Experimental Definition and 494 Threads

Dear All, The compilation by John Baez about the http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html" is a must read. However, only very few of the references are available online and for free. Also, I have not found any book providing a compilation of such papers...

The photoelectric current is known to be directly proportional to the intensity of incident light with fixed frequency. Questions: 1) What are the experimental values of this proportionality constant for various fixed frequencies? 2) Is there a theoretical derivation that provides a formula...

Hi! I would like to know if there is any direct experimental evidence of the electron distribution inside of the hydrogen atom. In the Wikipedia article http://en.wikipedia.org/wiki/Hydrogen_atom" you can see the solutions of the Schrödinger equation and the graphical representations of the...

On average... Whether it be defense, condensened matter, etc., how much? If it's too broad, could you guys just list the ones you do know of?

Were there any experiments that proved doppler shift of light on a fast moving object - that it has higher frequency if the object is moving towards you and lower if the object is moving away?

Hi, I have a problem with the experimental buckling load that I have deduced for a compressive axial load applied to a tube of circular cross section. The buckling load is 2.34% larger than the theoretical buckling load! The beam is connected to supports via knife edges; these are rigid bodies...

Consider that high quality experiments furnish data that relate proper time intervals to coordinate time intervals for different values of the relative velocity (life time dilationf moving mesons). An inteligent computer program could find out the best function of the relative speed which...

Homework Statement So we did a lab this week in my physics class. We had a car on a horizontal table, that was attached to a string with weights (The weights were over the edge of the table.) We then calculated the experimental acceleration and the calculated acceleration. These numbers were...

Homework Statement The problem let's us graph and give values for s(m) (distance) t(s) time and delta t (s) velocity. After plotting my second graph (including error bars) I used it to get the slope and the acceleration. But then it asks to determine the experimental error. Is there any...

Craig Hogen, in his paper Indeterminacy of Holographic Quantum Geometry, Phys. Rev D 78, 087501 (2008), has claimed noise seen in output of the GEO600 interferometric gravitational-wave detector is evidence for a fundamental minimum interval time. What is the time-line for the survival of this...

Homework Statement You have run an experiment and generated a histogram. Suppose you had 853 counts in the bin centered at 1.60, and 2,439 counts in the bin centered at 1.85. If you were to repeat this experiment (by measuring the same source for the same time period, delta t) you know...

Whats the scale reading error for a traveling microscope Hi At school we done an experiment to determine the refractive index of a liquid using real and apparent depth. We used a traveling microscope a glass beaker and a coin. One question we got was what was the scale reading error...

if say I have two carts that is initially at rest, one of the cart has a plunger and the plunger is set so that it's against the other cart. When I release the plunger both carts will travel at a certain velocity. The law of momentum conservation says that the momentum of the initial system...

Hi, I have two small issues while carrying out my experiments: 1) While using Mach Zhender interferometer setup to cause a phase delay, I would need to find out, by how much the fringes have moved. But all the fringes look very similar before and after causing the phase delay. Because of...

I love the experimenting side of Physics. I know you can't actually major in Experimental Physics so out of a couple degrees which one is most likely to focus on Experimenting. Engineering Physics, Physics, Applied Physics, Engineering, Materials Science? Also, what part of Physics has a...

Homework Statement What experimental evidence requires that the emission of energy by an atom be quantized? The Attempt at a Solution I can completely confused on what the question is asking. What do they mean by "experimental evidence"? Do I talk about Bohr and how he proposed that to...

Homework Statement http://img217.imageshack.us/my.php?image=dscf3381gv1.jpg2. The attempt at a solution http://img113.imageshack.us/img113/6683/dscf3380tp0.jpg It's really confusing, and the teacher didn't really go too much indepth on how to work this, so far i plotted the data, i used...

I want to see some results.

Hi all, I'm currently a fourth year physics student, working on my honours degree. The school that I'm at has almost no research happening in theoretical physics, but I've always been more interested in theoretical than experimental physics. For my honours project, I'll be working on...

I read somewhere that if a beam of photons all of like polarization are directed towards the surface of a disk (the disk being capable of rotation), the disk will rotate. This rotation is supposed to be experimental evidence confirming that photons have angular momentum. Is this true?

To put my question in perspective, I'm starting grad school in the fall, and as an undergrad I was pretty sure I wanted to be a theorist so my range of experience with experiment is limited - I like reading papers off arxiv, and it's pretty rare to pull a theory paper that isn't typeset in...

Hi there: First of all, I thank all the people who have answer my questions until now, they were really helpful for me... Now I have another Doubt, in the least squares method, in order to fit experimental data to find an straight line y = m*x + b. We need to obtain the...

I keep hearing that the "many worlds interpretation" is experimentally different than the collapse theories. But I haven't heard of anything other than "quantum suicide". Is there anything else? As far as quantum suicide, I fail to see how this differs from collapse theories. Isn't each...

Are there any experiments that show how light is treated as a frames velocity is changed (not the light source, rather the "eye".) For example if a huge clock that is counting down from 10 is 10 light seconds away before I accelerate (at t=0) to a velocity where my length contraction is *.5 (I...

Is there any experiments I could do to prove that the Drag Coefficient of a Sphere is more or less 0.5 depending on the roughness of the sphere?

