Not necessarily -- it's just a function of [itex]\lambda[/itex]. The size of a photon is not known and is a tricky theoretical concept. As a particle, it is a zero-dimensional point. But it has a wavefunction, and this gives it a sense of spatial extent. A photon is a quantum of energy of the electromagnetic force. It is not correct to think of the photon as any more general than that. Of course, in most problems of interest in introductory physics (electrons jumping energy levels and emitting quanta) the electromagnetic force is the main player.Thanks for that definition ... more or less is OK for me. The fact that we are dividing by the wavelength makes this quantum of energy by definition always one wavelength long. Is that correct?
I would need to know more details about what you are trying to do. What do you mean by primordial particles? What are their properties (mass, charge, spin, etc)? Are these particles free or are they interacting with each other? If they are interacting, are you considering them as occurring in bound states?Hi Bapowell,
Thanks for the response. My dilemma is that I am trying to get my head around the type of emission one could expect from primordial particles. Being so small, their would their ability to absorb and then emit more than one quantum at a time be limited or could you expect a continuous wave from such a small thing?
It depends on lots of things. The fact that dark matter is 'dark' is a result of the fact that it is electromagnetically neutral -- it emits and reflects no light. Therefore, dark matter particles should not be emitting any photons whatsoever. If they did, they would have spectral properties that could be observed. As a side note, the CMB was generated 13 billion years ago approximately instantaneously. It is a near perfect blackbody with a temperature of around 2.7 Kelvin and is exceptionally uniform to 1 part in 100.000. Dark matter is clumpy as a result of its gravitation (similarly to ordinary matter) and so even if it did somehow manage to emit radiation, it would be exceedingly difficult to generate such a smooth and pristine radiation field as the CMB.Hi Derek. Yes, this is my homework. I am 58 years old and am trying to do some original thinking with regards to dark matter. In my hypothesis I see dark matter as primordial particles being formed continuously. I am trying to ascertain the type of emission that such dark matter would produce. Is it single photons being emitted or is it a continuous wave. Would it be in the microwave region? Is it maybe CMB?
If they are non-interacting, then by this very definition they cannot emit photons.Hi Bapowell,
I am concerned this debate may take us outside the rules that this forum allows with regards to alternative views from the standard model. It is for this reason that I am trying to keep my questions as basic as possible. NOTHING in the universe is at or below 0 degrees K and as such MUST emit. Perhaps we should keep the debate along the lines of my question: would such (theoretical) non-interacting particles weighing 500 000 to 8 000 000 eV emit photon by photon or a continuous wave?
Hi Guys, surely the emission frequency cannot depend upon th SIZE of the particle?
If they are non-interacting, then by this very definition they cannot emit photons.
may I take it as an 'okay' .Sir?
Not necessarily the size of the particle, but rather the area in which the energy is bound or modulating. For visible light, it is the ratios of the before and after electron orbitals about the atom or molecule that determine the photon frequency. (Before and after radiation occurs that is)
But if they are emitting EM radiation then they are electrostatically charged. If I place two of your dark matter particles of opposite charges next to each other...will they not stick together?When I say non-interacting, I mean in the sense of the particle binding with other particles. Any EM radiation would either destroy such small particles or be absorbed. If the energy were absorbed these tiny particles would probably emit the energy pretty promptly. It is this emission that I refer to. Single photon?
Hi PhilDSP,
Perhaps you are referring to atoms with orbitals. These subatomic particles have weights that are on the same scale as a gamma ray photon. Is it possible that they could emit photons nearly their own weight?