Experiment Definition and 1000 Threads

An experiment is a procedure carried out to support or refute a hypothesis. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale, but always rely on repeatable procedure and logical analysis of the results. There also exists natural experimental studies.
A child may carry out basic experiments to understand how things fall to the ground, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of hands-on activities are very important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning, especially when used over time. Experiments can vary from personal and informal natural comparisons (e.g. tasting a range of chocolates to find a favorite), to highly controlled (e.g. tests requiring complex apparatus overseen by many scientists that hope to discover information about subatomic particles). Uses of experiments vary considerably between the natural and human sciences.
Experiments typically include controls, which are designed to minimize the effects of variables other than the single independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. Scientific controls are a part of the scientific method. Ideally, all variables in an experiment are controlled (accounted for by the control measurements) and none are uncontrolled. In such an experiment, if all controls work as expected, it is possible to conclude that the experiment works as intended, and that results are due to the effect of the tested variables.

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  1. X

    I How does the Lota Bowl water experiment work?

    Hello! Can anyone help me understand why this experience works this way? If we plug the hole on the left side, the water does not affect the cup that has the hole on the bottom. However, if we let go of this hole on the left side, the water will start to pour into the cup again. Is the law...
  2. A

    I Electron two-slit experiment in classical electromagnetism

    Was there any study of this experiment in the context of classical electromagnetism? It is often claimed that such an experiment is impossible to explain classically, yet, the only classical model I've seen employed is Newtonian mechanics (bullets). The EM fields associated with the electrons...
  3. R

    B Does this experiment prove that light speed is actually faster?

    Some people thought light speed is actually instantaneous which can be demonstrated by doing an experiment involving a taut clothesline and two clothespins. On each ends of the taut clothesline, put one of the clothespins on both ends and touch one of the clothespin will make the other one at...
  4. A

    I Problem involving a sequential Stern-Gerlach experiment

    An electron beam with the spin state ## |\psi\rangle = \frac{1}{\sqrt{3}}|+\rangle+\sqrt{\frac{2}{3}}|-\rangle##, where ##\{|+\rangle,|-\rangle\}## is the eigenstates of ##\hat S_z##, passes through a Stern-Gerlach device with the magnetic field oriented in the ##Z## axis. Afterwards, it goes...
  5. Ghost Quartz

    I Math of Electron Double Slit Experiment

    I'm looking for a good derivation of the "wave" patterns in this experiment. I suppose that if wave-particle duality is an obsolete idea, there must be a derivation from quantum mechanics that gets close results. Thanks in advance
  6. B

    B When do marbles behave like a liquid in a beaker?

    If we place a cork in a beaker then filled the beaker with normal-sized marbles, the cork will remain stationary at the bottom of the beaker. However, if we continuously decrease the size of the marble, at a certain point, the marbles will behave like a liquid and the cork will rise to the top...
  7. K

    I Information traveling faster than light? (thought experiment)

    Let us consider a hypothetical scenario, where we are able to translate any mass at a constant speed of 10m/s w.r.t to a given frame of reference. For simplicity, we are going to assume that the object is at rest initially. Case 1 - Now, consider 2 points A and B at a distance of 10m, and our...
  8. P

    I Violation of Special Relativity Principle?

    From the michelson-morley experiment, if a clock were to measure the time period of light hitting the mirror and returning back, it would be 2L/c, where L is the distance between the laser nd the mirror. For a moving observer, the time period would have a factor of *gamma*, the boost factor...
  9. Boltzman Oscillation

    B Deriving formula for force by thought experiment

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  10. P

    B Is an experiment planned to discern determinism and randomness in QM

    I can remember reading something about a future experiment which alledgely could decide if there is an underlying deterministic layer governing quantum phenomena or if pure, empty chance rules suppreme (which I can't imagine). It had something to do with arrival times but I can't imagine how...
  11. C

    MHB Identifying if an experiment is a binomial experiment

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  12. P

    B Question re photons/EM waves and the double slit experiment

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  13. C

    B Is quantum superposition involved in the Stern-Gerlach experiment?

