Sean Carroll over at Cosmic Variance gives us a tour de force and tour of forces of and on science and what this means for parapsychology and similar, er, pseudo-phenomena:
In the aftermath of the dispiriting comments following last week’s post on the Parapsychological Association, it seems worth spelling out in detail the claim that parapsychological phenomena are inconsistent with the known laws of physics. The main point here is that, while there are certainly many things that modern science does not understand, there are also many things that it does understand, and those things simply do not allow for telekinesis, telepathy, etc. Which is not to say that we can prove those things aren’t real. We can’t, but that is a completely worthless statement, as science never proves anything; that’s simply not how science works. Rather, it accumulates empirical evidence for or against various hypotheses. If we can show that psychic phenomena are incompatible with the laws of physics we currently understand, then our task is to balance the relative plausibility of “some folks have fallen prey to sloppy research, unreliable testimony, confirmation bias, and wishful thinking” against “the laws of physics that have been tested by an enormous number of rigorous and high-precision experiments over the course of many years are plain wrong in some tangible macroscopic way, and nobody ever noticed.”
The crucial concept here is that, in the modern framework of fundamental physics, not only do we know certain things, but we have a very precise understanding of the limits of our reliable knowledge. We understand, in other words, that while surprises will undoubtedly arise (as scientists, that’s what we all hope for), there are certain classes of experiments that are guaranteed not to give exciting results — essentially because the same or equivalent experiments have already been performed.