What is Meter: Definition and 309 Discussions

The metre (Commonwealth spelling) or meter (American spelling; see spelling differences) (from the French unit mètre, from the Greek noun μέτρον, "measure", and cognate with Sanskrit mita, meaning "measured") is the base unit of length in the International System of Units (SI). The SI unit symbol is m.
The metre is currently defined as the length of the path travelled by light in a vacuum in 1/299 792 458 of a second.
The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's circumference is approximately 40000 km. In 1799, the metre was redefined in terms of a prototype metre bar (the actual bar used was changed in 1889). In 1960, the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. The current definition was adopted in 1983 and modified slightly in 2002 to clarify that the metre is a measure of proper length.

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  1. A

    About filled gas inside a Geiger Muller meter

    Hi, I have a dumb question about the filled gas inside a Geiger Muller meter. I know it is considered as a gas detector. It requires a filled and quench gas for the probe. My question is: where does the gas get injected into for like a pancake probe. (Let's use Ludlum Model: 44-9 as example)...
  2. A

    B Is a "meter" observer dependent?

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  3. jim hardy

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  4. HethensEnd25

    Calculating Water Flow Using a Venturi Meter

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  5. M

    How to measure whether a smartphone is inside a 5 meter range?

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  6. P

    Venturi meter pressure difference

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  7. P

    Meter R for V^2/R measurement?

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  8. R

    B Meter Defined by Speed of Light: Uncertainty of Measurement

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  9. D

    Decide the resulting force (F) per meter on L2

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  10. R

    Checking pH meter calibration HCL >37%

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  11. T

    Electrodes liquid contact electromagnetic flow meter?

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  12. moenste

    Voltage that would produce full-scale deflection of a meter

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  13. M

    20 kOhms/V meter versus Digital meter in valve circuits

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  14. A

    Digital Force Meter: Is It Worthwhile for a Summer Project?

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  15. C

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  16. S

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  17. putta

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  18. Neil Hayes

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  19. G

    Calculate head loss per meter clarification

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  20. F

    How Do You Calculate Head Loss in a Venturi Meter Using Bernoulli's Equation?

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  21. L

    Meter Bridge: Finding Error in Resistance

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  22. I

    I Question about a g-force meter

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  23. A

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  24. I

    Odd voltage reading from digital volt meter

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  26. N

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  27. P

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  28. I

    Linear Thermal Expansion of a Meter Stick

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  29. F

    Water activity meter reading over 1

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  30. T

    Electrical meter and efficiency question

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  31. N

    How to measure this capacitance using a capacitance meter

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  32. B

    Particle beam has What Amount of voltage per meter LHC

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  33. Tonia

    How fast must a meter stick be moving if its length is....

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  34. N

    Understand pH Meter Functioning: An Electric Potential Difference

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  35. L

    How does a forward and reverse power meter work?

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  36. M

    Find for how much time, the car with stop and how many meter

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  37. J

    Best Portable Tesla Meters for Submersible Water Pumps

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  38. chikou24i

    Understanding Limit Current & Resistivity in Source Meter Machines

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  39. S

    Don't know how if the rule meter will be titled or not

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  40. litis

    Measuring Illuminance with Lux Meter - Can I Make Conclusions?

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  41. E

    Finding the *Time* it takes for yo-yo to travel 1 meter?

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  42. K

    Finding mass of a meter stick using torque

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  43. I

    Need a certain type of meter - don't know the name - Help please

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  44. L

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  45. M

    How to Test Amplitude-Phase Response of Sensors and Circuits using Arduino DUE?

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  46. Laurine

    How to Convert 180 Ton to kN/m?

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  47. D

    Using solar cell as a power laser meter

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  48. M

    100 meter running with constant acceleration

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  49. H

    What are the air speeds in a Venturi meter with varying tube diameters?

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  50. O

    Solar - Grid Tie - Energy meter increases?

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