Experiments Definition and 478 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. klotza

    History History's First Science Experiments - Comments

    klotza submitted a new PF Insights post History's First Science Experiments Continue reading the Original PF Insights Post.
  2. ScrollPortals

    Barrier to entry for hardware material science experiments?

    I read phys.org and science daily, daily. I read about all these amazing experiments and discoveries and I want to try my own experiments. A lot of articles are about emerging computing technologies, and often the article emphasizes how inexpensive these materials and processes are becoming. I...
  3. R

    Hobby rocket engine experiments

    I've started making my own sugar-based hobby rocket engines and I want to work on creating a de Laval nozzle for the specific fuel type and configuration I'm using. I don't have the resources to measure things like chamber pressure and exhaust temperature, so I wanted to try and develop an...
  4. Sid2100

    I Early Quantum Entanglement Experiments basic question?

    Reading about the early Quantum entanglement experiments by performed by Ernst Bleuler and H.L. Bradt and independently by R.C. Hanna in 1948, they basically used a pair of Geiger counters set around sodium22 and when an electron annihilation event occurred that produced a pair of photons the...
  5. S

    Experiments with interfacial polymerization

    I'm wanted to do an experiment with interfacial polymerization; producing nylon 6,10 with sebacoyl chloride and hexanediamine. I was wondering what aspects of this reaction I could research, or what variables I can change?
  6. S

    What are possible polymer chemistry experiments?

    I was wondering if there were any possible experiments that I can conduct in a high school lab setting.
  7. chastiell

    I About comparison to experimental reference values

    Hi again, probably this seems to be a simply question, but in last days i becomes a really strange one. We all know that there are many kinds of constants in physics, some of them, are found experimentally with great accuracy in too expensive projects, but no matter how accurate can be measured...
  8. Dadface

    I Test of Bell's Theorem: Experiments Beyond Polarization

    As I understand it most, if not all, experiments carried out to test Bells theorem test the local hidden variables assumption that photons have definite polarisations. What I would like to know is whether experiments on properties other than polarisation have been carried out. If not are there...
  9. T

    Interfacing with uCs class geared toward simple physics experiments

    Hey guys, So this is what actually made me join today. We are taking a interfacing class were most of us students don't even know how to code. However, I currently work in one of the research groups under the professor who is running the class, he gave me the assignment to figure out what parts...
  10. F

    B Speed of Light Invariant in Vacuum: Experiment Proof

    I am getting confused as to which experiment proved that the speed of light was invariant in a vacuum. At first I thought it was the Michelson-Morley experiment but that does not have a moving observer.
  11. A

    I Galilean Relativity: Can Experiments Tell Motion Relative to Other Frames?

    In Galilean Relativity, laws of mechanics are invariant across frames. In all the frames they are the same. So, in Dynamics and Relativity by W.D.McComb, it is written that this implies you cannot perform any experiment in an inertial frame that can tell whether an inertial frame is moving or...
  12. C

    In need of cool experiments for show called 'Quantum'

    Hello Everyone! My name's Christina and I work at the Everyman Theatre in Liverpool... We have a show coming up in the main space at the beginning of July that's going to be performed by YEP (Young Everyman and Playhouse)... and hopefully it's going to be a love story about all things Physics-y...
  13. Android Neox

    B Order of observations in Bell experiments

    I've been trying to find information on how Bell's experiment works on the macroscopic scale. I think that the scale of current measurements is meters, for the most part. I've been curious about how Bell's Inequality is supposed to work, Relativistically. Haven't found quite what I'm looking...
  14. G

    I Quantum experiments and entropy question

    Layman question here. I have often read that the known laws of physics, QM and Relativity, do not make a difference between past and future, they are perfectly reversible in time. The only fact which gives time its preferred arrow is the 2nd Law, the increase of entropy, which manifests in the...
  15. P

    X died of pneumonia doing experiments in the cold myths?

