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. L Drago

    B Heisenberg uncertainty principle -- Questions about a practical experiment

    Please review this experiment I watched from a video in YouTube and I think is correct. If there are flaws or there is a better experiment of proving this principle, kindly tell me.
  2. S

    Question about Rutherford experiment: Which of these could not be concluded?

    I don't think there is correct answer for this question. This is my reasoning: A) This is correct since most of alpha particles move in straight line B) This is correct since the deflection of some alpha particles is away from center point C) This is correct because a small number of alpha...
  3. V

    I Has superdeterminism been proven recently?

    Recently stumbled across [Unacceptable reference deleted by the Mentors] and the abstract says that an experiment that spanned 2000-2012 has proven that physics is superdeterministic. I have absolutely no background in quantum physics whatsoever which is why I can't verify or reject the claim...
  4. N

    I Special relativity & Synchronization of clocks

    Lets consider the following experiment: A-------CD-------B where C and D are synchronized clocks (same position), while A and B are two points at the "same distance" from CD. We move the clock C to A and take a photo Pa when it reaches A. We move the clock D to B and take a photo Pb when it...
  5. Agent Smith

    B Does average mean something like "as expected"?

    A conducts an experiment. I don't know how to describe this experiment, but let's say he measures the masses of ##3## things and computes their sum. He finds that the mean mass equals ##2## units of mass. He considers this to be special in some sort of way, something that demands an explanation...
  6. LightPhoton

    A QED and photon path experiments

    I was reading Optics by Hecht where he states that the law of reflection is only valid statistically and some photons might reach the observation point (P in image, S being the source) by following different paths, that is, the paths for which the angle of reflection is not equal to the angle of...
  7. D

    I How to Confirm the R-Value of a Piece of Insulation?

    I'm getting ready to winterize my home and was browsing the insulation aisle at Home Depot. They have a wide variety of insulating products from which to choose: soft foam, rigid foam, batts, etc. I got thinking it might be an interesting at-home experiment to confirm the R-values of some of...
  8. Nabir14

    What is this clay and rubberish metarial?

    I was feeling very bored so I wanted to play with my surroundings and I had: Crafting glue: And Rubber Dust: Near me so I (for some reason) mixed them together and rubbed them on my hand. After some time it started to take a spherical shape. It lost the stickiness of glue and started acting...
  9. no_onepotter

    Physics Experimental or Theoretical Physics in my PhD?

    Hi, I start my PhD education, actually offically it was one and a half month. And ı didn't decide to choose to experiment or theoric. Maybe, if you know or study this field,help me to decide. What is this two field advantages in STEM? If ı choose theoric, ı can find a job? Thanks for your answer...
  10. Q

    I Could Quantum Dots Between Optic Fibers Create Photon Interference?

    A quantum dot is placed in a line between two optic fibers The dot can emit a photon in every direction which is unknown. If the fibers are combined at a beamsplitter would there be interference if the photon is not observed outside the fibers? Do you know if somebody made such experiment...
  11. billtodd

    I Experiments to check for extra dimensions

    Suppose we want to verify that there are curled-up dimensions. What sort of experiments can you devise to check for them? I mean what sort of experimental data are we looking for? (I guess it would be in high-speed particles' accelerators, but sure there are also cosmological observations that...
  12. K

    I Question about microwave reflections

    Hello! I have an experimental setup in which I need to send microwaves (MW). I would like to reduce the unwanted scattering of the MW as much as possible and I was wondering what materials are best for this (in vacuum). For example, if I make some holders of metal (e.g. aluminum or steel) I...
  13. L

    Evaluation of an experiment: PET scans of a small source along the x-axis

    Hi, I did a PET scan and positioned a sample almost in the center of a moving carriage, taking measurements along the x-axis and measuring the counts. Each measurement took 60 seconds, and I took a total of 27 measurements. Here are my results As the display was in mm, I always assumed an...
  14. neilparker62

    Reaction Rate experiment: Potassium Permanganate and Hydrogen Peroxide

    I am picking up on an old thread having revisited the associated experiment. https://www.physicsforums.com/threads/reaction-of-potassium-permanganate-and-hydrogen-peroxide-solution.992713/ 10ml of Permanganate solution (0.0135 mol/liter) were reacted with 10ml of Peroxide and 10ml of vinegar...
  15. B

    I Quantum Eraser Experiment at home

    I was tryingt to find away to build a setup for conducting the quantum erase experiment, demonstrating the observer effect. It seemed impossible without expensive equipment for sending single photont and detecting single photons, then however I bumbed into this guide from scientific american...
  16. L

    Mathematica Plot normal distribution with measurement results

    Hi, I have completed an experiment at university as part of my internship and have now received several measurement results which I would like to analyze statistically and plot the results as a normal distribution in Mathematica. Is this even possible with Mathematica? Unfortunately, I haven't...
  17. S

