Absorption Definition and 495 Threads

If the electron absorbing the photon causes it to change from waveform to particle ? Then what causes the photon to change from waveform to particle when observed ? (That is exposed to another photon).

I first approached this problem with the idea that I could try to find the temperature of the HII region given that we already know the background temperature. Still, I am stuck on finding the region's temperature. A second approach was to try to find if the cloud is optically thick, which...

I have a question regarding the absorption of photons in a semiconductor. Assuming I have a doped semiconductor (e.g. nitrogen in titaniumdioxide) removing electrons and creating holes. Do the created holes influence the absorption of photons and therefore have a direct impact on spectroscopic...

The answer from answer key is electrons in gas absorb photon energy and causes electron to move to higher energy level. When electrons de-excite, photons emitted in all directions so dark lines occur. My question is if photons are emitted in all directions when electrons move from higher to...

I want to calculate the K and L absorption edges for Niobium (Nb). Could anyone explain the steps to calculate these absorption edges? I don't know how to use the Moseley law to calculate those values: https://en.wikipedia.org/wiki/Moseley%27s_law For reference, Niobium has: Shielding...

Hey, Can Anyone suggest me a common(Household) material that obeys Hooke's Law and is Similar to Rubber/silicon........Basically a material which helps in shock absorption. Please note: No fluids and No gases are allowed Thanks in Advance ;)

Hi, I am a material engineer and have a question about a formula derivation relative to microwave absorption. I really cannot figure it out after days of trying. This should be simple for a specialist. In this attached paper, how could one derive Eq(10) based on Eq (8) and (9)? Is k_2 in Eq...

According to my notes, the absorption law states that p ∨ (p ∧ q) = p, p ∧ (p ∨ q) = p I have found a video where they were discussing a partial absorption such as ¬q ∧ (¬p∨q) = ¬q ∧ ¬p This is not in my notes, but is this correct? specifically, is the terminology used to decribe this property...

My question emerges from my desire to calculate the optical depth, which should be unitless, for an inhomgeneous cloud of radius ##r##. For a homogeneous medium, the optical depth can be defined in terms of the density of a cloud relative to the density of the condensed medium: $$\tau = \alpha...

Basic stuff. Do emission and absorption spectra match? If so, why wouldn't hot stellar atmospheres exhibit both, cancelling? I'm a tourist...not physics minded..

Let's say we have a point source of an EM wave in a vacuum of total energy E, and an absorber atom at some distance from this source, whose first excited state is at the energy B, with B < or = E. The energy of the wave is constant as a whole, but at each point around the source the energy...

Lone homonuclear diatomic molecules have vibrational excitations and rotational excitations. However, due to lack of transitional dipole moment, these are strongly forbidden to absorb IR. Lone atoms don´t have the above excitations in the first place. Now, when a diatomic molecule collides with...

When a photon is absorbed, electrons move from a lower energy level to a higher energy level, so my answer is a, b, c, and f. I don't understand why the solution is b, c, d, e. Can electrons in this case move from a higher to lower energy level? Thank you.

Hello ! As I understand it, the different isotopes of the same atom have a slightly different spectroscopic absorption and emission where, for example, Deuterium absorbs slightly shorter wavelengths than Protium. My question is if two isotopes of different atoms, for example Tritium and Helium...

I did a prac where we tried to calculate the rydberg constant for hydrogen. We had a hydrogen lamp and we used a spectrometer that was hooked up to a photomultiplier tube to detect the wavelengths of light corresponding to the balmer series. In one section I need to write up a brief summary of...

##\alpha## is considered to be the absorption coefficient for a beam of light of maximum intensity ##I_0##. It's related to the complex part of the refractive index as we have shown above. Now, I have a doubt. Should I solve for ##k## from the quadratic equation in terms of the linear optical...

What determines the time between atomic absorption and emission of photons? Is there a correlation to blackbody radiation?

The Schwarzschild metric implies a potential different from that of Newtonian gravity. Is there a relationship between it and the process by which particles can be absorbed by other particles? (I haven't studied QFT yet)

Hello, is there a convincing experiment to visualize absorption spectra? At disposal I have: - Halogen lamps - Lenses - Straight view prism - transmission grating - slit, iris, screen - Sodium vapor lamp and mercury vapor lamp Unfortunately, I do not have a sodium vapor cell or anything...

The emission spectrum or resonance fluorescence for a quantum dot, atom or defect center are discussed in many quantum optics textbook, for example see "Quantum Optics" by Marlan O. Scully and M. Suhail Zubairy Chapter 10 , "Quantum Optics" by D. F. Walls and Gerard J. Milburn Chapter 10 and...

Hi all I couldn't find on the web anywhere but what I'm looking for is a real image of strong Balmer absorption lines for a 10,000° Kelvin star and also a real image of a weak Balmer absorption lines for both a much colder or hotter star that shows how the absorption lines are weak. Does...

Hi all, I'm doing some research on vapour absorption cycle machines, mainly water ammonia refrigerators. I've got a few questions. 1. What is the role of the water absorber? ie why do we need the water? 2. In the absorber we have a water ammonia solution. Is the ammonia a gas in the solution...

Hi there, I am a physical oceanographer teaching an introductory undergraduate Earth science class that has a unit on astronomy. I have a physics undergraduate background, took a few astronomy classes at the undergraduate level back in the day, and did a bit of undergraduate research in...

Hello! I am reading about dressed states, and I am presented a situation in which we have a laser (the pump laser) on resonance with a 2 level (atomic) transition, and a second, weak laser (probe laser) that is scanned over a frequency range. The absorption spectrum of the probe laser, for...

Wikipedia: "When a photon has about the right amount of energy to change the energy state of a system (usually an electron changing orbitals), the photon is absorbed." What happens if a somewhat higher energy photon arrives?

