Projects:2016s1-142 Code Cracking: Who Murdered The Somerton Man?
Contents
Topic
Code cracking and data analyzing.
Supervisors
Prof. Derek Abbott
Dr. Matthew Berryman
Team members
Yifan Ma
Yami Li
Abstract
Executive Summary
The Somerton man case is a very famous unsolved case which related to an unidentified dead man on Somerton beach in Australia. The aim of this project is to find out the new clues about the Somerton man case by comparing the content of various elements in the dead man’s hair with the hair of the normal man. In this project, the main research method consists two part, one part is the spectral analysis and the other part is the comparative analysis. For spectral analysis, through burning and scanning hairs extracted from Somerton man and control samples, the hair data with respect to elements content can be recorded. In this experiment, two set of data which are glass and quartz plate test are obtained. In theory, the purity of the quartz plate is higher, so the results of spectral analysis should be more accurate. However, in view of the fact that the hair sample during the quart plate test was not complete compared with glass plate test. Thus, the test data from both experiments are utilized for comparative analysis. The hair data comparison between Somerton man and control samples are processed by Matlab programming. The reason for choosing Matlab is that it can express the distribution of each element in the hair of Somerton man and control samples clearly. These significant and small differences in content are the focus of this project.
Acknowledgements
Thank Prof. Derek Abbott for his guidance, advises and explanations. He teaches me to understand the documents referred to this project and gives me useful feedback which improves my work quality. To James Chapel for his assistance on data analysis and plotting figures. To Dr Hong Gunn Chew for his guidance on the project schedule.
Task 1
Task 2
Introduction
This project is to study on an unsolved murder case that happened on the 1st of December 1948. At 6:30 am of that day, a man was found dead on Somerton beach. This dead man carried with no identifications and his teeth were not matched with any known person, so he is called Somerton man. After postmortem, the coroner picked some information from this dead man, such as the heart was of normal size and the death time was around 2 am of the found day. Besides, the coroner figured out that approximate three to four hours before death the man ate a pasty as meal which pathologist Dr. Dwyer suggested some poisons causing the man’s death. But the pasty should not be the source of poison through further research. Finally, after a series of investigations, the coroner still could not tell any conclusion about this man’s identity or cause of death and the dead man’s body was buried in Adelaide's West Terrace Cemetery in 1949. It became one of the Australia's most fascinating cold cases. [2][4][10] In order to continue the study of this case, a plaster cast of Somerton man was made in 1949. The hairs which were extracted from Somerton man plaster cast and other six different students are used for spectral analysis. [9] Hair data is recorded by Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and this instrument is effective for micro-sampling of solid material for trace elements and the analysis of predominantly cation. [1] For collecting data, the hairs were burned by laser. Then, the instrument measured the levels of different isotopes and the relatively values of elements. After testing, the comparison for experimental results between Somerton man and six other different students can be processed.
Motivation
The aim of this project is to find out the new clues about the Somerton man case by comparing the content of various elements in the dead man’s hair with the hair of the normal man. Even if the case has happened for decades, it is not been forgotten. The residents still would like to see the case solved. In addition, this project can expand the knowledge for data analysis, code cracking, engineering statistics and digital forensics. In fact, this dead man was suspected to be a foreign spy due to his unknown identity. So, it is meaningful for country security as well.
Objectives and Methods
1.Understanding the hair biology knowledge and some related chemical knowledge. 2.Hair mass spectral experiment: hairs were burned by laser. Then, the instrument measured the levels of different isotopes and the relatively values of elements. The scan speed of mass spectrometer was 5 micrometers per second. 3.Two tests: For glass test, the scan length of each control sample was 1000 micrometers. The method length was 230 seconds including 30 seconds background. The scan length of Somerton man’s hair was 6054.6 micrometers and the method length was 1240.9 seconds including 30 seconds background as well. For quartz test, two sections of seven control hairs have been tested and each hair is 500 micrometers, so there are fourteen control hair data and the total length is 0.7 centimeters. Somerthon man hair scanned 500 micrometers, each subsequent transect beginning where the previous finished for a total 96 sections (4.8 centimeter total) due to the limitations of the sample stage.