    Experimenting whether the diameter of a pot affects boiling time for water

    Hey guys, I'll try to be as direct as possible. So for school i'm doing an experiment at home trying to find out if the diameter of a pot affects the time it takes to boil water inside the pot as it says in the title. I had three different pots with three different diameters. I got half a liter...
  18. G

    I Coordinate Transformation versus Change of Synchrony Convention

    Rather than adding to this already long thread, I chose to start a new thread. Thought Experiment In this post, s is distance, t1, is the time of transmission, t2 is the time of reflection and t3 is the time of reception. All cases assume an orthogonal coordinate system. Case 1: From a God's...
  19. B

    I Experiment distinguishes Standard QM vs Bohm: Asymmetric beam splitter

    Background I was reading a paper, Delayed Choice Experiments and the Bohm Approach by Basil Hiley and Robert Callaghan. The Wheeler's Delayed Choice experiment was explained in a way that was very easy to understand. An interesting point in this paper is that when a Mach–Zehnder interferometer...
  20. Orodruin

    Insights The Slinky Drop Experiment Analysed

    Continue reading...
  21. M

    B The inclined plane paradox (proved)

    Hello, I invite you to watch this video. This is a simple experiment, which has never been carried out and which proves that momentum can undergo a 'repartition'... The Beauty of Momentum What do you think of this phenomenon ? What conclusion can we draw from this? Thanks a lot for your answers.
  22. M

    I Experiment on the variation of weight with temperature

    Hello ! According to what I have read on the internet, the weight of a body varies with temperature, its mass remaining unchanged according to the theory of relativity. My question is what experiment is done to corroborate that the weight of a body increases with the increase in its...
  23. C

    I Have You Heard of the SEW Experiment? Thoughts?

    The SEW Experiment, named after its authors, Marian 0. Scully, Berthold-Georg Englert &Herbert Walther, was published in 1991 under the title, "Quantum optical tests of complementarity," and can be found here: https://www.nature.com/articles/351111a0.pdf They built atom interferometers with...
  24. C

    I How To Experimentally Confirm the Wigner-Von Neumann Interpretation

    Consider a simple quantum eraser setup using polarizers: An incident beam polarized at 45º is sent towards a double slit. After slit A there is a horizontal polarizer and after slit B there is a vertical polarizer. At the back screen, if we run this experiment, we will see a particle pattern and...
  25. P

    Modelling the voltage measured across a dc motor

    Hi there, I have done an experiment measuring the voltage across the terminals of a dc motor, whilst running and then by holding it with my fingers to stop it. Done as demo for my high school class. The voltage reading was higher when the motor was running, which was against my expectations as...
  26. P

    How should this Beam Loading experiment be designed?

    The question and my attempt at a solution are attached. Thanks.
  27. Steve Rogers

    A water-bottle demonstration of atmospheric pressure

    I'd like to ask about an experiment on atmospheric pressure. To conduct the experiment, we need an empty PET bottle and make a small cut on the lower part of the bottle. A cut no greater than one-half the circumference is acceptable. Then, we press a table tennis ball against the cut to open the...
  28. S

    I Calculation of temperature changes (heating a cube in a microwave oven)

    Hello guys, I am currently running an experiment in my hobby room: I want to heat a cube in a microwave and then measure the surface temperature. Unfortunately, it takes about 20 seconds, so the cube cools down during this time which means I don't measure the actual temperature after heating...
  29. srnixo

    Understanding Time Measurement in Physics: Uncertainty and Calculations

    So as you can see in the image, I have noted the time in the [time column (s) ] on the table after conducting the experiment at home using the application phyphox. And now, I have some questions to fill in the remaining gaps: The first question: about ΔH (m) : Should I set it equal to zero...
  30. J

    B Question about double-slit experiment

    s
  31. J

    I How to improve the accuracy of Young's double slit experiment?

    My teacher asked me to find the separation of a double slit by finding the distance between fringes. I wonder how I can reduce the experiment error. So what can I do?
  32. R

    I Advice regarding sled experiment

    Hello. I would like to design an experiment where different sled designs are compared. Specifically, I would like to asses how sled design affects the amount of force required to pull a sled over 100 meters. Any suggestions you might have would be greatly appreciated.
  33. SCHROEDERFPM

    I What is the ideal fluid and setup for observing Magnetohydrodynamics?

    I have been reading about Magnetohydrodynamics and would like a bit of insight from anyone who has any knowledge on the subject. If I understand correctly when a conductive fluid is in motion it produces an electric field, and motion can be generated using a few methods one of which is a...
  34. mahdis

    Flow rate experiment not producing same results as the Hagen-Poiseuille law?

    I have repeated the experiment several times and it always shows my longer length has the fastest flow rate. the same results occur when I apply 300mmH pressure to the fluid bag on top, the flow rate is still faster in the longer pipe
  35. Sciencemaster

    Misc. DIY Experiment of Special Relativistic Effects?

