Spectrum Definition and 725 Threads

Does anyone know where I might find the natural spectrum of bodies in the universe? Something like http://upload.wikimedia.org/wikipedia/commons/2/27/Spectrum_of_Sunlight_en.svg as a sum of all known stars, black holes, pulsars, solar winds on planetary atmospheres, etc covering the entire...

What can we learn from Invariant Mass Spectrum?How to measure it?So,how to read it? Mass measurement is converted into energy measurement,but how could we make the quantity change continuously in order to form the horizontal axis? How to divide different particles to measure them...

How the Mean colour of visible spectrum is yellow? Shouldn't that be green according to acronym VIBGYOR?

For a definite particle,the decay mode is determinant,finite kind,which embody the characteristic of quantum mechanics. But for a specific mode of a definite particle's decay,the decay spectrum,ie,energy of products,continuous,or discrete? Decay is a process which has unique initial...

My question relates to wave/particle duality. If light is regarded as possessing both wave like and particle like properties, and visible light is just part of the whole EM spectrum of radiation, is it correct to say that radio waves for instance, ( being themselves part of the whole spectrum...

Homework Statement 2. Homework Equations 10 Log[10](g/mW)= GdBw The Attempt at a Solution I have attached a document of my approach to this question. I would like to know if my approach is correct? Thank you for your assistance

Why line spectrum of hydrogen includes no X-ray frequencies?

Any material or views? Thank you.

Homework Statement i have some questions and some of them i can't answer. The questions are form the "Spectrum Techniques Lab Manual Student Version" the link for this manual...

Simple questions. There is a formula for the POWER of Hawking radiation, but what's about it's spectrum? What is the shape of the power/wavelength curve?

Hello! I have a question about measurement of spectrum analyzer. I made some inductor by lithography, evaporator, and lift-off process, and tried to measure using spectrum analyzer. (The probing was GSG type) I swept the frequency from 100MHz to 5Ghz, and output power was monitored by...

Hello All, In this recent Navy publication, a team of researchers said they have discovered cusp confinement. This could be a major step towards fusion power. I am working on a write up of this publication. I am trying to understand their inferometry data. As far as I can tell, the...

Hi guys, My name is Maher, and I am not new to physics...I am specialized in Soil physics and mechanics...However, I have recently developed an interest in light physics... I am searching for a book or articles on Ultraviolet, in particular the separation and intensification of the...

I would like to know if the density matrix spectrum is always discrete or if it is possible it has a continuum spectrum. It is clear that a pure density matrix has a discrete spectrum but it is not obvious in general. I have heard that all compact operator has discrete eigenvalues and if it has...

I have just finished a junior-level lab assignment in which we used X-ray diffraction to determine the lattice constants of unknown materials. In the theory section of the lab write-up, it briefly explains the K-alpha doublet of the characteristic spectrum. I understand that it is the result...

https://www.physicsforums.com/attachments/74483 https://www.physicsforums.com/attachments/74483 Based in the absorption spectra above, why is 595 nm the best wavelength to measure protein concentration with Bradford dye (Hint: there are two important reasons for choosing 595). I think it has...

Homework Statement refer to the question Homework EquationsThe Attempt at a Solution from figure b , moving to the right, we know that the wavelength increases. since e= hc/λ , so the energy diffrenece should be increases as going to the right, so i consider line 1,2 and 3 is in a specific...

Hello! I want to ask about spectrum of Ac induction motor, first of all, we measure points at non drive end + drive end - radial+axial direction. At horizontal direction we measure not only velocity but also acceleration. Two questions: 1. I see a peak around 65000 rpm with sidebands at...

Hi! Here is my task: 1. Homework Statement Periodic signal is input signal for circuit (photo). a) Calculate and sketch amplitude spectrum of $$u(t+1ms)$$, b) Calculate participation (in percent) of DC component of power of total mean power of signal $$u(t)$$, c) Sketch power spectrum of...

Hi! 1. Homework Statement My task is to calculate amplitude and phase spectrum of this signal: Homework Equations My idea is to calculate complex Fourier series of this signal, $$f(t)=\sum_{n=-\infty}^{n=+\infty}Fne^{j\frac{2n\pi t}{T}},$$ where...

Hi,Guys. I have registered 2 spectrum's. 980nm induced spectrum of NaLaF4:Er3+ glass and NaLaF4:Er3+ ceramics. Now, i have to explain the observed differences. So the first one and obvious one,is that in the case of glass, luminescence bands becomes wider,because of the lattice structure of...

Dear friends, I would like to find the spectrum of the linear operator ##A\in\mathscr{L}(\ell_2,\ell_2)##, which I have verified to be compact and eigenvalueless, defined by ##A(x_1,x_2,x_3,...,x_n,...)=(0,x_1,\frac{1}{2}x_2,...,\frac{1}{n-1}x_{n-1},...)## but my book does not give examples of...

Homework Statement Prove that in the 1D case all states corresponding to the discrete spectrum are non-degenerate. Homework Equations \hat{H}\psi_n=E_n\psi_n The Attempt at a Solution Okay so, what I am stuck on here is that the question is quite broad. I can think of specific...

For scalar modes \mathcal{R}_k originating in the Bunch-Davies vacuum at the onset of inflation, I have the following equation for their primordial power spectrum: P_{\mathcal{R}}(k)=\frac{4\pi}{\epsilon(\eta_k)}\bigg( \frac{H(\eta_k)}{2\pi} \bigg)^2, where: c = G = ħ = 1, k is the...

Are each of the color lines in the emission spectrum correspondant with a single band in the atomic orbital? For example if an electron rises to the 3p band it will emit one line of color only.

