Brief introduction: Hello all, been subscribed to the Universe Today Newsletter for over a year, but my first time visiting the forum.
Anyways, as I was reading some of these alternative theories, and the papers on the MOND theories, as well as going over the information I knew about dark matter & energy, kinda furthers the question in my mind "do we really know what we are doing? Or are we creating models based on information that could be indeed faulty?
I first encountered the question when I was in a yahoo chat room (don't laugh). I was arguing quite heavily with someone over something I considered basic knowledge, and she asked me "how do you know, it's just a theory?" At first I responded the way any other person would, throwing out scientific ideas and evidence to back up my claim. The answer is ultimately, we don't know, which is why it is a theory.
The problem isn't the idea of scientific theory in itself, I mean, if we're wrong, big deal, we just change our minds and come up with another model, right? It's easy to look as far as simple theories. If we find out that hawking radiation doesn't actually exist, we just write it off as if its nothing. If we find out that Quazars aren't actually far away galaxies, not too big a deal, just requires more explaination.
But what about something that pages and pages have been built upon? Such as the almighty powerful equation, E=mc^2? If you don't believe it could happen, it's come fairly close. I'm sure you all know what GRBs (gamma-ray bursts) are, right? The line of research concerning those has taken many dramatic terms. We first thought that the only thing that explained the amount of energy emitted by those could be caused by dramatic events in our own galaxy. The reason being is that our all powerful equation limited the amount of energy that could be produced from a massive object. When the shocking news came in from the distance of the GRBs, the equation took a hit, and with it, everything we thought we knew. It was only after looking at a fairly simple concept that we found a model that still fit the equation: a near miss for certain.
While Einstein's theories are relatively safe, there are other theories that are running into trouble, in particular, the proposed theories of dark matter, and dark energy. We have built several theories on dark matter, dark energy, and the expansion of the universe, yet, not once have we detected Dark Energy directly. Dark matter has only been detected a few times around the world, and is explained only by fast moving stars on the outer fringes of our galaxy. Both of these things have alternate explainations. Tests for WIMPS and nutrinos are rigorous, and requires a virtually 100% clean environment to preform them. Based on this, combined with the overall few detections, it's very possible that the testing solution got contanimated with another atom or subatomic particle, or the energy given off in a collision was more minute than anticipated. There are other alternate theories of gravitation that can also describe unusually high sigma speeds (I am gonna write my theories on Dark Matter & Energy on another section of the forum immediately following htis). To be honest, we are writing pages upon pages about theories that are scarcely proven, instead of concentrating our efforts on proving them even more.
The expansion of the universe is another theory that could run into trouble. The expansion is predicted by photons of light across the universe. The distance in itself is the problem. While our measurements are quite accurate within a few thousand light years about hte path of a beam of light, over billions of lightyears, it's next to impossible to accurately predict how bright or dim something is or should be, which is the chief explaination based on quazar and supernova observations.
My purpose is to simply point out that sometimes we have too much faith in abstract ideas that only hold up under models that we have no way of testing, because if the brilliance of Einstein can run into that kind of trouble, the next hit on a major theory may not just be a 'near miss'