    Can science text writers please stop repeating these sorts of unfounded, unscientifically grounded anecdotes in science texts as if they are fact. I was just reading in Universe 8th ed. astronomy text and found this passage: "Sadly, Goodricke paid for his discoveries with his life; he caught...
  16. S

    A Asymptotic momentum eigenstates in scattering experiments

    In a typical collider experiment, two particles, generally in approximate momentum eigenstates at ##t=-\infty##, are collided with each other and we measure the probability of finding particular outgoing momentum eigenstates at ##t=\infty##. Firstly, what does it mean for the particles to be in...
  17. R

    Induction Motor Builds & Experiments: What PSU to Use?

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  18. D

    I Are Classical Design of Experiments Models Too Limited for Modern Needs?

    I need to build up knowledge about Design of Experiments and have a fundamental question about the real goal of DoE. Most classical texts start with discussing in considerable detail full factorial design plans where each factor only has two levels. The underlying statistical model is...
  19. K

    Interesting mechanics experiments

    Hello! I am new to this forum so I don't know if I am posting this under the right part. Anyway, I am an undergrad and my phys 101 mechanics course requires to come up with an experiment related to the course content, write a report on it and present it to TAs. I decided on a simple pendulum...
  20. I

    B Calculating c in Thought Experiments: Q&A for Physics Community

    Let's say that, for the purpose of a thought experiment, I want to use the following as a calculation of the speed of light. Assume the following scene is an inertial, non-accelerated frame. 1. I have two clocks, A and B, which start out one millimeter from each other, and are perfectly...
  21. A

    MHB Binomial Experiments: Find Probability of x=5, x>=6, x<4

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  22. H

    I Software Designs Quantum Experiments

    Anton Zeilinger of the University of Vienna was trying to design experiments to produce certain quantum states and wasn't having much luck doing it. "I realized I was just guessing," he said. So why not have a program do that guessing. It can try a million guesses. So he did. While the...
  23. RoboNerd

    Question on theory for solving 2015 AP Physics C Free Response Questions

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  24. B

    Thought experiments about Gravitational Waves

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  25. A. Neumaier

    Are tracks in collision experiments proof of particles?

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  26. Shreyas Shree

    Physics experiments for undergraduates

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  27. T

    Exploring Quantum Mechanics Through Experiments

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  28. ontodva

    What prior experiments justified the notion of entanglement?

    In 1935 Albert Einstein, Boris Podolsky, Nathan Rosen, and Erwin Schrödinger introduced the notion of quantum entanglement. What prompted that notion and what justified their belief it was a real phenomenon?
  29. W

    Very precise Michelson-Morley experiments

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  30. S

    Exploring Weight Measurements in Water Experiments

    Homework Statement I place a water filled beaker on an electronic balance and zero the reading. Meaning the balance will not be measuring the weight of the water and the beaker. a.) If a ball is resting at the bottom of the beaker. What would the balance be measuring? b.) If I immersed and...
  31. P

    What experiments should I choose for my third year Physics degree?

    I have just entered the 3rd year of a Physics degree and I am required to choose four experiments from the following for the practical laboratory. Ive had a decent look into subject area each experiment embodies but I feel I don't have a good jist of how they really are, and I know I don't...
  32. F

    Design of Experiments Ideas - Control Systems?

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  33. W

    Probability and Random Experiments

    Homework Statement Problem Consider a random experiment with a sample space S={1,2,3,⋯}. Suppose that we know: P(k) = P({k}) = c/(3^k) , for k=1,2,⋯, where c is a constant number. Find c. Find P({2,4,6}). Find P({3,4,5,⋯}) I am primarily interested in part 1, finding C. The rest...
  34. D

    How to count coordination number in experiments?

    We all know the coordination number is an important characteristic of a system consisting of many particles. But in experiments,except CT,do we have any easier and cheaper way to know it? Thanks for help.
  35. Boro Petrovic

    Are time dilation experiments conclusive?

