Low-Pass Filters: Commentary on a Remark by Feynman
| dc.creator | Ramm, A. G. | |
| dc.creator | Weaver, O. L. | |
| dc.date | 2004-04-23 | |
| dc.date.accessioned | 2026-07-07T04:31:07Z | |
| dc.date.available | 2026-07-07T04:31:07Z | |
| dc.description | In Feynman's lectures there is a remark about the limiting value of the impedance of an n-section ladder consisting of purely reactive elements (capacitances and inductances). The remark is that this limiting impedance $z=\lim_{n\to\infty}z_n$ has a positive real part. He notes that this is surprising since the real part of each $z_n$ is zero, therefore it is impossible for the limit to have a positive real part. A recent article in this journal offered an explanation of this paradox based on the fact that realistic impedances have a non-negative real part, but the authors noted that their argument was incomplete. We use the same physical idea, but give a simple argument which shows that the sequence $z_n$ converges like a geometric series. We also calculate the finite speed at which energy is propagated out into the infinite ladder. | |
| dc.identifier | https://arxiv.org/abs/math-ph/0404055 | |
| dc.identifier | http://arxiv.org/abs/math-ph/0404055 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/57707 | |
| dc.subject | Mathematical Physics | |
| dc.subject | 78A02, 78A40, 78A55 | |
| dc.title | Low-Pass Filters: Commentary on a Remark by Feynman | |
| dc.type | text |