An anomaly in the logic behind the Big Bang?

Question

I have heard it said before that unlike every other scientific theory; in which if some evidence or a result arises which contradicts the theory, a new theory then has to be hypothesised and the old one 'thrown out'...

...the Big Bang theory is the only one in which as tests and results have come back to the lab, the theory has just been adapted to make it work. (I.e. dark matter being introduced to make the maths work).

Is this an accurate statement?

I personally don't doubt the idea of the Big Bang, it just seemed curious scientific practice if this were true.

P.S: Ironically enough, I read on the BBC science news website that hubble had just taken a picture which apparently 'showed dark matter' for the first time. (Clearly a method behind the madness)

Answer 1

Not at all--theories get adapted all the time. That's what the scientific method is.

Build a model. Work out the consequences of the model. Compare with experiment. Adjust if necessary. When a theory works pretty well for a while and then comes up just a little wrong, we don't just pitch it, we fix it.

The most fundamental theory of physics--classical mechanics--has been adjusted over the years. The must fundamental theory of biology--evolution by natural selection--has been adjusted. You could go on and on like this.

Answer 2

The ideal of a theory being entirely abandoned when a single discrepancy is found is an idealization that hardly ever occurs in reality. Good general theories are actually quite nimble about such things, and roll with the punches unless some *fundamental* discrepancy is found. By "general theory", I mean something that's qualitative and somewhat vague like "the universe expanded from a very dense state billions of years ago". This is well supported by observations such as Hubble expansion and cosmic background radiation. A specific theory would be that the description obeys general relativity's solution for a homogeneous and isotropic expansion with zero cosmological constant, as was once assumed. Such a thing might indeed come into conflict with observations, and "patches" like dark energy and inflation may have to be proposed. The general theory, however, still stands firm.

Keep in mind that no theory is ever considered the final word on any subject in physics; they are all recognized as merely "effective" until something better comes along. It is just those exceptions disproving specific interpretations of general theories that lead to such progress.

Answer 3

No, the Big Bang says everything started in close proximity to everything else, and now are flying apart as if we are debris in an explosive start. Dark matter wasn't introduced just to make it work. Dark matter was discovered by its gravitational effects in our universe. Both things (Big Bang and Dark Matter) are well supported by actual observation.

Theories come and go. Their usefulness is that they can be used to model the way things are right now, solve problems and make reliable predictions of conditions in the future. Just because a theory has a few "patches" does not say it is wrong or right. So long as a theory is useful it will get patches until it just won't run anymore. That usually happens when two or more of the patches are contradictory of each other.

Answer 4

Well indeed it seems that the Big Bang fills up a lack regarding the very beginning of the Universe...There are too many evidences that there was a beginning of it (e.g. background radiation, expansion of space, multiple forms of galaxies etc.). That beginning as the Big Bang can be imagined like a start of revealment of the "reality". For sure there was something even before it, but that was another reality, undetectable from this one. We like it or not, there is a necessity of a "Big Bang" theory.