    Before posting reply, please think about time as a concept that is used to describe a change relative to some other change. For example, a traveler will arrive on a destination after Earth completes x rotations. At the beginning, people used Earth rotation as a reference change and called it a...
  36. B

    Continuing my experimentation with bismuth

    The more i study this strange element, the more interesting it becomes. I found that bismuth only shows it's colorful oxides when exposed to air while hot/molten. I decided to go outside and polish the sample using an abrasive liquid known in Brazil as "Saponáceo Cremoso". Don't know what it's...
  37. micromass

    At Home Experiments to Prove Scientific Facts

    The idea of this thread is to make a kind of collection of experiments of important scientific facts that you can do at home. Many students in high school are quite frustrated with science, because they see it as a collection of facts to memorize. The purpose of this thread is to show how many...
  38. J

    2 simple special relativity thought experiments

    Hi. I'm learning about special relativity and want to see whether I understand it correctly. As such, I had 2 thought experiments that I answered, and I want to see whether these answers are correct. If not, could someone please tell me the correct answers? Thanks! Thought Experiment 1: Super...
  39. N

    Quantum physics experiments for EEI

    (Hope this is the right forum) For my year 12 physics EEI (extended experimental investigation) basically a report. I was hoping to find a suitable quantum mechanics experiment that i could conduct. Does anyone know of an experiment like this? Thanks in advance
  40. U

    Experiments to distinguish 3-body and 2-body decays?

    I was wondering are there any experiments to distinguish between 2 and 3-body decays? For example, consider decay of the muon and the pion: The pion only emits 1 muon neutrino ("missing energy") and 1 muon. The muon however, emits 1 muon neutrino, 1 electron neutrino and 1 electron. How is...
  41. D

    Measuring Electron Recoil from Photon Emission: Experiments & Methods

    Has electron recoil due to photon emission ever been confirmed by experiment? cause I can't find any reference to electron recoil being measured anywhere I look. If it has been measured, what methods do they use?
  42. C

    Other Want to know how experiments were performed through history

    Hi, I'm so hungrey for learning about the history of physics and chemeistry and learning how the experiments werer performed throughout history (The actualy experimental setup, and how the equations were derived). Are there any good boks to be recommended? There must be some books that actually...
  43. davidbenari

    Questions on the Urey-Miller experiments (OrgMol. formation)

    My knowledge of Earth science is basically null so please bear with me.My first question relates to the soundness of assuming a primitive atmosphere rich with H2O CH4 NH3 and H2 gases (Also not too much presence of O2, as the Urey-Miller atmosphere has to be a "reducing atmosphere"). The...
  44. A

    Understanding Quantum Eraser Experiments

    I would like to start a discussion about the most basic principles behind quantum eraser experiments. I understand this has been debated here many, many times and for some of you there is nothing to talk about, but I still find it interesting and would like to get some of your opinions. I know...
  45. P

    Rotational motion thought experiments

    So say we have a stick in space with the CM in the middle and we apply two forces of equal magnitude and direction over the same time, one force at the CM, and the other at some distance away from the CM. Ideas: 1. One would obtain just translational motion the other would have both...
  46. S

    Diffraction effects in slit experiments

    In double slit experiment with a single source,I am finding the traces of one slit when I have the other one open. I think this is due to diffraction effects.May I know how to tackle this?
  47. itssilva

    Supersymmetry: Theory and Experiments

    Supersimmetry, by itself, is a neat, elegant concept; I've read somewhere else (think Griffiths' Introduction to Elementary Particles, if memory serves me right) that it allows the various running couplings of the Standard Model to converge to a single value at high enough energies; however...
  48. K

    MHB Do independent experiments add to probability?

    There are two categories of objects, A and B. From long term observation, experiment 1 is known to be 70% accurate i.e. it predicts type A or B correctly in 70% of cases. Experiment 2 is totally independent. It uses different methods and different characteristics. It is also known to predict...
  49. Rodrigo Cesar

    Delayed Erasure follow-up experiments

    does the double slit experiment with the Delayed Erasure follow-up experiments prove that objective reality does not exist ? How is it possible to detect the particle without affecting it? My understanding up until now has been that the results differ with/without a measurement because the...
  50. W

    Thomson and Rutherford's experiments

    Homework Statement If Thomson's "plum pudding" model was correct, what could have happened when Rutherford fired high energy alpha particles at gold foil?Select all that are True. Alpha particles are reflected. Alpha particles pass right through with no deflection. Alpha particles...
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