Locrian

The problem is that saying something "is in two places at once" in QM just doesn't have much meaning. You have a state function. When you measure the position, you will not find that the particle is in two places. The slit business is dependant on not measuring the state function until after it has passed through them. You can't say it went through both. You might say the probability distribution depends on your assuming it did, but even that is just one way of looking at it. Also, there are plenty of people who can defend the MWI just fine. There certainly is no definitive reason you couldn't accept it, though I don't.

You've recieved several answers to this question in this thread. However, I don't think any of them are nearly complete, and might even be misleading. Condensed matter scientists make up a large group of all physicists, and I've read reports that suggested condensed matter and materials physicists make up more than two thirds of all physicists. No one has mentioned anything that they work on in this thread; neither have they mentioned modern studies in decoherence, electromagnetism, quantum logic or other useful areas of physics. Basically, almost no scientists are searching for anything that has been listed here. One great way to see what physicists are exploring is to go to university web pages and look to see what research is being done. You'll find that only the biggest universities have the time and money they can spend on high energy physics, and even then this is only a minority of physicists at the facility. Here is my take on one of the biggest questions in physics right now (which, of course, is composed of myriad smaller questions): How can we best predict the properties that emerge when matter is condensed and/or strongly correlated and placed in various conditions?