Wirt Atmar wrote:
> Kent writes:
>
>> "AN INTRODUCTION
>>  According to the National Academy of Sciences, the Earth's surface
>>  temperature has risen by about 1 degree Fahrenheit in the past
>> century,  with accelerated warming during the past two decades.
>> There is new and  stronger evidence that most of the warming over
>> the last 50 years is  attributable to human activities."
>>
>>  Now if it accelerated that could be a problem.  Notice we have now
>> shifted  from empirical evidence to speculation.
>
> The proper term isn't "speculation." It's "extrapolation," a
> completely different process.
>
> Everything about science is designed to *predict* the world around
> us. In fact, the quality of those prediction are the sole measure
> that we have to gauge our level of understanding.
>
> Every facet of science works in this same manner. Newton determining
> the path a baseball will take is no different than NOAA trying to
> determine the path that the global climate will follow. If you truly
> can characterize the intial conditions accurately, and you have a
> very good mathematical model of the physics of the process at hand,
> prediction is not all that difficult, especially now that we have
> mechanical computing devices that no longer require hand cranks.

I'm startled by this, coming from Wirt. Those are *huge* 'ifs'.
I presume you are familiar with the 'butterfly effect' in chaos theory,
otherwise known as 'sensitive dependence on initial conditions'?
This points up the practical difficulties of 'characterizing the initial
conditions accurately'. For all practical purposes, you simply can't.
Then you need the 'very good mathematical model'. For the weather, we simply
don't have that. Yet, if ever.

Newton might have been able to track a baseball (though as America hadn't
yet been invented, he might have wondered what it was exactly), and he could
even determine roots (Newton's Method http://www.yiin.ca/chaos/newton.htm).

And maybe tracking the path from 'initial conditions' to final root is just
about within our grasp now we no longer need hand cranks.
But predicting *which* root we will arrive at is utterly beyond us. Yet, if
ever.

--
Roy Brown

Posting with the OEnemy, tamed by OE-QuoteFix
http://jump.to/oe-quotefix

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