Hi -- you mean 1933, right? Sorry I didn't make the chronology clear. I'll do it now. In the 1920s, we first discovered the speeds of external galaxies. In 1933, Zwicky showed that something about them didn't make sense. Since then, we've made periodic confirmations of this "dark matter."
Hi -- you mean 1933, right? Sorry I didn't make the chronology clear. I'll do it now. In the 1920s, we first discovered the speeds of external galaxies. In 1933, Zwicky showed that something about them didn't make sense. Since then, we've made periodic confirmations of this "dark matter."