What is Experiments: Definition and 475 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.

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  1. I

    'Toy' universe complying with Bell experiments

    After reading a bit about Bell's theorem and various hidden variable theories, I thought a little about the detection loophole, and how it gets around Bell's theorem while still allowing a pretty much 'local' Universe. The main argument against this, as I understand it (correct me if I'm wrong)...
  2. F

    Imitating ice for room-temp experiments

    Hello! I'm trying to come up with ideas for ways to simulate extraction methods for asteroid mining. I've got a few ideas based off of internet & database searches, and have an idea I'd like to work on. It involves the separation of materials using centripetal force. Materials would...
  3. G

    FTL warp experiments: Media hype or significant?

    FTL "warp" experiments: Media hype or significant? http://www.huffingtonpost.com/2012/09/17/warp-drive-star-trek-feasible_n_1890679.html This is just one article, but they're are plenty more to be found. There is one thing that confuses me though. Alcubierre's warp drive idea seemed to...
  4. L

    Where can I learn about modeling and simulating situations and experiments?

    Where/how can I learn about modeling and simulating situations/experiments for any physical situation (optics, thermodynamics, nuclear reactions). I'm an Computer Engineering student and I don't believe there are any classes being offered for modeling and simulation. What would be a good start...
  5. M

    Well I want to get some EXPERIMENTS: - in which we have clear

    Well I want to get some EXPERIMENTS:- in which we have clear Well I want to get some EXPERIMENTS: - in which we have clear confirmation of Pauli's exception principle? well have my idea. I would try to measure the probability density of my system Ψ, and if I found some region in which it...
  6. S

    Physics help please - Sources of error in lab experiments

    Physics help please -- Sources of error in lab experiments Ok so i need some help with a few labs.. some I've tried out and a few i just can't get.. what i want to know is whether the limitations and sources of errors that i wrote down for each of these labs are correct or not and what i could...
  7. A

    A few double slit experiments.

    Hello Lets make a few double slit experiments. Lets say we have water pond with a set of point size emitters on the left and a set of independent wave energy detectors on the right side. http://img560.imageshack.us/img560/571/slits1.png Now let each point emitter emits wave but with big...
  8. S

    Intuition for General/Special Relativity theorems without experiments

    I am not a mathematician, so I always used to wonder about following. "I never heard Einstein conducting any experiments, But how he predicted the physics properties the way it is explained in Relativity Theorems. These are some of the breakthroughs of that time, But without the intuition...
  9. M

    How can I find reliable sources of information on the LHC and its experiments?

    I'm sorry that this is probably in the wrong place, but I couldn't find a place to post where I am allowed to start threads which was relevant. I'm hopefully starting a degree in particle physics next year, I'm currently in my last year of high school. Myself and one other student at my...
  10. R

    How are electron position measurement experiments measured out?

    Im interested in knowing what kind of sensors are used and it's overall execution, thanks.
  11. G

    Combining data from replicated experiments?

    How do you go about combining data from replicated experiments? Should you just combine everything into one big set of data and then analyze it, or do you analyze the data from each experiment, and then combine the analyzed data into one set of finalized data? I'm not too sure on what to do...
  12. M

    Do the SQUID experiments falsify Bohmian mechanics?

    In the experiments done with superconducting rings by Delft and Stony Brook, currents are shown to be moving in both directions simultaneously. Doesn't this falsify the idea that a pilot wave detemines a single evolution of the states? Can that be explained without the addition of multiple...
  13. Doofy

    Advice on the most relevant oscillation experiments to mention in my report?

    I'm busy writing something about neutrino oscillation - nothing big, just a few thousand words, a bit of theory, a bit of experiment. I'm trying to do a section summarising the diffierent types of experiments - ie. ones involving solar, atmospheric, reactor and accelerator neutrinos - but there...
  14. S

    I have a question on pseudogravity as invoked in thought experiments

    I have a question on pseudogravity as invoked in thought experiments related to the principle of equivalence. One invents ‘gravity’ opposite to an accleration to explain weightlessness, the bending of light beam, the dilatation of time period, and twin paradox. I can explain all of the above...
  15. fluidistic

    Questions about fusion point of water, experiments

    I've been playing in the lab with distilled water and noticed that the smaller water drops are, the longer I could over cool them. In fact, even with 20 ml of distilled water, I couldn't get it to freeze when it passed by 0.0°C. Instead it would go around -3.5°C, then freeze almost instantly and...
  16. Doofy

    Solar neutrino oscillation experiments - how do they extract the parameters?

    In oscillation experiments that use solar neutrinos, it seems that the mixing angle \theta_{12} and the mass squared difference \Delta m_{12}^2 can be determined from comparing measurements of the neutrino flux to theoretical models of what the Sun should be emitting. However, I am...
  17. M

    Physics electric kettle experiments?

