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

Vesto Melvin Slipher was the first astronomer to clearly define the factorsthat determine the "speed" of a nebular spectrograph. This brief historicalsummary recounts the way these ideas developed and how Slipher's early work ongalaxy Doppler shifts was so quickly extended in the 1930's when Milton Humasonand Edwin Hubble at Mt. Wilson Observatory began to push the velocity-distancerelationship to such a depth that no one could doubt its cosmologicalsignificance.

V.M. Slipher and the Development of the Nebular Spectrograph