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.
As a result of various searches on the Net, I have ended up here on this fantastic site. Specifically, it was an old 2008 thread in which was closed, so in order for me to expand on such discussion I've decided to make my own thread; by which I will go a slightly different direction with...
HI all
How can Michelson itself predicted contraction of length and Einstein about constancy of light from negative result of MM experiment.
forget about existence of ether, light speed always same in moving frame of reference and importantly in any direction so how can one except shift in...
https://www.osapublishing.org/optica/fulltext.cfm?uri=optica-2-7-611&id=321243
"In our experimental test, we used light whose statistical behavior (field second-order statistics) is indistinguishable from classical, viz., the light from a broadband laser diode operating below threshold. Our...
Homework Statement
A student designs an experiment to measure how electrically charged a plastic rod is. She knows a charged rod will deflect a stream of water from a tap.
The student plans to measure the angle of defection of the water stream when she brings the rod towards it.
She expects...
In Young’s double slit experiment, if we use a single electron, then the electron-wave would divide itself into two wavelets due to two narrow slits. Similarly would the electron-matter divide itself in that experiment? If it would not, then through one slit, both the electron-wave and...
In afshar's experiment, it shows that the single photon goes through only one of the slits and produces an interference pattern. How is this possible?
In this experiment, do we really know which slit the photon went through?
< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >
Hey,
So I am not sure if this is in the right section but feel free to move it.
We are conducting an experiment at school at the moment and are having difficulty understanding all the theory...
Homework Statement
A sheet of mica ( approximate 6-7 µm) covers one slit
of a double-slit apparatus and has a n= 1.582. There is a central maximum of 539 nm. What is the exact thickness of the sheet of mica?
Homework EquationsThe Attempt at a Solution
I think you can solve this with the...
I've been reading some cursory stuff about quantum mechanics, and I want to understand it better - so I have a little thought experiment that I'm curious about.
Let's say there are two rooms that are connected by a thin wall with no window. A person is told to stand in one of the rooms for a...
I was wondering if the double slit experiment had been conducted in space away from interference from Earth's magnetic core/field. I know the scientific community would have considered all variables and would have set proper controls for this experiment but I am unable to find any notes on this...
Hi, I'm wondering how much prior knowledge I would need to get a lot out of this book. I'm considering taking an undergraduate General Relativity course next semester to help me learn parts of this book. I have some basic experience with curvilinear coords/tensor analysis along with a brief...
Hi,
I have been performing an experiment to determine whether there is any correlation between pH and the rate of electrolysis. I have performed it using monobasic, dibasic and tribasic acids of constant concentration. However, I can't seem to find any correlation. Is there something I should...
Dear PF forum,
I have a problem with Train experiment.
Perhaps someone can take a look at it and tell me where did I go wrong?
V = 0.6c;
Gamma = 1.25
Train length = 1500
Platform length = 1200, so the light can reach the observer at the same time.
I draw the space diagram for that problem...
Has the double slit experiment ever been performed with an adjacent reflection? With quantum weirdness I'm curious as to whether the reflection would give the same results as the actual apparatus as to which slit the particle wen through.
WARNING. I'm not a physicist! If there was a universe that only had 10000 photons and we observed all of them then ran the double slit experiment would we get a normal pattern or an interference pattern? If we observe a particle is that it forever in the universe that we happen to be running...
The experiment is described at p26 of http://arxiv.org/abs/quant-ph/0402001
In this experiment we see that we sum measurement results and not measure the sum.
Is then the quantum measurement operator not :
$$S=A\otimes B\otimes\mathbb{1_{64}}-\mathbb{1_{4}}\otimes A\otimes...
The results of the double slit experiment lead to the conclusion that a photon travels as a wave. Question 1: Is it possible to track the journey of the photon? It seems to me (correct me if I'm wrong) that from the moment we release the photon till contact with the detector we don't know what...
I have thought about an experiment which to demostrate gravitomagntism: spinning massive cylinder creates gravitomagnetic field above it. Oscillating pendulum above the cylinder departs from its trajectory because of "gravito-Lorents" force.
To calculate magnetic force above the cylinder I use...
Hi guys, so I'm having a little trouble completing my physics lab report here due to not being able to find many errors to discuss about. The experiment that I conducted makes use of a basic current balance:
http://www.pasco.com/prodCatalog/SF/SF-8607_basic-current-balance/
As you all know...
Can someone please point me to an experiment (photons/electrons/whatever) where detectors were placed on both slits, this seems like a really big hole in the experiment if they stopped at having just the one detector. (Excuse the pun)
Homework Statement
Angular Speed of the 8 gap wheel Is variable.
Red Laser (wavelength around 656.6 nm)
Approximate the length of the traveling ray to the mirror in meters.
Using the length of the traveling ray, calculate the speed of light.
Homework Equations
c=lambda*f
The Attempt at a...
In a double-slit experiment, the distance between slits is 5.0mm and the slits are 1.0m from the screen. Two interference patterns can be seen on the screen: one due to light of wavelength 480nm, and the other due to light of wavelength 600nm. What is the separation on the screen between the...
Suppose two balls A and B are connected by a compressed massless spring initially, and they are not under any other forces. The spring is then released and the result is observed.
Scenario 1: Ball A has the same mass as Ball B.
Scenario 2: Ball A has greater mass than Ball B.
Define the...
