Pop physics

Ok so here we are in the 1970’s and we are very confused. There is this extra mass around the galaxy and we don’t know where it’s coming from but…it’s there! It must be there. It was certainly a time when many a physicist was questioning their sanity. But what has happened after that…? I have no idea, and I don’t have the time to figure that out. So, let’s skip to the stuff I do know. What has been established since…I don’t know, the 1990’s maybe….is the amount of ‘stuff’ in the universe. I’ve included a graph of all the ‘stuff’ in the universe as we know it today. So what we did is count all the stars and galaxies and gas that we could see and then compared it to the amount of gravity we could see and saw there was a lot missing. And by the looks of things we are missing a lot of energy in addition to the mass we were missing (remember that ‘stuff’ includes both mass and energy, E=mc^2). And so when we put all the ‘stuff’ we need back in we get the graph I’ve included. I’ll talk more about the graph tomorrow.