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Some Frequently Asked Questions about MADS.

Dr Jason Braithwaite

See also, the MADS web site and Magnetic Hallucinations (an article outlining which magnetic fields induce hallucinations and possible sources in the domestic environment).


A great deal of information has been published in recent issues of Anomaly concerning magnetic fields and haunt-type phenomena. Methodological issues, appropriate devices, researcher assumptions, protocols and an outline of ASSAP’s new MADS system have all been covered in some detail. Anomaly has concentrated a good deal on these issues because it is a hotly debated area of some prominence. Based on questions raised by these articles and other presentations given at conferences etc, we have compiled a frequently asked questions (FAQs) article which we hope will help to bring a good deal of these themes together in the context of modern research. Many of the questions have been directed towards the types of magnetic fields deemed important, MADS and how people / members can get access to it and so on. We address the main questions that have been asked repeatedly as, we assume, this is where more information is needed.

What is MADS?

MADS is the name given to the Magnetic Anomaly Detection System recently developed for parapsychological investigations. It consists of two, high-speed digital fluxgate magnetometers that are directly interfaced to separate laptop PCs. They measure both AC and DC components of the magnetic field and can do so 250 times a second, in 3 orthogonal directions simultaneously. Individual readings are also provided for each direction. MADS covers a frequency range from DC – 125Hz and an amplitude range of + / - 1000mG (100,000nT). It is incredibly sensitive (down to 0.5nT) and can measure weak fields even in the presence of a large static field. The purchase of the PCs was funded by ASSAP, with all other funding coming from private business donations. It represents the most advanced system currently being used in field-based apparitional research and can also be applied to other laboratory-based studies as well. It is very easy to use and fully automated providing the investigator with a detailed real-time representation of the magnetic environment being studied.

So why is MADS so important?

The idea that some apparitional phenomena and haunt-type experiences have a magnetic component to them has been gaining considerable currency over recent years. The evidence looks obtained so far looks promising. The laboratory evidence, using weak, complex magnetic fields to stimulate hallucinations, is compelling though the field-based research is found wanting in many respects. One of the problems with the field-based research is that most of the technology used so far is wholly inappropriate and could be misleading. There are two main ideas about the role of magnetic fields. One is that haunted locations contain complex magnetic anomalies (similar to those artificially produced in lab experiments) that have brain stimulatory properties; the experience of apparitions is seen here as a magnetically induced hallucination. The other idea is that apparitions exist as external paranormal phenomena that are themselves magnetic or related to magnetic fields in some other, unspecified way. One popular variation of this theory is that apparitions produce electromagnetic disturbances, particularly when they first appear. This gives rise to the popular idea of a ‘ghost detector’. Irrespective of the reader’s own position, these possibilities need to be tested properly. This is why MADS is so important. Many investigators and groups are now going out and buying cheap EMF meters, often in the belief that they are ‘ghost-detectors’. While these meters can show electromagnetic fields, within severe technological limitations (rarely appreciated by their operators), they are not capable of detecting the kind of fields used in the laboratory experiments. Therefore, they cannot differentiate between the two competing theories. MADS, on the other hand, can measure the relevant fields. The MADS project as a whole is directed at these aims.

So what magnetic fields / parameters should I be looking for in an investigation?

A full description of these is outside the scope of the present article, suffice to say the following. Magnetic fields found in our environment are produced by both natural and artificial sources. The main natural source is the Earth's magnetic field, called the geomagnetic field. This is often described as a static field. Confusion arises here because the term ‘static’ implies that the magnetic field does not change. However, due to other atmospheric variables impinging upon and distorting it, the geomagnetic field actually does change very slowly over time. Important artificial sources include all devices that are powered by electricity. Researchers should be measuring all ambient magnetic fields in suspected haunted locations, both static and varying, irrespective of source. Typically the geomagnetic field varies normally around 1 - 10nT (though changes of up to 250nT can occur during geomagnetic storms) over a period of hours. On average the geomagnetic field is around 50,000nT (500mG) in the UK but this can be altered quite substantially by the local geology (i.e., natural magnetic anomalies). Most artificial sources of magnetic fields produce varying fields. They vary in sympathy with the 50Hz mains supply. These sources might typically add around 200nT of varying fields to the ambient static fields in the average house. Varying fields over 500nT (and certainly over 1000nT) are considered high. Nearby thunderstorms can produce varying fields in the region of 10 – 100nT. When taking readings in a supposedly haunted location, you should survey the ambient static field across the area (i.e., over space). This will typically vary 10 - 50nT across a normal room, according to the presence of magnetised objects, usually made out of steel. You should then examine the varying fields, usually (though not exclusively) produced by powered equipment. Magnetic fields increase dramatically as you approach their source, so allowing you to identify local ones. Though typical values have been given here, you should not assume that readings outside these values are indicators of anomalous phenomena. Many natural and artificial sources can produce fields well outside these parameters. These figures are to be used only as a guide, based on expected variances. Another, often over-looked, component in this area of research is exposure duration. It is important to document not only what fields are present, but also how long they are present for (especially in the presence of complex fields made up of numerous components that may be coming and going themselves). This is important as it is clear from laboratory studies that prolonged exposure to specific magnetic fields is crucial for stimulation to occur (approx 20mins in the laboratory). Finally, note that the values given above, though helpful, only pertain to field strength and nothing else. It is at this point things get more complicated.