4.Experiment results analysis: For a healthy person, the hair growth rate is approximate 0.4 millimeters per day [7]. So based on glass test data we can get about 2.5 days information of control and 2 weeks information of Somerton man before his death. From the quartzes test data we can also know the element content differences between Somerthon man and control samples hair. All the experiment data is plotted by Matlab and the plotting figures are listed in Appendix A. Then, the comparison between Somerton man and control samples is processed. The comparisons are focus on the different elements content in hair which can provide some useful information related to Somerton man. 5.Put forward some reasonable assumptions and new clues: Based on experiment data analysis, some reasonable assumptions needs to be presented. These assumptions can be related to some activities and the living environment before his death. 6.Validation of assumptions and clues: Once these assumptions are confirmed, they can be served as new clues for the case to provide more direction.
Literature Review
1.Previous Studies In addition to police men’s investigation, there already have several academic studies. Prof. Derek Abbott has worked on this case for more than 2000 hours. [9] His team took the hairs from Somerton man’s plaster cast and recorded elements data by ICP-MS. Since 2009, it had become a final project for the University of Adelaide students and some students had participated this project. In 2013, the project group plot some Somerton man’s hair elements’ content figures and compared with control samples. [6] They have analysed the differences between Somerton man’s hair and control samples. However, those hairs’ data were all got from glass test. In this project, we redo the analysis based on the data that got from quartz test. In addition, we will compare those two different data figures. However, the new data should not be compared with old directly due to different drift values. The new data will multiply a constant which is got from the glass test remainder that is a bit rest of Somerton man’s unburned hair. Besides, the different year of plasters needed to be considered as well. 2.Software Hair data is recorded by Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and presented in the form of Excel tables. Matlab is used to plot figures which are used to show the elements comparison results clearly. It has some graphing capabilities and can be applied for making engineering plots.[3] In this project, the massive hair element data are plotted by Matlab command ‘scatter’. Then, use command ‘hold on’ to put the Somerton man’s and control samples hair data on the same figure and make the comparison clear. 3.Hair elements Hair analysis can demonstrate the content level of the heavy mental and essential elements in human body. [3] The different value of some essential elements in hair may be correlated with nutritional status and diseases, such as calcium (Ca), chromium (Cr), zinc (Zn), copper (Cu), and selenium (Se). The high values of some elements such as lead (Pb), arsenic (As), mercury (Hg), and cadmium (Cd) in hair can indicate the intoxicating phenomenon. [3] Using this analysis method can discover the useful information about the Somerton man healthy condition and has possibility to find the cause of death. 4. The relation between living environment and hair elements The living environment can affect the content level of elements in human body. This effect not only caused by polluted water and food, but through the injury and radiation. Trace elements values in hair can reflect the source of behaviors including the diet hobbies, smoking and medication. Human absorbs pollution source by different ways such as oral, breath, injection and radiation. These contaminants stored in different body organs and tissues can affect human health. Hair is a good indicator of environment change. Normally, it shows the variation of trace element in human body as the hair growth.
Glass test data analysis
Data screening
The hair data was recorded by mass spectrometer and the data was got from glass test. There are 44 elements gained by laser ablation (shown in Table 1). Three of these elements are needed to be mentioned. The first one is sulphur (S7) which must exist in human’s hair. The value of Sulfer can be refered to the drift value of the environment. The second one is lead (Pb206), the high level of Lead is harmful for human health. The third one is strontium (Sr88). This element has high percentage in Adelaide’s soil compared with other areas. So, the analysis of the change tendency of Strontium’s value will provide useful information about Somerton man’s living environment before his death. Table 1 Elements table for glass test
Element classification
Some recorded hair data contains toxic and heavy mental elements which are harmful for human health in high values. However, most are essential elements for human body. Table 2 shows the toxic elements and essential elements in hair. The comparison of toxic elements content in hair is an important research subject. Table 2 the Different Type Elements of Hair
In previous study, the hair data analysis is based on glass test result. However, the impurity material has influence on element values, thus, the data analysis mainly relies on quartz test rather than glass test in this project. Compared with glass plate, the quartz plate is a purity material composition. Table 3 shows the main composition of glass and quartz. Table 3 The different Elements of Glass and Quartz
Element content comparison
In order to speculate the cause of death and living environment, the Somerton man hair data should be compared with control samples. In this experiment, six normal people’s hairs are selected as control samples. Then, the mass hair data is disposed by software for a visual comparison.
