Why IHRA is so important: When antisemitism is emboldened it seems to get very bold, and much more toxic than I would have expected from October 7th.

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A small‑scale sonic‑boom model compares to the speed of light by matching the Mach‑cone geometry to its optical analogue—Cherenkov radiation or photonic Mach cones—where a particle or pulse outruns light in a medium, not light in vacuum. What a sonic boom represents A sonic boom forms when an object moves faster than the speed of sound, causing pressure waves to merge into a shock front shaped as a Mach cone Wikipedia . The cone angle depends on the ratio Mach number = v object v sound . Mach number= v sound ​ v object ​ ​ . The optical analogue: outrunning light in a medium Multiple sources confirm that the closest physical equivalent to a sonic boom for light is Cherenkov radiation Science ABC +2 . Key facts: Light slows in materials such as water (n≈1.33) or glass (n≈1.5), reducing its speed to ~225,000 km/s or ~200,000 km/s 1 . A charged particle can exceed this reduced speed without violating relativity. When it does, it emits a cone of coherent light, just as a supersonic jet emits a cone of compressed sound waves 1 . This produces the characteristic blue glow in nuclear‑reactor water 1 . 1 Source This cone is the optical Mach cone, directly analogous to the sonic‑boom shock front. Photonic Mach cones: a literal small‑scale model Experiments have filmed a Mach cone of light by slowing light in engineered materials Physics World : Silicone‑rubber panels doped with aluminum oxide slow scattered light. A laser pulse in a faster channel outruns that scattered light. The scattered wavelets form a photonic Mach cone, mimicking a sonic boom’s geometry. This is a laboratory‑scale demonstration of a “light boom.” How to compare the two models The comparison works by matching dimensionless ratios, not absolute speeds. For sound: M sound = v object v sound . M sound ​ = v sound ​ v object ​ ​ . For light in a medium: M light = v particle v light in medium . M light ​ = v light in medium ​ v particle ​ ​ . If either ratio exceeds 1, a shock cone forms. Thus, a small‑scale sonic‑boom model (e.g., a supersonic object in water or air) can be compared to light by: Choosing a medium where light is slowed (water, glass, engineered panels). Using a particle or pulse that exceeds that reduced light speed. Observing the resulting cone (Cherenkov radiation or photonic Mach cone). Comparing cone angles using the same Mach‑cone geometry. Important differences Sources emphasize key distinctions: Sonic booms involve nonlinear pressure waves; Cherenkov radiation is a linear electromagnetic effect 1 . Sonic booms require macroscopic compression of air; photons interact too weakly with air to create a pressure shock 1 . Cherenkov radiation is produced by charged particles, not by light itself (unless using slowed‑light setups). 2 Sources Putting it together A small‑scale sonic‑boom model compares with the speed of light by using media where light slows, then creating conditions where a particle or pulse outruns that slowed light, forming a cone identical in geometry to a sonic Mach cone. The comparison is made through Mach‑like ratios and cone angles, not through absolute speeds.