The National Measurement Institute (NMI) has released three new videos in its seven-video series explaining the basic units of measurement.
Aimed at informing young people, the new videos are entitled How We Measure Brightness, How We Measure Electricity and How We Measure Substance.
Australia’s Chief Metrologist and head of the NMI, Bruce Warrington used an imaginary journey through time and space from the popular television series Dr Who to talk about each basic unit.
In the videos, Dr Warrington discussed how each unit was measured and how this had changed over time.
In How We Measure Brightness, Dr Warrington said that up to the middle of last century, many countries had their own standards for light output, often based on the brightness of a standard candle or ‘candlepower’.
“In 1948 the international community adopted a new unit, based on the light glow from molten platinum, and called it the candela,” Dr Warrington said.
In How We Measure Electricity he told viewers that the basic electrical unit in the international system was the ampere, the unit of current or how much charge was flowing each second.
Finally, in How We Measure Substance he related how from 20 May the number of molecules in one mole was set at “6 point 022 140 76 times 10 to the power 23”.
“Even though it’s huge — 24 digits long — a mole of water molecules is roughly a spoonful,” Dr Warrington said.
The previous videos dealt with measuring time, distance, weight and temperature.
He said the series was part of NMI’s outreach to improve science, technology, engineering and mathematics (STEM) education.
The full suite of videos can be accessed at this PS News link.
