Experimental Definition and 527 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. A

    Thermodynamics : Only experimental?

    Ok I read in a book that thermodynamics is an experimental science. What exactly does experimental science mean? Also does computational science come under experimental science or as an alternative to it?
  2. R

    Experimental Evidence of Quantum Gravity?

    The proportionality constant of big G (like Planck's constant) seems to suggest that gravity is a quantized 'thing'... does anyone know of any experiments (perhaps with a Watt or torsion balance) that show evidence of this?
  3. V

    Idea for experimental test of LQG

    Hello! Long time peeker, first time poster. I recently made a GR joke/brainteaser on a pop sci blog I frequent, and the tirade of nutty reactions it provoked drove me to an agitated contemplation of the matter, which gave rise to a few ideas. I was thinking that maybe a Gallileo type...
  4. A

    Calculating acceleration using Experimental equation

    Homework Statement Determine the y intercept and slope of the linearization equation of the graph. Find an experimental equation. From this and the theoretical equation given in the introduction, determine the acceleration on the object. Context: I recorded data for the distance vs velocity...
  5. A

    Finding a Function from Experimental Data

    I've been given a set of data from an experiment: x= 0, 1, 2, 5, 7, 10 Y=(3), (5), (8,7), (25,4) (40), (66,2) My mission is to come up with a function that i can use, based on these values I've been given. I've tride to LN the values so I get a straight line (Y=kx...
  6. Q

    What Is the Uncertainty in the Gradient of My Linear Graph?

    hi, just a simple question i have a linear graph y=mx+c lets say my y values have an uncertainty of ±1 . my x values don't have uncertainties. so what will my gradient's uncertainty be? PS: can i just use the linear least square fit function from microsoft excel? do they calculate...
  7. A

    Computational and Experimental Work

    Both computational and experimental physicists' jobs are to match the results proposed by the theory. Can someone explain to me how the computational physicist studies nature? (ie does physics)? Also in subjects such as computational particle physics, the only reason we need models is because...
  8. S

    Physics Career Advice needed for desperate Phd student in experimental physics

    Hello all, I am a new member here and am currently doing my PhD in nanoscience related area. My husband is a successful phd and currently in academia. I joined phd right after my masters, and hence have no industry experience. However, I am keen to enter industry after I graduate...
  9. Physics Monkey

    Good discussion of experimental data/techniques?

    Hi all, I'm looking for books or papers that give a pedagogically clear and reasonably up-to-date discussion of various experimental techniques in condensed matter physics. For example, ARPES, STM, NMR, muSR, ... As I suspect may be true for many theorists, I learned what I know of...
  10. S

    Physics Experimental or theoretical physics?

    I am currently a high school student who is very interested in all of science in general, but physics in particular is most intriguing to me. While perusing possible careers in physics, I have found that most are split into either experimental or theoretical. I was wondering if you would care to...
  11. X

    Particle Lifetime in Gravity: Experimental Evidence?

    Hello, I was wondering if the particle lifetimes as measured by observers increases in gravitational heavier areas. Relativity seems to suggest this, and there seems to be little criticism of this concept but I couldn't find any experimental evidence supporting this. Has this ever been shown? Or...
  12. A

    Theoretical vs Experimental physics

    whats the big difference to between a theoretical physicists and a experimental physicist? do they have or need different skills? would it be possible to become both?
  13. D

    Calculating the error of a experimental results

    hello everyone, I've completed a experiment regarding torsional oscillations to determin the tortional ridgity in two types of wire. The final result is about what is to be expected but I am having trouble in calculating the error in my C " torsional ridigity" value. The formula used is...
  14. A

    How can you measure the volume of a floating irregular object?

    Homework Statement How does one experimentally measure an irregular object's volume given that said object floats on water? The Attempt at a Solution It seems to me that the simplest solution to this is to submerge the whole object by pressing down on it to the point that only the object...
  15. S

    Engineering Whats the difference between an engineer and experimental physicist?

    Apart from the obvious that one has a PHD and spent more time in school. When it comes to skillsets and capabilities, can one do more than the other? What about an engineer with a phd? Perhaps my idea of what a physicist does is that they just do very abstract work, can an...
  16. X

    Has there been experimental evidence for neutrinos being affected by gravity?

    Hello, I was wondering if there was any experimental or observational evidence for neutrinos being affected by gravity. Be it through detected lensing or other means. All I could find were some papers on lensing none of which seemed to have actual results out of the error margin.
  17. S

    Calculating Ksp of Ag2CrO4 from Experimental Data

    Homework Statement Hi, I need to calculate the Ksp of Ag2CrO4 based on experimental data. During the experiment, 1.25g of pure copper was placed in a 1.00 L solution of silver chromate. When the copper was extracted, only 1.24g remained. Balanced chemical equation: Cu + Ag2CrO4 -->...
  18. X

    Experimental confirmation of indistinguishability of identical particles?

