Tunable Free-electron X-ray Radiation from van der Waals Materials – A Spiritual Insight


In a recent publication in the journal of Nature Photonics, [1] researchers have developed a technology that allows for X-ray emission from free electrons impinging on a van der Waals material. This new finding may enable more precise radiation sources that could lead to breakthroughs in medical imaging and other areas. The current X-ray emission technology is large, expensive, and cumbersome. The new material allows for controlled radiation release with a narrow spectrum that can be tuned allowing for higher resolution at a lower energy level. This new technology could actually lead to breakthroughs in a variety of fields, including in the analysis of chemicals, solid state materials, biological materials, medical imaging, security screening, and other areas that have need for higher accuracy and precision in X-ray sources.


  1. Michael Shentcis et al., “Tunable free-electron X-ray radiation from van der Waals materials,” Nature Photonics (2020). DOI: 10.1038/s41566-020-0689-7

The research paper reports the experimental observation of a proof of concept from theoretical models in regards to this technology. The researchers had published a series of theoretical papers describing how two dimensional materials are able to create X-rays. These papers which are cited in the present paper [1] led to the beginning of their studying X-ray sources based on the unique physics of two-dimensional materials. Based upon this theoretical work, they were able to manufacture a two-dimensional heterostructure and observe how electrons impinging on the structures can emit X-rays. 

Two dimensional materials are unique artificial structures that were first developed back in 2004 with the discovery of graphene. Two men, Andre Geim and Konstantin Novoselov were awarded the Nobel Prize in Physics for this discovery in 2010. These scientists and subsequent researchers discovered graphene has very unique properties that are different from graphite properties. Note, the initial discovery was conducted by peeling off very thin layers of graphene from graphite.  The  properties of graphene are strength, almost complete transparency, electrical conductivity, and light transmitting capabilities that allow radiation emission, which is a property related to the present research. These properties set graphene in a unique place, along with other two dimensional materials that will keep researchers busy studying these materials for applications in biological sensors, solar cells, semiconductors, display monitors, etc, for many years.  

The term van der Waals is taken from a man named Johannes Diderik van der Waals who won the Nobel Prize in Physics in 1910, over 100 years ago, for discovering this property of physics of materials. His discovery was on van der Waals forces which are weak, short-range electrostatic attractive forces between uncharged molecules, arising from the interaction of permanent or transient electric dipole moments. Graphene exhibits this property, and this new study [1] reveals how van der Waals materials are also useful for the production of X-rays. The research paper reports how the researchers produced different van der Waals materials and sent electron beams through the materials at different angles. This allows for the control of the precision and accuracy of the X-ray emission. The researchers demonstrated precise tunability of the radiation spectrum at very high resolution due to this method of van der Waals materials.  The paper provides a proof of concept for a very innovative use of two dimensional materials for the generation and control of X-ray radiation.  Professor Kaminer states that “The experiment and the theory we developed to explain it make a significant contribution to the study of light-matter interactions and pave the way for varied applications in X-ray imaging (medical X-ray, for example), X-ray spectroscopy used to characterize materials, and future quantum light sources in the X-ray regime.” This is definitely a very fascinating discovery!

The Spiritual Insights that we receive from this type of research is related to the discovery of sending an electron beam at different angles relative to the position of a van der Waals material leads to the release of X-rays along with the ability to more accurately and precisely control the amount of X-ray radiation which may lead to higher resolution measurements. The first thing I thought of was how this material behaves as a sort of lens and how the hermeneutic or interpretive method, theology, or doctrine we hold on to also acts as a lens for our understanding of truth, righteousness, and holiness in our lives. Another way we could analogize this research is related to only superficially reading the Scriptures as opposed to taking the Scriptures seriously as literally being the Words of God, and taking the time to study for the deep spiritual truth and meaning found in the Scriptures. This requires us to ponder, pray, and meditate on the Word of God. Let’s look at an example.

Yeshua during his ministry frequently taught in parables to illustrate profound, divine truths. A Parable is a simple story used to illustrate a moral or spiritual lesson. These were a common rabbinic teaching method which were familiar to the people of his time. Parables are not always correctly understood however, even his disciples needed Yeshua to explain them. The example I would like to look at is the very familiar parable of the Good Samaritan which is often misunderstood. 