Excel
At first, the hair data of Somerton man was plotted by Excel (shown in Figure 1). The X axis demonstrates the scan time of mass spectrometer. The Y axis demonstrates the relative value of elements content. Figure 1 Somerton man’s hair data
However, only 28 elements were shown on the chart. Some data was missing due to the shortage of Excel. Besides, most elements are not clear except sodium (Na23). Some traces are out of range and not obvious, such as the elements located on the bottom of this chart. So, these troubles result in the difficulties of contrast. The control samples hair data plotted by Excel (shown on appendix A) as well. Unfortunately, they all have the shortages as the Somerton man’s data chart.
Matlab
In order to solve these problems, Matlab can be used to plot each element’s content distribution. 44 elements comparison figures have been plotted and shown on appendix A. Some comparison figures of element value display the results clearly. However, some figures have difficulties to find the tendency. The elements figures’ classification is shown on table 4. Table 4 Classify elements by comparison results
The quality of the results is considered below, four elements (Na23, Mg24, Si29 and Ca43) have the similar tendency. Meanwhile these four elements are all contained in glass material in previous study. This phenomenon can assume that the recorded elements values are affected by glass slice. However, the elements which do not exist in the glass will not be affected. In table 4, the same value means that the content of elements in the Somerton man and control samples can be regarded as the same value. Different value represents a significant difference in element content, and the change trend is not similar. No tendency means that the comparison figures can’t show the law of change and the results can’t be compared. Figure 2 shows the lead (Pb206) relative value comparison between Somerton man and control samples. Figure 2 Lead (Pb206) Value Comparison
The X axis demonstrates the scan time of mass spectrometer. The Y axis demonstrates the relative value of Lead content. The mass spectrometer scans from the root of hair. Therefore, the smaller number of X axis represents the closer to death time. In Figure 2, the content of lead in control samples is very low and there is slight upward trend only in a short period of time. However, there have found a very high level of Lead in Somerton man’s hair compared with control samples especially the end of his hair. This situation of high lead content is worthy of attention. Through further studying the distribution graph of lead content, it clearly shows a tendency that the lead value has a visual reduction before his death. So, it can be affirmed that high level of lead was not the main cause of his death. In fact, the high level of lead content can be related to the living environment and the rapid decline in lead content may represents the recent replacement of the living environment. Thus, some of the geographic information in 1948 needed to research, such as solid analysis, petroleum quality, water quality and nuclear power plant location. Figure 3 shows the mercury (Hg202) relative value comparing between Somerton man and control samples. Figure 3 Mercury (Hg202) Value Comparison
The X axis demonstrates the scan time of mass spectrometer. The Y axis demonstrates the relative value of mercury content. There have found a higher level of mercury in Somerton man’s hair compared with control samples. This value from root to the end of hair is basically the same. Through research, mercury is a highly toxic heavy metal pollutants of biologic toxicity. It is difficult to be discharged back into the organism. So it is a serious threat to human health. However, mercury is ubiquitous in nature. There are trace amounts of mercury existing in plants animals and food. Normally, human can eliminate toxins through excretion and metabolism to keep the amount that should not influence health. This is the reason for finding mercury in human’s hair. The main pollution of mercury is from chlor-alkali, plastics, batteries, electronics and other industrial emissions. The Somerton man’s higher level of mercury may be due to his living area. Thus, this should not be regarded as the cause of his death. The strontium value between the Somerton man and control samples’ hair are obviously different. Figure 4 shows the strontium (Sr88) relative value comparing between Somerton man and control samples. Figure 4 Strontium (Sr88) Value Comparison
The X axis demonstrates the scan time of mass spectrometer. The Y axis demonstrates the relative value of strontium content. Strontium exists in mineral water. It is an essential element for human. This element can prevent hardening of the arteries. At the root of Somerton man hair, the content of strontium is significant high. This means the living area for Somerton man contains high level of strontium content before his death. In addition, the strontium value shows an increasing tendency in his last two weeks. However, strontium is not a toxic element and the increasing tendency is not the cause for the death of Somerton man. Reasonable inference is that the Somerton man changes living environment two weeks before the death and this is the same with the speculation for lead content change.