If we take an indivisible unit of time (a Planck time perhaps), could the possible retro-causality hinted at in the Quantum Eraser Experiment be a process where the retro-causality goes back along the same plank unit rather than back in time per se
Metaphor - I don't travel to a different train...
Think about an electric charged object moves linely, it will produce current hence the magnetic field.
But if the obserser moves together with the electron charged object, so there is no relative movement between them, that means the electric charged object is static to the observer, hence...
Imagine red box as a fully enclosed device powered by electricity
when turned off, it weighs 5kg, it is pushing down with force cca 49 Newtons
when turned on, it would weight more, let's say 6kg, pushing down with force cca 58.86 Newtons
is it in theory possible to make such device...
Hey so i have a naive question that i always had since i was young, but i never really could find an answer to it.
Lets say you have a black hole isolated in a vacuum, in a closed system.
Dark matter is supposed to be a sort of weakly interacting massive particle, which exerts a gravitational...
some time ago I posted a question re acceleration data. I bought an accelerometer and logged some data.
when stationary the accelerometer (can mention the brand if that is not spamming) read 1g, when thrown in the air got what was expected with 0g ie weightless when the accelerometer switched...
Homework Statement
Suppose, the following equation describes the relation between an independent and a dependent variable physical quantities(that will be measured by experiments; for example, temperature, current, voltage etc) x & y :
##y = ax^2 + bx + c##
We have to find the values of the...
Standard quantum mechanics text-books discusses Born rule, which states that the probability of finding a particle in a certain region in space is given by
$$ |\Psi ({\bf r},t)|^2d^3r $$
Thing is, I never have seen a discussion about how you can actually measure the particle position in a...
I'm familiar with the delayed choice experiment, and I'm trying to suss out this new setup.
http://www.sciencealert.com/reality-doesn-t-exist-until-we-measure-it-quantum-experiment-confirms
Reading this article is not very beneficial if there's a confounding typo. Paragraph 10:
Should that...
Hi guys i don't know much about physics but I am interested in learning about it i have
According to wikipedia virtual particle hasnt never been observed but i think that they are wrong it has been observed in this experiment...
I'm just a layman with an interest in science, so my terminology won't be accurate. Sorry.
Set up for question: the wave-front splits as it passes through the slits and must (I guess?) condense to a point upon impact with the recording device (paper/film etc).
The question: if a photon is...
Not sure where to post this but is anyone else intrigued by sonoluminescence? I'm designing an experiment so if anyone wants me to harvest data for them I can integrate another measurement into the design.
Let's start doing some research on this site!
Hi Folks,
I am not sure I can appreciate the quantum weirdness that supposedly exist because I do not fully understand the experimental set-up of the double slit experiment. I watched the following which left me with some unanswered questions
I have some questions about the experimental...
enangle 2 electrons. Capture 1 electron by using this method http://news.discovery.com/tech/photo-first-lights-captured-as-both-particle-and-wave-150302.htm. Send an electron from Earth to the moon. Have an detector on the moon that measure a property of entanglement and same with on earth...
I need some ideas for an assignment in Physics: I am to determine an experimental protcol which will allow me to determine if statistical differences occur in the data that I will collect. I am collecting data to find the reaction time of two subjects.
For example, one student a few years ago...
In chemistry book I read that faraday observed that when two metal plates called electrodes, are placed in an electrolytic solution and an electric current is passed, the solution breaks up into charged particles called ions" but I am confusing that if it was a electrolytic solution then it...
The experiment I am thinking of is simple:
- A typical (ideal) photon polarization quantum entanglement setup with Alice and Bob.
- Alice and Bob detectors are constant at 90 deg. angle difference (such as they allways get perfect corelation with different result)
Plus:
- Between Alice and...
For the past year or so, I've been experimenting with Isobutane. I used to get it in relatively cheap canisters of r600a from amazon.com and AliExpress, and that worked fine. Now, however, AliExpress has NO purchase options for r600a, and amazon.com will not ship it to the US, even though they...
(a) Suppose we split a laser into two beams "A" and "B". Is it at all possible to do something to one of the beams, so that, when we bring them back to overlap at the detector(s), they will follow the statistics of two-photon systems?
(b) If we use two separate lasers that are phase-locked by...
Homework Statement
Say if I had a system with 3 springs on the left, 1 spring in the middle, and another 3 springs on the right. I add masses to the central spring and calculate the extension. After all my measurements, I plot a graph of spring against mass. If I then repeat the experiment...
Hi, I was trying to think of a way to generate a Poisson distribution using a single deck of 52.
Say I am looking at the position of the Ace of spades in the deck after a number of shuffle rounds (1 shuffle round is 7 riffle type shuffles). Success is that an Ace of spades is on top of the...
Homework Statement
It is known that the theoretical resistivity of copper is approximately: 2*10^-8 Ωm. But after I conducted an experiment to find the resistivity of copper, the results turned out to be: 1.68*10^-8Ωm.
This is a very small error that can be easily dismissed due to "human...
As you know, this year, 2015, is the year of light: http://en.wikipedia.org/wiki/International_Year_of_Light
I want to create a video clip limited to 90 seconds to show in our university's TED-like show to make students excited about light.
Do you have any idea? any experiment?
I'm not a physicist, but I have a layman understanding of some aspects of Quantum Mechanics. I just watched a video explaining the experiment, where you put two differently polarized sheets behind each slit, but then erase the polarization with third polarizing sheet that's located between the...