Why is the Big Bang theory the most widely accepted theory of the creation of the universe?

Science states that space is endless, and ever expanding. But, if we are inside the planet earth, the planet earth is inside the galaxy, the galaxy is inside space, then what is space inside? What is it expanding in? And if space is endless, how can it expand?

It is often said that the the phrase "before the BIG BANG" is meaningless because the BB is the beginning of things, time included. My question is "Is the phrase truly meaningless?" I take it as axiomatic that a real event occurs only if it were already a possible event. If the BB did indeed happen then it must have been the fruition of an antecedent possibility - some entity 'before the BB'. ERIC STOCKTON, ORKNEY UK

I believe that it is assumed that the 'laws of physics', as we know them, apply throughout the universe. Is this a reasonable assumption or is our concept of cosmic reality an error?

What if we look at the universe completely wrong? In other words, what if all the laws of gravity, physics, and everything are actually wrong? Would people keep trying to make a fictional world with fictional rules or strive for the truth? Nick-14

Hello. I wonder what you think about the following: About 13.7 billion years ago, there probably was a Big Bang. The astronomers start their counting of time from that. What do the philosophers think of what happened before the Big Bang? JB from Sweden

Astronomers routinely observe the most distant objects and the earliest events in the universe. If we had a telescope powerful enough, could we observe the Big Bang and if so, could it be observed whichever way we looked?

Why does the Universe need to have a beginning (or an end)? I am trying to understand why so many scientists believe in the Big Bang theory and why more people don't believe that the Universe has just always existed.