Exploring the Feynman-Wheeler Theory

[fargoth]

while looking into huygen's principle i found a site that showed its just another way to look at waves in 1\3\5\...odd dimensions.

but i bumped into this:

The Huygens-Fresnel Principle is adequate to account for a wide range of optical phenomena, and it was later shown by Gustav Kirchoff (1824-1887) how this principle can be deduced from Maxwell's equations. Nevertheless (and despite statements to the contrary in the literature), it does not actually resolve the question about "backward" propagation of waves, because Maxwell's equations themselves theoretically allow for advanced as well as retarded potentials. It's customary to simply discount the advanced waves as "unrealistic", and to treat the retarded wave as if it was the unique solution, although there have occasionally been interesting proposals, such as the Feynman-Wheeler theory, that make use of both solutions.

i wanted to know more about this wheeler theory, i tried googling for it, but couldn't find more then 10 lines about it...

anyone knows what this theory is, and where could i find some mathematical info on it?

 

[robphy]

As a first reference, look at
http://nobelprize.org/physics/laureates/1965/feynman-lecture.html

and maybe
"Interaction with the Absorber as the Mechanism of Radiation"
John Archibald Wheeler and Richard Phillips Feynman
Rev. Mod. Phys. 17, 157–181 (1945)
http://prola.aps.org/abstract/RMP/v17/i2-3/p157_1

If you don't have access [and/or to find other discussion on it], you might try googling the quoted title.

 

[fargoth]

thanks, I am reading it right now... (the nobel lecture)

i'll post some questions later, but i got one with little relevance - what does he mean by this sentance:

As a matter of fact, when we look out anywhere and see light, we can always "see" some matter as the source of the light. We don't just see light
(except recently some radio reception has been found with no apparent material source).

i know its off-topic, i'll ask the on-topic questions after i'll finish reading, but i wanted to know where has radio reception with no apparent material source been found..

 

[robphy]

I think he is referring to the "Cosmic Microwave Background"
http://www.astro.ubc.ca/people/scott/faq_basic.html
http://map.gsfc.nasa.gov/m_uni/uni_101bbtest3.html

 

[fargoth]

but isn't the CMB emmited by matter? isn't it just the black body radiation of the edges of the universe?

anyway, i finished reading the nobel lecture, it was, as expected, fun to read.
I love feynman's lectures.
it seems feynman abandoned the wheeler theory a long time ago, it was just one of his ideas for QED which has been left out.
i think i'll leave the second link for tomorrow though

 

[robphy]

In the faq I directed you to, there is this question and answer (which addresses your boldfaced section and is why I gave that url)

Why is it called a "Background"?

We refer to this radiation as a background because we see it no matter where we look. It clearly doesn't come from any nearby objects, such as stars or clouds within our Galaxy, or even from external galaxies. It is clearly a distant, "background" source of radiation. You can think of the whole Universe as being filled with this background of microwave photons.