Experimental Definition and 494 Threads

So, here's the deal: I'm trying to complete the publishing of a paper dealing with my thesis from almost two years ago, and I finally wrote a program that I believe will tell me how different geometries will influence the outcome. Here's the setup, I am modeling the radiation that goes through...

Hello! :-) I' have a problem... I fitted experimental data with a second order exponential theoretical curve: y = A1*exp(-x/t1)+ A2*exp(-x/t2) + y0 and I have these data for 4 repetitions of the same experiment: first time: Reduced Chi-Sqr = 6,81066E-4 Adj. R-Square = 0,41005...

Do experiments like 1971's Hafele & Keating show that SR relativistic effects of time dilation are not mere products of measuring symmetry? Does such an experiment show that for the jets it is their clock that has kinematic time dilation in relation to the other clock that 'remains'...

Hello everyone, i return to complete the final year of my degree in the next 12 months and go on to do further studies ie masters and phd depending on how long they will put up with me and all of my questions. I have had quite a long break, and have been continuing to study pure mathematics...

Long story short: I have a B. Sc. in EE, and currently doing PhD in Experimental Condensed Matter Physics. I plan to go for industry. I found that it would not be difficult for me to pass the Electrical and Computer PE exam (both the "Computer Engineering" and the "Electrical and...

Hello Can someone, please, briefly describe or give a manual on how to use the spectrometer on the photo to measure an atomic spectrum. I tried to google that already, but failed. http://www.daviessports.co.uk/netalogue/600/A46395.jpg Deep thanks!

With automata replacing everything in this world, including a lot of laboratory functions, would experimental researchers be obsolete as well, with computational researchers as the only ones remaining? Or am I looking at it too simplistically? I prefer experimental work to computational, but...

I have some experimental data (not hypothetically, this is real data), which has a downward sloping shape. A sharp decrease initially, before settling to what looks almost like a downward linear slope. To investigate further, I decided to take the base 10 log of the y-axis data. The...

Hi All, I want to run some small nuclear transmutation experiments for a nuclear battery project. However, my knowledge of nuclear physics is very theoretical and I was looking to get mentored by a physicist or nuclear engineer who has experience with working with radiation sources. Here is...

I'm studying Physics and I'm currently on my 3rd year. My aim is to work with theories, so I find mechanics, electrodynamics, quantum mehcanics and so on pretty interesting. Also I have a good math background, so I know advanced linear algebra, analysis, topology and differential geometry. The...

Homework Statement I did a 'three point bend test' and a 'tensile test' on the material as-rolled Aluminium. I then messured and calculated the proepties of the metal and compared it with the literature values found on a CES software. Unfortunately, I can find significant differences for...

Hello all, I used the micrometer in my lab that has a resolution of 100 nm. so, my measurement looks something like, 0.2345 mm, with an uncertainty of 0.00005 mm. But I don't want to write, (0.2345 +/- 0.00005)mm in my data table because it just looks a little awkward to have so many...

Hello, I've been trying to learn physics recently with the long term goal of understanding GR and cosmology. As a result, I have many questions, so I'll just get started.. In the famous double slit experiment, there is a coherent light source aimed at a double slit which produces an...

So I am almost done with my physics degree and I am taking a physics lab class this semester. I hate it. I don't learn anything on it. 90% of the time we're just working to get the equipment to function correctly and the other 10% deciphering the lab instructions. I resorted to just making...

Before quantum mechanics hit the scene, I would expect most physicists (and people) would have answered the above question with the basic assumption: Two observers see the same result in an experiment because we live in the same universe. Today, most people (and some physicists)...

Hello, Grad school admissions are about over, and it looks like I will be choosing between UIUC, Cornell, or U Chicago for CME. I have research fellowships from Cornell and U Chicago, still waiting for financial details from UIUC. I'll visit UC and Cornell over spring break, but location...

Hello everyone, the forum looks great and I have been reading it for a long time, but I have only registered. I am writing this post because I have to analyse two flow fields in a wind tunnel. 1) The first flow is generated from a helicopter blade, with Re=2000000, Mach=0.92 and...

Apologies for the break from format, but I'm not sure how to make this fit! I'm designing an experiment to compare the insulation properties of several materials. I would like to find the Thermal Conductivity (K) or the U (or R) values of these materials. However essentially all I am after...

I'm working on an open-source textbook on special relativity. The text below is what I currently have on experimental searches for tachyons. There seems to have been quite a bit of work on this kind of thing in the 60's, but very little in more recent times. Does anyone know of any better...

Homework Statement 1. Take dimensions of the beam (B, D, web and flange thickness, L) – T- cross section 2. Take the beam span geometry and material properties from the instrument 3. Ensure the beam and load cell are properly aligned and apply a positive (downward) preload to the beam of...

Hi, I don't know if this is the proper part of the forum to ask this, but I'm trying to figure out how I can obtain a certain value from an equation that contains an integral if I want to use experimental data. To keep it simple, the equation looks like this: B= (∫G(f)df)2 / (∫G(f)2df) where...

A naive question from someone who knows nothing about the subject: I was wondering how much we can tell experimentally about what's going on inside a star. Can we determine, say, how the temperature or pressure vary as a function of the radius? Thanks in advance.

I've been toying around with an experimental idea for an efficient way to store hydrogen for use in hydrogen fuel cells, but recently I haven't been able to think of much more to add to it. I've thought of using cooling and pressure together to put the hydrogen to a liquid form for more...

Hi everyone I have a quick question in regards to an experimental report I'm writing for my year 11 Physics class. Basically we have to test different variables that could effect a bungee cord fiber in relation to stress and strain by increasing the weight force on the fiber until it snaps. For...

