What is Experiment: Definition and 1000 Discussions

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.

View More On Wikipedia.org
  1. S

    B Double Slit Experiment with a Medium in front of the slits

    Hi, I was wondering what would happen with the interference pattern if I had a medium with higher refractive index than air in front of the slits. Would the interference fringes become narrower?
  2. S

    I Kim's 1999 delayed-choice quantum eraser experiment

    As I understand the delayed-choice quantum eraser experiment, first performed by Kim in 1999, entangled photons are used to determine which-way data, and the which-way data is obtained by virtue of where the entangled particles land, as opposed to using a measuring device that may be collapsing...
  3. D

    B Einstein's Train Thought Experiment

    So I got this from an article on wikipedia that covers Einstein's train thought experiment: A popular picture for understanding this idea is provided by a thought experiment similar to those suggested by Daniel Frost Comstock in 1910[13] and Einstein in 1917.[14][12] It also consists of one...
  4. A

    Help with an Experiment Concerning a Copper Sulfate

    Hi, I'm in 12th grade and for my senior project I am doing an observation on the effects copper would have on plant growth. I have used copper sulfate to create increasing concentrations of copper in which I used to water my test plants. After further research of lately, I found that copper...
  5. J

    B Proietti 2019 experiment: Doubt in measuring A1(B1)

    Hi everyone! Sorry for the bad english! Paper: https://arxiv.org/abs/1902.05080 I guess I understood the experiment until the moment Alice and Bob chooses to measure A0(B0) or A1(B1). I guess it's kind of straightforward that without a bell state measurement with photon alfa(beta) and photon...
  6. Ken Hughes

    B Interference of Light in the Double-Slit Experiment

    It is said that interference occurs when a peak (of the light wave) meets a trough and the wave cancels to zero, giving a dark band on the screen. However, if light waves are bands or "shells" of high densities of photons interspersed with bands of zero photons, then how can this be? When a peak...
  7. M

    Michelson-Morley Experiment: the importance of the laser position

    Why was it important that both arms were parallel and perpendicular to the rotation of the earth?
  8. A

    Simple experiment with magnets

    I made a little experiment with magnets. I got two small bars of magnets. They obey the usual attraction-repulsion rules by approaching their faces together in various permutation. Accidentally, one of them is broken into two unequal pieces. When I managed to put the two broken pieces side by...
  9. F

    I Particle in a box experiment confirmation

    Is there any experiments that validate the results of particle in a box with infinite or finite potential. Thanks
  10. TachyonLord

    Why Are My Newton's Rings Experiment Results Inconsistent?

    When monochromatic light is incident on a plano convex lens(as shown in the picture), these dark rings are produced which are observed with the help of a traveling microscope. The procedure requires us to measure the diameter of each ring (We need to measure the diameter of at least 10...
  11. PeterDonis

    A A Realization of a Basic Wigner's Friend Type Experiment

    See this recent paper: https://arxiv.org/abs/1902.05080
  12. A

    A Has the 2-stage Stern-Gerlach experiment been performed?

    In http://www.feynmanlectures.caltech.edu/III_05.html#Ch5-S1, Feynman mentions that the 2-stage Stern-Gerlach experiment, which proves the electron spin states to be in a superposition, has never been actually done! I have also not seen any paper reporting such an experiment. My question is, has...
  13. T

    Path-choice experiment in the framework of the MWI

    In a Mach-Zehnder interferometer the light arrives independent on the path at one the two detectors because of complete constructive resp. destructive interference at the final beam splitter. Is it possible to modify the device such that dependent on the path either detector A or Detector B will...
  14. S

    I Exploring the Double Slit Experiment: The Mystery of Empty Space on the Screen

    General question to members, when you look at the results and the interference pattern of the double slit experiment for electrons. Does anyone have information on what the empty space is on the screen. The electrons fixed location on the screen shows gaps always. I watched one persons theory...
  15. O

    Tips - physics video experiments

    Hello. In my bachelor thesis I make motivational video experiments in physics (for high schools). I want to mention some already existing videos. I know videos from our country or channels from YouTube. However if I'm looking for some videos from Universities or professional organizations...
  16. TachyonLord

    Melde's Exp: Why Transverse & Longitudinal Arrangements Differ?

    Homework Statement Why working formula for transverse and longitudinal arrangement in melde experiment different in Melde's experiment ? Homework Equations None. The corresponding equations are all derived from the same fact. The Attempt at a Solution So, I have understood that the tuning...
  17. N

    Sophisticated Experiment (Thermal Conductivity of Housing Materials)

    Hi everyone, I am currently a third year University Student in the UK and I'm in the midst of doing my dissertation. My dissertation topic (Effective methods of decreasing the thermal Conductivity of Housing Materials) requires that I produce several experiments to test and analyse a certain...
  18. K

    Why Do Voltage-Current Graphs in the Franck-Hertz Experiment Show Tops and Dips?

