Why does it look like a ripple on a pond instead of a three dimensional object?
It doesn't look like a three-dimensional object because an electron is not a three-dimensional object, at least not as we usually understand the term.
The video was made back in 2008, and has been seriously misrepresented by some pop-sci sources. It's not a picture of an electron, it's an image of laser light pulses that have interacted with an electron that cannot be seen in the video but is presumed to be in the moving dark area at the center of the video.
From the article : "the resulting momentum distribution will be smeared out and show interference fringes that depend on the different ionization times".
"Four stroboscopic images taken at different XUV-IR delays (t0) are presented in Fig. 1(c) (a complete movie spanning one full optical cycle is available in Ref. ). The clear up or down asymmetry in the momentum distributions confirms that each image corresponds to ionization at one particular phase of the IR field so that the momentum distribution is shifted up or down in the direction of polarization of the IR field."
I agree with nugatory, the electron is not a particle in the sense we are accustomed so it lacks intrinsic geometry. See this for discussion .
Glad to see others like Rodney Brooks approach.
Its a bit different, but has the advantage of being true.
I really do believe an intuitive understanding of QFT is a good place to start in understanding QM.
After reading an intro QFT text, I don't even know what a particle is anymore, much less how we can count them.
You don't count particles using QFT but a particle detector ;-). QFT describes the probabilistic counting rates, no more no less.
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