English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present a Michelson-Morley type experiment for testing the isotropy of thespeed of light in vacuum and matter. The experiment compares the resonancefrequency of an actively rotated monolithic optical cryogenic sapphireresonator against the resonance frequency of a stationary evacuated opticalcavity made of ultra-low-expansion glass. The results yield an upper limit forthe anisotropy of the speed of light in matter (sapphire) of Delta(c)/c < 1 x10^-16, limited by the frequency stability of the sapphire resonator.

Electromagnetic cavity tests of Lorentz invariance on Earth and in space