The elephant in our living room

The expression "The elephant in the living room" is used in cases where obvious issues are overlooked. I imagine this as a middle aged English lady sitting in her living room drinking some tea. Behind her and her sofa stands a medium sized elephant. He is overlooking her shoulder to get a glimpse of the next British Idol on the TV. If you visit the lady the discussion may go like this:
Me: Wow! There is an elephant behind your sofa lady!
Lady: There is certainly not. My living room is not a Zoo.
Me: But I can see him. He is right behind you watching British Idol.
Lady: Well if he really is there he is not doing much harm behind the sofa, is he?
Me: He just shit on your floor though.
Lady: Well if you really must know I put an old carpet behind him so there is really no harm done.

I do this all the time in my physics studies. I don't want to bore you with the details but I make a living trying to figure out how atoms and molecules stick to things. Things can be other molecules, atoms or surfaces. I don't do this by testing but by calculations based on models.

My problem is that the models I use are not correct. With not correct I mean that I know that they are not true. What I hope is that these models despite being not correct can still be useful and harbor some fractional truth in them. After a while I forget that they are untrue because that happens when you do something day after day. This is my elephant in my living room. Sometimes when I compare my predictions with actual reality (usually experiments) it is like the elephant taking a shit on my floor. When this happens I can either close my eyes and blame the experiments for being poorly conducted (I may be right, that happens) and hope that the elephant who just shit on my floor REALLY is not there (if he is not, then neither is the shit). I can also acknowledge the shit on the floor and put an old carpet behind the elephant for next time. This is my weapon of choice and in practice it means that I start patching my model to work a little better. The obvious question you may have is now: Why the hell do you not just acknowledge the elephant and get on with your life? The reason is that elephants are problematic to move through house doors; it is simply impossible to move him. In my work, I don't know of any better way to do what I do. Also if I thought about that elephant all day my work would be no fun at all. I could also move to another living room, which I don't want to since I have grown attached to my home. And my new living room is likely to have an elephant too.

So contrary to what you may have thought, the old lady is just like me. We don't acknowledge the elephant because we can't move him. And if we can't do anything about him; why trouble our happiness with acknowledging him? In case we don't want to live in shit we do have to acknowledge the consequences of having him though. By putting an old carpet behind him.

Economists have elephants in their living room as well. It is fun to tease them about this because they often REALLY don't know it is there. So far we may not be smart enough to argue with an economist about the benefits of free market and capitalism, since we saw (from yesterdays discussion) that he always has some clever answer to everything. But we will soon be able to visit his living room and tease him about his elephant and, even funnier, his ignorance about it. And I bet he doesn't even put an old carpet behind him.