Science at the gate: GT200 and what can Thai society learn from it?
Opinion» Opinion
TECHNOLOGY
Published: 10/02/2010 at 12:00 AM
Newspaper section: News
About two to three years ago, I was approached by a then member of a subcommittee for human rights protection under the National Human Rights Committee. He wanted to seek my opinion on a seemingly mysterious instrument used then by the Institute of Forensic Science, under the Ministry of Justice, to scan for traces of explosive substances on suspect individuals in the far south of Thailand.
According to him, this instrument led to a great number of individuals being arrested. He knew that I was a scientist and working on the science of measurement.
I asked him a few questions concerning the principles of operation of this mysterious instrument. He did not know the answers, so I could not form an opinion. A scientist can form a proper opinion if ‐ and only if ‐ he or she has enough correct information. Otherwise, that opinion would be the same as ordinary guesswork.
I then asked if he could provide me with the instrument’s instruction manual and specifications. These two documents generally come with any instrument. The response was another “No”.
That really perked my interest. I then tried to gather other less technical information such as its character, its look, how it is used and so on. Based on the answers, it seemed to me then that this mysterious instrument was an ideal one: it was compact, portable, user‐friendly, highly sensitive and highly precise and could work with a variety of substances.
The “ideal” aspect sounded extremely suspicious to me, however. In my experience, nature does not like to allow highly precise examinations to co‐exist. One can have one precise examination at a time. Generally, if an instrument is extremely precise, it would be for a very specific use. If one wants to have both, i.e. high precision and extensive usage, then one has to allow the instrument to have a bigger size or the operating procedure to be complicated and to take a very long time.
In this light, one can compare general X‐ray photography to MRI (Magnetic Resonance Imaging). While the former is less complicated and can be used with many parts of the

body, the latter is huge and complicated. It cannot be used on a variety of things but is very precise.
The X‐ray photography is good enough for very many diagnoses. However, if better and more precise information is needed, the doctor will have to use different instruments such as an MRI, CT or others.
The MRI is an application of a physical phenomenon called NMR (Nuclear Magnetic Resonance.) The NMR is normally used by chemists to specify the chemical structure of samples under investigation. This is because the nucleus of an atom subjected to a magnetic field would emit or absorb electromagnetic waves specific to the atom. Different nuclei emit or absorb electromagnetic waves of different frequencies.
The MRI uses the magnetic signals generated by nuclei of hydrogen atoms in our cells or bones to build up an image. One is familiar with the tunnel‐like structure wherein a patient is placed during an MRI process. This tunnel generates a magnetic field to align the nuclei of the hydrogen atoms. When the nuclei are systematically stimulated by electromagnetic waves in radio frequency (RF) range, they will generate magnetic signals.
I’ve explained this NMR and MRI at length because I suspect that if the mysterious instrument ‐ which has now become famous as the GT200 Remote Explosive Detection System ‐ is not a joke and can really work, then its operational principle would be based on NMR and MRI.
Some people may wonder why I suggest these NMR and MRI, because nothing indicates that the GT200 can generate a magnetic field. My rationale is that there is the Earth’s magnetic field everywhere, though at a low level. There is an NMR system which makes use of Earth’s magnetic field. It is known as Earth’s field NMR. This is also an NQR (Nuclear Quadrupole Resonance) which needs a low magnetic field as well.
The NMR and MRI may be the answer to the question of signal generation. These signals still need to be interpreted, however. And I have a problem imagining this part. In any case, this is just my guess. It would be much easier to conclude that the GT200 does not work. However, a scientist cannot give a proper answer from not knowing. I mean, as a scientist, I cannot conclude that something does not exist because it sounds unlikely or I cannot find it or it does not fit my knowledge and experience.
One problem, which I mentioned earlier, is that the correct information about the GT200 has not been made available to the public.
If the government is serious about solving the growing problem of public distrust regarding the instrument’s precision, effectiveness and efficiency, it can start with full disclosure of the relevant data and information from all relevant agencies.

From this data and information, scientists can then start their work in investigating its operating principle and plan further experimental tests.
If the operational principle is not given, then one has to find out what kind of physical principles would be possible based on the available information and the instrument’s actual condition.
For example, I raised the possibility of NMR and MRI. These principles should be examined in detail in order to design a series of proper tests, one by one. After performing such tests, primary conclusions can be drawn. This path is quite complicated and time‐consuming but it must be walked through, unless there are other ways.
On the other hand, one can start examining the character of the GT200 as claimed by its producer. These claims include its ability to draw power generated by the movement of its operator up to 3000 volts and its ability to create an electromagnetic attraction between the substance being detected and itself. One can check all these claims to see whether they are fulfilled. If they are fulfilled, one will have to design more sophisticated tests. The same procedure as the one discussed in the previous paragraph must be carried out.
If the claims are not fulfilled, however, one would have to go a little further to see how various users in the past could use it to identify the locations of explosive substances. In my opinion, the investigation should not start with any pre‐judgements whatsoever. Nature never needs our agreement to allow a phenomenon or natural law to exist. We know quite a number of phenomena and laws that contradict our common sense.
The investigation should be carried out in a discrete manner since its conclusions could lead to several consequences. For example, how should those innocent individuals who were arrested because they were identified by the GT200 as explosive carriers be apologised to and compensated?
Either the GT200 does work, or it does not work ‐ there must be a scientific and sound explanation. If it does work, there must be an explanation. If it is does not work, there must also be explanation. The explanation is for both its users and the public.
Many people may be concerned that the investigation into the GT200 will lead to public distrust of science or forensic science. I disagree. I think that one needs to make a distinction between bodies of knowledge called science or forensic science, and other bodies or organisations whose names contain the word “science” or “forensic science”. Science is a collection of knowledge that belongs to humanity. It is our heritage. Our ancestors passed this knowledge down to us for our use, which is to eliminate irrational beliefs, ideas or practices from our own life and society. This knowledge belongs to no individual in particular but to everyone.
If the GT200 does not work, then the instrument is irrational. To continue to use an ineffective instrument would also be irrational. These irrationalities must be eliminated and that is the duty of science as well as other disciplines.
However, science can fulfil this duty if, and only if, the users of science ‐ scientists and non‐scientists alike ‐ are honest to its principles.
Many people have said on various occasions that Thai society is not based on scientific thinking. That is one big problem of society. Now is the time for those people and for people in the science community to show what scientific thinking is, and to prove that scientific thinking can lead to sound and impartial explanations. Society will see this and learn from it. In the end, they will judge by themselves whether science does matter, or not.
Author: Sivinee Sawatdiaree
The author has a PhD in Natural Science, Theoretical Physics, Faculty of Physics, University of Hannover, Germany. She is a member of ‘Wonglor’ (Circle of Friends) which is a group of young people and their senior friends who share an interest in the well‐being of society.
The author appreciates the spirit of Jessada Denduangboripan of Chulalongkorn University, who has shown his concern and willingness to fight irrationality.