Hi, I was watching the following video. I need your help to clarify few important points. Thanks a lot in advance! Question 1: I'm not able to understand picture #1 below. I think that the frequency increases vertically downward but what about the horizontal scale? Compared to picture #1...

My professor gave us a formula for absorption cross section, but he said he did not remember where he found it. The formula is given by $$\sigma_a =\frac {1} {| \mathbf E_i|^2} \int_V k \epsilon^{''}_r | \mathbf {E} |^2 dV = k \epsilon^{''}_r |\frac 3 {\epsilon_r +2}|^2 V.$$ Where does...

I read articles talk about the absorption of the exciton in a solvent, such as TIPS Pentracene in toluene. My question is does the absorption spectrum keep the same for aggregate TIPS Pentracene , in case if I want to know for a layer of TIPS Pentracene?! My second question is: let's say I know...

Why SAR value at body is allways higher than at head?

The doped a-Si: H layers in a HIT solar cell do not contribute to the photocurrent. The light they absorb (according to their absorption curve below) is lost. For a doped a-Si: H layer at the front side of the cell that is 25nm thick, what percentage of light at 400nm will be lost due to...

Hello everyone, We conducted an experiment with a strontium-90 source and some different thicknesses of lead. With 2.1mm of lead the count rate (corrected for the background) was 0.69 counts per second, 3.0mm 19.7cps 6.8mm 15.4cps 13.8mm 10.0 cps This would...

Quick question: let's say we have an atomic electron in the ground state which requires, say, one "unit" of energy* to jump up to the next orbital energy state. If a photon arrives with a bit more or less than this, say 1.00003 or 0.99997 units of energy, is there some finite, non-zero...

Why do we see more absorption lines in stellar spectra than emission lines?

Hi All In another thread I answered was a question related to this and noticed another as well, so I thought I would give the full answer in its own thread rather than write it out twice. The other question has been deleted but here is the full detail anyway. First see...

Hello all, I have a monochromatic laser peaking at 808 nm and some non-scattering sample. I want to measure the absorption with a spectrometer. I can use the Beer-Lambert law to do this, but since it is a monochromatic laser I have some doubts. I could do a weighted-average, taking into...

Homework Statement: I am having difficulty understanding what exactly is happening when radio transmissions are being absorbed by oxygen at 60GHz at the atomic level. Homework Equations: Refraction/reflection, oxygen absorptions/attenuation, frequency I have tried to find the answers online...

Hi I'm preparing some BCNO phosphor samples. Their basic structure is hexagonal Boron Nitride (h-BN) but it's doped with carbon and oxygen. The simplest BCNO phosphors are usually made from urea and boric acid alone, this already produces a BN structure with C and O impurities. I'm trying to...

True black materials theoretically absorbs all wavelengths of visible light. True white materials reflect all wavelengths of light. If a material which was black at room temperature was heated up to incandescence so that it was emitting all visible wavelengths (white light), and then light was...

Hi, I am a bit out of my league here, but had a question. I have 5 pieces of .25" thick foam/padding of different densities, and I wanted to measure which one absorbs the most energy (weakens the impact) when struck by a fist/punch or even a ball, how would I do that? I ran across a...

I eventually managed to find that a CO2 molecule can absorb about 8% of infrared energy passing through it that's radiated from Earth but its actually been incredibly hard to find a comparable figure for H2O molecules. Has anyone got a percentage figure for H2O in the form of atmospheric water...

Summary: The experimentally measured absorption spectrum of 1,3-pentadiene molecule exhibits a peak absorption (light absorption) around 224 nm corresponding to an electronic transition. Estimate the length of the molecule. I thought of using lambert law A = c*l*e but we have none. how do I...

Summary: MIT researchers have created a material that is 10x blacker than any other material ever recorded. The foil captures at least 99.995% of incoming light. Does this mean that there is practically no EM re-radiated?

The point that I want to know is how two frequencys react with each other and does electron's frequency wait to reach to higher frequency on that fraction of second when they(photo's frequency and electron's frequency)collapse to each other than go to higher energy level or what?

I'm not that familiar with the current theoretical standing on how electrons "absorb" photons, as in the sense that electrons in an atom absorb photons and move from lower to higher energy states. But during the absorption of a photon the electron, if you set units of c=1, gains energy and...

I have read oodles of hand wavy qualitative text about 'the greenhouse effect' and it is clearly dominated by the absorption characteristics of H2O vapour. What I struggle to understand is the part of CO2 in radiative absorption, in relative quantified terms. CO2 has absorption peaks at 2.7um...

In nuclear magnetic resonance, when should one process spectra in absorption mode and when - in magnitude mode? What is benefit of using the first one and the second one? For example, I need to integrate spectrum. In this case, what should I use - absorption or magnitude mode?

Hi everyone. Firstly, I'm not a physicist, so relatively "intuitive" explanations would be greatly appreciated :) I'm confused by the following: Let's say we have a partition / wall, which resonates at a specific natural frequency. If the resonance is relatively high Q (low damping), then...

Hi, I wonder why with electromagnetic radiation, there's some radiation that penetrates with Earth atmosphere such as visible light, while other can't like gamma radiation. What does the penetration of any em radiation on any object depends on

Hello: Do anyone remember a law to calculate an area of a sphere ,some thing like the specific surface area but relative to absorption of radiation ?

Hi everyone! Terahertz time-domain spectroscopy (THz-TDS) is a spectroscopic technique that is using the radiation in the THz range. https://en.wikipedia.org/wiki/Terahertz_time-domain_spectroscopy A THz-TDS setup consists of an emitter and detector. The emitter creates a short broadband...