I don't get it, why is metric better?

[graham]

who treat Trump seriously and get their news from Fox.

[krw]

You can crawl back in your socialist cesspool now.

[Trenbidia]

"Nobody ever went broke underestimating the intelligence of the American public." H. L. Mencken

[J. Clarke]

You're assuming that the "handling cost" is nonrecurring. Why would that be the case?

[dpb]

On 08/12/2016 7:56 PM, J. Clarke wrote: ...

No such thing; it only has to be at or below the percentage difference of fuel cost difference...for Powder Basin, that's a lot of slop...and, while smaller for NG, it's not zero...

[dpb]

...

And, just to be fair, in _today's_ NG glut markets, an effiency-weighted price on a $/MWhr basis the same market points in May were

Powder River Basin Coal $4.33/MWhr Central Appalach Coal $18.78/MWhr Natural Gas Henry Hub $15.78/MWhr

so Powder River coal wins pretty handily; bituminous Appy coal is a little more than NG.

But, the actual utility fuel costs to put power on the grid is far more complex involving delivered prices, the terms of fuel supply contracts, and the workings of fuel markets. Particularly the coal-fired plants have long-term contracts in place that insulate them from shorter-term fluctuations. This is much like the airlines and their fuel contracting; great to be locked-in when prices are rising, not so good at the moment when global oil is in the dumper. That isn't going to last forever, though...and anyone who thinks NG is going to stay so cheap for a really, really long time is just dreaming imo...

[J. Clarke]

Note what he said: "the handling costs have already been amortized into the plant design/construction and so while they're there, it's not like it's a new, added cost"

[dpb]

It is, of course, a /MW(e)hr cost of operation which is what they're harping on...the only point in showing coal prices is that even in today's markets, market coal prices are still within competing rankings despite the tanking oil market and NG supplies having really depressed NG at the moment.

One has to remember, however, that if one has invested up to $1B or so in a generating station, that's an investment that can't just be lightly walked away from 5-10 yr down the road when the pendulum again swings; these are 40-yr minimum kinds of decisions one must make and that decision may have to predate the actual time by another 5 year or more...not easy to read those tea leaves without some uncertainty...

[Puckdropper]

dpb wrote in news:nons44$lv9$ [e-mail]:

After all, someone might figure out how to attach a coil and magnets to their poor grandmother's casket for when she inevitably begins spinning in her grave.

Puckdropper

[ascalon]

replying to John McCoy, ascalon wrote: Nonsense. A standard cup of liquid is 250 ml (mililiters). It is also a quarter of a liter, so it is easy to visualize if you buy your juice, milk etc. in bottles of 1 l, 1.5 l , 2 l. And if you can visualize a cube with each side 39 in, here you can "see" the cubic meter and figure out the volume of your neighbour's pool.

[<william]

If you want great precision, a fractional system will always be better. A fraction by definition can express any rational number with perfect precision. A decimal is much more limited. For example, you cannot express

1/3 in decimal with perfect precision, at least not using a finite number of digits. When used in calculations, decimals can and will accumulate errors, and sometimes the result can be wildly different than the true answer even after just a few steps. Correctly identifying and handling accumulation of errors in floating point arithmetic (like decimal, but usually using a binary number system) is a very difficult and complex area in computer science.

The metric system is generally considered better for two reasons:

1) It is much more rigorously standardized conceptually. Every unit is, obviously, based on multiplication or division of 10. A kilogram and kilometer is a multiple of 10 (i.e. 1000) of a gram and meter, respectively. And this applies to all types of measurements--length, volume, area, mass, etc. It's much easier to translate, e.g., lengths into area as the conversion factors are typically much simpler. Even the names of units are standardized: kilo-, milli-, etc. 2) Arithmetic with decimals is also much simpler because it's similar to regular arithmetic with whole numbers. Calculating with fractions requires more book keeping. The most common calculations are pretty simple in US customary units, but in science and engineering you're often dealing with arbitrary numbers with much more precision. IOW, you're not always or even rarely juggling standard dimensions that co-evolved to work well with common sums and multiples.

