• Question: What actually is the big bang theory?? :) What is your opinion on it?? :)

    Asked by madsmith98 to Anil, Blanka, Cees, Emma, Mike on 22 Jun 2012. This question was also asked by asiansupreme, schmick, whmichandjake, whsethandjosh, whmillyandcourtney.
    • Photo: Michael Cook

      Michael Cook answered on 22 Jun 2012:

      The Big Bang Theory is a really successful TV sho- oh right, the other one.

      The Big Bang Theory is one explanation for how the universe began. The idea is that the whole universe – every single tiny bit of matter and energy – was once all crumpled up into an infinitely small space, and suddenly and violently expanded very fast (like an explosion). This scattered the matter in the universe, and started off the systems that created stars, planets, and life!

      (As you can tell, I only know the short version – none of the details!)

      I think it’s a great theory. Lots of experiments have been done to try and see if it is true, and lots of those experiments seemed to agree. One of the things they did was measure a type of radiation in the universe, and they found that the amount of radiation was exactly what they expected to find if the big bang theory was true.

      Of course, we can’t be totally sure yet. But the more experiments we conduct, the closer we get to an answer!

    • Photo: Emma Trantham

      Emma Trantham answered on 24 Jun 2012:

      Michael’s given a great answer to this question (and to be honest that’s as much as I understand about the theory). As the results we’ve got from experiments so far seem to support this theory I tend to believe it’s probably what happened, although of course I will be happy to change my mind if new evidence that shows the opposite comes up.

      Just as an aside, you may already know this, but when scientists call something a “theory” referring to something in science they are generally not meaning the same thing as when we talk about “theory” outside of science.

      We sometimes say things like “I have a theory that the supermarket will be really busy Saturday afternoon”, meaning “I am making an educated guess that the supermarket will be really busy Saturday afternoon”. (Ok so you probably don’t say this very often but just go with me on this…!)

      If I wanted to make this prediction in a science context I would say “I hypothesize that the supermarket will be really busy Saturday afternoon”. So a “hypothesis” is an educated guess on what you think will happen, and it is testable (so I can go down to my supermarket on Saturday afternoon and see whether it is busy or not).

      In science “a theory” is not this educated guess about what happens but is instead an explanation of what scientists know happens/happened based on the many experiments that have been done. So the big bang theory isn’t physicists predicting what happened, they are saying this big bang happened and we are putting all the details we know about it under the umbrella term “the Big Bang theory”. Having a theory doesn’t stop us from doing more research into a subject, and in fact, if evidence comes to light that doesn’t fit the theory, (assuming it is accurate) the theory is “disproved”.

      I hope this has made sense and I haven’t waffled on too much – please do send me another question on it if I’ve confused you at all.

      But to summarise:
      hypothesis = educated guess that is testable
      theory = explanation of what happens based on lots of research

    • Photo: Blanka Sengerova

      Blanka Sengerova answered on 24 Jun 2012:

      Between them Mike and Emma have already answered the question pretty comprehensively. Mike’s explanation of ‘once upon a time the universe was an infinitely small blob the contained everything in it and then it started expanding’ is about as much as I feel I know about the whole process.

      It’s important to know that a theory can always be changed subtly based on new information as it emerges – science is all about uncertainly that gets reduced as time goes on, but probably can never disappear altogether.