Now Ian Steer posts Who discovered Universe expansion?:
Swedish astronomer, Knut Lundmark, were much more advanced than formerly appreciated. ...I credit Lemaitre because he was the first to publish a cosmological model with red-shift proportional to distance, and to publish observational data to back it up. I don't know how Hubble stole the credit.
Lundmark was the first person to find observational evidence for expansion, in 1924 — three years before Lemaître and five years before Hubble. Lundmark’s extragalactic distance estimates were far more accurate than Hubble’s, consistent with an expansion rate (Hubble constant) that was within 1% of the best measurements today. ...
Hubble’s research in 1929 yielded a value for the Hubble constant that was inaccurate by almost an order of magnitude. It was adopted because it was derived from multiple methods — including one still in use (brightest stars) — and was cross-checked with multiple galaxies with distances based on proven Cepheid star variables.
"I don't know how Hubble stole the credit."ReplyDelete
As the article linked says, Hubble provided the proof (using cepheid variables rather than galaxy diameters).
Lemaitre was a Roman Catholic and quoted the Bible so he was ignored. Or may be was not politically connected.ReplyDelete
Also, Lemaitre was probably not greedy about getting credit for himself.ReplyDelete
The article says Hubble provided the proof, but we know now that his data was wildly inaccurate, so I do not see how it could be proof.
Science is a continuing process of improving measurements. Hubble's data were not wildly inaccurate, they were the best available at that time. And using cepheid variables to measure distance was the best method available, and remained so until the supernovae data of today. Hubble had no way of knowing there were two different of Cepheids, which is why his estimates were wrong.ReplyDelete