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  14. M

    B Double Double Slit Experiment -- Question about Variations

    emitter -> double slit -> double slit -> detector. Was an experiment ever made where two double slits are placed at some distance between each other? What kind of interference pattern would you get? What would happen if second slits were placed at the position where there is destructive...
  15. DougFisica

    I Observables on the "3 polarizers experiment"

    Observables on the "3 polarizers experiment" Hi guys, I was analyzing the 3 polarizers experiment. This one: (first 2 minutes -> ) Doing the math (https://faculty.csbsju.edu/frioux/polarize/POLAR-sup.pdf) I realized that the process is similar to the Stern-Gerlach' experiment. Using spins...
  16. O

    I Observing a double-slit experiment

    Do I have the proper understanding of the following three double-slit experiment situations? #1 While a standard double-slit experiment is run via a Mach-Zehnder interferometer apparatus that completely lacks which-way detectors, can an ordinary human experimenter be present and watch that...
  17. M

    How to interpret the Standard Error in this experiment?

    Does the S.E. of $38.72 mean, I sould expect to win or lose up to $77.4 (2x S.E), 95% of the time?
  18. G

    Superdeterminism ruined the significance of DCQE experiment

    I keep thinking that the universe "knows" when, how, where these know-it-all (no pun intended) physicists did their experiment so all the results are not only consistent, but perfectly normal, nothing freaky about it. I'm no longer capable of thinking like a normal human being and subsequently...
  19. P

    A First findings from Fermilab's 'muon g-2' experiment revealed

    https://www.rearpost.com/post/fermilab-discovery-hints-new-physics
  20. deadbeef

    I Interference Patterns & Photon Paths: Exploring the Double Slit Experiment

    Hi. As i understand in double slit experiment photon can arrive at slits through different paths (longer and shorter) and it would still show interference pattern. My question is - if there was some path cutting device in a way of photon (on longest path after length that photon arrive at...
  21. Viky1147

    Calculate scaled down human model weight for practical experiment

    Hello, I need to scale down a human model by 1:20 i.e, i need a human model of 9 cm height scaled down. Help me calculate the weight of the 9 cm scaled down human model. Regards, Viky
  22. T

    I Large scale entanglement experiment

    This is the paper and here is the video. As far as I know, this is an entanglement related experiment done so far in such a large scale. I want to know whether entanglement related experiment has been done so far on a larger scale and what can be the possible use of such phenomenons.
  23. W

    B Symmetry of parity: Mistake in the experiment?

    Recently I saw this YouTube video from Veritassium about CPT -Symmetry: In this video an experiment of Prof. Chien-Shiung Wu is presented, which has proven that parity is not symmetric, by observing the emmition of electrons from Co60 atoms with synchronised spin. After thinking about this...
  24. S

    I Michelson-Morley Experiment: Objection Explained

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  25. Justice Hunter

    B Thought Experiment : Try and get Alice to "0%" the Speed of light

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  26. StevieTNZ

    I Another Wigner's Friend Thought Experiment Paper

    https://phys.org/news/2021-05-future.html The paper in question can be found at https://www.nature.com/articles/s42005-021-00589-1 This thread is for discussion of the said paper.
  27. Shreya

    Plasma Experiment Involving Magnetic Fields

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  28. G

    B Quantify Quantum Eraser Experiment

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  29. Sophrosyne

    B Twins Paradox Thought Exp: What Happens When Reunited?

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  30. L

    B Some questions about Wheeler's delayed choice experiment

    Based on Wheeler's delay choice experiment, the following results of experiment1 can be achieved. Experiment 1, the light passed through the BS1, 50% of the light is transmitted on optical path A, and then passed through the polarizer P2(the polarization angle is 135°),and the polarizer P3 (the...
  31. P

    I Experience based on Millikan's experiment

    Hello! As I said in the summary, this is inspired by Millikan's experiment. Suppose you have 19 (closed) packages, all filled with different quantities of the same unknown object (which has a mass of m). You then weigh these packages one by one. How could you estimate the mass "m" of that...
  32. M

    Oscillating spring experiment uncertainty

    I know how to do the individual uncertainties but just not sure of the order.
  33. H

    Young's double-slit experiment - Bright fringes occurring

    I think the answer is E because each bright fringe is differed by a wavelength, in other words, one wavelength is equal to 2π. (For example, the first bright fringe is d * Δy/L = 1*λ.)
  34. Milsomonk

    A US Muon-g2 experiment - reading recommendations

    Hi folks, Hope everyone is keeping well. I've recently read the headlines of "strong evidence for new force of nature" pertaining to the Muon g-2 experiment. Interesting as I find the article in the BBC linked below: https://www.bbc.co.uk/news/56643677 I'd love to read some...
  35. R

    A Eddington's Experiment: Sources for Calculations

    Can anyone suggest me a few sources for his calculations?
  36. hugo_faurand

    Get electrical signal of a piezoelectric with ultrasound

    Hello everyone ! I'm working on ultrasound probes, and I wanted to measure the electrical signal generated by a piezoelectric device (a transducer). Here is a sketch of the experiment : The goal of the experiment is to compare the electrical signal of the piezoelectric cell and compare it...
  37. jackiepollock

    Why Does the Pattern Blur When I Approach in Young's Double-Slit Experiment?

