[ltp] how to start with thinkpad T60?

[Mario Butter]

On Feb 17, 2008 5:37 PM, James Knott <james.knott@rogers.com> wrote:
> Mario Butter wrote:
> Maybe.  Apparently no one knows for sure how Fahrenheit set those points.
> http://en.wikipedia.org/wiki/Fahrenheit

Actually, it is known how he set the points. 0 was the coldest liquid
brine solution possible at the time (water + salt + ammonium chloride)
and 96 was body temperature (there was a big hoopla about making
things multiples of 12 at the time, and 96 was a multiple of 12). This
made the freezing point about 32 and the boiling point about 212
(accuracy was not as good as we have today). Later on, when it was
decided to "standardize," the standard points were set at freezing 32
and boiling 212, both at one atmosphere of pressure. This made body
temperature and the liquid point of the brine solution off by a degree
or so, but gave exactly 180 degrees between freezing and boiling. It
also has the "side effect" of all common human encountered
temperatures being roughly between 0 and 100. It's rare to break 100
or to have negative temperatures in most human occupied regions of the
planet. With Celsius, however, the normal range is roughly -20 to 30,
meaning it's common to need to use negative numbers.

> 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.

Actually, you've got it backwards. The calorie is defined as the heat
required to raise 1.00 g water from 288.5 to 289.5 K. And the energy
needed to change water temperature varies a bit depending on the
energy already present, it's not fixed. The unit of energy of one
degree in the Celsius system is equal to 1/100 of the temperature
difference between freezing and boiling of water at one atmosphere.
It's got nothing to do with any metric measurement.

> 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?).

It's so rare to convert pounds to ounces that I rarely do it. I mean,
if I go to the store and I want a pound and a half of deli meat, I
don't weigh out 1 pound, then weigh out 8 ounces. I weigh to 1.5
pounds on the scale. And I've never used grains except when reloading
ammunition, and I've never had to convert them to any other unit. Same
with the liquid measurements: my gas tank holds 12.6 gallons of fuel,
not 12 gallons, 2 quarts, and 1 pint or so. You're trying to make the
situation hard by using units that don't even make sense in the
situation and converting between them. And when was the last time you
made a cube that had to hold a certain amount of fluid? If I needed to
do that, it would be trivial to do the conversion.

> 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.

I like it as well, but I don't claim that someone who uses a different
scale than I do is "backwards."

> 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.

Well, actually, it would be 2 ft and 5 2/3 inches. And guess what -
construction rulers and tape measures usually have the thirds of
inches marked. So, I would just measure to that mark and voila.

> 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.

Actually, the SAE measurements are NOT metric. If you look at the bolt
head, if it has three marks on it, it's an SAE measurement and not
metric. SAE bolts continue to use their standard sizes.

> 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.

As I said, the temperature unit in SI is Kelvin. Celsius' original
temperature measurement placed boiling at 0 and freezing at 100 (yes,
it went backwards). At the time the SI system was being adopted in
France, Napoleon had just overthrown the crowns of the France. So,
they were not about to adopt a system designed by a wealthy German
aristocrat who was a member of the British Royal Society. They
reversed the Celsius' scale and used that. However, when SI was
"standardized" in the 1950s, the temperature unit chosen was Kelvin,
rather than Celsius. so, while Celsius is common in countries that use
SI, it's not actually the "standard."

-- 
Mario

http://mario.silent-tower.org/