Moving-average Filter in Matlab
Some comparison figures cannot be shown clearly by Matlab plotting. Thus, the Moving-average Filter should be applied. Firstly, selecting a window size for Filter. Then, calculating the arithmetic average of outliers within the window and make the average of the demand as outlier’s window centre point. After that, moving the window as window size and the average method is repeated until this process is complete. This method has a good inhibitory effect on periodic disturbance and makes the figure smoother. It is suitable for high frequency oscillation system. All of the elements content figures have been plotted by using moving-average filter and shown on appendix B. After using moving-average filter, the comparison figures have some new founds, such that more similar tendency elements are found and some clear comparison figures have been shown. The details are shown on table 5. Table 5 Classify elements by comparison results
Through filtering, As75, Ag107, Cd111 are the new found toxic elements which have high level in the Somerton man’s hair. The content distribution is shown as follow: Figure 5 Cadmium (Cd111) Value Comparison
Cadmium is an element present in the nickel-cadmium battery and it is a toxic element which can create poison gas when boiled. The average content value of cadmium in Somerton man is much higher than control samples especially when the scan time is 1400 seconds. However, the change trend of this element are similar with lead and content value of cadmium shows a decreasing tend for his last time. Unlike lead, cadmium is more toxic and it can be regarded as the clue for the death of Somerton man. However, this kind of battery did not appear before 60 years. That can be indicate this battery is not the source of cadmium. It can also be observed from the figure that the hair for control samples contain cadmium as well. Thus, it can assume that this kind of element may come from drinking water or food, or other frequently used items. Figure 6 Silver (Ag107) Value Comparison
Through the observation of Figure 6，the silver content of Somerton man is higher than control samples. Besides, the value change for silver in hair of Somerton man is not obvious and the whole tends to be stable. Thus, this element should not be used for the speculation of Somerton man living condition. Besides, the element of silver is not harmful for human healthy. It can only make some colour change for skin. Thus, this element will not be researched in this project. Figure7 Arsenic (As75) Value Comparison
Arsenic content level in Somerton man is increasing during the last two week. At the tip of Somerton hair, the arsenic content is similar with control samples. That means this content level is not harmful for human. Besides, the living area of Somerton can be assumed as same as control samples. However, the arsenic level is significant high at his last few days and the arsenic can be used for making toxicant. So, changing living area or being poisoned should be considered. This comparison figure can be regarded as one valuable clue.
Knowledge Gaps
This project can generate several new clues for the case of Somerton man. Meanwhile, these new clues were confirmed by comparative analysis of elemental contents. New clues can provide more directions for the future research.
Quartz test data analysis
Data screening
Compared with glass plate, quartz plate is more pure. So, some elements recorded in the glass experiment were not present in the quartz test and some elements have different relative atomic weight. The recorded 35 elements in quartz test are shown in Table 6.
