Quanta Definition and 69 Threads

In the "single photon" 2-slit experiment, I understand one of the basic assumptions is that a photon gun only produces whole photons, or, at least, it's assumed that only whole photons (or waves with whole photon level of energy) make it through the 2 slits. But since a photon detector only...

This is something that's bugged me for a long time and since I don't have any particular expertise in the subject, maybe I'm missing something obvious. But here goes. I was taught that the term particle in QM is synonymous with quanta. That is, that a particle is the lowest excitation level of a...

Hi, I had the PET scan as an experiment a few weeks ago and then had to write a protocol. The aim of the experiment was to count the number of gamma quanta resulting from pair annihilation. The events were analyzed using the coincidence method. Here is an excerpt from the table including error...

Quanta Magazine recently published "Clashing Cosmic Numbers Challenge Our Best Theory of the Universe" I am no fan of Quanta and I am not a cosmologist but there is certainly the increasing buzz that something is wrong with ##\Lambda##-CDM and cosmological models thanks to the JWST. Is...

hello i would to get some help with my homework. 1. true 2. i dont know 3. true 4. i dont know 5, false 6. i dont know about 2,4,6 i really have know idea what to think I really appreciate help

What is the lowest frequency/energy where photons have been observed? That is, electromagnetic waves observed as quanta, not continuous waves? Resolving noise that is not thermal noise, not shot noise from the discrete nature of the electrons in the receiving electronic, nor from the...

Usually we hear about people working on a theory of quantum gravity, in order to avoid the singularity in the center of a black hole for example. But what if it's the other way around to some extent as well? What if it's gravity keeping quantum objects from doing their greatest reality-defying...

But then I learned a photon can be split into two or even three photons (red-shifted, energy is conserved), and also photon can lose energy and still be a photon (Raman effect, inelastic scattering). Now, I am not sure what it means when it is said photons are quanta of light (smallest unit of...

I read somewhere in Quanta magazine that (if I understood correctly): When A and B watch C, then C in A's reality may be different than C in B's reality (as B is seen by A?) What if A and B watch each other? We could make chain: A in A's reality, B in A's reality, A in B's reality in A's...

hi there, i have always loved Science, and from astronomy transitioned into particle physics because of the Higg Boson, learning about the implications of Dark Matter, and Dark Energy. i am also studying things like Zero Point Energy, have always been fascinated with the flight dynamics of...

We say that vibrations of Faraday lines of force create electromagnetic waves.Now photon is the quanta of electromagnetic field.Is photon also the quanta of electromagnetic wave? How can the same photon represent both if so?

I’m trying to understand how a solid body changes the wavelength of radiation it re-radiates from that which it originally absorbed. I’m thinking in context to the way that the Earth absorbs higher frequency radiation from the sun, but when it re-emits the energy it’s at a much lower frequency...

1. The problem statement Consider the case of 10 oscillators and eight quanta of energy. Determine the dominant configuration of energy for this system by identifying energy configurations and calculating the corresponding weights. What is the probability of observing the dominant...

Imagine a two-state system, e.g., a single nucleus that can be aligned or anti-aligned with an external magnetic field. If that nucleus is in a "mixed state" at time zero, such that it's wavefunction is 50% up and 50% down at time zero, why can that nucleus absorb a "quanta" of radiofrequency...

I'll be entering my sophomore year as a physics major and all the classes seem really cool and standard; however, there is one class I'm curious about. It's called "Relativity and Quanta" and it's description is as follows; "Special relativity: Lorentz transformation, dynamics, and conservation...

Dear All, I have a couple of (noob) questions regarding Doppler Shift and light from a quantum physics perspective: a) Since different observers will see the light at different frequencies depending on their reference frame / velocity thus resulting in Doppler Shift, does that mean that any...

A quantum mechanical oscillator with the Hamiltonian H1=p^2/2m +(m(w1)^2 x^2)/2 is initially prepared in its ground state (zero number of oscillatory quanta). Then the Hamiltonian changes abruptly (almost instantly): H1→H2=p^2/2m +(m(w2)^2 x^2)/2 What is the mean number of oscillatory quanta...

Homework Statement Consider a small cluster of four copper atoms. Assume, that each atom can oscillate around its equilibrium position independently of the other atoms. Let us model each direction of vibration as a harmonic oscillator, whose energy is quantized Evib = ¯hω(n +1/2), where ω =...

I am starting a Phd in statistics this year at Montréal University (CANADA). Discussion about physics and quantum mechanics are my interests. THanks to all!

I am very confused. Here are a couple of facts I can't connect : Quanta is the Delta of values of energy. Quanta is a packet of energy. a packet doesn't really stop at a finite distance from its peak. The Energy of a wave is the total energy of its quantas.

Hello. I want to share a thought experiment that could tell Quantum Mechanics apart from Pilot-Wave interpretation. It goes like this: Quantum Mechanics vs. Pilot-Wave: Quantum Mechanics: Waves collapse to particles. Waves disappear when particles are detected. Pilot-Wave: Waves are real but...

In QFT, an ultraviolet cutoff is imposed to avoid singularities. One physical reason for why this works may be that there actually is an ultraviolet cutoff from spacetime being quantized. Since in GR spacetime is responsible for the force of gravity, and gravitons are the hypothesized quanta of...

I am a junior in high school and after I spent some time studying quarks and antiquarks, I continue to raise more questions about their relationship to other fundamental quantities. I tried searching the internet for answers but the posts I've been reading only raised more questions for me. Are...

