What is Measuring: Definition and 1000 Discussions

Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. The scope and application of measurement are dependent on the context and discipline. In natural sciences and engineering, measurements do not apply to nominal properties of objects or events, which is consistent with the guidelines of the International vocabulary of metrology published by the International Bureau of Weights and Measures. However, in other fields such as statistics as well as the social and behavioural sciences, measurements can have multiple levels, which would include nominal, ordinal, interval and ratio scales.Measurement is a cornerstone of trade, science, technology and quantitative research in many disciplines. Historically, many measurement systems existed for the varied fields of human existence to facilitate comparisons in these fields. Often these were achieved by local agreements between trading partners or collaborators. Since the 18th century, developments progressed towards unifying, widely accepted standards that resulted in the modern International System of Units (SI). This system reduces all physical measurements to a mathematical combination of seven base units. The science of measurement is pursued in the field of metrology.

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  1. Ygggdrasil

    Measuring off target mutations during CRISPR gene editing

    https://www.physicsforums.com/insights/dont-fear-https://www.physicsforums.com/insights/dont-fear-crispr-new-gene-editing-technologies-wont-lead-designer-babies/-new-gene-editing-technologies-wont-lead-designer-babies/ is a newly developed tool that allows researchers to easily make changes to...
  2. Sandeep T S

    I Measuring the Speed of Light: Time of Flight Experiments

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  3. Kenny555

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    Homework Statement [/B] Find reading of ohmmeter. Homework Equations V=IRThe Attempt at a Solution I am a beginner of this topic and I think it is simple as ohmmeter directly measure the resistance of the resistor which is 2k ohm while the correct answer is 1.67k ohm. I have no idea how to get...
  4. Sandeep T S

    I Speed of Light Measured by Jupiter's Moons: Error 26%?

    Romer measured speed of light using moon's of Jupiter but he got value with a error of 26%. Is anyone did same experiment in modern era? And what value they got?
  5. S

    Measuring the resistance of a resistor

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  6. Eucliwood

    B Measuring Angles: Negatives & Quadrants

    <Moderator's note: Moved from the welcome forum. General question on the measurement of angles and thus no homework.> So we have a physics lab and here's the diagram. I do know how to calculate all but i got negative angle. Does that mean that that angle is reference to the negative x quadrant...
  7. I

    Measuring Pressure For Compressible Fluid Systems?

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  8. R

    I Difference between preparing and measuring

    I’m understanding that if you prepare a QM system, say 2 electrons in a singlet state and do nothing to the system then when the measurement is made the 2 electrons will still be in the singlet state. If that is true, then I don’t see anything surprising that if Bob measures his electron as up...
  9. N

    I Measuring Star Radii with General Relativity

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  10. Dr. Courtney

    How Can Doppler Radar Improve Drag Coefficient Measurements in Physics Labs?

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  11. F

    Measuring the current from a micro generator affects its output?

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  12. prashantakerkar

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  13. runningman19

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  14. A

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  15. P J Strydom

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  16. T

    B Measuring Objects using Dissimilar Units

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  17. M

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  18. P

    Measuring small differences in the phase of light

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  19. 4

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  20. C

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  21. K

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  22. R

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  23. C

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  24. Elbraido

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  25. J

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  26. P

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  27. S

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  28. J

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  29. Lukeblackhill

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  30. Passionate Eng

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  31. F

    I Does measuring an atom collapse the wavefunction of its parts?

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  32. C

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  33. B

    Measuring the speed of sound in an iron tube

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  34. yubson

    Question about measuring the internal resistance of power supplies

    In measuring the internal resistance of a power supply, why is a resistor with low resistance used?
  35. X

    B Measuring entangled particles along several angles

    Heya, I was wondering what happens when you measure the spin of particles along several different angles on an entangled pair. As far as I understand Bell's theorem, it basically says that if you first measure particle A in some angle, and then measure a particle B at some some angle, you'll...
  36. C

    B Measuring the Universe's expansion rate

    From our perspective the Universe is expanding faster the further away things get, correct? Given that we are measuring further and further back in time my question is this. If you were at the furthest known point in the Universe looking back at our galaxy and attempting to measure the expansion...
  37. J