Data comparison figures
All of the quartz data is recorded. In order to comparison, the data of element has been classified as four sets of data: • Control sample hairs: Files name are Hair02-Hair08. For control hairs, it analyzed 2 sections of each hair, each 500um in length, so there are 0.7 centimeters control sample in total. The number of samples is seven, and each person takes two hairs as the two samples. • Somerton Man: It analyzed 500um sections, each subsequent transect beginning where the previous finished for a total of 96 sections (4.8cm total). • Standards: The files named NIST612-1 to NIST612-20 (20 transects) are standards and were run to ensure that the instrument wasn’t grifting too much during the analysis, they can be used to compensate for the drift if need be as they were run at intervals during the sample acquisition. • Background: Transits of 100um lengths across the quartz, files are Glue -1 to Glue–4. For the quartz test data, each element needs to plot three comparison figures. The first comparison is the comparison of four sets of data which are control samples, Somerthon man, quartz and standards. The second one is enlarged graph for the first comparison figure. The third figure shown fourteen control samples’ hair data comparison. Using the different colour dots to represent the four sets of data. Blue dots represent control samples, red dots represent Somerton man, yellow dots represent standards and green dots represent quartz background. The Figures (8-14) show the comparison of four sets of data. The X axis for all of the figures describes the scan times of the laser. The Y axis represents the relative value of elements in four sets of data.
The comparison result of silver (Ag107) value between four sets of data is shown in Figure 8. Yellow dots represent the drift values which are basically stable and indicate that the drift change is not significant. Thus, the recorded data is reliable. Green dots represent the silver content in quartz. As can be seen from the figure, the content of silver in the quartz is very small. Therefore, this set of data has little effect on the test data. In general, the silver element content in Somerton man’s hair is higher than the control hairs. In quartz experiment, the relative content value of silver in the hair is a table value and it is similar with the glass experiment result. Figure 9 Carbon (C13)
Figure 10 Sulphur (S34)
Same as silver, the standard values for sulphur and carbon are constant which means the instrument wasn’t drifting too much. By comparison, the carbon and sulphur relative values are similar among Somerton man and 12 control hairs. Only two samples have significant differences and these samples come from one special person. Carbon and sulphur are essential elements in human hair. The change in the content of these two elements can be a direct indicator of a person's living environment. Based on the comparison results of the Figure 9 and 10, the living environment conditions for Somerton man and six control samples are similar but different from the special one. Thus, the living environment of Somerton man can be confirmed. Figure 11 Calcium (Ca43)
Figure 12 Potassium (K39)
Figure 13 Strontium (Sr88)
Compared with the elements relative values between Somerton man and control samples, Figure 11, 12, and 13 have some similarities. The relative values of calcium, potassium and strontium in Somerton man’ hair are higher than most control hairs. However, the content of these three elements in two samples is close to the content of Somerton man’ hair. Moreover, these two hair samples both are from the one person. Based this result, it can be speculated that the content values of these three elements in the living environment for Somerton man and this special sample are similar. Figure 14 Lead (Pb206)
It has mentioned in the previous chapter that lead is a toxic element, and the data obtained from the glass plate experiment show that the lead content in Somerton man’s hair is significantly higher than that in control hairs. This phenomenon still exists in the quartz plate test. Since the incomplete hair for quartz plate test, the trend of lead content value in the hair before Somerton man dying cannot be expressed. However, the content of lead in Somerton man’s hair is indeed higher than the control hairs. The difference in lead levels does not indicate that the death of Somerton man is caused by the high level of lead in the body. The difference may be due to the fact that the lead content in human living environment is different from 60 years ago. Figure 15 Comparison of the relative values of some elements in control hairs
For control hairs, two sections of each hair have been analysed. There are fourteen control hairs which are from seven persons. By comparing these 14 samples, it was found that there was a difference in the elemental content between the samples, especially the first control person’s hair. Figure 15 shows the relative value of the first sample is significantly higher than the other samples. These elements are Mg, Ca, K, Mn, Na, Li, Sr. In addition, by the analysis and comparison results of several previous graphs, the values of the elemental contents of this sample are similar to those of Somerton man. From this result it can be inferred that this control sample and Somerton man have similarities in the living environment or lifestyles.
