Save the date

Sometimes scientists postulate the existence of a substance to make their observations conform to their ideas. Like phlogiston was this imaginary stuff that escaped and created heat when you set fire to something. The ether was this all-pervasive invisible fluid through which waves could propagate across space. They’re gone now; subsequent research obviated the need for them. Now new research suggests that there’s no such thing as dark matter. As a consequence of this, the estimated age of the universe gets bumped up from just under 14 billion years to more than 26 billion. So, update your calendars, I guess.