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MOMcCray
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I am interested in naturally occurring electromagnetic waves, is there a reference that lists wavelength, frequency, electric and magnetic fields, etc.?
Welcome to Physics Forums.MOMcCray said:I am interested in naturally occurring electromagnetic waves, is there a reference that lists wavelength, frequency, electric and magnetic fields, etc.?
Redbelly98 said:The relationship between frequency and wavelength is
f = c/λThis relationship holds for both natural and man-made radiation, whatever the source. It is shown graphically here, along with the photon energy:
http://www.electrical-res.com/EX/10-17-19/SURA_Electromagnetic_Spectrum_Full_Chart.jpg
The amplitude or intensity of the radiation would depend on the nature of the source and your distance from it. I've never hear of any all-encompassing compilation as you are asking for. I guess you would probably have to pick a few examples and do some research or ask questions about specific cases.
a 12,398 Angstrom wavelength photon is a 1 eV photon. a 1.2398 x 10-6 meter wavelength photon is a 1 eV photon. Visible light is from ~4,000 to about 6,500 Angstroms (2 to 3 eV).MOMcCray said:what is the 1.24x10 to the -6 / eV? The kenetic energy of the photon? The stregth of the electricfield? ?
Redbelly98 said:The relationship between frequency and wavelength is
f = c/λ
Why do you think that? The frequency is c divided by wavelength, as I said before.MOMcCray said:frequency = c x wavelength.
Whoah, missed that. :uhh: Sound waves shouldn't even fit on their frequency scale (> 105 Hz)QuantumPion said:Why do they list sound waves and ultrasound on that chart under low frequency electromagnetic waves? :grumpy:
Redbelly98 said:Why do you think that? The frequency is c divided by wavelength, as I said before.
Whoah, missed that. :uhh: Sound waves shouldn't even fit on their frequency scale (> 105 Hz)
The chart refers to them as "Sources and Uses of Frequency Bands", not as types of EM waves. Anyway, my stereo generates electrical signals at 10's of kHz, and the ultrasound machine also uses electronics to generate the ultrasound frequencies, so there are EM waves that are directly related to sound.QuantumPion said:Why do they list sound waves and ultrasound on that chart under low frequency electromagnetic waves? :grumpy:
Technically, you could say the electric and magnetic field strength depend on the volume occupied by the photon, which would be different depending on the specific situation. In practice, electric and magnetic field strength are useful when talking about E-M waves classically, and not so useful when treating E-M fields as discrete photons.MOMcCray said:How are the electric and magnetic fields related to frequency,wavelength,energy of the photon?
Redbelly98 said:Technically, you could say the electric and magnetic field strength depend on the volume occupied by the photon, which would be different depending on the specific situation. In practice, electric and magnetic field strength are useful when talking about E-M waves classically, and not so useful when treating E-M fields as discrete photons.
Not really. So far you have asked pretty general questions, so the answers must be general.MOMcCray said:Could you be more specific...
That depends on how much physics you already know. I can take a guess, and suggest the textbook Physics: Principles With Applications by Giancoli. It covers electricity, magnetism, and optics at a basic level.... and or suggest some sites where I could get more information about E-M fields.
Redbelly98 said:Not really. So far you have asked pretty general questions, so the answers must be general.
That depends on how much physics you already know. I can take a guess, and suggest the textbook Physics: Principles With Applications by Giancoli. It covers electricity, magnetism, and optics at a basic level.
https://www.amazon.com/dp/0131021532/?tag=pfamazon01-20
It sounds like the Giancoli book will be a good place to learn (or relearn) the basics. It uses algebra and trigonometry--no getting around that if you want to learn physics--but not calculus. I've seen it used for high school honors physics, as well as college physics for non physics majors.MOMcCray said:Thanks. I took a year of college [classical] physics and a couple years of college calculus in the sixties. Later I became an MD. Now I'm retired and trying to understand some of the basics that underly our universe. Somewhere physics took a right turn and took off. I'm trying to catch up. Asking general questions that lead to more and more specific questions. I've needed a new textbook. Thank you for your recomendation.