So what else do I need to measure?

As a bare minimum we would suggest that researchers need to know frequency, as well as field strength. In other words, the field strength associated with each frequency component present. This is important for a number of reasons. Firstly, only small windows of frequencies have been shown to have brain stimulatory properties that result in powerful hallucination. These are typically below 30Hz (1-30Hz are the most popular in the laboratory). Little above this has much direct influence on experience. That’s not to say higher frequencies don’t have other effects (e.g., on equipment etc which is also important in some cases) but they are not crucial to stimulated hallucinatory experiences per-se. What this also means is that simple 50Hz sine wave sources, from the mains electricity supply, are unlikely to be the crucial stimulatory component of these fields. However, these simple fields may become distorted, erratic (due to faults, particular appliances and circuit loads) or interact with other sources to create very complex time-varying magnetic environments. Such environments may well have the capacity to stimulate hypersensitive brains. The point is that complexity rather than just strength seems crucial irrespective of the nature of the source.

So what is magnetic field complexity and how can I measure for it?

Magnetic field complexity can be realised in a number of forms. For instance, complexity could be a field that is changing in strength (amplitude) either regularly (indicating an amplitude modulated field) or irregularly. The degree and magnitude of the change could also be altering adding another component to the complexity. Another factors might be mixed field frequencies. There may be many different frequency components contained within the measured fields and these may come and go. There is also the shape of the varying field, as seen by MADS, for instance, as it varies over time. It could be sinusoidal, square-wave, pulsed or a combination of these which might appear as random. From this you can see how complicate measuring complexity can be. However, even with the correct use of relatively simple meters, the researcher would be able to measure a basic form of complexity; that of varying amplitudes.

What does this mean applied to a haunting?

One prediction might be that certain areas (i.e., haunted areas) may be magnetically distinguishable from others (baseline areas) and, as such, may be influencing the perceptions of susceptible observers. The investigator’s task is to see if the location where a witness experiences an anomalous event in some way differs from other similar areas. Note that, if we are trying to see if a magnetic field affected a witness, we need to measure the field where they were standing (sitting, lying etc) when they witnessed an event. Many people simply take measurements from ‘haunted rooms’ with no regard to where people were when they reported seeing / hearing / feeling something. Also don’t fall into the trap of simply looking for ‘hot-spots’ in terms of simple high amplitudes. High amplitudes from artificial sources are everywhere. If these were crucial then haunt-type experiences would be reported far more frequently than they are. So clearly, in relation to human experience, finding a high reading is not as important as what might first appear. Instead, we need to measure fields where witnesses were and look at amplitudes, frequencies and complexity. These can then be compared with baseline areas where nothing has been experienced.

What about high strength fields and higher frequency fields?

