The End of Infinity

Everything that has a beginning has an end. We know how the universe began, and how old it is (some 13.7 billion years), but we don’t know the end. Or do we? To know the end of the universe is to acquire enough data to compute a constant known as Omega.

            Envision a rocket leaving the planet, there is a certain speed that it must be going to escape the gravity of the Earth, we call this escape velocity. Omega works off a very similar idea. If the big bang imparted enough velocity to the galaxies (escape velocity if you will) then the universe will continue to expand ever onwards. However, if the galaxies are not fast enough, then think of them as a rocket that has not achieved escape velocity. Eventually gravity would pull everything back to the way it all was in the beginning, what scientists call “the big crunch”, the converse of the big bang.

            Whatever fate awaits the universe one day can be determined by the numerical value of Omega. Omega is the total amount of matter in the universe divided by the minimum amount of matter needed to create the big crunch. If Omega is greater than 1, the galaxies will fly apart forever, and if it is less, then someday the big crunch will happen. Knowing that there are about five hydrogen atoms per cubic meter of space, our best guess is that Omega is valued somewhere between .98 and 1.1 so the fate of the universe remains a mystery.