Best to first review the basics of E-M fields and also oscillations & waves, which are all covered in the Giancoli book. I'll just note that physicists refer to the energy of a photon. It is not considered kinetic energy, which is the energy of motion of a massive object.Looking at your previous replies there seems to be a disconnect between the wavelength, freqency and the keinetic energy of E-M waves and their electric and magnetic fields. I am not completely surprized by the disconnect and I am very interested in how it is resolved.
You're describing the oscillation of the field strength. The photon volume would usually not change during an oscillation cycle, but is determined by for example any mirrors or obstructions that are present. Or the photon may not be confined to a volume at all in some cases, for example an atom emitting a photon into free space.You said the electro and magnetic field strength had to do with the volume occupied by the photon and varied under different situations. Interesting. The field strength varies repeatedly from zero to max and back to zero. But I suspect there is more. Under what situations do the field strengths vary. Does the volume of the photon vary and this gives rise to the repeating variable field strengths?
That is pretty much the definition of what a photon is.My fantasy is that photons represent packets of energy, quanta [gamma>radio].
I have never heard of anyone talking about the "inertial mass" of a photon. But yes, their trajectories are bent by gravity. That gets into the realm of general relativity, not my area of expertise.They have an inertial mass and velocity> kinetic energy. Their trejectories are bent by gravity. etc.
Well, that's sounding pretty speculative, i.e. outside the mainstream view, which means off-limits in terms of our forum guidelines of discussion. We're here to teach, learn, and discuss mainstream science. I take your comments as an attempt to learn about photons and E-M fields, so that's okay.Here is the disconnect.
They have an inherient energy [gamma>radio] apart from their kenetic energy.
It is this inherent energy that is responcible for the electro and magnetic fields.
The gamma fields are greater than those of radio.
Thanks,MOM
Redbelly98 said:It sounds like the Giancoli book will be a good place to learn (or relearn) the basics. It uses algebra and trigonometry--no getting around that if you want to learn physics--but not calculus. I've seen it used for high school honors physics, as well as college physics for non physics majors.
Best to first review the basics of E-M fields and also oscillations & waves, which are all covered in the Giancoli book. I'll just note that physicists refer to the energy of a photon. It is not considered kinetic energy, which is the energy of motion of a massive object.
You're describing the oscillation of the field strength. The photon volume would usually not change during an oscillation cycle, but is determined by for example any mirrors or obstructions that are present. Or the photon may not be confined to a volume at all in some cases, for example an atom emitting a photon into free space.
That is pretty much the definition of what a photon is.
I have never heard of anyone talking about the "inertial mass" of a photon. But yes, their trajectories are bent by gravity. That gets into the realm of general relativity, not my area of expertise.
Well, that's sounding pretty speculative, i.e. outside the mainstream view, which means off-limits in terms of our forum guidelines of discussion. We're here to teach, learn, and discuss mainstream science. I take your comments as an attempt to learn about photons and E-M fields, so that's okay.
I have had a similar problem with thermodynamics, in particular heat engines. A year or so ago I took some time to learn the very basics, and just yesterday bit the bullet and ordered a recommended textbook so that I can spend the time and effort to learn more of the details. I love that there are used, discounted copies of textbooks easily available online.
Electromagnetic waves are a type of radiation that consists of oscillating electric and magnetic fields. They are produced by the acceleration of charged particles and can travel through a vacuum.
Electromagnetic waves occur naturally through various processes such as the movement of charged particles in the Earth's magnetic field, the sun's nuclear reactions, and the natural decay of radioactive materials.
Examples of naturally occurring electromagnetic waves include visible light, radio waves, microwaves, infrared radiation, ultraviolet light, X-rays, and gamma rays.
Yes, some naturally occurring electromagnetic waves can be harmful. For example, prolonged exposure to ultraviolet light from the sun can cause skin damage, and exposure to gamma rays can be dangerous to living organisms.
Scientists use specialized instruments such as telescopes, spectrometers, and detectors to detect and study naturally occurring electromagnetic waves. They can also use mathematical models and simulations to understand the behavior and properties of these waves.