Before we answer this we need to make a distinction in relation to how magnetic effects are being reported in the popular literature. This distinction refers to fields associated with ‘anomalous experience’ (often interpreted as paranormal) and fields associated with ‘anomalous events’ (also often interpreted as paranormal). The laboratory evidence for crucial fields involved in inducing strange human experience is well documented. We have coined the term ‘Experience Inducing Fields’ (EIFs) to describe and distinguish these particular types of magnetic fields. Irrespective of the cause and the source, the magnetic fields induce an experience and we find the term ‘Experience Inducing’ to be a useful one as it does not force us into a particular interpretation of the fields from the start. It merely defines the critical function and potential outcome from exposure to the fields. As noted above, only small windows of frequencies have been shown to have consequences for consciousness. These are typically below 30Hz frequency and less than 500nT in strength. This seems important in order for the incoming fields to be integrated into the overall current perceptual gestalt. This is interesting for a number of reasons. Firstly, the field strength is not excessive at all and would be readily available from an everyday living environment. Secondly, such field frequencies could be created by complex distortions in the magnetic environment from either natural sources (i.e., tectonic movement, structural building factors, local geology, etc) or man-made sources (i.e., certain appliances, malfunctioning house wiring configurations, etc), or an interaction of both these sources. It is entirely conceivable that such EIFs could occur in our everyday living environment, under certain circumstances. In the presence of such a magnetically remarkable environment, an individual with an increased neuronal susceptibility to these fields may well react to such exposure (though note other factors such as, direction / distance to skull, time spent in the fields, levels of arousal etc, are also important). In contrast to these well documented EIFs, some investigators argue that other fields of much higher strength and frequency (MHz range) are also important. If this is the case then these fields seem to be associated with extreme anomalous events and poltergeist-type episodes. For the moment, we term these hypothesized fields ‘Event Related Fields’ (ERFs). In contrast to EIFs, reports of ERFs seem to be brief, transient and very intense in nature. They have no implication for cognition. From this it would appear difficult to see how they could have stimulatory qualities unless the intensities were incredibly high, and even then a brief pulse is unlikely to be enough to set off a cascade of excitable activity in the human brain. Furthermore, it is not clear that there are commonly available sources with such sufficient amplitudes in the everyday living environment to be of any real concern for experience. Therefore, the actual rationale and the evidence for seeing ERFs as underlying haunt-type phenomena is questionable. Indeed, there are no well documented instances of these fields being implicated in anomalous events in peer-reviewed scientific journals, though there are for EIFs. It would seem that the importance of ERFs is something of an urban myth perpetuated by the unregulated internet. We feel it is important to put the evidence, as it currently stands, in the proper context. On balance, by far the most likely candidates in ‘classic’ haunt-type experiences will come from low frequency fields. For other spontaneous cases, contributions from higher ERFs could theoretically occur, though this remains to be convincingly demonstrated in a single case. However, what EIFs and potentially ERFs (if they exist) do imply of course is that magnetic anomalies may come in a variety of forms, with distinct underlying physical characteristics, and with diverse consequences. Given that EIFs have been repeatedly demonstrated, in laboratory conditions, to produce hallucinations, the logical way forward is to look for them in the field. It is the specific study of such EIFs that MADS was designed to evaluate.

Do developments like MADS mean that other approaches, using much cheaper devices are worthless?

This is a tricky question. It depends not just on the technology but also the assumptions underlying the use of the technology. The big problem is that many people think, that even the most simple EMF meter is some kind of ‘ghost detector’. Let us be clear, a magnetic field meter does just that; it measures magnetic fields, no more, no less. It is up to the researcher to decide the cause of these fields and the consequences of being exposed to them, based on inference and theory. A simple hand held meter is useful for assessing simple household EMFs; that’s about as simple as we can make it. However, strange experiences are associated with very complex fields at specific low frequencies. Such frequencies and complexities, quite simply, cannot be measured by simple, cheap meters. Some of the more expensive meters may be sensitive to relevant frequencies but they can’t tell you much about them, only that a change has or is occurring. This is fine for, say, a preliminary site examination, identifying areas containing unusually high levels of household EMFs. However, these may be completely irrelevant in terms of EIFs. As noted earlier, high levels may not be crucial (indeed the evidence suggests they are not) while complexity, which such meters cannot measure, is. The problem is knowing what your meter can and cannot tell you and interpreting your data appropriately. Based on estimations from the laboratory studies, MADS is capable of providing the magnetic signature of haunt-type experiences, which means it provides a far more comprehensive understanding of what is taking place. The types of magnetic fields known to produce sensations in the laboratory can be fully measured and detailed by MADS with little effort whatsoever. If you have been using simple meters then it is not the case that your results are a waste of time. However, they are very limited in their explanatory power and relevance to important stimulatory fields. Once we all realise this then it is fine. A good metaphor is the human eye. Here light enters the eye and travels to the brain where nerve impulses are converted into what we perceive as colours, shapes etc. However, the human eye can only see across a certain bandwidth or spectrum of light. We cannot see into either the infra-red or ultra-violet light spectrum, but such light energy still exists. So our eyes are tuned to a particular spectrum section that gives us a snapshot we can use and is informative to us. However, there is a good deal more to the full light spectrum than the bandwidth our eyes are tuned for.

How can I get the best out of a simple meter?