I was studying black body radiation and how quantization of energy solves the problem of ultraviolet catastrophe. But I have a very fundamental doubt. A black body can be assumed as a cavity with a small hole with radiation leaking out of it. As the temperature of the black body is increased we...

This will probably end up being a stupid question with a simple answer, but if you don't ask and just accept things then where's the understanding? Anyway, the spectrum of emission is usually shown as some form of Intensity vs Wavelength, my question is how does it relate to time and how is it...

Hi pf, I just noticed that when light shines onto my tv screen (when it is off) you see thin bands of colors reflecting back (see picture attached). I just wondered why this was and also why it ONLY happens if DIRECT light (from a bulb or the sun) hits it. Also, you only ever seem to get 4...

I am trying to implement what's called the "second spectrum". Basically, you do this: 1. Take a time series of length N. 2. Divide it into m segment, each of length N'=N/m. 3. For each segment m, do a Fourier Transform. The result is the 'first spectrum',S_i^{(1)}(f_1), i=1,...,m 4...

Would one expect the emission and absorption spectral lines for Hydrogen to be at slightly different frequencies ? So if electrons are excited to higher energy levels on absorption of photons and then fall back down again emitting photons, would there be any difference in frequency. Assuming...

I've heard any many places that the density of states (DOS) can be determined from an x-ray photoelectron spectroscopy (XPS) spectrum. Perhaps someone more knowledgeable than me can explain how this is done, or can direct me to a good resource? Thanks!

Hi! I try to construct the emission spectrum from relativistic electron rotating in homogeneous magnetic field - synchrotron. In my lecture notes a found out one really easy derivation using the invariance of \frac{I'}{(\nu')^3}=\frac{I}{\nu^3}, where I is the specific intensity and \nu is...

It is given in my book that " If the spectral lines are expresses in terms of Wavenumber, then the visible lines of the Hydrogen spectrum obey the following formula: Wavenumber = 109,677(1/22 - 1/n2) Here, I cannot understand that how can the visible lines be expressed in terms of...

Homework Statement Chlorine has two naturally occurring isotopes, Cl-35 and Cl-37. Show that the vibrational spectrum of HCl should consist of closely spaced doublets, with a splitting given by ##\Delta \nu = 7.51x10^{-4}\nu ## where ##nu## is the frequency of the emitted photon. Hint: think...

Hey guys, Cannot seem to find the answer to my question within the Owners Manual for our high-frequency spectrum analyzer. When performing the 2-port calibration, it gives the option of testing in forward or reverse, which is a function of the test cable's orientation (male or female). Is it...

Hello, I've just been accepted and will begin as an undergraduate in physics this fall. I'm planning on taking classes, in addition to the required courses, concentrated in particle physics, QM, field theory, etc. Also, I took courses on Set Theory and Topology, and fell in love with what I...

Hello guys, i have saturated spectrum of Rb. My goal is to identify which lines i see. http://imagizer.imageshack.us/a/img835/8787/xvwr.png So from http://www.opticsinfobase.org/oe/fulltext.cfm?uri=oe-15-10-6293 I have identified that there are to 2 Isotopes: Rb85 and Rb85, further from...

Is there something like a "neutrino spectrum"?. Would it be analog to light spectrum?. Sorry for the ignorance, just curious. AGZ

I was told at school that when a hydrogen electron gains heat energy enough to excite it shifts to a higher energy level, then after a very small period it falls back to its ground energy level, that means all the energy it gains should be lost, but if that is true since hydrogen has an electron...

Why cold gas is used for producing an absorption line spectrum

The most probable velocity of thermal neutrons can than be approximated by the Boltzmann constant and is given by the following: v = sqrt (2kT/m) where k is the Boltzmann constant T is the temperature m is the mass of the neutrons My question is why is the above equation not the...

I am doing a final year project, my Prof gave me 2 prism. He wants me to do so: A white laser is shot on a prism producing a visible light spectrum, use another prism to converge the spectrum back into a laser. For me, it is theoretically impossible and I tried to convince him that it...

is it possible to work backwards from a spectrum to which operator?

Dear Physics Buddies, How are well all, okay I hope. I was wondering if I might browse all your infinite intellects and ask you a very simple question. I am working with some medical images in MATLAB and my collaborators would like to know the orientation of the fibres that it contains...

Homework Statement Hello, I have a question regarding hydrogen spectral emission. A hydrogen source is viewed with a grating spectrometer, one spectral lines occurs at 20.5 degrees in the 1st order. What angle will this line appear in 2nd order (viewed through same spectrometer) a)...

Hi. I have an electric field E(r) which can be equivalently characterized by its Fourier spectrum \tilde{E}(k) through E(r)\propto\int\tilde{E}(k)exp[ik\cdotr]dk The Maxwell equation states that in a homogeneous and isotropic medium ∇\cdotE=0 So, applying this equation to my Fourier...

why do the atoms in excited state alone could emit line spectra?can't they emit when they are not in gaseous state? why only molecules can emit band spectra?can't atoms emit them

Homework Statement I've attached the problem Homework Equations d*sinθ=mλ The Attempt at a Solution I've tried a couple of methods. I considered solving for m when θ=90 degrees => sinθ=1 because 90 degrees is the highest possible angle and will (in my mind at least) yield the highest order...

Is the rather continuous spectrum of the Sun due to redshift/blueshift of the radiation emenating from the Sun? I understand that the emission spectrum of Hydrogen in the visible range is quantized to four discrete values, but I'm trying to understand how all frequencies of visible light are...

Do less bright stars have redder spectrum?