In this Article…
Nanotechnology defined by NIST Physics laboratory:
National Institute of
Standards and Technology
in the US Technology Administration that makes measurements and sets standards as needed by industry or government programs.
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I don’t know about you, but the mental images generated by the name “The National Institute of Standards and Technology” includes bored bureaucrats in sterile environments waiting to re-measure the closely guarded, sacred yard stick of antiquity. Again.
Man, is that wrong. The NIST is part of the Dept.of Commerce. Their entire existence is focused on the positive health and well-being of our economy. As the dynamic wizardry of scientific advances blast the boundaries off the known, rearranging matter in never-before-seen configurations, creating new materials, imagining new applications, these guys have the challenge of essentially applying creative pragmatism to magic in order to enable effective trade.
They work side-by-side with universities, research labs, manufacturers, and businesses in an agile and effective approach to providing standardization that facilitates rather than eliminates, free, fair, and open trade.
The NIST Center for Nanoscale Science and Technology (CNST) supports the U.S. nanotechnology enterprise from discovery to production through two major initiatives:
|Standardizing, optimizing, popularizing, and training best practices in weights, measures, and manufacturing techniques to maximize trade potential.||Working with partners from education, industry, and government to create standards for next generation products, equipment, methods, and procedures.|
- Nanotechnology in the NIST Electron Physics Group: physics.nist.gov 1
- Most of the research of the NIST Electron Physics Group is in Nanostructure Science or Nanotechnology.
- Quantum Physics Division: physics.nist.gov 2
When they say jump, they’ll tell you exactly how high.
SI Base Units (International System of Units)
Definitions of the 7 SI base units (symbol in parenthesis)
1. Unit of length: Meter (m)
The meter is the length of the path traveled by light in vacuum during a time interval of 1/299 792 458 of a second.
2. Unit of mass: Kilogram (kg)
The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram.
3. Unit of time: Second (s)
The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.
4. Unit of electric current: Ampere (A)
The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10-7 newton per meter of length.
5. Unit of thermodynamic temperature: Kelvin (K)
The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.
6. Unit of amount of substance: Mole (mol)
- A mole is the most common way to measure a chemical substance.
- The mole is the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12; its symbol is “mol.”
- When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles.
- My daughter’s highschool celebrated “mole day”
7. Unit of luminous intensity: Candela (cd)
The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.
For a detailed discussion and view of measurements see the following:
- National Institute of Standards and Technology (NIST) – Physics Laboratory: physics.nist.gov 3
- NIST – Technology Services – Weights and Measures: physics.nist.gov 4
- A Dictionary of Units www.ex.ac.uk
Quantities and Units, General
- A quantity in the general sense is a property ascribed to phenomena, bodies, or substances that can be quantified for, or assigned to, a particular phenomenon, body, or substance. Examples are mass and electric charge.
- A quantity in the particular sense is a quantifiable or assignable property ascribed to a particular phenomenon, body, or substance. Examples are the mass of the moon and the electric charge of the proton.
- A physical quantity is a quantity that can be used in the mathematical equations of science and technology.
- A unit is a particular physical quantity, defined and adopted by convention, with which other particular quantities of the same kind are compared to express their value.
- The value of a physical quantity is the quantitative expression of a particular physical quantity as the product of a number and a unit, the number being its numerical value. Thus, the numerical value of a particular physical quantity depends on the unit in which it is expressed.
The international standard unit of length, approximately equivalent to 39.37 inches. It was redefined in 1983 as the distance traveled by light in a vacuum in 1/299,792,458 of a second.
Terminology for Metric Lengths:
- Yoctometer – 10 to the -24th power
- Nanometer – 10 to the 9th power
- Kilometer – 1000 meters
- Yottameter – 10 to the 24th power meter
The everyday metric system
- 1000 millimeters = 1 meter
- 100 centimeters = 1 meter
- 1000 meters = 1 kilometer
Mass (or weight):
- 1000 milligrams = 1 gram
- 1000 grams = 1 kilogram
- 1000 kilograms = 1 metric ton
- 1000 milliliters = l liter
- 1000 liters = 1 cubic meter
- 10 000 square meters = 1 hectare
- 100 hectares = 1 square kilometer
- Micro means 1/1 000 000
- Milli- means 1/1000
- Centi- means 1/100
- Kilo- means 1000
- Mega- means 1 000 000
- m for meter
- mm for millimeter
- cm for centimeter
- km for kilometer
- g for gram
- mg for milligram
- kg for kilogram
- L for liter
- mL for milliliter
- m2 for square meter
- m3 for cubic meter
- km2 for square kilometer
- t for metric ton
- ha for hectare
Some special relationships:
- 1 milliliter = 1 cubic centimeter
- 1 milliliter of water has a mass of approximately 1 gram
- 1 liter of water has a mass of approximately 1 kilogram
- 1 cubic meter of water has a mass of approximately 1 metric ton
Legal/official (exact) definitions of inch-pound units as set by U.S. law:
- 1 inch = 25.4 millimeters
- 1 pound = 453.59237 grams
- 1 gallon = 3.785411784 liters
Note: In Canada the inch and the pound are defined identically, but 1 Canadian gallon = 4.54609 liters.
International System of Units (SI) Inch-Pound Conversion Factors:
- Multiply inches by 2.54 to get centimeters (this conversion factor is exact)
- Multiply feet by 0.305 to get meters
- Multiply miles by 1.6 to get kilometers
- Divide pounds by 2.2 to get kilograms
- Multiply ounces by 28 to get grams
- Multiply fluid ounces by 30 to get milliliters
- Multiply gallons by 3.8 to get liters
- Greek nanos (with long “a”), nannos, little old man, dwarf, from nannas, meaning uncle.
- A metric prefix meaning one billionth of a unit or 10-9.
- A prefix meaning one billionth (1/1,000,000,000).
- A prefix meaning one-billionth in the American numbering scheme, and one thousand millionth in the British system.
- A nanometer is a unit of spatial measurement that is 10-9 meter, or one billionth of a meter.
- One billionth of a second (10-9 seconds).
- One thousandth of one millionth of a second.
- A unit of distance measure that equals 10-10 meters.
- A unit of length equal to one ten-billionth of a meter
- A unit of length equal to one hundred-millionth (10-8) of a centimeter, used especially to specify radiation wavelengths. Also called angstrom unit.
- Micro – Prefix meaning one millionth.
- Macro (macroscopic) – Large enough to be perceived or examined by the unaided eye.
- However, macro meaning something seen by the naked eye is misleading. A view of earth taken by the Hubble Telescope is a “macro” view of earth, but certainly not one that can be seen by the human eye.
- Macro, unlike micro, does not imply a specific unit of measurement. A micro is one millionth of something, whereas macro is a general term meaning anything larger than micro.
- Contains a flash animation comparing the size of an ordinary pin magnified 10, 100, 1000, 10,000, 100,000 and 1,000,000 times. www.cellsalive.com/howbig.htm
- Molecular Expressions
- Contains a flash animation starting with the Milky Way at 10 million light years from earth, moving exponentially through sub-atomic particles to the smallest particle known, the quark. micro.magnet.fsu.edu
- Department of Energy (DOE) – Office of Basic Energy Sciences – The Scale of Things
- Provides graphics illustrating the size of things ranging from an ant to nanotubes. www.science.doe.gov
Content also contributed by Jerry Flattum