters is a bit more, something like
a head taller.
Note that two different units were used here, centimeters in the first
case and meters in the second, yet the amount of mental work to get a
notion of the length of the stick was exactly the same. No additional
mental work whatsoever was needed because two different units were used
in the two examples.
In some cases it may be handier to use centimeters if you need that kind
of accuracy, while in other cases it's more practice to use meters because
you are not intending to be that accurate. The great thing is that in either
case it's equally easy to understand what kind of measurements we are talking
about without having to do any mental math.
The same goes for most of the other everyday units. For example it's
easy to grasp that "516 grams" is about as heavy as a half litre of
water (because 516 grams is close to half a kilogram). Again, no mental
calculations neeed. And so on.
--
- Warp
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On Mon, 23 Aug 2010 15:43:54 -0400, Warp wrote:
> I don't really agree with that. The metric system makes it trivial to
> switch between units as needed without the need of any calculations
> whatsoever.
>
> For example, a person can be 180 cm tall, or 1.8 meters tall, or 1
> meter
> 80 cm tall. All three of these are completely and trivially exchangeable
> with each other without the need to do any kind of mental calculations
> whatsoever.
You're making a mental calculation there - you're dividing by 10. It's
easy, but that doesn't mean there's no calculation at all.
Jim
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Warp <war### [at] tagpovrayorg> wrote:
> Darren New <dne### [at] sanrrcom> wrote:
> > I don't think it really matters that things are
> > specifically multiples of 10 until you start getting into figuring out
> > ranges of numbers where exponents come into play.
>
> I don't really agree with that. The metric system makes it trivial to
> switch between units as needed without the need of any calculations
> whatsoever.
>
> For example, a person can be 180 cm tall, or 1.8 meters tall, or 1 meter
> 80 cm tall. All three of these are completely and trivially exchangeable
> with each other without the need to do any kind of mental calculations
> whatsoever.
>
> This makes it much more intuitive and easy to quickly get a grip on
> everyday measurements, as compared to familiar measurements (such as
> your own height). For example, if someone tells you "the stick is 160 cm
> long", then you immediately get a mental image of how long it is if you
> yourself are 180 cm tall: It's something like a head less than you.
well put. The thing about Imperial Units is... is it 10 of my foot or 10 of my
daughter's foot? makes for a substantial change...
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On 23-8-2010 22:33, Jim Henderson wrote:
> On Mon, 23 Aug 2010 15:43:54 -0400, Warp wrote:
>
>> I don't really agree with that. The metric system makes it trivial to
>> switch between units as needed without the need of any calculations
>> whatsoever.
>>
>> For example, a person can be 180 cm tall, or 1.8 meters tall, or 1
>> meter
>> 80 cm tall. All three of these are completely and trivially exchangeable
>> with each other without the need to do any kind of mental calculations
>> whatsoever.
>
> You're making a mental calculation there - you're dividing by 10. It's
> easy, but that doesn't mean there's no calculation at all.
>
Oh come on, you are not dividing, just shifting the decimal point.
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On Mon, 23 Aug 2010 23:04:42 +0200, andrel wrote:
>> You're making a mental calculation there - you're dividing by 10. It's
>> easy, but that doesn't mean there's no calculation at all.
>>
>>
> Oh come on, you are not dividing, just shifting the decimal point.
Which by definition, mathematically, is division (or multiplication if
it's the other direction).
"Shifting the decimal point" isn't a recognised mathematical operation,
well, it wasn't when I took maths. Multiplication and division are.
Just because one takes a shortcut doesn't mean it's a different operation.
Jim
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Jim Henderson <nos### [at] nospamcom> wrote:
> On Mon, 23 Aug 2010 23:04:42 +0200, andrel wrote:
>
> >> You're making a mental calculation there - you're dividing by 10. It's
> >> easy, but that doesn't mean there's no calculation at all.
> >>
> >>
> > Oh come on, you are not dividing, just shifting the decimal point.