    As I searched online an answer suggested that the blurry effect might be a speckle pattern. However, it still hasn't explained the reason why when my body come near the pattern gets blurry.
  38. Rzbs

    Coriolis effect and water experiment

    Is the Uganda water experiment (that shows corilios effect on water drain) a scientific experiment or not? I searched but I couldn't find a final answer to this question. There are two opposite opinions, which one is correct? Or this argument is an open issue yet? Thanks for your replies...
  39. OneAverageGuy

    B Questions on the Michelson Morley Experiment

    I've heard claims the Michelson Morley experiment proves light moves at the same speed in all reference frames. However, after looking through the experimental setup, I do not see how they can make this claim. The entire experiment, from my view, was conducted in Earth's reference frame. His...
  40. C

    Wall made of Pendulum -- thought experiment

    If your house wall is made of pendulum or a ball attached to a string on top. It won't attract seismic forces. Whereas if the wall is fixed solid. It can attract seismic forces. What is the physics explanation of it? Is it because you try to deflect momentum or inertia? What is the right...
  41. HoneyBee

    Chemistry Finding rate constant from pressure change in an experiment

    Is there any way that I can find concentrations and then find the rate constant, k? And, using them, make an Arrhenius graph to find activation energy (including the catalyst)? Any help would be much appreciated. Change in pressure was found using a Vernier Gas Pressure Sensor. The starting...
  42. L

    A Thought Experiment: Aether Medium

    I would like to conduct a thought experiment. If some form of medium exists, what would it be made of? What form would any constituent parts take? Would those parts exhibit any properties? How would they function as a medium? What relation would the medium have with atoms and other particle...
  43. John_Dee

    Thought Experiment - Centripetal Force

    Ok, so we know that if one were inside a donut-shaped spaceship that is rotating around it's axis, that the passengers will experience centripetal force. It seems obvious to say that the ship is rotating relative to the nearby stars and planets. So far, so good. But... what if we removed all...
  44. ayans2495

    Calculating initial temperature of iron block submerged into water

  45. Marilyn67

    A GBAR Experiment (CERN) - Genève

    Hello, My question concerns the (improbable but possible...?) results of the GBAR experiment at CERN which should resume in May 2021, according to my latest information. (delay due to Covid 19). Most scientists (and me too) believe that antimatter behaves the same as matter in a gravity field...
  46. K

    I Constant beam, both slits analyzed double-slit experiment?

    I keep seeing that it's assumed that photons interfere with each other, and there are other points of proof for this like destructive interference, etc., but I've never seen an experiment in which a constant beam is used but both slits are analyzed or the energy required for measurement is...
  47. B

    B Measuring a change in gravity - thought experiment question

    Imagine I hang a mass from the ceiling of a building using a rope. The mass is hanging 2m above the floor. Also tied "in line" with this rope, and between the weight and the ceiling, is a scale that measures the weight of the mass. Let's say the scale reads 10 Newtons. Now, between the...
  48. A

    Classical Home Experiment / Demo / Training Kit for students to use at home?

    Dear all, could you kindly recommend Physics Demo home kits (mechanics, Optics, Sound, Electricity/Magnetism) for secondary school level, to practice and learn at home? many thanks
  49. B

    B How is the measurement done for the double slit experiment?

    How is the measurement of which path the particle took done for the double slit experiment? When electrons are being sent through the slit. Or when photons are being sent through the slit. Is it an active process or a passive process? I haven't seen an explanation for this and perhaps this...
  50. R

    I Some questions about the photoelectric experiment

    Background: self-studying. Very confused. Here are some initial questions I have about the photoelectric experiment. Some more may pop up later. 1. The book says we know photons exist due to energy considerations (such as emission or absorption). They also say that this photon energy is...
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