It is now known that in this world everything can be measured, absolutely everything. The universe and much more that surrounds a person is connected with measurements. So, measure the speed, time, distance is not difficult. For measurements, there are special devices. The science that deals with measurements is metrology. Metrology calculates all information with extreme precision. It is important to know in which units something is measured. For example, a person knows for sure that time can be measured in seconds, hours, and even milliseconds. Speed can be measured in kilometers per hour, distance in meters or kilometers.
Units of measure are usually present in physics. Since school, it is physics that helps me learn about measurements. With the help of this science, you can transfer any measurements to the SI system.
The value of physics is very large, it has been used at all times. Using units of measurement you can measure even brightness. Science moves further, opens up new horizons, it does not stand still and develops. There are units of measure that are outdated today:
- 1 The value of brightness units
- 2 Where this knowledge may be needed
- 3 Modern brightness unit
The value of brightness units
- Nit - This is an outdated unit, it used to be used in the SI system, its dimension is approximately 1kd / 1 m². Now the standards of this unit have not been used for a long time and have been replaced by completely new ones.
- STILB - used in the GHS system. The brightness of the luminous surface with an area of 1 cm 2 is 1 stilb. It is also almost obsolete, and is not used by modern humanity.
- LAMBERT - non-systemic brightness unit, began to be used for the first time in the USA. Called this unit in honor of Lambert Johann Heinrich. The German mathematician, astronomer, physicist and philosopher, a scientist in his origin was French. Lambert is abbreviated as lb.
- APOSTILB - The unit for illuminated surfaces is also used in the GHS system. It was discovered by the French scientist physicist Andre Bloddel. APOSTILB since 1978 is officially considered obsolete and is no longer used.
Where this knowledge may be needed
Many people like to guess crossword puzzles and crossword puzzles. Authors inventing scanwords use original terminology and increasingly want to confuse the reader. It is necessary to try to solve the exact answer. You think, for what the knowledge of unit of brightness can be necessary? Scanward may well contain a similar question.
For example, such a case. It is necessary to unravel a word from the scanword from the word: EXCELLENT. To make it easier to solve this word, there is a hint - it is a unit of brightness of the luminous surface, the word itself consists of 3 letters. According to the prompts you can easily determine what the word is. The answer to the scanword: NIT.
Modern brightness unit
The science that studies light processes is called photometry. It characterizes electromagnetic light emission. In photometry, measurements are made using a spectrum range that does not differ from the visibility review of the human eye. Brightness determines the flow, which is sent only in a certain direction of the visible surface, it can fully characterize the luminous body.
In the international measurement system (SI), brightness can be measured in candela per square meter. If earlier the measurement of brightness served as NIT, now it is customary to measure it in candela.
Candela per square meter (cd / m²) - is a derivative of brightness in the SI system, based on two dimensions: luminous intensity and square meter area.
Depending on the scale at which it is necessary to measure the brightness of the surfaces, there are measurements such as candela per square centimeter, candela per square foot, candela per square inch and even a kilo candela per square meter.
Kilokandela per square meter (ccd / m²) - is also a measure of brightness, but unlike the usual candela, it is a multiple of the derivative in the SI system.
The modern world has progressed so far that progress is reaching new and new heights. So, appeared special converterwith which you can convert absolutely any units of brightness to any other. It will not be difficult, it is enough to write the unit of measurement that needs to be translated, and get the correct answer. The correctness of the answer may not always be extremely accurate, but with certain errors, because sometimes converters can round only up to 10 digits after the decimal point. Some converters can be reduced to exponential notation, for example: 1,103E +6. E is an exponential that is easy to translate in mathematics by multiplying by ten to a power.