    I'd like to perform an experiment that will build intuition for Special Relativity in the real world. While I do believe that it occurs in the real world, I'd like to be able to prove it for myself, and I feel that such an experiment would help others on this forum as well. Is there an...
  36. S

    I Question about an interesting experiment video (two magnetic balls in tubes)

    In this video... https://www.physicsforums.com/media/magic-magnetic-balls-defy-physics.6951/ ... a pair of magnetic balls in two vertical tubes, roll upwards when the tubes are rotated, irrespective of the direction you rotate them in. A couple of questions... [1] Say the tubes are mounted...
  37. James_AA

    I Laser and nano-holes experiment

    Hi everyone, let me propose an experiment to see if you agree with my points. There is a 1cm2 1-micron thick aluminum substrate with a matrix of 100x100 nano-holes each with 100x100nanometers cross section separated by 100nanometers. Then, we focus a 1W laser with visible wavelength: 1-...
  38. A

    I How Can I Design an Experiment to Ensure Simultaneous Light Arrival?

    I want to construct an experiment similar to that described by Einstein in his thought experiment: https://en.wikisource.org/wiki/Relativity:_The_Special_and_General_Theory/Part_I#Section_9_-_The_Relativity_of_Simultaneity How would I design it to ensure the light from the flashes at the back...
  39. T

    I Quantum behavior experiment flawed?

    I would like to discuss this experiment, could it be flawed?: http://people.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf Let's start here with another setup: In the video it's shown that the field is continuous and splits 50/50 at the beam splitter, no matter how much it's attenuated. Also...
  40. PhysicsRock

    Estimating Error in Wavelength from Graphical Approach

    As part of my studies, I'm obliged to take an experimental course at the moment, where I have to conduct experiments and write a composition. Today we examined spectral lines of helium with a prism. As part of the evaluation, I had to plot the measured diffraction angles of different colors /...
  41. V

    Verification of ideal gas law experiment

    TL;DR Summary: I measured the mass of CO2. Can someone verify my calculations? I took a soda bottle and filled it with Carbon Dioxide then weighted its mass as I changed pressures. My figures get very close (5-10%) within the calculated values for psig but not psi-absolute. Can someone confirm...
  42. K

    I How experimentally robust is Giant Dipole Resonance in 88Be?

    I saw this paper, Observation of the X17 anomaly in the decay of the Giant Dipole Resonance of 88Be 2308.06473 I would like to know how robust and how established is experiments involving on Giant Dipole Resonance How easy would another research team to use on Giant Dipole Resonance...
  43. gxa

    Real Experiment-MCBEND Simulation

    Do I need to apply normalization these two graphs to make them similar to each other and if so, how can I do this? I would be very grateful if you can help me if these results are consistent. I compared the results of the experiment and the results of the mcbend simulation.
  44. Entropix

    I Hydrogen balloon experiment -- How high can it rise?

    If we launch a hydrogen balloon from the Earth surface (let's say it has a 2 meter radius) and assuming it's strong enough so it doesn't pop/disintegrate (it's made out of carbon nano-tubes). Where this balloon will stop? I'm more interested in the exact altitude it reaches or if it will keep...
  45. Salmone

    How is an autocorrelation function computed? (Dynamic Light Scattering)

    In an experiment of Dynamic Light Scattering, how is an autocorrelation like the one in the image computed? Mathematically a correlation function can be written as ##G(\tau)=\langle I(t)I(t+\tau) \rangle##, in an experiment like the one I mentioned the scattered intensity light is collected by...
  46. M

    Instrumentation Amplifier for Wheatstone Bridge Output

    I am going to do some experiment on mechanical mechanism , studying stresses Thing that in my mind Arduino Strain gauge Instrumentation amplifier I want to know that which Instrumentation amplifier i should use to get good output voltage from wheatstone bridge circuit and also easy to use...
  47. new_scientist

    I Is the energy destroyed in this experiment?

    Suppose you stand on a spherical permanent magnet in space and you hold an iron ball in your hand, you can neglect the gravity force by this magnet mass. You stand and throw the iron ball upwards with some kinetic energy, the ball will eventually stops at some height because it is attracted by...
  48. Q

    Physics IA: Distance B/w Pendulum & Alum. Block, Finding Damping Coefficient

    TL;DR Summary: I am doing an experiment for my Physics IA and don't know the theory behind it I am working on a Physics experiment for my school where I vary the distance between a simple pendulum and an aluminium block, and get the damping coefficient for each distance. Below are the images...
  49. M

    What are some fun permanent magnet experiments for kids?

    Howdy. My kids and I like to experiment with things, we're looking to play around with some permanent magnet experiments and when I googled a question it brought me here, so I figured, heck, might be able to get my questions answered as well :)
  50. Grelbr42

    I The Potential of Back-to-Back Photons: an Experiment

    In some cases, photons can be produced in "back to back" (BTB) conditions. For example, electron-positron annihilation produces two photons, each at 0.511 MeV, with equal and opposite momentum. Or pretty close, up to the original velocities of the electron and positron. Start with a source of...
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