That doesn't mean metric is the best possible choice. Base-10 is a really crappy multiple. It's an historical accident that we use it, and it has nothing to do with the number of fingers we have. Units of 10 cannot express very well 3rds or even 4ths. People undoubtedly still conceptualize those things as fractions even when using decimal. Arguably we'd be better off using base-12, or even base-60 like the Babylonians. 12 is evenly divisible by 2, 3, 4, and 6. 60 is divisible by 1, 2, 3, 4, 5, 6, 10, 12. People are already familiar with base-12 and base-60 units as it's how we count time. And some other familiar measurements loosely (but inconsistently) utilize those units. (We still express those units using decimal notation, though, which can be confusing.)

Computer science uses base-2 (binary) because of similar properties related to how arithmetic works. Base-8 (octal) and especially Base-16 (hexadecimal) is common in software. The former makes it more intuitive to work with groups of 3 in the context of binary numbers, while the latter makes it more intuitive to work in groups of 2, 4, and 8. You can get used to thinking in different bases fairly easily. I think math would come easier for many young kids if they practiced using different number systems explicitly. I never really "got" English grammar (beyond rote memorization) until I began learning Spanish in high school. Spanish class did more to help me understand English grammar than any English class ever did.

[Puckdropper]

wrote in news:[e-mail]:

*snip*

Good post, well thought out and presented

I thought, though, that CS used base-2 because that was what the hardware did. As I understand transistors and TTL, they natively work with the presence or absence of a voltage, which lends itself to base-2.

Puckdropper

[Bill]

Base 8 and 16 are "shorthand" for base 2. e.g. 14 (Decimal) = 1110 (base 2) = 16 (base 8) = E (base 16).

People don't like 0s and 1s, but computers do, so we have software that translates between various bases. Of course 14 need not just be an numeric value, it could also represent an instruction which tells a computer to increment a register, or to do some other thing.

Bill

[Martin Eastburn]

Forgot a popular number base - Icono hexadecimal Base 26. Used the alphabet and numbers. This was for large 64 bit and 128 bit parallel processors for the military and used in the 360 by some.

Last I heard, the military division of IBM was closed down. Times change.

Mart> Puckdr>> wrote in

[John McCoy]

Puckdropper wrote in news:57d9e993$0$55914$c3e8da3$ [e-mail]:

You are exactly correct - computers use base 2 because of the hardware, it has nothing to do with arithmetic (some early computers used base 3, which is easy to implement in an analog computer and does make some arithmetic easier).

Programmers use hex (base 16) because it's easier than a whole bunch of 1s and 0s. Experienced programmers can do basic math in hex in their head, whereas no-one can do math in their head with binary numbers bigger than a few digits (other than multiply/divide by 2, of course).

John

[Bill]

Or we can quickly convert binary to decimal, perform the operation and convert back! : ) No prob.

[krw]

In most of life, close enough is, well, close enough.

But no one can decide what the base unit should be. Some like microns (micrometers), others use angstroms. That's just the tip of the iceberg, too.

When I'm measuring, I avoid the bookkeeping by deciding on my result ion and then calculate using just the numerator. For instance, if

1/32" is "good enough", I don't use 1/2" or 1/4", rather 16(/32) or 8(/32).

They taught us arithmetic in different bases, up to base-32 (and, of course conversion between them) in fifth and sixth grade.

[krw]

[krw]

Shorthand in that it's easier to make binary machines but base-16 is just as much of a base as base-15 is (though neither, in that context are particularly useful except as learning tools).

Note that floating point often uses base-16 arithmetic. Base-2 is just a representation of the base-16.

[Bill]

There are shortcuts with base 8 and 16 since they are powers of 2. base

15 wouldn't be useful in this context.