Of all the concepts and topics that get tossed around, the Big Bang is one of the most controversial. Sure, it’s a scientific theory that’s quite old — it’s been around since the 1940s — and the evidence in favor of it has been overwhelming since the 1960s. The idea is simple: that the Universe had a beginning. That it had a birthday. That there was a day without a “yesterday,” where matter, radiation and the expanding, cooling Universe we recognize did not exist before a certain moment in time. And yet, here we are. Which brings up a slew of questions to any curious mind. Mark Trubnikov is one such curious individual, and he wants to know:
These are all good questions, and they’re all common conceptions that people have of the Universe, for good reason. But are these assertions true?
- full of particles and antiparticles of all different types, as well as radiation,
- all of which was expanding away from every other particle, antiparticle and quantum of radiation,
- all of which was cooling down and slowing down as it expanded.
The fact that the Universe is homogeneous and isotropic tells us that the Big Bang happened simultaneously, some 13.8 billion years ago, at all locations equally. But we can’t see it at all locations equally; we can only see it from where we are. Our vantage point is inherently limited. Which is why you often see illustrations like the one below: of our Universe as seen from where we are, and with us at the center.