Hi everyone, Could you please tell me how would you rank these PhD for someone looking for a future career in the financial quant industry? (assuming I have math background and decent programming skills). Thank you in advanced! Between parenthesis are the specific research groups found in each...

I started out with a video of someone "measuring" the speed of light by microwaving a chocolate bar. Not surprisingly, this turned out to be partially bogus. http://morningcoffeephysics.com/measuring-the-speed-of-light-with-chocolate-and-a-microwave-oven/ This sparked some more questions...

I know what the letters mean, E = Energy of the photon, h = Planck's constant, f = frequency of the photon. But what does it mean for a particle to have a frequency, something that I'd associate with a wave. And what can you think Planck's constant is representing? Any replies would be much...

Just a general inquiry, and not for any personal gain and or theory, I would like to know if anyone has developed a formula for measuring the vibrational rate of an atom.

I was reading a section of a chemistry textbook describing electron energy shells. It compares the electrons to light saying that electrons energies are quantized and so are light energies. Electrons can only jump from one specific energy level to another with no intermediary energy levels. I...

Quantum field theory deals with the quantization of the electro-magnetic field, and finds its quantum: the photon. Electric and magnetic fields are classical fields. Can QFT quantize also them, and find their quanta? It is often said the electrons are field quanta (particles are quanta)...

http://arxiv.org/abs/1404.1750 How many quanta are there in a quantum spacetime? Seramika Ariwahjoedi, Jusak Sali Kosasih, Carlo Rovelli, Freddy P. Zen (Submitted on 7 Apr 2014) Following earlier insights by Livine and Terno, we develop a technique for describing quantum states of the...

I just listened to a lecture on this, and I'm not sure I quite get the point. What the lecturer did was examine coherent states in the simple harmonic oscillator then linked excitations of an oscillator to the number of field quanta. The goal of the lecture was to show how Maxwell's...

Hey everyone so normally I prefer the challenge of conceptualizing these types of things myself but I really am stuck. I can't grasp the concept of Plancks quantas and it seems like an important first step in understanding quantum mechanics. It seems from what I've read that he basically found...

edit: Nevermind, I found the answer myself :X

How can discreet quanta of photon energy make up a continuous electromagnetic spectrum, whose wavelengths are any arbitrary value? Is there overlap of quanta, temperature dependency, or so many finely divided energy levels that the spectrum just appears continuous? Electron energies are...

Hello, I am fairly new to quantum physics, I am trying to understand where discrete quanta come from... I think that energy levels and particle angular momenta (and momentum?) are all quantised in quantum theory. Is there a simple explanation of why there must be discrete levels... is it...

what does it mean when someone says field quanta are not spatially localized? does it mean they are in superpostion or they are just moving very fast? sorry if I sound daft

http://books.google.co.uk/books?id=rcrf0P8DSe0C&pg=PA159&lpg=PA159&dq=how+quantum+field+theory+is+possible+are+field+quanta+real&source=bl&ots=ikthHRxMHp&sig=jLOBZzBHtVYmh02f8pXzSIUYIlQ&hl=en&sa=X&ei=6r7dUJfzEYSe0QXjwYC4Bw&ved=0CG8Q6AEwBQ#v=onepage&q=how%20quantum%20field%20theory%20is%20possible...

What is "Magnetic flux quanta"? is there any animation describing this subject?

Hello, This is my first time using this forum, I just have a quick question that I'm trying not to get too held up on by re-reading (skimming) the chapter several times. Anyways: Homework Statement "Consider the case of 10 oscillators and eight quanta of energy. Determine the dominant...

https://www.physicsforums.com/blog.php?b=3873 What do you think? :-p Can you shed some light on that mess? Or even better, can you further confuse it?

Homework Statement A radio station operates at a frequency 103.7MHz with a power output of 200kW. 1)Determine the rate of emission of quanta from the station. 2)If we treat the radio station as a point source radiatng uniformly in all directions, find the number of photons inside a...

Could our cosmos consist of only identical particles?

Hi, I've been on the other PF forums for some months, where QM is often mentioned and I assumed I had some basic understanding of it, but I thought I would come here to clarify. I read http://en.wikipedia.org/wiki/Quantum_mechanics" on it and I'm still unsure if I have it right or even...

Hi, Why do photons come in quanta? Why are the quanta not bigger or smaller or continuous? Thanks, Anna.

not sure if here or beyond standard model or higher energy physics is the best place -- mods feel free to move to best forum. suppose dark energy does exist and is part of einstein's cc. is there a quanta associated with it, and is it boson or fermion? if SUSY, then does this quantum also...

This is a question I've had for some time, but didn't think to ask whenever I was around someone who might have been able to answer it. If energy and matter are made of quanta, then why is quantum physics coming up with so many irrational results instead of integral ones?

Learning the basics of quantum theory, one thing I can't quite grasp is how quanta, especially the e=hf equation, works within the law of the conservation of energy. I imagine the heat death of the universe for example, and taken to the extreme end all masses have been converted to energy...

Non-spatial resolution of quanta (split off from "Local realism ruled out?") I have taken the liberty of creating a new thread since this sub-discussion in https://www.physicsforums.com/showthread.php?p=2561841&posted=1" had diverged a bit from the OP. You distinguish two isomorphic...

When gravity is expressed in tools of QFT, the quanta is the spin-2 graviton. What is the quanta according to LQG, SF, CDT, and other BI theories? Is it the spin network? What role does the graviton of QFT quanta play and BI ?

Are sound waves released in quanta? If so, what are these bosons called? If I'm wrong, please explain why?