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.
Used a mass attached to a dynamic cart via pulley to examine motion under variable acceleration. As the mass was increased, my calculated friction force shows a decrease. I know that friction should increase with larger mass. Any suggestions as to why my calculations show a decrease? Used the...
Homework Statement
The Observer (me) is at Inertial Frame of Reference:
1)
I am sitting at a car moving east v=30 km/h relative to earth
A bird flying east v = 10 km/h relative to earth
What is the speed of bird for me?
2)
I am sitting at a car moving east v=30 km/h relative to earth
A bird...
Homework Statement
I used error propagation equation to calculate errors in x and y for each individual data. Error in y is negligible. My goal is to find the uncertainty in the gradient.
2. Homework Equations
The plotted equation is eV=h\frac{c}{2dsin(\theta)} ,where Plank's constant, h, is...
My question is that in Michelson Morley experiment, how they produced the light? what was the light source and has anyone used sunlight as a source yet to re-confirm that experiment? I am interested in sunlight as a source of light due to certain reason... Please if you know kindly mention the...
When we are measuring the spin of the electron in the experiment, we choose the spin property as its eigen state for the measurement. The eigen vectors corresponding to these states could be time dependent. Can we still break the problem into solving time independent Schrodinger Equation and...
Homework Statement
We were given five samples of nichrome wire, each with a different diameter but the same length. A micrometer was used to measure the diameters. We then measured and recorded the electrical resistance, R in Ohms of each nichrome sample with a DMM. I will try to summarize all...
I'm very interested in researching polymerization chemistry for my school science fair.
All the ideas I have are either too expensive or not complex enough.
Homework Statement
I am about to do an experiment where we masure the average speed of a cart released from the top of an inclined plane that has little friction (air track). The speed measurement is done by a photo gate. This is repeated a hundred times.
Homework Equations
I need to come up...
Millikan Oil drop experiment.
For my current lab, we are recreating the milian oil drop experiment to measure the charge of an electron. However, we are using 1-micron diameter latex spheres in place of oil drops.
Problem:
I am having difficulty deriving an equation for the speed of the drop...
Hi all,
I have recently done my first experiment in fluid mechanics, and it was a gravity current experiment using UDVP. I have augmented the data, as to remove noise, and performed the statistical analysis.
I have text files which contain the velocities measured by each sensor over the time...
Hi,
If you had a sealed round bottomed flask on some lab scales and you recorded the mass and then you removed all the air with a vacuum pump and then found the mass of the flask again would the difference between the two readings really be an estimate of the mass of the gas in the flask? The...
I know that clarifications about delayed choice experiment was asked million times, and I understand the idea, but I was not able to find the discussion of this particular situation anywhere, though I tried hard. This setup is described in Brian Greene's Fabric of the Cosmos book (note my...
Homework Statement
Hello :) This is a last resort. I'm stuck on what to do to complete this lab report table.
We are required to conduct an online simulation at this link: Buoyancy Online Simulation
This is the document of the lab report I'm required to fill up (I'm stuck at part 2)
Homework...
Hello, i am a high school student who is interested in physics. Me and my friends want to build something cool. Can be anything related to science. Nothing too complicated but nothing too easy. Something interesting and safe. No dangerous suggestions please. I do not have any qualifications as i...
http://www.feynmanlectures.caltech.edu/I_15.html#Ch15-S3
I'm reading through Feynman's chapter on special relativity in the first volume of his books in order to have a more comprehensive idea of it as I go through the special relativity homework given to us as extra credit for our...
Why mercury go inside the water in andrews experiment.
Because as we know density of mercury is greater than water so why mercury go inside the water in andrews experiment on co2.
Hello,
in the double slit experiment, what will be the result if two persons are checking the experiment using the same equipment to perform the experiment, but one person will take note from which slit is passing the electron while the other is not checking. Will they see the same thing...
Let's say a memory qubit inside a quantum computer is in state
## α \left|1\right>+β\left|0\right> ##
This computer is equipped with a device that emits photons that carry the same qubit as the aforementioned memory location.
Alice and Bob, that are very far from each other, receive and...
Homework Statement
So we had to the simple pendulum experiment and were measuring the effect of the length of the pendulum on its period of motion. However, our results produced a line of best fit that was significantly higher than the expected line of best fit (with length vs period squared)...
In Michelson-Morley experiment, the two light beams arrive in phase at the detector, so they say this means waves are traveling at the same speeds because they arrive in phase at the detector,
What if the waves started in phase and their path difference is an integer multiple of the wave lengths...
Howdy y'all!
If you could help with the following question, my physics class and I would be extremely grateful.
A charged oil droplet is suspended motionless between two parallel plates (d=0.01m) that are held at a potential difference V. Periodically, the charge on the droplet changes as in...
I wonder if my thought experiment in proving the finite speed of field lines is valid.
Say a spherical conductor has a cavity with positive charge Q inside as shown.
say that the beginning of the universe starts at time 0, where there is the charge Q in the cavity and that the conductor is not...
Homework Statement
In this experiment, we're trying to study the characteristics of a light bulb. Here are the steps outlined for us:
1. Use a potentiometer to vary the voltage across the bulb measured by the voltmeter V. Collect data of V-values and corresponding I'-values from the ammeter...
Homework Statement
Evaluate the experiment below, identifying energy loss and errors, and access their effect on the efficiency?
The experiment was 'Determining the efficiency of energy conversion of boiling water in an electric kettle'.
