When Your Gravity Fails and Negativity Don’t Pull You Through: The Case for Negative-Mass Dark Matter

In early December 2018 the physicists' blogosphere went berserk because of a 2017 paper (in fact still a preprint to this date: arXiv:1712.07962) in which the author James Farnes, University of Oxford, tries to explain Dark Matter and Dark Energy with a seemingly preposterous hypothesis: the presence of a negative-mass fluid that permeates the Universe. …

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La Teoria della Relatività: Generale, Ristretta, Speciale o meglio Locale

Quando ero bambino trascorrevo interminabili pomeriggi nel paese dove abitava una delle mie nonne. Specialmente durante l’inverno, poco interessato ai risultati delle partite di Serie A e attanagliato dalla noia, mi capitava di guardare dalla finestra le luci provenienti da un altro piccolo centro abitato, abbarbicato sulla cima della collina di fronte. Le luci delle …

Touring the Solar System

Recently, I have read a very recommended book called "The Interstellar Age: Inside the Forty-Year Voyager Mission" by Jim Bell (see its Goodreads entry). The book, as you can imagine from the title, recounts the story (so far) of the two Vogayer spacecrafts, and of the people who made this possible. There is also a …