Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
This may at first sound like a stupid question. But after some years
as a radio enthusiast, I don't know what a radio wave is - what it really is. Supposedly, modern physics does not believe there is such a thing as "action at a distance". In other words, if you launch a radio wave and I intercept it, there must be a transfer of "stuff" between you and me. You can't just say that if I wiggle an electron at point A, I can cause a wiggle at the same wiggle rate at point B. I mean you can say it, but it doesn't explain anything. OK, so the latest science says that electromagnetic energy is really particle-waves. I guess this means that when I transmit, my antenna is firing particles in the form of low-energy photons (energy packets), and that these photons do not really exist anywhere but exist only as probability waves - until, of course, someone intercepts the wave. Then, magically, the photons appear at the receiving antenna, in which they manage to produce oscillating electrons. So, the best I can ascertain is that radio waves are really probability waves. I'm not sure that really helps with an intuitive understanding. Does anyone have a good description for what a radio wave really is? - JJ |
#2
![]() |
|||
|
|||
![]()
JJ wrote,
So, the best I can ascertain is that radio waves are really probability waves. I'm not sure that really helps with an intuitive understanding. Does anyone have a good description for what a radio wave really is? - JJ Yes, go ask your question on sci.physics.electromag and you'll get some answers, although I can't guarantee they'll be of any use to you. 73, Tom Donaly, KA6RUH |
#3
![]() |
|||
|
|||
![]()
A radio wave is an electromagnetic field. On my first day of fields
class, I asked the professor what an electromagnetic field was. His reply: "An electromagnetic field is a mathematical model that enables us to explain certain phenomena which we can measure." The professor was Carl T. A. Johnk. I have in front of me his text, _Engineering Electromagnetic Fields and Waves_. On page 1, it says, "A field is taken to mean a mathematical function of space and time." "Stuff" isn't transferred from one place to another by electromagnetic fields, but energy most definitely is. Force can be applied through space from one place to another by means of an electromagnetic field, and energy can be transferred by means of a field. Since the energy contained in a field can be calculated, I'll go out on a limb and say that a radio wave can be regarded as a form of energy, like heat or falling water. Perhaps a purist or physicist can find grounds to argue with that statement, it's certainly a valid concept for engineering purposes. As far as photons and waves go, be really, really careful in extending your everyday experience to quantum mechanical objects. Feynman very nicely illustrates in "Quantum Behavior" in his book _Six Easy Pieces_ that neither particles nor waves is adequate to describe such things: "Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen. .. . Historically, the electron, for example, was thought to behave like a particle, and then it was found that in many resepects it behaved like a wave. So it really behaves like neither. Now we have given up. We say: 'It is like *neither*'" I highly recommend this book, and other of his writings, if you're interested in understanding these phenomena on a more basic level. Roy Lewallen, W7EL jj wrote: This may at first sound like a stupid question. But after some years as a radio enthusiast, I don't know what a radio wave is - what it really is. Supposedly, modern physics does not believe there is such a thing as "action at a distance". In other words, if you launch a radio wave and I intercept it, there must be a transfer of "stuff" between you and me. You can't just say that if I wiggle an electron at point A, I can cause a wiggle at the same wiggle rate at point B. I mean you can say it, but it doesn't explain anything. OK, so the latest science says that electromagnetic energy is really particle-waves. I guess this means that when I transmit, my antenna is firing particles in the form of low-energy photons (energy packets), and that these photons do not really exist anywhere but exist only as probability waves - until, of course, someone intercepts the wave. Then, magically, the photons appear at the receiving antenna, in which they manage to produce oscillating electrons. So, the best I can ascertain is that radio waves are really probability waves. I'm not sure that really helps with an intuitive understanding. Does anyone have a good description for what a radio wave really is? - JJ |
#4
![]() |
|||
|
|||
![]() "Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen. I love that part, and I always picture Ed Norton of the Honeymooners.. ![]() I picture it more or less, as sort of a tide in the wheeler foam, changing the probabilities. Works for me.. |
#5
![]() |
|||
|
|||
![]()
Roy Lewallen wrote:
"Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen. . . Historically, the electron, for example, was thought to behave like a particle, and then it was found that in many resepects it behaved like a wave. So it really behaves like neither. Now we have given up. We say: 'It is like *neither*'" OTOH, quantum physics predicts the outcomes perfectly and has never been proven wrong so it doesn't matter what we call photons. If you really want to understand this stuff, you need to read a good book on string theory. May I suggest _The_Tenth_Dimension_, by Jeremy Bernstein or catch the two NOVAs that were on tonight. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#6
![]() |
|||
|
|||
![]()
Cecil Moore wrote:
Roy Lewallen wrote: "Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen. . . Historically, the electron, for example, was thought to behave like a particle, and then it was found that in many resepects it behaved like a wave. So it really behaves like neither. Now we have given up. We say: 'It is like *neither*'" OTOH, quantum physics predicts the outcomes perfectly and has never been proven wrong so it doesn't matter what we call photons. If you really want to understand this stuff, you need to read a good book on string theory. May I suggest _The_Tenth_Dimension_, by Jeremy Bernstein or catch the two NOVAs that were on tonight. Is that where we'll learn all about virtual photons, the fourth dimension, and their application to measuring voltage? Roy Lewallen, W7EL |
#7
![]() |
|||
|
|||
![]()
Roy Lewallen wrote:
Cecil Moore wrote: Roy Lewallen wrote: "Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen. . . Historically, the electron, for example, was thought to behave like a particle, and then it was found that in many resepects it behaved like a wave. So it really behaves like neither. Now we have given up. We say: 'It is like *neither*'" OTOH, quantum physics predicts the outcomes perfectly and has never been proven wrong so it doesn't matter what we call photons. If you really want to understand this stuff, you need to read a good book on string theory. May I suggest _The_Tenth_Dimension_, by Jeremy Bernstein or catch the two NOVAs that were on tonight. Is that where we'll learn all about virtual photons, the fourth dimension, and their application to measuring voltage? Yes, six of the dimensions are thought to support the fabric of space, the æther, if you will. String theory has yielded a unified field theory including massless gravitons. The point is that just because photons do not behave like pure waves or pure particles, doesn't mean they are useless. It just means that we don't yet have a one word handle to describe their true nature. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#8
![]() |
|||
|
|||
![]()
Roy Lewallen wrote in message ...
.... (writing about Richard Feynman's books) I highly recommend this book, and other of his writings, if you're interested in understanding these phenomena on a more basic level. I strongly agree. You'll also find some interesting words about it in the opening pages of the "Antennas" chapter of King, Mimno and Wing's "Transmission Lines, Antennas and Waveguides." I would go so far as to say that everything we've summarized about "radio waves" in all our writings is all just models to explain our observations. On some level, we don't really know what anything is; we just have ways to communicate about those things. We have models. Some of them seem pretty darned good, but perhaps we're just looking at the actions in one tiny corner of our multi-dimensional universe and we may find that all our models are woefully inadequate to cover the big picture. So what? They work for what we're doing right now. We can deal with the inadequacies when they arise. We can stay constantly on the lookout for them, and accept them and learn from them. A couple hundred years ago, Newtonian physics seemed adequate, and for the time, for what people were observing and designing, it was. But we've learned more, and refined our models. You should expect it will continue to happen, as long as curious humans are around to ponder the problems. In fact, just because our models are somehow "better" now than they were five years ago, or fifty, or five hundred, that doesn't necessarily mean that the earlier models are now worthless. You just need to know their limitations, and apply them only where the limitations are practically unimportant. We still use Newtonian physics for a lot of engineering work because it's not worth the effort to add relativistic terms when we know that they won't be observable, and other errors will dominate. Cheers, Tom |
#9
![]() |
|||
|
|||
![]() "Tom Bruhns" wrote in message ... On some level, we don't really know what anything is; we just have ways to communicate about those things. We have models. Cheers, Tom I like that definition, Tom. Instead of struggling with what every tiny thing is, just model it, apply it to your needs, and life (and radio waves) goes on. Al KA5JGV |
#10
![]() |
|||
|
|||
![]()
But that's NOT a definition.
Alan WN4HOG -- Windsurfing Club: http://www.ibscc.org "Al - KA5JGV" wrote in I like that definition, Tom. Instead of struggling with what every tiny thing is, just model it, apply it to your needs, and life (and radio waves) goes on. Al KA5JGV |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Smith Chart Quiz | Antenna | |||
How to connect external antenna to GE Super Radio III | Antenna | |||
Review: Amateur Radio Companion 3rd Edition | Antenna | |||
Nonlinear wave propagation | Antenna | |||
Amateur Radio Legal Issues List | Antenna |