The method/system -
1. Weigh accurately 1000g of water...
Consider a set up with a power supply(dc voltage) ,and a photocell (metal plate + collector) ,and an ammeter. Frequency of light is constant.
When V gradually increases from 0 (anode linked to the collector, anode to the metal plate), the photoelectric current is said to be increasing until it...
Compton hit the electrons in a carbon target with x-rays and measured the changes in the wavelengths of the scattered photons versus their deflected angle. He correlated that with the energy and momentum the incident photon gave to the electron.
My question is why does this not happen in...
Hi,
I have a thought experiment which seems inconsistent with the 2nd Law of Thermodynamics, so there is probably a flaw in the idea somewhere.
Imagine a single molecule of a heavy gas (such as SF6) in a pipe 2.5 metres high and 100mm diametre. The pipe is upright and under the normal...
I am puzzled over einstein's thought experiment on simultaneity.
In this experiment, a man is standing on a train platform. A woman is sitted in the middle of a moving train traveling towards the man. When the train is half past the man, lightning strikes at the same instant at both ends of...
Hi,
I am looking for a video helping intuition on pressure, in the context of kinetic theory of gases.
I remember seeing a video where someone poured a bucketful of little hard balls (lead sinkers for fishing?) onto an electronic scales (a dynamometer, really) showing that this corresponds to...
some years ago it was big news when some aerogel bulk launched at the tail of a comet and bits of the comet dust got stuck in the gel. this was going to be recovered somehow and analysed.
I do not know any more about that particular experiment but it died out of the mainstream news.
anyone...
Hello everyone, I am not a physicist but I have been studying this subject. I came across an article and I'm having trouble understanding. I would appreciate if you could help me.
https://arxiv.org/pdf/1103.0117v2.pdf
Thanks.
Not sure where the best place to post this is, but here it goes.
Imagine you were sent back in time, far enough back when a lot of the now known scientific laws, rules equations etc, haven't been discovered yet. You're someone who is intelligible with many scientific fields, and you have...
Hey, I was watching this video
About the quantum eraser experiment (I suggest you watch too, so we would be speaking in the same terms). As I understand it, The experiment goes such that:
first the photon enters through the slits as a superposition,
then the photon gets measured to gain...
The RAVE project site: https://www.rave-survey.org/project/
In the above image taken from one of the RAVE DR5 video, surveyed stars are shown in 3D and color coded according to their positive or negative radial velocity relative to the Sun.
I'm a bit puzzled that stars on one 'side' tend to...
My setup:
plastic box (~1l) with the cover painted black mat
the bottom of the box covered with sponges saturated with ethyl alcohol (90%) to the limit (all over sponge capacity poured back to bottle)
turned upside down and placed on ~0.5kg of dry ice.
I can see a 'rain' of particles of...
I have had many people claim that QM has never made a prediction that has been contradicted by experiment.
Yet as i understand it Qm predicts the vacuum energy density is 10^122 erg per cubic cm whereas the measured energy density of 10^-8 erg per cubic cm. So how is that not an example of an...
Homework Statement
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Hi everyone, some school mates sugested id try this forum for help with this work i have :)
- will try to keep it short
We were trying to induce current in a coil and confirm the experimental results with math, but the math is way off and nobody is sure...
Stark effect (shifting and splitting spectral lines due to external electric field) is calculated in nearly all QM textbooks as application of perturbation theory (alongside Zeeman).
Wikipedia article ( https://en.wikipedia.org/wiki/Stark_effect ) has a nice figure with n-th level splitting into...
To get this out of the way: I know how a kundt's tube generally works and how you can use it to determine the speed of sound.
For anyone who hasn't heard of it, you take a tube and "feed" it a resonant frequency.(very similar to a rubens tube)
The nodes of the resulting standing wave in the...
Homework Statement
We recently conducted a physics lab in class where we designed an experiment to "prove" the kinematic equations. We used photogates, ramp and a car.
Homework Equations
We have to show v = u+at and the other kinematic equations are true with our collected data.
The Attempt...
I watched a documentary by Brian Greene, "The Illusion of Time" a few weeks ago, and a question has been bothering me ever since. In the documentary he explains that an alien, traveling toward the earth, would see into our future. So here is my question.
The second half of a college football...
Hi guys!
For a school experiment we are supposed to connect a 9v battery to a 180 ohm resistor and multimeter and calculate how long it take to die at different temperatures .
does anyone know how can i do this using a formula? I will need it in my report.
Thanks for the help! :)
I would like to show you my own opinion about DSE. I might be silly but I suspect data filtering issue.
Let's suppose we have a detector DA for slit A, DB for slit B and a interference detector D0.
If we consider the photon a wave pulse it means it will go either through a slit or through both...
Hi
In the FH experiment, what is physically happening when the excited mercury atom hits the metal plate? why does it induce a current drop?
Thank you for any help :)
You have a glass (or plastic) dish (like a small transparent dish). You shine light onto its flat surface. Your lab partner discovers that 55% of the light has been transmitted, 55% is reflected. What is the absorbance of the dish (not in the log scale, just as a regular %age)?
State a...
Homework Statement
The distance between the 1st bright fringe and the 21st bright fringe in a Young's double-slit arrangement was found to be 2.7 mm. The slit separation was 1.0 mm and the distance from the slits to the plane of the fringes was 25 cm. What was the wavelength of the light...
In the Stern-Gerlach experiment , they used silver ions with a an unpaired electron in the outer shell...The typical result from passing the silver ions through a Non-uniform magnetic field is to separate spatially the bean into two types of "spin"...In other words the non-uniform B filed cause...