For an investigation, I have built a mousetrap car. The two variables in this investigation is the mass of the mousetrap car and the distance it travels. When there is no added mass on the cart, it does not travel far due to massive wheel slippage. As I increased the mass it carried, it traveled...

I'm in my last year of college as an undergraduate physics B.S. and have so far tried astronomy and materials science research internships and haven't liked either of them that much. I enjoy the theory behind astrophysics but don't enjoy programming all day. On the other hand, I like the...

I am trying to measure the relative permeability of a few materials, but the numbers I'm getting don't quite make sense. Maybe someone here can figure out what might be going wrong. My setup is as follows. I'm making solenoids using 30 AWG magnet wire wrapped around ferrite, steel and wood...

Hello, I am a senior undergraduate (USA) who wants to go to graduate school for either engineering or experimental physics. I am an A/B student and have taken all the recommended classes as if I was preparing to apply to physics graduate schools. I am not sure I am satisfied with an...

Hey, Does anyone know a link to a paper talking about the experimental verification of indistinguishability of some free particles? For example showing it for free neutrons or something. Thanks!

I've recently done an experiment where I've obtained the strain of a channel section beam in bending. I used a strain gauge to get the strain from the midspan and also used dial gauges to get the deflections of the beam under different loading conditions. Along with the readings I've...

Homework Statement An experiment was done to test the validity of the equation a = 2/3 g sin∅ for a rolling cylinder. A hockey puck was rolled down a wooden ramp at 5 different inclination angles, and the time it took to roll down the length of the board was recorded. ∅ was found using...

Homework Statement A wooden box is at rest on a ramp inclined at an angle Ө to the horizontal. W is the weight of the box and its contents. A frictional force prevents the box sliding down the ramp. A reaction force acts on the box perpendicular to the inclined plane. The inclined plane is...

Hello! Recently, I read abt some experiments related to probability which involved tossing of coins.It listed the experiments performed by following- Comte buffon:- 2048 heads from 4040 tosses. J E Kerrich:-5067 heads from 10000 tosses. Karl Pearson:-12012 heads from 24000 tosses. My...

Greetings, My questions below could be categorized into a mixture of “history of chemistry” and “experimental basis for chemistry”. I’m having difficulty phrasing the questions that I have, so I’m going to start by stating them as directly as I can, and then spend the rest of this post...

Enrico Fermi was a successful theoretical and experimental physicist. Is this still something that someone can do, or is it practically impossible today? If it is pissible how can someone achieve this?

I am a student from India i just finished my class 10 exams . I want to appear in IPHO 2014 and IPHO 2015 . So let me tell you what preparations i have done uptill now . I read all the theory and solved almost all problems from resnick/halliday's FOP I am solving problems from IE IRODOV ( i...

Homework Statement You are going to examine the viscosity of a fluid by dropping a ball bearing into a cylinder of fluid and measuring the fall time. You will use a ruler to measure the height, h, of the fluid column, and a stop watch to measure the fall time, t. The ruler and stop watch...

Hi It is not seldom to hear about a physicist who did his/her PhD in theoretical high-energy physics/astro-physics/solid state, who then move on to a rather quantitative position in the industry, e.g. in a bank. I hear the same about people that did an experimental PhD, where statistics and...

See attached PDF for details: How do I calculate errors on the fit parameters, p?

What is the experimental proof of Newton's law of universal gravitation? Specifically, how has it been established that the gravitational force between two masses varies inversely as square of the distance between them ( as opposed to, say, as 1/R^(2+x) where x is small |x|<<1 )?

Homework Statement We've been given an assignment to work out a formula for the period time of a compound pendulum. This is right in the beginning of an introductory physics course which means we haven't covered inertia or torque yet. So we're just supposed to find an approximate relation...

1. After I calculated from my original data with lowest significant figure of 3, I got 0.3765 and uncertainty of 0.1274 2.original data with lowest significant figure of 2 .calculated value of 0.69897 and uncertainty of 0.0789 The Attempt at a Solution This is how I answered...

I am looking at the cross-sectional shape of a sagging membrane. I have several theoretical models, neither of which fit perfectly. So rather than comparing values, I'm comparing shapes. One model fits fairly well, however I'm unsure of which quantity is correct to specify a 'goodness' of a...

Have you recently came across and remember titles of papers about real experiments concerning the famous double slit electron behaviour? I have found some about electron diffraction, but I'm still looking for those that showed how interference pattern is broken when we watch where the...

Hello everyone, I'm considering becoming an Applied Physicist. I just need some help. Here are the questions I would like answered. -What would a Theoretical Applied Physicist research? -What would a Experimental Applied Physicist research? -Which one would have more of a likely...

Some experimental covariance curve for entangled photons gives abs(Cov(0)) less than 1. For example : Violation of Bell inequalities by photons more than 10km apart by Gisin's group in Geneva. Does this mean that experimentally we can't predict with certainty in this case ? In order to...

I would like to find a useful function to predict the output based on the input. I'm trying to figure out how to get the transfer function given actual input and output data. What I've tried is getting a transfer function using Fourier transforms. I'm attemping to do a fft on both the input...

Professor of Physics History at CalTech, Dr James Woodward has been investigating an idea called the Mach Effect, which is supposed to be based on Mach's Principle and which is claimed to allow a means for propellantless propulsion without violating Conservation of Momentum. The idea is that...

I am not completely convinced that the modern resolution is correct. Is it? Is anyone aware of any experiments that have been done that relate to this effect? Reference: http://en.wikipedia.org/wiki/Ehrenfest_paradox

This was a recent experiment done to determine the epistemic versus ontic status of ψ: Can different quantum state vectors correspond to the same physical state? An experimental test http://lanl.arxiv.org/pdf/1211.0942.pdf