u/jarekd

"An antenna model for the Purcell effect" - presence of resonator helps with emission, could it affect radiotelescopes?

In Purcell effect just presence of resonator in distance helps with emission, here discussed for antennas.

Radiotelescopes are focused on absorption as positive signal - could such Purcell effect affect them? Would it be seen as negative signal?

Negative is clearly also observed (e.g. in https://iopscience.iop.org/article/10.3847/1538-4357/ac0e93/pdf ), but interpreted as "noise, calibration error": https://www.reddit.com/r/radioastronomy/comments/1su7nzq/are_there_cosmic_sources_of_negative_radiation/

nature.com

u/jarekd — 2 days ago

▲ 88 r/jpegxl

JPEG XL behind flag in Firefox 152 released on June 16th 2026

bugzilla.mozilla.org

u/jarekd — 12 days ago

▲ 20 r/AntennaDesign

Marine propeller can cause excitation or deexcitation of resonator in front. As EM and hydrodynamics are quite similar, could we cause deexcitation of excited resonator by some antenna to which we can also practically apply time symmetry e.g. helical?

Radiotelescopes see also negative signals e.g. https://arxiv.org/pdf/2107.02695 - could they be explained by such caused deexcitation?

u/jarekd — 19 days ago