[ltp] how to start with thinkpad T60?

[James Knott]

Mario Butter wrote:
> On Feb 17, 2008 3:13 PM, James Knott <james.knott@rogers.com> wrote:
>   
>> Units in science can be redefined as better data and measurement
>> techniques appear.  Even back in the 18th century, air pressure was
>> specified for determining the freezing point of water in Celcius.
>> Fahrenheit is "backward" because like every other measure in the
>> imperial system, it is largely arbitrary and there is nothing that can
>> tie it, in a coherent system to anything else.
>>     
>
> Fahrenheit is defined according to the temperatures of the freezing
> and boiling points of water at one standard atmosphere, like Celsius.
> It is not "arbitrary."
>   

Maybe.  Apparently no one knows for sure how Fahrenheit set those points.
http://en.wikipedia.org/wiki/Fahrenheit

At least Fahrenheit is one of the more sensible imperial measures, as it 
was created by a scientist and not decreed by a king etc.
However, it still leaves the fact that it's not part of a measurement 
system.
>   
>>  The metric system is design so the various measures are related to other measures.
>>     
>
> To what other part of the metric system is the Celsius scale related?
> And, BTW, the standard SI temperature scale is Kelvin, so you're not
> even using the SI metric temperature scale. For your information,
> temperature is one system that is not integrated into the metric
> system, tied to other metric units.
>   

Tied in this sort of manner.  One gram of water = 1 cc and requires 1 
calorie to raise it's temperature 1 degree C.  (Yes, I know a calorie is 
not an SI unit and is in fact equivalent to 4.184 joules).  The Kelvin 
is of course tied to the motion of atoms, which determines temperature.  
Zero K means no motion at all.


>   
>> Then tell me which one is easier to work in.  Try scaling over
>> the various ranges of length, weight etc.  In the metric system,
>> everything relates to powers of ten, so scaling simply means moving the
>> decimal point or changing the value of an exponent.  You don't have to
>> worry about converting from pounds to ounces to tons or inches to feet
>> to furlongs etc.  It is a measurement system and not a collection of
>> arbitrary measures.
>>     
>
> Err, it's trivial to work in units of tenths with ANY system. There
> are, for example, 10 "0.1 lb" units in a pound.
>   

OK, kilograms to grams is simply 1000x.  What about pounds to ounces or 
grains?  Lessee now, one pound = 16 oz and 1 ounce = 437.5 grains.  So 
for pounds to grains you've got to multiply by 16 and then by 437.5.  On 
the other hand converting kilograms to grams is simply a matter of 
pushing the decimal place over 3 digits to the right.  The same 
situation occurs with liquid measure, but worse, where you've got 
different size gallons, quarts, pints and ounces, along with different 
quantities of ounces in a pint or pints in a quart or gallon.  Now 
suppose you need to determine the dimensions of a cube to hold a 
quantity of liquid.  1 litre is 1000 cc, so cube root of that is 10 cc 
on a side.  Now, try that for a quart (which quart?).

> I have no issues with working in either system. Perhaps the people who
> are backward are those who have trouble using more than one system?
>   

I grew up with the imperial system and started using metric in high 
school science classes.  At first I hated it because it was different.  
But the more I used it the better it looked.
> As an example, if I were measuring a piece of wood that I wanted to
> cut into thirds, and that piece of wood was a yard long, I would make
> my cuts at one foot intervals, a point that is clearly marked. Other
> easy divisions used for construction are similarly marked. If that
> piece of wood were a meter long, I would make my cuts at
> 33.33333333333333333... centimeters. This would usually not be marked
> on my ruler, since there is a reliance on decimal marks implied in the
> SI system, rather than marks based on fractions common in
> construction. Works really good for science and engineering, however
> for "real world" applications like construction, etc, the SAE system
> works well. Especially since the SAE system COMES FROM those same real
> world applications.
>
>   
And if that piece of would you wanted cut in thirds were 7' 5"?  I'm 
sure every piece of wood you want to cut into thirds is always exactly 
three feet long.  Or do you just get out your measuring tape and start 
marking off 1' pieces and trim off what ever is left over or go find 
another piece if the first isn't long enough.  If you create special 
situations that just "happen" to fit, you can "prove" anything.
> And virtually all SAE measurements have been tied to physical
> constants over the years, as have most SI units. So the argument that
> they're "arbitrary" is nonsense.
>   

Nowadays, SAE standards have come a long way from not that long ago.  
During world war 2, there were a couple of different U.S. thread 
standards and a few more in England.  This made it difficult to 
manufacture and exchange weapons, vehicle parts etc.  Any single 
coherent system, whether metric or not is far better than a mix of 
arbitrary systems.  Also, a lot of "SAE" standards are now metric.  Take 
a look at the newer engines in production today.

> And the standard unit of time measurement in the SI system is hours,
> minutes, and seconds. These are not related to each other in powers of
> 10.
>   

Somethings, such as time measure, I suspect are too deeply woven into 
our culture, to dislodge.  The only time measurements that have any 
relationship to easily observed phenomenon are the day and year, with 
the month loosely related to the moon.  Even at that, those 
astronomically based measures are subject to natural change over the 
millennia.

> BTW, do you even know why the use of Celsius is common in countries
> that use the SI system, even though it's not part of the SI system?
>
>   
As I recall, Napoleon had a lot to do with spreading the metric system 
around Europe.  The SI system is generally a refinement of the original.

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