It is believed by paranormal investigators that ghosts or spirits can be detected through fluctuations in the earth’s electromagnetic field using an EMF detector. I personally do not believe this is a reliable method for doing so. I believe EMF fluctuations can happen normally at certain places even without paranormal intervention. Without knowing whether spirits are just energy or something else, do they have mass or not, it is difficult to tell if they give off their own magnetic field or simply disrupt the earth’s magnetic field as they move. Given the fact that the earth is one big magnet with a molten metal core that is moving around and covered with an immense ocean that is also moving, it is natural to assume that these magnetic fields do not remain static. I do believe that EMF may one day be the key to uncovering a lot of what is happening around us. Until we can see the Electromagnetic spectrum in three dimensions like we do with Infrared imaging, any data collected from EMF detectors will be purely speculation. PKEI has researched EMI (electromagnetic imaging) but this technology is in early development and still a ways off. I also believe when this technology becomes as useable and portable as thermal imaging, it will be much more expensive to own. This would put the technology out of the reach of most paranormal investigators such as it has with thermal imaging. EMF has been used in some new and interesting ways lately to rule out natural phenomena. Investigators have been using techniques such as trying to get spirits to manipulate an EMF detector repeatedly by asking questions and monitoring the response to rule out the random and increase the validity of their results. I am glad to see this being done because it shows that there or those out there that realize that an EM spike alone is not enough to prove paranormal activity.