At the core of biology and other sciences lies a problem-solving approach called the scientific method. 1  Make an observation. 2  Ask a question. 3  Form a hypothesis, or testable explanation. 4  Make a prediction based on the hypothesis.  Test the prediction.
Xi. Xi is the 14th letter of the Greek alphabet. It is pronounced in Modern Greek, and generally or in English. In the system of Greek numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh. Xi is not to be confused with the letter chi, which gave its form to the Latin letter X.
The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is equal to one lumen per square metre.In photometry, this is used as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface.iktionary (0.00 / 0 votes) Rate this definition: lux (Noun). In the International System of Units, the derived unit of illuminance or illumination; one lumen per square metre. Symbol: lx. Origin: From lux; from lewk-.