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Why you should not trust successful people's advice: Survivorship bias.

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The video's metaphor does not generalize but this article explains the concept better:

Off-topic, but I saw "Kelvin", and snap, I knew... something we use all the time.

("The warrior mathematicians solved the problem almost as soon as they saw it. Lord Kelvin, they told the Navy, had already worked out the calulations in 1887.")

I like CFL light bulbs at 5000K (Kelvins). To me, the common 2700K look orange.

[Bold wording is my emphasis]

"The kelvin is a unit of measure for temperature based upon an absolute scale. It is one of the seven base units in the International System of Units (SI) and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.

The Kelvin scale is named after the Belfast-born, Glasgow University engineer and physicist William Lord Kelvin (1824–1907), who wrote of the need for an "absolute thermometric scale". 


Colour temperature

The kelvin is often used in the measure of the colour temperature of light sources. Colour temperature is based upon the principle that a black body radiator emits light whose colour depends on the temperature of the radiator. Black bodies with temperatures below about 4000 K appear reddish whereas those above about 7500 K appear bluish. Colour temperature is important in the fields of image projection and photography where a colour temperature of approximately 5600 K is required to match "daylight" film emulsions. In astronomy, the stellar classification of stars and their place on the Hertzsprung–Russell diagram are based, in part, upon their surface temperature, known as effective temperature. The photosphere of the Sun, for instance, has an effective temperature of 5778 K.

Digital cameras and photographic software often use colour temperature in K in edit and setup menus. The simple guide is that the higher the 'colour temperature' in K then the more white or blue the image will be. The reduction in kelvin will give an image more dominated by reddish, warmer colours.

Kelvin as a measure of noise

In electronics, the kelvin is used as an indicator of how noisy a circuit is in relation to an ultimate noise floor, i.e. the noise temperature. The so-called Johnson–Nyquist noise of discrete resistors and capacitors is a type of thermal noise derived from the Boltzmann constant and can be used to determine the noise temperature of a circuit using the Friis formulas for noise.

Unicode character

The symbol is encoded in Unicode at codepoint U+212A K kelvin sign. However, this is a compatibility character provided for compatibility with legacy encodings. The Unicode standard recommends using U+004B K latin capital letter k instead; that is, a normal capital K. "Three letterlike symbols have been given canonical equivalence to regular letters: U+2126 Ω ohm sign, U+212A K kelvin sign, and U+212B Å angstrom sign. In all three instances, the regular letter should be used."[15]


That Lord Kelvin sure knew a thing or two, Marlene. :)

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