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Plummeting insect numbers threaten collapse of nature
08-12-2019, 04:59 PM
Post: #54
RE: Plummeting insect numbers threaten collapse of nature
(08-08-2019 06:40 AM)toml_12953 Wrote:  How many radians are in an ice sheet?

Approximately Pi radians if it's a reasonably flat, planar ice sheet when the angle is measured over distances short enough that Earth's curvature isn't significant. Sorry, couldn't help myself. ;-)

The Radian:
I sensed some confusion in the thread about this unit of measure. The Radian isn't "unitless", it's a unit of angular measurement in its own right, just as with Degrees (with arc-Minutes and arc-Seconds) and Grads (100 Grad = 90 Deg). The Radian is derived from two lengths (which are a basic SI dimension): the radius of a circle (length #1) is circumscribed around its circumference (length #2). The end points of that radius length thus circumscribed define one Radian of angle around the circle as defined by the radii from those endpoints to the circle's center. It is the ratio of the two lengths, r/C, the "meter/meter" length units which cancel each make it "dimensionless", and therefore a scalar quantity. "Dimensionless" is not "unitless". The list of dimensionless units in the field of Physics is quite lengthy. The quantity in the set of these dimensionless units is a cardinal number (a positive integer by necessity) that's considerably greater than zero, but nevertheless countable and finite, and therefore its cardinality is a subset of the natural numbers.

Regarding the allegedly plummeting global insect population:
I've not yet read the treatise and can therefore make no judgment as to its credulity and veracity of its claims; my jury is still out. Nevertheless, since this is a calculator forum, insect population growth and shrinkage is stochastic. It should tend to follow Poisson and Exponential distributions, depending on whether one uses birth/death events per unit time, or time between birth/death events. Modeling specific population subsets of them in an HP or TI calculator (or a Casio or Sharp) shouldn't be insurmountable. The raw data, however, might need to be stored externally and distilled with some pre-processing for calculator use. I would anticipate the data sets regarding global insect populations are large.



Pickett: N4-ES, N600
TI: 58, 30-III, 30x Pro MathPrint, 36x Solar, 85, 86, 89T, Voyage 200, Nspire CX II CAS
HP: 50g, Prime G2, DM42
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RE: Plummeting insect numbers threaten collapse of nature - jlind - 08-12-2019 04:59 PM

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