    Homework Statement I have two questions concerning the Franck-Hertz experiment on Mercury. The first one is to explain the tops and dips in the voltage-current graph (https://en.wikipedia.org/wiki/File:Franck-Hertz_en.svg). The second question consider the experimental setup, and why there is...
  19. A

    Help with Copper and Zinc's Effects on a Plant Experiment

    Hi, I'm in 12th grade and for my senior project I wanted to do an experiment on the effects that copper and zinc have on mung beans. I have copper sulfate pentahyde and zinc sulfate monohydrate, which I had purchased because I have seen information on other similar experiments where these were...
  20. dRic2

    B Thought experiment -- A radioactive decay detector and randomness

    Take one radioactive element and put a detector all around it so that you can immediately detect whenever it will undergo radioactive decay. Have a clock connected to the detector to note the "exact" instant at which the atom decays. Let's say that after 3min after the clock started counting the...
  21. TachyonLord

    Sources of errors in a spectrometer experiment

    [Note from mentor: this lacks the homework template because it was originally posted in a non-homework forum.] I know this seems like a very dumb question but every other error I think of has been covered in precautions and the only errors I can think of are dumb ones. Help ! I had to plot the...
  22. I

    Comp Sci Why Is My Java Monte Carlo Simulation Not Approximating Pi Accurately?

    Homework Statement There is a square and a circle is inscribed inside. Simulate an experiment where raindrops drop on this surface. Some raindrops can drop in or on the border of the circle. Some can drop outside the circle. The area of the square divided by the area of the circle gives you pi...
  23. M

    I Differential cross-sectional area - Rutherford's experiment

    I'm struggling to understand the importance of the differential cross-sectional area in Rutherford's scattering experiment, dσ/dθ. In one part of my course notes it is explained as 'the number of scatterings between θ and θ + dθ per unit flux, per unit range of angle'. However, dσ itself is...
  24. J

    I Exploring Simultaneousness in Einstein's Thought Experiment

    Let's modify Einstein's thought experiment on simultaneousness. A person G on ground sits in the middle of two fireworks. The fireworks are wired (equal distance) to an ignitor just in front of the person G. A person T on a train of constant velocity V passes by the ignitor and pushes the button...
  25. J

    Machine Learning or Deep Learning for a Lab Experiment

    Hi, I want to try out a bit of machine learning or deep learning with an optimisation problem in the lab. However, I'm confused at what the best option would even be or whether my optimisation problem is even applicable to either. Firstly, the lab set up hasn't been built yet, I am computing...
  26. A

    Pressure / Volume Gas relationship Pendle Hill experiment

    I was reading about the Pendle Hill experiment by Henry Power and Richard Towneley showing the relationship between Volume and Pressure in gas that eventually became Boyle's Law. The higher they got the greater the volume became. My question is, was the gas measured in the barometer isolated...
  27. TachyonLord

    Fizeau's Experiment (Speed of light)

    Homework Statement In the Fizeau's Experiment to determine the speed of light, let the gear have N teeth, the frequency of the rotating gear being f, the distance traveled by the light beam/ray L (distance b/w the gear and the mirror) and let there be n eclipses(blocking of the light beam)...
  28. Wrichik Basu

    Classic double-slit experiment in a new light

    An intense beam of high-energy X-ray photons (violet) hits two adjacent iridium atoms (green) in the crystal. This excites electrons in the atoms for a short time. The atoms emit X-ray photons which overlap behind the two iridium atoms (red) and can be analyzed as interference images. Credit...
  29. F

    Standing waves on a string experiment -- Relative amplitude of harmonics

    Hello forum, I am wondering why the higher order (higher harmonics) standing waves developed on a string under tension generated by an oscillating mechanical vibrator (set at the same amplitude but with variable frequency) have lower amplitude when compared to the lower harmonics (the...
  30. RealKiller69

    I Quantum Oscillator in 1D: How Can a Real Particle Have an Imaginary Velocity?