I've run into a problem which has been bugging me for days. I know its related to the Stern-Gerlach experiment about firing hydrogen through an inhomogeneous magnetic field, but all i can do is give a vague qualitative description of the answers, and not an actual numerical one (because I don't...

Homework Statement I just purified alkaline phosphatase, and my calculated molecular weight is 100000 g/mol, while literature value is 89000 g/mol. According to how others in my lab did calculations, my calculations are performed correctly, so I am left to explain why my purification is...

What are the important experimental verifications of QFT that someone studying QFT should be familiar with? The wikipedia QED article mentions the anomalous magnetic moment of the electron and the Lamb shift. The Higgs Mechanism article states "Although the evidence for the Higgs mechanism...

Use the experimental values to calculate the enthalpy change in the system. Observation Experiment Quantity of reactant 1 100.0 mL of 1.00 M KOH(aq) Quantity of reactant 2 100.0 mL of 1.00 M HBr(aq) Initial Temperature (oC) 20.0 Final Temperature (oC) 22.5

Hey, In my physics we derived certain properties of conductors in electrostatic equilibrium using Gauss' law. One property seemed to "mathematical" to me. It says that the whole charge of a conductor in electrostatic equilibrium is located at the surface. The proof is at follows. Since the...

Wasn't sure which section this should be in, so please move if inappropriate. If a plot between two variables theoretically should pass through the origin, should you force the linear regression through the origin. I seem to get a much better value for my gradient when forced through the origin...

Hi, I'm trying to use experimental modal analysis to determine the modal parameters of a beaker. I'm using a shaker and have successfully obtained FRF's (I think!) Has anybody got any idea what I've to do from here? I've read what feels like a million articles but can't figure out how to...

Hello, I need some help with setup/equipment used for a study to determine the natural frequencies on some small, lightweight samples (12in x 1.5in x .12 in.) in a catilever beam setup. The samples are made of carbon fiber and kevlar so they are fairly flexible to begin with. I am working on...

Hi All, Does anybody know if there is an experimental setup which is able to distinguish between a state of light with one photon and state with n = 2 ? This is about the bosonic behavior of light, according to which two photons may be in the same physical state - and in stimulated...

Pretty much every professor in my physics department has said that it when it comes to American physics graduate school, it is harder to get in as a theory student than as an experimentalist. Do graduate programs consider computational physics, numerical material sciences, etc... essentially...

Does anyone here have one of these book readers? I want to know how good the 'experimental' PDF support is. For instance, will it display Alan Hatcher's Topology book?

My posts have been rude i am just annoyed that all though i have learned a lot about cosmology i have learned nothing that matters, you guys spend years of hard work doing things only you can, i wish you had a bigger budget to work with, so that theory could be tested, i know you would like...

The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many times. I've just discovered that Tom Roberts has recently revised it. It now has information on experiments performed since the last edition seven years ago, and a larger section on...

Hi all, I was wondering if PhD students in theoretical aspects of cosmology,gravitation, black holes... etc do any/much analysis of experimental data, and just mainly omit observational technique, or if their entire education is in learning physical theory and making predictions and solving...

First off thank you all for all the advice that has been given. I am new to this forum but I've already received plenty of good advice. So, I love physics. I have decided that that is what i want to earn degrees in (phd if I am cut out for it). My math knowledge is ok. grades in the high...

Hello everyone, I have a couple of hopefully easy questions about undergraduate degrees. I am a 3.74 GPA student at my university and am currently in my 3rd year of college, on a 5 year plan. I am a double major in both Physics and Applied Mathematics. The following are my questions. 1)...

My teacher has given me a Extended Experimental Investigation to do that requires physics. I know a bit about it (the very basics) and I'm not sure on a few things about it. For my task I have forgotten to measure my displacement and I was wondering if anybody knew a way I could still find it...

Homework Statement

News from Claus Lammerzahl, from Bremen, on success yesterday 6 Nov. 07 of production of BEC in microgravity in a drop tower experiment: Yesterday the first BEC in free fall was produced by a team at Bremen University. A condensate of 10^4 to 10^5 atoms was created in a few milleseconds in a...

Can you tell me How Much is the difference between theoritical and experimental astrophysics?

Bee Hossenfelder (who used to post here as "Hossi") has organized a 5-day workshop on XQG. A brief summary with links: http://www.perimeterinstitute.ca/esqg07/ The schedule of talks (5 Nov - 9 Nov) is here...

any ideas of which experiments best illustrate this Homework Statement Homework Equations

Homework Statement Experimentally measured time of fall vs. distance for a freely falling object Distance, x (m) Time, t (s) 0.1 0.148 0.2 0.196 0.3 0.244 0.4 0.290 0.5...

Is there any experiment that shows the increase in mass ( or kinetic energy ) of a moving body when seen from an observer at rest ? I know that sincrotons ( particles accelerators ) must change the frequency bla bla .. But once that these particles have been accelerated and hit a target...

I was wondering if any of you guys could help me. Is there any simple way to set up an experiment to calculate the birefringence of a birefringent crystal? I've trudged through papers and the most helpful one was "Measuring birefringence properties using a wave plate and an analyzer" by...