We think so, yes. The matter we know about, the stuff that makes up all the stars and galaxies that we know of, only makes up about 5% of the universe – so there’s still 95% of it out there that we don’t really know about!
It seems so, yes. Whilst we can’t directly observe dark matter (hence the ‘dark’), we can see the effects that it has, in terms of its mass affecting the gravitational field. This indirect observation demonstrates that there has to be *somethingMATOMO_URL
Comments