This is a tricky one as it depends on the meter and on what the researcher wants to be able to say about his / her findings. Do you simply want to measure and evaluate the area for household magnetic fields? Or alternatively, do you want to see if haunted areas a magnetically more complex environments than baseline areas? In terms of the first question even the most basic meter can be useful if it is employed in the proper manner. Let us assume two scenarios, one where the meter is very simple giving a straightforward amplitude (field strength) reading and one with a slightly more complex set up that can be interfaced to a computer. The simple meter can be used effectively only to carry out a household EMF survey. This is important and should always be done, if only to identify and eliminate possible sources, but these fields themselves may not be directly relevant to EIFs. If the meter is single-axis then a source can be traced more accurately as the operator simply follows the direction of the highest readings. However, the disadvantage is that single-axis meters always underestimate the true magnetic reading at a given point in space because they only pick up fields in one direction. For a more accurate picture the operator will need to take readings in 3 separate orthogonal directions and pool the data using the Root-Mean-Square (RMS) procedure or its modified counterparts (True RMS / Corrected RMS, dbRMS, and so on). This will give a single, overall reading at one point in time. However, this can be very time consuming. Alternatively, a 3-axis meter will do this automatically for you so all you need to do is note down the readings from the LCD / needle display. The problem here is that unless you are given the individual readings from x,y,z directions you cannot tell which direction is contributing the most to the overall field and source localisation can be tricky. Both meters are fine for generalised basic surveys of field strength. However, noting variances from the meter can be difficult to do by hand. To do this more effectively meters that interface with computers are a big advantage. Here, not only can amplitude be documented, but also how that amplitude varies over the measuring period. Note that this variance can be used as a general index of one form of complexity and may potentially implicate the presence of stimulatory EIFs. However, we give a word of caution here. All of the above relates to evaluating amplitudes. We have no idea what frequency(s) these amplitudes represent. Most basic meters are ‘frequency-weighted’ which means they are tuned to be very accurate over a certain bandwidth. At other frequencies, readings may underestimate (or even overestimate) their relative contribution. Furthermore, the final reading is an ‘average’ over a whole frequency range. We cannot distinguish the amplitudes for each frequency component. As most meters are geared for household wiring configurations they are specifically optimal at 50Hz / 60Hz but roll off sharply below this (usually picking up nothing below 35Hz) and may cover a range right into the MHz region. This means that even if you do document an increase in variance, it may be coming from frequency components far above that which is crucial. It is up to researchers to note what their meters are tuned for and what they can and cannot do. Very few meters go below 30Hz, yet this is the exact area of the most potent fields.

Can I get to use MADS on my investigations?

Yes you can! As an ASSAP member you have a vested interest in MADS and can use it for a variety of studies. MADS is still undergoing the final stages of testing and development to make it as easy to use as possible. This includes software configurations etc that we are currently finishing off. Once completed, the plan is to make MADS available to ASSAP members and groups. However, choosing to use MADS will require a well thought-out project on your part. Analysing the data takes a good deal of time; that’s unavoidable if you want that degree of detail. So we must use MADS as effectively as possible and only where careful research dictates. We suggest that you request its use for your most interesting cases, and only where you think it could prove useful.

How can I go about requesting the use of MADS?

Once the development stage is finalised to a level that we feel people most will be able to use it, members will be told via ASSAP News and ANOMALY. The first stage will be to hold a series of training weekends for groups / members in order to make sure that potential operators have a good understanding of how to take measurements in an appropriate manner. They will then be shown how to set up MADS, how to configure it for their personal use, and how to analyse the data using the simple software we have provided for you on the laptops. We hope these weekends, though intensive, will represent advanced investigator training as well as being fun weekends as well with like minded individuals sharing ideas. No member will be allowed to use MADS for their own projects unless either they, or some member of their group, has attended the course and received this training. Also, when MADS is out on loan it will be sent with an operator. This is mainly for reasons of security and insurance; MADS is far too expensive to send through the post. The operator can also provide on-site support for the use of MADS. We hope to train as many operators as possible so that we can meet most requests. However, this will take time.

Will I get support with using MADS?

Yes you will. The courses outlined above are the first step. We are also in the middle of writing an operators manual which should cover everything you need to know and support your knowledge from the course. This will also include a step-by-step guide for summarising and analysing the data. The operators will also be available for assistance as well. As MADS is a very scientific piece of kit, we will also be operating a consultancy service (free of charge to members of course) to help you employ MADS as effectively as you can. So imagine you don’t really know much about magnetism but have an interesting idea. Contact a MADS consultant and they may be able to guide you into developing the idea into a more rounded project suitable for MADS. It could be a laboratory based exercise like ESP, PK, a mediumship experiment, lucid dreaming, a survey of a sacred site and so on. Conversely, you may be quite expert and know exactly how you want to deploy MADS; in this case it is still a good idea to run your ideas past the consultant so he / she can confirm that MADS can do what you want it to do. Basically, it is in everyone’s interest that you get the full support you need. At present there are two people that know the system well enough to field preliminary or advanced enquiries. These are Jason Braithwaite and Ian Topham. Future consultants will be trained to help so no one should be stuck.

