New scientific theories are cropping up all the time. And that is just what they are - theories. So the Higgs boson particle has been seen. What a lot of tripe this is. It has only been shown to exist mathematically. The particle itself is still not proven to exist.
Large galaxies eat up smaller ones. It would have been thought that this had been believed for some time. Apparently it hasn't been generally accepted. New findings show that the Milky way will be absorbed into larger galaxies billions of years from now.
The Milky Way did expand by taking in smaller galaxies. Now it has peaked and this slowing down will allow Andromeda to absorb our home galaxy. When the Magellanic Clouds become part of the Milky Way that will be about it.
As galaxies become larger they produce less stars. The reason for this is not known. There are a lot of conflicting theories about this. Research by the Galaxy And Mass Assembly (GAMA) survey done by Australian observatories is ongoing. We can expect either new theories or selection of the most probable one.
Science by Ty Buchanan