>
> Which by definition, mathematically, is division (or multiplication if
> it's the other direction).
still, it doesn't demand any calculation at all to correlate 1.80 meters to 1
meter and 80 cm or to 180 cm. They are all equivalent, even in digits...
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On 23/08/2010 7:47 PM, Darren New wrote:
> I think I figured out the real differences there. It's not the "power of
> ten" stuff. After having to decide between 0.2 liters of beer or 0.3
> liters of beer, I realized it's something different.
>
Yes, It is what you are brought with. :-P
>
> Distance: As big as your finger (inch), your foot (foot), your arms
> (yard), how far you can conveniently walk (mile).
>
It's true then. Americans don't walk much. :-P
> Weight: Again, a little bit almost unnoticeable size of a coin (ounce),
> convenient to carry in one hand (pound), convenient for weighing people
> or animals (stone, which nobody seems to actually use any more), about
> as much as you can reasonably ship someplace (a ton).
>
We use stones for weighing people. For instance I am 12 stones but I
would like to be 11 and a half. Or 11-7, that is 11 stones 7 pounds or
73 Kg.
>
> There's nothing lighter than an ounce,
>
What about a dram (not a "wee dram" ;-) ) there are 16 of them in an
ounce and 437.5 grains in an ounce.
>
>
> In practice (for those of you who are used to metric), in every-day
> usage, imperial weird units don't really cause the sort of problem that
> people seem to think it causes. I no more have to frequently convert
> inches to miles than you frequently need to figure out the number of
> minutes in a year. Once you're talking miles, the number of inches is as
> immaterial as asking how many miles are in an inch when you're measuring
> to construct a chair or something. The worst stuff is measuring your
> room to be 12 3/4 feet, and finding out carpet is sold by the inch or
> something.
>
This is true but I would measure the length to be 12' 9" or 12 foot 9
(inches is understood).
--
Best Regards,
Stephen
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> Imperial measurements are generally based on humans, so it's pretty
> convenient for everyday usage.
So long as you don't need to convert between units or do any calculations.
Buying carpet was one example, another is when you tell me you weigh X
pounds and I usually deal with stones, I have no clue whether that's a lot!
Or if you measure someones height with a tape measure marked in inches,
what's that in feet? Or if you are following a recipe that calls for 10 oz
of flour and you want to make 4x the quantity for a party, how much flour do
you weigh out if your scale is in pounds and ounces? These calculations may
seem relatively simple if you're good at mental arithmetic, but people who
aren't struggle (all of the ones above I've witnessed at least once).
> Metric has the advantage that you don't get into weird problems with units
> when you do science.
Yes, it's very odd looking through an imperial science text book where every
formula has some bizarre constant like 537.4 in it!
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scott a écrit :
>> Imperial measurements are generally based on humans, so it's pretty
>> convenient for everyday usage.
>
> So long as you don't need to convert between units or do any
> calculations. Buying carpet was one example, another is when you tell me
> you weigh X pounds and I usually deal with stones, I have no clue
> whether that's a lot! Or if you measure someones height with a tape
> measure marked in inches, what's that in feet? Or if you are following a
> recipe that calls for 10 oz of flour and you want to make 4x the
> quantity for a party, how much flour do you weigh out if your scale is
> in pounds and ounces? These calculations may seem relatively simple if
> you're good at mental arithmetic, but people who aren't struggle (all of
> the ones above I've witnessed at least once).
>
>> Metric has the advantage that you don't get into weird problems with
>> units when you do science.
>
> Yes, it's very odd looking through an imperial science text book where
> every formula has some bizarre constant like 537.4 in it!
>
>
Is it really any weirder than 273.15?
Likewise, I don't think 9.81 is a more convenient constant than 32.2!
My biggest beef with the imperial units is that I usually screw up the
16th and 32nds marks on my measuring tape and end up cutting my planks
just a little too short. It is much harder to mix up the cm and mm lines.
--
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/* gmail.com */}camera{orthographic location<6,1.25,-6>look_at a }
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