What if competition for MADS is high, how will its distribution be decided?

This is an interesting question and one the executive committee will need to discuss in detail soon. We guess we will have to gauge demand at first. In terms of the reader, the more notice they can give then the more likely they are we can get something organised. I (JJB) suggest that any request for MADS be accompanied by a research proposal detailing the experiment or investigation. These can be assessed by a peer-review process and MADS deployed to the project deemed the better one. Here the term ‘better’ does not refer to the biases of the reviewer, but to the clearest proposal made which demonstrates a clear understanding of how MADS would be used and how the data would be interpreted. We can help with the submission process as well. This again would ensure that MADS is employed where it is needed most. Of course it will also be available for the spontaneous case from time to time so it would always be worth checking. This is just a proposal at present.

What if I want to get my own MADS, can I get one based on your design?

Yes you can. Full detail of MADS will be given at the end of the development phase to the extent that anyone could go and copy the system. The more the merrier. A paper has been submitted to a top international peer-reviewed journal detailed MADS and when this is published all the information will be available to everyone. We would encourage anyone to think about this and provide as much support / detail as we could.

What if I am not very technical?

This does not matter. MADS is not just for the technical people. It is to be used where its contribution will be most effective. The consultancy service should help the non technical people in the earlier stages. Also an operator will set it up for you for your project. Don’t be afraid of using MADS; consider it educational and a valuable experience.

Isn’t MADS too expensive for groups or individuals?

It is true that MADS is expensive but cheaper sensors can be used and these are in the price range of most groups. MADS uses digital sensors, model number 540 from Applied Physics Systems USA. These are the top of the range. However, a cheaper model, the 539 is also very, very good as well. It lacks some sensitivity and features of the 540, but in many respects it is a comparable sensor. It is also about $800 cheaper than the 540. We see many groups extremely well equipped these days usually with handfuls of EMF detectors. A cheaper 539 sensor is about the price of a decent digital camcorder or the combined price of about 3 of the most popular EMF meters. So it is by no means out of reach when viewed in these terms. We suggest also that in order to help raise funds, groups carry out training vigils for new members or the public, give seminars or talks and charge a small fee for these. This will help with the funds. Also if you are doing any media work, ask them for a small fee to your group or ASSAP as a whole and get ASSAP to put the money to one side for you when you get the rest.

Could I use MADS for my own media promotions?

Although we are keen to promote MADS as much as possible, on the whole we would have to say no. However, we are open to proposals at any time. The problem, at the moment, is that there are many highly sensationalised programmes being aired. These are causing a good deal of confusion and are having a very real detrimental effect on serious research, particularly at the amateur level. We would not want MADS to be associated with that type of promotion as what it represents is the serious scientific investigation of haunt-type experiences. MADS has appeared on BBC2s ‘Working Lunch’ and the Sky Discovery channel. If the proposed project were serious then using MADS would be possible.

What about other environmental variables?

Paranormal investigators often deploy a number of instruments to measure things other than magnetic fields, such as temperature, sound, light, infra-red, ultra- and infra-sonic etc. Indeed, ASSAP has in the past advocated a ‘blanket monitoring’ approach to vigils. There is no reason why you should not continue to deploy such instruments, in case any other environmental factors are implicated in hauntings. However, as with EMF meters, you should understand the scientific limitations of such equipment. Often cheap, it may not be sensitive or accurate enough to measure physical quantities to a scientifically useful standard. The MADS approach is quite different in that it starts with reproducible laboratory experiments. We then go out into the field to look for similar magnetic fields in haunted locations. It is a scientific approach because we start with a theory, that EIFs cause haunt-type experiences, and then test it. It is either true or false. With blanket monitoring, there is no theory, as such, so we cannot test one. However, if consistent results were obtained through such monitoring, at different haunted locations, it might lead to a specific theory that could later be scientifically tested. It might lead to laboratory experiments as well as field work. So there is no need to stop measuring other environmental variables but do bear in the mind the limitations of the approach and the equipment. Don’t assume that unusually high or low readings are anomalous. You should also ensure that you take readings at non-haunted, baseline locations for comparison. You should also consult relevant experts for their opinion on how unusual readings could have been caused naturally.