    I have got a simple qstion. We have a particle in 1d oscillator with E0( fundamental level).We know that phi~ e^-x^2 for any x, so We can measure a position and get a value x=a, such that V(a)>E0 . In this case T<0 so the velocity of the particle is imaginary, how is this even possible?, (a real...
  31. P

    B Superposition of traps (thought experiment)

    Hi Pf Instead of placing a screen on each path of an interometer i propose to place opticz traps. in both cases it will unable the photon to go further. i wonder if one on the traps will be heavier or if there will be symmetry (superposition).
  32. fluidistic

    A The different interference patterns in the double-slit experiment

    I've read on page 107 of the pdf http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=617AE275E5CECF5F0AFD69ACBC52141B?doi=10.1.1.205.6529&rep=rep1&type=pdf that . Thus it seems that there are three different interference patterns. 1: We do not try to detect the electron passing through the...
  33. alan123hk

    Experiment for the existence of electrostatic field

    I am still puzzled by the issue of existence of electrostatic field. According to the classical electromagnetic theory, electrostatic field can be created by an electrically charged particle. The electrostatic field surrounding the electrically charged particle does not stop close to the...
  34. jedishrfu

    BBC 4 Experiment on the Spreading of a Pandemic

    BBC 4 with the help of a smart app tracks the spread of a theoretical pandemic:
  35. Sandeep T S

    I Wave function collapse in a double slit experiment

    Is anyone did experiment on wave function collapse in double slit experiment. Could you please share information about that, and also share research paper about that experiment. What kind of observation done here, what kind of equipment used for that?
  36. M

    I Double-slit experiment: Alternating results

    How can the results of a double-slit experiment change just by adding a detector at the point of entrance of the split? Is it really so that if there is a detector, we will only see two lines and if there is no detector we will see interference?
  37. Frederick T

    B Travel at 0.5c & Observe Redshifted Light Traveling at c

    It's come to my attention that if we were to travel in a spaceship at 0.5c directly away from our sun, I would observe that the light from the sun as being red shifted. What I would also observe was that this red shifted electromagnetic wave would in fact travel away from me in the spaceship...
  38. R

    I Photon detector on a dual slit experiment

    My experiment is to place a detector on one of the slits in the dual slit experiment so That it would record or not the passage of the photon, and then reset the detector to its base state, Erasing the result. In such a case, would the interference pattern be destroyed simply because the...
  39. Sandeep T S

    I Hertz Experiment: Original Paper on Photoelectric Effect

    Can anyone share original paper of Hertz experiment on photoelectric effect.
  40. fluidistic

    I Charge carrier density: Hall experiment vs Fermi-Dirac statistics

    Many times, the charge carrier density of a material is determined from a Hall effect experiment, from ##R_H=1/(ne)## (SI units). Where ##R_H## is determined from a measured voltage and other controllable parameters. As far as I know, this simple formula comes from the obsolete Drude's model...
  41. S

    What can I investigate regarding the mechanics of bikes?

    << Multiple threads on the same subject merged, Thread moved to the schoolwork forums, and the OP has been reminded to show more effort on their own schoolwork questions >> I want an investigation/research that is simple to experiment practically (I don't have fancy equipment. My main piece of...
  42. R

    I Thought experiment about superposition.

    Suppose I could restrict an electron to a very small space byfor example using multiple magnetic fields, then could I not be sure with 100% probability that the electron was there before and after a measurement? Wouldn’t such a experimental set up dis prove the idea that the electron had freedom...
  43. DLeuPel

    I Measuring the Effects of Dark Energy on Bound Objects: An Experimental Study

    I’m thinking about modifying some force related equations to include dark energy in them for an essay on physics. My reasoning is that if it can separate galaxies the objects in our day to day lives must also have a small tendency to move apart. To do so, I have to dispose of an already done...
  44. J

    I Detecting Interference Patterns with Large Objects: The Double Slit Experiment

    Why is it so difficult to detect interference patterns with larger objects in the double slit experiment(e.g. bacteria)?
  45. J

    I Retro-causality thought experiment

    It has been mostly substantiated by virtue of experiments such as wheelers delayed choice quantum eraser experiment that we are able to retroactively impact past events of particles. However could this apply to the universe. When physicists are carrying out experiments today, which are creating...
  46. J

    Growing piezoelectric crystals experiment

    Homework Statement I'm not sure if this is a forum for these kinds of things. But anyways, at school I and a handful of other kids are devising an experiment to send up to ISS to test it over a period of 30 days next year. (Yep, we're quite fortunate to have this opportunity!) We've chosen to...
  47. S

    B Double slit experiment w/ light shining thru one aperture only

    Hi, Will there be interference if I point the laser thru one of the openings of the double slit aperture only while the other one is open? And is the interference more pronounced or the same if I shine it thru both the apertures at the same time.
  48. S

    I Time dilatation thought experiment

    Hello everyone, this is my first post on this forum, I am a new member and the other day was pondering on a question related to the passage of time. So, I have the following thought experiment: Suppose there is the following setup: We have two small toy cars, identical, each capable of...
  49. S

    B Double Slit Experiment with Gamma Rays

    Hi I was wondering what would happen if you use Gamma Rays in a double slit experiment. Would you see the same interference pattern?
Back
Top