To find an answer, let us ask some questions and get some answer, and reach a conclusion:
1) How much electrical charge exists in our universe?
Readers familiar with Coulomb’s principle of charge conservation would answer:
“Since electrical charge can never be created or destroyed but only separated, therefore, the total electrical charge in our universe is zero.”
2) How much momentum exists in our universe?
Readers familiar with Newton’s second principle of mechanics (written in its relativistic form) would answer: “For an isolated system such as our universe, the total momentum (both linear and angular) in our universe is zero.”
3) How much energy is contained in our universe?
Readers familiar with the first principle of thermodynamics (written in its relativistic form, which recognizes that mass is a form of energy, according to Einstein’s E =
mc2) would answer: “Since energy can be neither created nor destroyed but only changed into different forms, then the total energy of our universe is zero.”
I remember reading in Nature that the positive energy of all mass in the universe was approximately equal to the negative energy of space, which would mean “our Universe is simply one of those things that happen from time to time.”
Hence the question “What was before Big Bang?” does not arise.