No Dark Matter = Proof of Dark Matter?

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We’ve been failing to detect dark matter for decades. Finally, the latest failure to detect dark matter may have actually proved its existence. One of these is true: either most of the matter in the universe is invisible and formed of something not explained by modern particle physics OR our understanding of gravity is completely broken. The debate over which is true has raged for decades, but may finally have been resolved in an unlikely way: the proof that dark matter exists, and really is an exotic, unknown substance, may have come from the discovery of two galaxies that appear to have no dark matter at all. Today on Space Time Journal Club we’ll look at the papers that reveal this discovery:

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Hosted by Matt O'Dowd

Written by Matt O'Dowd

Graphics by Kurtis Ross

Directed by Andrew Kornhaber

Produced By: Kornhaber Brown

The effect of dark matter was first noticed in 1933, when the legendary Swiss astrophysicist Fritz Zwicky noticed that the galaxies in the Coma cluster were moving too quickly to remain gravitationally bound within that cluster. He guessed the presence of “dunkle m aterie” – a dark matter invisible to his telescope but whose gravitational effect held the cluster together. As with many of Zwicky’s predictions – like the existence of neutron stars and gravitational lensing - this wasn’t taken seriously until decades later. The hunt for dark matter began in earnest after the early 70s when Vera Ruben, discovered that the rotation rates of spiral galaxies were too fast given the mass of their visible stars alone. They should throw themselves to pieces spinning that quickly – that is, unless, a gravitational force of unseen origin was holding them together.

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سلطان الخليفي