Now this edition of problems unsolved will be concerned with topics of cosmology and astronomy.
Vast majority of this universe is dark matter, and this absurdly-unbelievable fact can be linked to “dark matter”, which accounts for approximately ¾ th of the mass of the universe. Dark matter is hypothetical matter that scientists can neither observe nor measure, but can infer its existence due to its gravitational interactions with known matter. . It is certainly alarming to suddenly discover that the universe contains large amounts of invisible matter, but this is exactly what happened when astronomers, measuring the amount of hot gas in and between galaxies, learned that clusters of galaxies contained five times more material than was expected from visible galaxies and hot gas. This led scientists to declare that some other, invisible, “dark” matter made up the remainder of the material. Now that scientists have discovered dark matter, the questions of what dark matter is, how much of it there is, and what effect it has on the universe remain to be answered.
P.S : The post by me on the “WOW!” signal is much more amazing than this and it seems to be a bigger problem to me.