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

Why do some discoveries, which appear in hindsight to be obviously majordiscoveries, have so little impact when they were made. These are discoveriesthat were ahead of their time, but for some reason the scientific community wasnot ready to absorb them. I got interested in Slipher after learning that by1914 he had observed nebular redshifts up to 1000 km/s. Why did this notconvince people at the time that the nebulae were extragalactic ? Was thisanother example, like Zwicky's (1933) discovery of dark matter in the Comacluster, of a discovery which was too far ahead of its time ? I conclude thatSlipher's situation was different from Zwicky's. The significance of Slipher'snebular redshifts was partly recognised at the time, but I believe that itsfull significance was masked by van Maanen's work which turned out to beerroneous and reduced the impact of Slipher's discoveries.

Slipher and the Nature of the Nebulae