http://www.straightdope.com/mailbag/mlightwaveparticle.html
I belive the answer cronos gave and Ed’s simplification isn’t all that complete. Of course, volumes have been dedicated to such hot topics.
Something that could be enlightening is not simply accepting the fields exist, but to know something about them. Current theoretical physics suggest that electromagnetic fields are formed by particles influence on each other’s energy levels. Big deal you say. The interesting thing, is that the shape of these fields is determined by the ripples in the vacum that host space time. That’s right, ripples in the vacum. I would think it is a much more satisfying answer.
Respectufully,
Salvador
While ripples in vacuum (sort of) can certainly explain gravity, any explanation of the other forces in this manner still leaves a lot to be desired. And while there is, of course, a lot more which can be said about electromagnetic fields, I didn’t think that it would help clarify the matter to say any more about them. I’m assuming that most of my audience hasn’t had anywhere near the necessary background to appreciate, say Quantum ElectroDynamics (and for that matter, I’m not particularly qualified to explain it, either).
Ripples in vacuum isn’t any more explanatory than waves in a non-existant ether. How can their be ripples in vacuum? Vacuum is the lack of matter?
Ripples in space-time is a little better, but it still leaves the fabric of space-time undefined and mysterious. So instead of waves in an unexplained electromagnetic field, you have ripples in an unexplained space-time. Not an improvement.
Chronos and Ed give a good attempt at explaining something that reasons really aren’t understood by physicists. The behavior is as a particle or a wave, depending on how you look and what you look at. But the mechanism of wave/particle duality is still unknown.
On the contrary, it’s very well known. The “mechanism” is that “wave” and “particle” are both metaphors that break down if too closely examined.
One is reminded of “Bluspels and Flalansferes: A Semantic Nightmare”, by C. S. Lewis.
Right, wave and particle are metaphors. But why is QED behavior sometimes best described by wave metaphor, and other times by particle metaphor? Why is there a duality of behavior? That’s why I said the mechanism of duality is not understood. The how of behavior is understood and computes nicely. The why is unresolved.
There are at least four meanings for the word “why”: motivational, justificational, logical, and causal.
The motivational “why” here is a question for theology, and the justificational “why” for is for that specific subdivision of theology known as theodicy. The answer to the logical “why” can only be "because the equations say X."
For the causal “why”, current knowledge, which seems to have disproven the “hidden information” hypothesis (the notion that, although the Uncertainty Principle denies us exact knowledge of quanta, the quanta themselves “know” what they are doing), the answer appears to be, “There is no ‘Why’.”