I think talk of energy fields etc can be useful when conducting certain exercises, but are old-world models of subjective explorations of the body (a body which essentially follows the laws of biology and physics). There would be processes yet undiscovered about how our body functions, but I don't think the old-world models should be taken too literally. I disagree that if these subtle energies existed as literally defined they are inherently outside the reach of science. The limits placed on what the scientific method can investigate seem to be based on old world thinking as well. It is important to attempt to understand the worldview that existed when these concepts or labels such as chi and prana were first developed. In ancient times, anything not detected by the ordinary physical senses were essentially regarded as beyond the ordinary physical world. However, science and technology have vastly enhanced our powers of perception and engineering into areas once deemed beyond the limit of the ordinary physical senses, and some phenomena we can detect and influence now would be considered part of the unseen or spirit world in ancient times. I tend to think that TCM, yoga, meditation, etc, are similar in status to alchemy. Alchemists made some interesting observations with the tools and knowledge available to them at the time, but the scientific method transformed it into modern chemistry. It could be argued that alchemy also had a major spiritual component but you get the point. Science and technology have a long way to go and I do not place strict limits on what it can explore or detect. For a long time consciousness was assumed to be beyond the reach of science and limited to philosophy, but this has rapidly changed in my lifetime. It is early days and may take centuries or perhaps even millennia for such investigation to mature, but if you look at how much the scientific method has achieved so far in other areas, you can almost guarantee that science and technology will bring a lot to the table when given enough time with the right tools and methodology. For some people, physicalist explanations tend to take the special magic out of it. This is not helped by the fact that some physicalists are reductionists with little imagination or sense of wonder for future possibilities, and are dismissive of the goodness that can be experienced with yoga and meditation. However, for others, physicalist explanations are even more wonderful, e.g. knowing what causes a rainbow does not take away any sense of wonder and enhances it. I guess I'm a physicalist with skeptic tendencies, but I previously spent time fascinated and exploring meditation and yoga and Eastern philosophy, finally concluding that it is in a proto state, should not be taken too absolutely, highly dependent on biology, does not really understand and cannot cure my illness, and if there is anything to it beyond subjective experience, may be within the reach of future science but a lot it would not survive unscathed in the fullness of time and proper investigation. As for powering an LED from chi, there is a million dollars waiting for him or anyone else if they can demonstrate that in controlled conditions: http://en.wikipedia.org/wiki/One_Million_Dollar_Paranormal_Challenge . Too 'enlightened' to use powers for fame or fortune? It's already on Youtube of all places. Prove generations of smug skeptics wrong, revolutionize science and medicine, and donate the money to charity!