Two data comparison
Two tests data comparison table
In the glass plate test and the quartz plate test, 31 same elements were recorded and shown in table 7. Table 7 the Same Elements in Two Data Sets
Comparison of Somerton man’s two hairs
In the last two chapters, we compare and analyze the differences between Somerton man and the control samples in the two experimental data. Next, the two experimental results of Somerton man's two hair data will be compared. We hope to compare the two groups of experimental data to find a same trend but different values data, and then multiply a constant number with one of the test data to obtain the other test data. Figure 16 (a) Silicon (Si) value comparison in quartz test
Figure 16 (b) Comparison of the relative values of Silicon (Si) in Somerton man hair
Figure 16(a) is a comparison of the silicon data obtained in a quartz plate experiment. The silicon content in the standard is reduced. So that the silicon content in the hair data is reduced. It is shown that the environment of test has influence on test result. From Figure 16 (b), these two hairs of Somerton man have significant different in the relative value of silicon. Besides, the trend of these two sets of data is significantly different. Thus, it cannot find the constant number from Figure 16. The following figures that from Figure 17 to 20 are the different elements comparison results of two Somerton man’s hairs. It is hard to find the same trend from this comparison. Therefore, it is necessary to find another suitable way to compare the two sets of data. Figure 17 Comparison of the relative values of Arsenic (As75) in Somerton man hair
Figure 18 Comparison of the relative values of Strontium (Sr88) in Somerton man hair
Figure 19 Comparison of the relative values of Lead (Pb206) in Somerton man hair
Figure 20 Comparison of the relative values of Sulphur (S34) in Somerton man hair
Future Works
At this project, Somerton man’s hair elements data which got from glass test and quartz test have been plotted. The future works as following: • Re-analysing the uncommon elements value of Somerton man’s hair • Find the Somerton man’s living environment clues • Find the same trend part from two Somerton man’s hair comparison figures. • Gain the constant number to multiply one test data
Project Management
Timeline
The timeline Gantt chart has been attached in appendix B. It has listed the key milestones of the project (shown in Table 4). Table 7 Key Milestones of the Project
Work breakdown
The key task for the project is plotting and comparing data figures. Then, finding clues from the comparison. Due to two group members have different study directions, the project work is individual.
Task allocation
The project has two directions. In general, two group members work on different specific tasks. This report devote to analyzing the mass spectrometer data of the Somerton man hairs. The other group member works on cracking code and writing software
Management Strategy
To ensure finishing project on time, we have set the following strategies: • Meeting with supervisors frequently • Receiving effective feed backs from supervisors • Finish tasks without delay • Communicate with group member frequently.
Budget
The project has 500 dollars budget but the software tools are open source in the University of Adelaide. So we do not need cost money on this project.
Risk Management
The risks of project are listed in Table 2. The first risk should be considered is misunderstanding project tasks. So, the well communication with supervisors is essential. For this report, the crucial task is plotting figures by Matlab. Matlab unavailable will have influence on project processing. However, the Matlab is available on the computers of university. So, this risk can be negligible. Table 8 Project Risks
Conclusions
In this project, three important comparisons of experimental data were made. These three comparisons are related to glass test, quartz test and the comparison of glass and quartz test results. In the comparison of the experimental data of glass plate test, the relative values of element content for lead, mercury, arsenic and cadmium in Somerton man’s hair are significantly higher than control samples in certain period of time. However, these elements’ content have been reduced to a safe range before his death. Thus the high content of these elements cannot be regarded as the main cause of Somerton man’s death, only as a reference to the change of living environment. In the comparison for the data of quartz test, the total amount of recorded elements were reduced from 44 in glass test to 35 which is due to the high purity of quartz plate. Thus, some elements in glass test are excluded. Through comparison, the content of carbon and sulphur in Somerton man’s hair has a large difference with the fourth sample. In addition, the content of potassium, strontium and calcium are similar with the first sample. Therefore, it can assume that Somerton man’s living area is different with the fourth sample, but similar with the first sample. The data comparison between glass and quartz test does not achieve the desired results. So, the experimental method may need to change in the future work.