    Measuring 800V AC signal with 16-bit DAQ card within 1% accuracy

    I'm trying to measure high voltages with a DAQ card. Obviously I'm going to have to attenuate the voltage, but I need to make sure that I can measure accurately (within 1%) The code width of the DAQ is Vcw = 20Vpp/2^16 = 305.176uV For this code width to be within 1%, the minimum voltage I...
  38. Lukeblackhill

    Mechanical Collision: Measuring Sound & Heat

    Morning! My question is this: If we consider a situation of mechanical collision, in the real world we shall observe certain loss of energy into heat or sound. Can we find mathematical equations to measure the amount of sound or heat produced using only mechanical variables, such as mass...
  39. T

    Measuring one second with a bouncing ball

    Hello Theoretically any ball that bounces 1.225 metres high is in the air for one second. This is fairly precise, +/-4% time variance is +/- 10 cm height variance, so bouncing to a height of 1.13 metres is 0.96 seconds and to a height of 1.32 is 1.04 seconds. The theory is at least dependent...
  40. J

    PMMC measuring Instrument reading

    Homework Statement Homework Equations For question 14 PMMC measures average value MI measures RMS value The Attempt at a Solution I think PMMC should give 0 V But book answer is B i.e 1 V (where am I wrong?) and MI should give 1.414 V. For this book answer matches my answer.
  41. P

    I Measuring particles through experiments

    How is it reliably ascertained that the "particles" 'measured' can be "proven" to have "traversed the experiment" and are not just conveniently (or inconveniently depending on perspective) incident / external? Is this obtained through statistical analysis from a large number of repetitions...
  42. erik giles

    I Measuring Speed in Relativity - Einstein's Work Explained

    Good morning. I've just completed working through Einstein's work on special and general relativity. Do I understand that, in relativity, a moving object cannot measure its own speed without an external reference to compare to? IE, there is no experiment it can conduct to determine its own...
  43. W

    QM: Probability of measuring momentum

    Hi all, My question is in reference to the following paper: https://arxiv.org/pdf/1202.1783.pdf In equation 3.8, the author computes an order-of-magnitude approximation of probability of measuring negative momentum from the following wavefunction: $$ \Psi_k =\sum_{k=1,2}...
  44. A

    Measuring Range Extension "homework"

    a) dimension the moving-coil movement so that it indicates full deflection at 25 V given Values: Voltage Source: U2Max = 25V; moving-coil movement: IM = 100µA; UM = 270mV Rv = ( U2Max - UM ) / IM = (25V - 270mV) / 100 µA = 247,3kΩ b) the internal resistance is increased by 20 %...
  45. C

    Measuring the Speed of Sound: Examining the Frequency of Clicks

    Homework Statement This is a problem from the Cambridge Natural Science Admissions Assesment. A student carries out an experiment to measure the speed of sound. A loudspeaker that emits sound in all directions is placed between two buildings that are 128 m apart as shown. The student and...
  46. Const@ntine

    Chemistry Measuring the Mass & Electric Charge of Molecules

    Homework Statement Hi! So I stumbled upon this simple "plug n' play" exercise in my Physics textbook. Basically it gives you certain molecules/atoms, and tells you to measure the Electric Charge, and its Mass. Pretty simple, but I hit upon some hickups. Anyway, let's get to it: Find the...
  47. Hawksteinman

    Throwing a pen and measuring gravity

    Homework Statement We were given this question on a worksheet last lecture. The question is this: ‘Throw a tennis ball/your pen/some non-dangerous object into the air, straight up (and catch it again), observe its motion. Use your observation to measure the gravitational acceleration due to...
  48. S

    Measuring uncertainty spec for an oscilloscope?

    I just started learning about oscilloscopes and I am confused on how to calculate the uncertainty. The uncertainty measurement on the device says '1/2 the smallest division'. I am unsure which 'division' this refers to since there are horizontal scales and vertical scales. In my experiment I...
  49. T

    Measuring the Power Output of a Generator

    Hey folks, I built a generator for fun and I would like to find out how much power it is producing when I use it. I have a way of measuring mechanical power in but I am not quite sure on how to measure electrical power out. I'm thinking I could use some LEDs to create a load (or maybe...
  50. Pushoam

    Measuring the output from a Transistor Amplifier

    Homework Statement I understand that the DC current will not flow through the capacitor once the capacitor gets fully charged. So, after a long time , only AC component of the net current flow through the capacitor. How to show that all of the carying voltage appear across the capacitor...
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