<p><span class="h-card" translate="no"><a href="https://fedi.astrid.tech/users/astrid" class="u-url mention">@<span>astrid</span></a></span> <span class="h-card" translate="no"><a href="https://glaceon.social/@lily" class="u-url mention">@<span>lily</span></a></span> speed of light in copper is like 0.99c, however, the energy (and therefore signals) on a PCB aren't propagating through the copper! the copper is there for the light to [extremely over simplified] bounce off</p><p>the signals are propagating through the insulator. basically all of the energy on the PCB is stored in the insulators (whether the PCB dielectric or the capacitor dielectric)</p>