    Does the experiment confirming Bose Einstein condensation prove that identical particles are indistinguishable? How does that reconcile conceptually with Maxwell distribution to which Bose Einstein distribution converts? Is this a result of the strength of interaction among the identical...
  19. O

    What are some experimental errors associated with spectrophotommetry?

    This isn't an actual calculation homework problem I'm having but rather a lab discussion. I'm trying to find experimental errors of the experiment where you determine an equilibrium constant using spectrophotometry. The reaction is: Fe 3+ + SCN - = FeSCN 2+ we used Fe(NO3)3 - iron (3)...
  20. StevieTNZ

    Experimental Results vs Predictions

    So this has been on my mind: When an experiment is performed and results gathered/calculated etc and checked against theoretical predictions: * when you take into account random errors and * when you take into account systematic errors, and the result is within the one predicted, are you...
  21. N

    U Physics 12E 7.71 Conservation of Energy: An experimental apparatus with mass

    The question is shown below the --- or this question and answerbook is from U Physics 12E #7.71. I uploaded a JPG that can be seen at http://i43.tinypic.com/35j9jja.jpg I don't understand this problem. I see that to solve this Conservation of Energy and N2L are merged using x, and that h from...
  22. S

    Engineering Experimental physics or engineering (of some kind)

    Im a junior getting a BS in physics, and I am in the "what do I want to do with my life" phase of my college undergrad career. currently I am stuck between deciding between continuing physics, getting a PhD and focusing on experimental physics, or getting my BS and post bacc plus masters in...
  23. L

    Schools Safety grad school for experimental particle physics

    I'm a senior undergrad and will be applying to grad school soon. The field I'm interested in is experimental high-energy physics. There are already about six schools I'm looking at applying to, but I'm wondering if anyone has any advice about possible safety schools. My overall GPA is about...
  24. M

    Photoelectric effect - experimental

    Photoelectric effect -- experimental Homework Statement Suppose you are doing an experiment to determine the work function of a metal.* You get k.e.$_1$, $\nu_1$ and k.e.$_2, \nu_2$. * We know that k.e.= $h\nu - W$ but when you solve the simultaneous equations, we have a $h$ slightly...
  25. S

    Experimental High Energy Physicist: Daily Life & How to Use Creativity

    Hi everybody. Can you talk some about dealy life of an experimental high energy physicist who work in CERN, FERMILAB e.t.c as full time worker. What does he or she do? I think only a few people do real things. A few people prepare experiments to research and decide which variables will be used...
  26. G

    Mode shapes in experimental modal analysis

    Hi, I am doing experimental modal analysis of a cylindrical casing. I have 64 FRFs. I have curve fitted dominant modes and obtained a synthesised FRF. Now when I see the animation of mode shapes corresponding to each of the frequencies in FRF, I am finding a not-so-significant (amplitude...
  27. teroenza

    Experimental negative work function?

    Homework Statement I have experimentally determined the work function from the intercepts of a fit line in graph of stopping potential (J) versus frequency (Hz). This is from a photoelectric effect lab. The value of the intercept, which I believe is that of the work function, is returned as...
  28. L

    Canal rays experimental set up - a doubt in this

    Canal rays experimental set up -- a doubt in this Homework Statement Please go through my attachment. It has been mentioned that luminous stream of particles were observed behind the cathode. Homework Equations Behind the cathode means , Whether right of the cathode or left of the...
  29. M

    Theoretical Resistance Vs Experimental

    Homework Statement Suggest a reason why theoretical and experimental results for resistors R1 and R2 are different for: experimental R1 and R2 in series vs R1+R2 and Experimental R1 and R2 in parallel vs 1/R1+1/R2 R1=23.080 Ohms R2=41.289 Ohms Series Experimental=58.769 Ohms Series...
  30. F

    Programs Considering PhD in experimental physics and facilities

    Like many, I'm applying to graduate schools in physics this fall. My interests lie in experimental condensed matter/physical chemistry, although I think this question applies to any field. As we all know, modern science is big and expensive. I was considering some smaller schools, but was...
  31. N

    Experimental Verifications of the UPs?

    Hello, I'd differentiate between two different UPs: 1) The one talking about the standard deviation and which is in essence a statistical UP only appearing when comparing N identically prepared measurements; 2) The historical one talking about experimental errors and thus supposedly...
  32. I

    Experimental question detecting light scattering with photodiode

    Hi, so I am trying to build a cell counting apparatus using light scattering. The setup is a (green) laser shining through a clear bottle full of (Dicty) cells suspended in a stirred solution. The idea is to put a photodetector at some angle by the bottle; a greater cell density should result in...
  33. D

    Experimental determination of Stefan's constant

    Homework Statement I am using an apparatus to determine Stefan's constant using incandescent lamp and photovoltaic cell where the following formula is used. Stefan's cont = 2.43 X 10 (-4) { Vs’/ T} result in joule per sqr meter per sec per quad Kelvin. Where Vs’ = Vo +Vs in volts with Vo...
  34. Spinnor

    Is the CMK matrix a constant for all experimental energies?