    Physics "electric kettle" experiments? Alrighty all you geniuses. I have a physics assignment that I need to actually start, I've been away from school for the past 2 weeks so I haven't really heard much about what is actually required; but going by my task sheet "Your task is to identify...
  18. G

    New quantum experiments and its implications

    Hello everybody, I just read the following article: http://arstechnica.com/science/news/2012/04/decision-to-entangle-effects-results-of-measurements-taken-beforehand.ars http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys2294.html (This last one I didn't read as I don't have a...
  19. A

    Unlocking the Mystery of Mass & Charge: LHC Experiments

    Biggest problem which LHC is worried about is knowing how mass is related to particles.does this mean that physical significance or understanding about charge is discovered.? If yes,what charge is.? If No,why scientists are not concerned to know about what fundamental charge is by conducting...
  20. 5

    Solving Pressure and Force in Gas Experiments

    Homework Statement a) Suppose that in the experiment involving P vs. T, the slope of the graph of P vs. T is 235 Pa/L/ Determine the pressure of the gas at T = 0 degrees celsius. b) The radius of the syringe is approximately 5 mm. Suppose that the pressure of the gas inside the syringe...
  21. G

    Question about Gunter Nimtz's experiments

    I've searched, I found something in the archives, and several other places on the net, but i wonder, how further experiments debunked this phenonemon? I saw this explanation : "Aephraim Steinberg, a quantum optics expert at the University of Toronto, Canada, uses the analogy of a train...
  22. R

    Can You Conduct Quantum Mechanics and Particle Physics Experiments at Home?

    I'm highly interested in the studies of particle physics as well as quantum mechanics. Are there any experiments I can try at home to demonstrate some of the more fundamental ideas related to these areas? Thank you for your time.
  23. G

    The role of lambda in Bell (1964) and experiments

    Moved from https://www.physicsforums.com/showthread.php?t=590249&page=3 to avoid confusion with the classical example in its OP. ThomasT and I are mainly discussing Bell (1964) here. The example discussed relates to 2 spin-half particles in the original EPR-Bohm example, see Bell (1964). The...
  24. D

    What are some Thermoelectric experiments?

    Ok. So I am currently doing a term on thermoelctrical physics and was told to perform an extended experimental investigation on this topic. The teacher has given me some examples but none seem to jump out to me. I was wondering in\f anyone has a few topics which are relatively advanced for a...
  25. DennisN

    Confess Your Stupidity: Tales of Mishandled Tech & Awkward Experiments

    I was just writing in another thread about a stupid experiment I did when I was young. This made me think that it might be fun with a thread of such confessions from members. Most people have done stupid things; what I'm after is sheer stupidity; e.g. technology...
  26. R

    Undergrad Research in Cold Fusion & Experiments: US Programs

    Does anyone happen to know any undergrad research programs in the U.S. that deal with cold fusion and related experiments?
  27. mishima

    Why Use Impulse in Experiments?

    Is impulse only really used in real life because of the instruments you might have? I'm having trouble understanding why this idea is a useful physical construct. The best I found is that just like work can be thought of as a "transfer mechanism" of energy, impulse is the "transfer mechanism"...
  28. A

    On Thought Experiments: Question

    Hello friends, I woke up this morning with a thought that would not leave me alone. I have been thinking about it and it could be my lack of conceptual understanding of thought experiments and perhaps even quantum physics, but here it is: what is the importance of thought experiments...
  29. A

    Designing an Airtrack for Mechanical Experiments: How to Get Started

    Hello, Could anyone help me understand what I am doing here. This is NOT a homework question. I am a mechanical engineer in my final year at uni, and my project is to design and build an airtrack for a range of undergraduate mechanical experiments. Im sure many of you have seen videos of...
  30. M

    Ref for single electron double slit experiments

    Hi there, Single electron realizations of the double slit experiment is always mentioned as one of the standards 'proofs' of particle/wave duality, along with a series of pictures with single dots appearing in an interference pattern. Has anyone ever made the experiment with single...
  31. X

    Are there any books describing only experiments?

    Hello, I was wondering if there are any good recommendable physics books out there of which the main goal is to describe performed experiments and their results. I'm mainly interested in quantum mechanics right now but other fields such as general and special relativity are very welcome as well...
  32. E

    How experiments end and scientists move on

    I was discussing my REU applications with a professor of mine and he picked out a number of experiments, I won't name which, that he said I should be weary of. I was a little confused by his selections, so I asked him what was wrong with the particular experiments. They were all very respectable...
  33. L

    Laser for optics experiments

    I'm looking for a good laser for optic experiments. All the professional papers I've read show the use of a 351nm Argon Ion laser. A new 30 mW one of these is about $6,000, but I see used ones pop up on Ebay from time to to time. My question is, is there a difference between this laser used...
  34. S

    The Design Of Experiments vs the design of experiments

    There are always a large number of posters in the statistics section of math forums ( - in physicsforums, but also on other math websites) who present their situation as: "I 've collected all this data, how how do I analyze it?". These posts are not a random sampling of the population of...
  35. R

