26 MAY 2015 by ideonexus

## <em>g</em> Presumes Unidimensionality

In a multidimensional set of interrelations among tests, one axis can be found that accounts for as much of the interrelatedness as possible, even when it is known that more dimensions are required. The g-men have defined that largest dimension as g. They haven’t discovered it, as they are fond of saying, any more than the Greenwich Meridian was discovered by the International Meridian Conference in 1884. Any set of interrelated tests has to have a largest dimension, so under this d...
Folksonomies: iq measurement
Folksonomies: iq measurement
1  notes

11 DEC 2014 by ideonexus

## Milli-Helen

"I give them fifty milli-Helens," he said. This went totally missing on everyone. "A milli-Helen is enough beauty to launch exactly one ship," Zane explained, and the older Crims all laughed. "Fifty's pretty good."

14 NOV 2014 by ideonexus

## Science of a Second

The old definition of a second was based on the rotation of the Earth. As it takes the Sun one day to rise in the east, set in the west and rise again, a day was almost arbitrarily divided into 24 hours, the hour into 60 minutes, and the minute into 60 seconds. However, the Earth doesn’t rotate uniformly. In fact, it’s rotation decreases at a rate of about 20 millionths of a second every calendar year due to tidal friction caused by the Moon. Atomic time relies on the energy transition w...
Folksonomies: measurement second
Folksonomies: measurement second

24 AUG 2014 by ideonexus

## How Metric Measurements Relate

In metric, one millilier of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to ehat up by one degree centigrade--which is 1 percent of the difference between its freezing point and its boiling point. An amount of hydrogen weighing the same amount has exactly one mole of atoms in it. Whereas in the American system, the answer to "How much energy does it take to boil a room-temperature gallon of water?" is "Go fuck yourself," because you can't directly ...
Folksonomies: measurement metric standard
Folksonomies: measurement metric standard

19 DEC 2013 by ideonexus

## Measurements Change Dramatically Depending on the Methodo...

Benoit Mandelbrot asked his famous question “How long is the coast of Britain?” long before this symposium was written, but it perfectly captures the sort of puzzle people in this crowd love. The question seems simple. Just look it up in the encyclopedia. But as Mandelbrot observed, the length of the coast of Britain depends on what you use to measure it. If you draw lines on a map to approximate the coastline, you get one length, but if you try to measure the real bumps in every inlet an...
1  notes

David Brook's relating Benoit Mandelbrot's experience measuring the British coast.

21 JUN 2012 by ideonexus

## Archimedes Discovers How to Measure Volume

Hieron asked Archimedes to discover, without damaging it, whether a certain crown or wreath was made of pure gold, or if the goldsmith had fraudulently alloyed it with some baser metal. While Archimedes was turning the problem over in his mind, he chanced to be in the bath house. There, as he was sitting in the bath, he noticed that the amount of water that was flowing over the top of it was equal in volume to that part of his body that was immersed. He saw at once a way of solving the proble...
Folksonomies: discovery measurement
Folksonomies: discovery measurement

Asked to measure the volume of a crown, he discovers it will displace water in a tub.

20 JUN 2012 by ideonexus

## The Importance of Quantification

The rudest numerical scales, such as that by which the mineralogists distinguish different degrees of hardness, are found useful. The mere counting of pistils and stamens sufficed to bring botany out of total chaos into some kind of form. It is not, however, so much from counting as from measuring, not so much from the conception of number as from that of continuous quantity, that the advantage of mathematical treatment comes. Number, after all, only serves to pin us down to a precision in ou...

Even rough numerical scales are better than nothing.

20 JUN 2012 by ideonexus

## The Evolutionary Unit of Measurement

The starting point of Darwin's theory of evolution is precisely the existence of those differences between individual members of a race or species which morphologists for the most part rightly neglect. The first condition necessary, in order that any process of Natural Selection may begin among a race, or species, is the existence of differences among its members; and the first step in an enquiry into the possible effect of a selective process upon any character of a race must be an estimate ...
Folksonomies: species measurement average
Folksonomies: species measurement average

Is the species, not individuals within the species.

07 JUN 2012 by ideonexus

## The USA Should Adopt the Metric System

You, in this country [the USA], are subjected to the British insularity in weights and measures; you use the foot, inch and yard. I am obliged to use that system, but must apologize to you for doing so, because it is so inconvenient, and I hope Americans will do everything in their power to introduce the French metrical system. ... I look upon our English system as a wickedly, brain-destroying system of bondage under which we suffer. The reason why we continue to use it, is the imaginary diff...

Kelvin predicts Britain is stuck with it, but America will adopt.

22 MAR 2012 by ideonexus

## Decibel Scale is Logarithmic, Like the Richter Scale

In fact, a physics colleague, Mark Srednicki of U.C. Santa Barbara, brought to my attention a much greater gaffe in one episode, in which sound waves are used as a weapon against an orbiting ship. As if that weren't bad enough, the sound waves are said to reach “18 to the 12th power decibels.” What makes this particularly grate on the ear of a physicist is that the decibel scale is a logarithmic scale, like the Richter scale. This means that the number of decibels already represents a pow...

Krauss describing a particularly egregious science-blunder in an episode of Star Trek.