    Is the CMK matrix a constant for all experimental energies that we can presently explore? Thanks for your help!
  35. S

    Experimental confirmation of electroweak?

    Can you clear something up for me? I see that the discovery of the W and Z boson in 1983 is described as confirming the electroweak unification theory. I was thinking that the W and Z were carriers of just the weak force. I don’t see how the experimental discovery of the W and Z show...
  36. D

    Experimental data on the extraction of radium/polonium?

    I'm having difficulty finding some secondary data on the extraction of radium or polonium. Nothing specific, really just any practical data available on the topic - I'm getting desperate! Historical data would be preferable, however modern data would still be great. By 'data' I just been any...
  37. Disconnected

    Experimental Evidence for Conciousness as the Fifth Force.

    So I know that "Conciousness as the Fifth Force" gets a lot of hate around here, but hear me out, this is legit. So my mother always told me "A watched kettle never boils". The other day, I found this out to be true. Every morning (okay, sometimes it's the afternoon) I wake up and put on...
  38. M

    Maximum jerk for experimental module

    Maximum "jerk" for experimental module 1. A landing module has a mass M with three springs each of stiffness k that hover over the surface (height not given). If the final touchdown velocity is to be Vtd, what is the maximum jerk (time rate change of acceleration) the module experiences given...
  39. S

    Going on to do Quantum: Astrophysics versus Experimental Physics

    I'm doing an undergraduate in astrophysics at the moment. In Sept, I'll have to decide between continuing the single honours in astrophysics or doing a double honours in experimental physics and mathematical physics. My goal is to go on to do a masters, preferably in the UK, in quantum...
  40. S

    Projectile motion experimental vs theoretical results

    in projectile motion, why the experimental results are different with theoretical result? thank you
  41. N

    Physics Life of an experimental physicist

    Whats the work life of an experimental physicist like? Hours? Pay? Activities and duties? etc. etc.
  42. C

    Heat Loss From a Closed Box - Experimental Help

    Hi everyone. I am currently carrying out an experiment whereby I have a closed tank of water submerged in a larger tank. The water in the smaller box is heated and I am interested in the heat loss from the tank. I have done a rough theoretical calculation based on U values, where by I obtain...
  43. F

    Why aren't more people excited about experimental physics?

    If I look at physics threads here, I can find hundreds of people who want to do theoretical physics but not so many want to do experimental. Why is that? Most of the beauty in physics has come through experiments, after all. I especially liked the Cavendish experiment which was an awesome...
  44. M

    Engineering Experimental Physics and Engineering

    Hello. I’m sure that this question has already has been asked, and if so, I would highly appreciate it if someone would link it to this thread. I’m torn between choosing a career of experimental physics or of engineering, and I’m wondering if there is any possibility of doing both. I have...
  45. DrChinese

    Experimental Test Limits Predictive Power Beyond Quantum Theory

    As an example of how far things have come post Bell/Aspect, here is a just announced experimental test which limits any future expectations one might have on "completing" QM: An experimental test of all theories with predictive power beyond quantum theory, Terence E. Stuart, Joshua A. Slater...
  46. P

    Experimental support of string theory?

    I'd like to hear what people have to say about the following paper, which is way beyond my level knowledge, but could be exciting(?): http://arxiv.org/abs/1104.2302
  47. A

    Where can I find experimental data

    Does anyone know where I can find experimental data on the life time of charged pion decay? More specifically the life time of a negatively charged pion decaying into either an electron and an electron neutrino or into a muon and a muon neutrino.
  48. maverick280857

    How Do Theoretical Concepts Guide the Design of Particle Physics Experiments?

    Hi, I've spent an enormous time through coursework and self-reading on learning different things in basic particle physics theory, such as scattering cross-sections, decay rates, etc. I am looking to connect the things I have learned in theory to experiments. This may seem a little vague, but...
  49. P

    Simplest Experimental Method to Determine Heat Gain from an Engine in a Room

    Homework Statement This isn't an assignment per se but rather a thought exercise proposed by a professor during class. The scenario is that you have a room where an internal combustion engine is used to run a machine. You have no information about the machines power output or efficiency...
  50. A

    Experimental Predictions from String Theories

    Can someone give me some specific experimental predictions that come from string theories--things that at least in principle could experimentally unambiguously be confirmed or disproven? Thanks.
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