    The QED experiments Feynman describes in his Auckland lectures on Vega website

    Hi all, I am looking for some more information about the experiments that Feynman describes during the lectures that he gave in Auckland which can be viewed on the vega science trust website. The first experiment is where photons are transmitted or reflected by one surface with a second similar...
  36. H

    Bell inequality experiments and photon polarisation issue

    I am confused by the role of photon polarisation in Bell inequality experiments. The original logic of EPR as I understand it is based on the HUP such that QM predicts that measurement of momentum on one particle should affect the measurement of position of the other particle. Yet across...
  37. H

    Trying to gain a better understanding of laboratory experiments

    I'm not nearly as good at laboratory work as I'd like to be. I'm therefore searching for a book (or books) that describe, at an introductory level, the following topics: - Methods of using computer code to interface with hardware (e.g. using GPIB/IEEE addresses to extract information from...
  38. B

    Experiments that try to contradict theories (but proved them)

    Hey, I'm looking for examples of Experiments by physicists who tried to prove a theory wrong, but ended up with results that agree with theory. I'm not talking about experiments that were done on a widely accepted theory. for example, Robert Milikan's experiment of the photoelectric...
  39. G

    Bell's Experiments & Hidden Variables

    Hello everyone, I was reading about Bell's theorem on Wikipedia. One thing I found particularly interesting: In particular number 2. The points he made can be found at http://bayes.wustl.edu/etj/articles/cmystery.pdf . While I did not understand all the steps from Bell's Theorem, I think...
  40. Telemachus

    Thermal radiation experiments

    Hi there. Here is the deal. In my lab work, I've done experiments concerning on heat conduction. Now my professor had corrected my inform, and asked me a question for which I have no answer. I consulted for my work the book "heat conduction in solids" by H.S. Carslaw. The book says at the...
  41. V

    Experiments in quantum entanglement

    Two or three years ago there was an interview in a science journal with a physicist who had worked on the large hadron collider. The interviewer asked what he wanted to do next,and he replied that he'd like to do some experiments in quantum entanglement but had no funding. Apparently donations...
  42. S

    Why Am I Not Getting Bands in My Western Blot Experiments?

    Hi Forum, I have been working with Western blot for a while now. I got beautiful results in the beginning when I started the experiment. Now I am stuck with three more antibodies, which I have been trying for the last 5 months, and not getting any result. I could not get any band at all...
  43. Avatrin

    History Experiments and history of phyics

    Hi To gain a more intuitive understanding of physics, I want to learn about the experiments that led to the formulations of the theories. What books can you guys recommend?
  44. D

    Experiments supporting Newton's gravitational theory

    Apart from Cavendish two lead attracting spheres experiment are there any other experiments (done in lab scale) that support Newton's gravitational theory? Dose scanning prop instruments (AFM, STM) suffers from drift due to gravitational attractions between the instrument mass (not the tip...
  45. S

    Identifying Metal from Photoelectric Effect Experiments

    Homework Statement In a photoelectric effect experiment, 200.0 nm light was applied to a metal surface causing release of electrons. It was determined that a minimum 1.90V opposing electric potential was required to prevent the released electrons from striking the collection electrode. Based...
  46. B

    Mechanics of Stern-Gerlach Experiments Question.

    In an SGY-SGZ experiment, where the magnetic field were placed along the y and z axis, we could write the equation: http://bit.ly/pSN1u2 for state of spin +Y, +Z, -Z respectively with the prob amplitudes a and b. take the bra \left\langle +Z\right| to the eq: http://bit.ly/qugX1b...
  47. A

    Under what conditions will wave functions collapse in double slit experiments?

    1. Will wave functions collapse in a photon double-slit experiment after we place a detector at one of its slits and detect one photon? 2. Will wave functions collapse in a photon double-slit experiment after we detect a photon on the screen? 3. Will wave functions collapse in an electron...
  48. M

    LHC Experiments Challenge Speed of Light: 22nd Sept News

    "Speed-of-light experiments yield baffling result at LHC" - 22nd Sept News Article?! http://www.bbc.co.uk/news/science-environment-15017484 Came here to get some further information and I can't find a thread. If there already is one about this, sorry I should delete it. Very interesting...
  49. M

    Old experiments with superluminal speed

    Hey guys, I'm just wondering what the general opinion is of these two articles: http://www.electrogravityphysics.com/html/speed_of_light.html http://www.telegraph.co.uk/science/science-news/3303699/We-have-broken-speed-of-light.html It seems strange to me that if these two...
  50. M

    Exploring Proton Decay and HyperKamiokande Experiments

    I am not quite sure wheather this is the appropriate section. (since the question is about an experiment). I wondered about the following -when the Kamiokande-colaboration is going to release new results on proton decay bounds- since their last new bounds where in 2009 (Judging from their...
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