Luke 10:23-37

10:23 Turning to the disciples, He said privately, ‘Blessed are the eyes which see the things you see, 10:24 for I say to you, that many prophets and kings wished to see the things which you see, and did not see them, and to hear the things which you hear, and did not hear them. 10:25 And a lawyer stood up and put Him to the test, saying, ‘Teacher, what shall I do to inherit eternal life?’ 10:26 And He said to him, ‘What is written in the Law? How does it read to you?’ 10:27 And he answered, ‘You shall love the Lord your God with all your heart, and with all your soul, and with all your strength, and with all your mind; and your neighbor as yourself.’ 10:28 And He said to him, ‘You have answered correctly; do this and you will live.’ 10:29 But wishing to justify himself, he said to Jesus, ‘And who is my neighbor?’ 10:30 Jesus replied and said, ‘A man was going down from Jerusalem to Jericho, and fell among robbers, and they stripped him and beat him, and went away leaving him half dead. 10:31 ‘And by chance a priest was going down on that road, and when he saw him, he passed by on the other side. 10:32 ‘Likewise a Levite also, when he came to the place and saw him, passed by on the other side. 10:33 ‘But a Samaritan, who was on a journey, came upon him; and when he saw him, he felt compassion, 10:34 and came to him and bandaged up his wounds, pouring oil and wine on them  and he put him on his own beast, and brought him to an inn and took care of him. 10:35 ‘On the next day he took out two denarii and gave them to the innkeeper and said, ‘Take care of him; and whatever more you spend, when I return I will repay you.’ 10:36 ‘Which of these three do you think proved to be a neighbor to the man who fell into the robbers’ hands? 10:37 And he said, ‘The one who showed mercy toward him.’ Then Jesus said to him, ‘Go and do the same.’ (NASB)

Because of this parable in Luke 10, today we generally know what it means when someone is called a “Good Samaritan” meaning that person shows kindness, mercy, compassion, and care for another person who is in need. This however is following centuries of reading this parable told by Yeshua. One point to be made is in the First Century, Samaritans were not thought of as “good.” In addition to popular misunderstanding of the Samaritan, the parable of the Good Samaritan is largely misunderstood. This story was not meant to make people feel guilty about not giving their money to poor people. It was also not told to cause one to feel guilty about not taking care of those who surfer. The Parable was designed to make people look into themselves, into their hearts to see whether they truly love God perfectly and loved others perfectly and to seek out the One alone who can provide forgiveness of sin and eternal life. Those who moved to the other side of the road and passed by without helping were not living worthy of the gospel. (Philippians 1:27) This illustrates another important point of the parable in its spiritual meaning, Yeshua was not teaching a mitzvot based salvation, but a salvation that comes from the heart which leads to our purpose of serving God and others. Parables teach us that studying God’s Word requires us who are listening or reading to think. Yeshua told parables to see if we really understand the truth of the Gospel. 

Because the Bible contains important spiritual truths, it holds a sacred status in both Judaism and Christianity. Both Judaism and Christianity hold to the conviction that the Bible contains the Words of God and is a receptacle of divine revelation. This belief in the inspiration of Scripture however has not generated one uniform hermeneutical principle for its interpretation. For example, some people argue for the literal interpretation of the Bible because the Word is complete. Others insist that the pages of the scriptures must always have a deeper spiritual meaning because God’s message and truth is profound.  Still others believe that some parts of the Bible must be treated literally, while others only figuratively.  As a result, there are four major types of hermeneutics that have emerged, (i) literal, (ii) moral, (iii) allegorical, and (iv) anagogical.

The literal interpretation states that the biblical text is to be interpreted according to the peshat (plain meaning) which is conveyed by its historical context and grammatical construction. It is believed the peshat (plain meaning) is corresponding to the original intent of the author. This type of hermeneutic is associated with the belief in the verbal inspiration of the Scriptures meaning each word was divinely chosen by God and placed within the writer. Some people claim that this approach to interpretation does not account for the differences in style and vocabulary indicated by each individual who wrote. 

The second type of interpretation is the moral interpretation. The moral interpretation seeks to establish moral and ethical lessons from the passages in the Scriptures. The allegorization (symbolic interpretation) was often utilized to achieve this approach. Take for example, in the Letter of Barnabas (http://www.earlychristianwritings.com/text/barnabas-lightfoot.html), he interprets the dietary laws in the book of Leviticus as not forbidden from eating the flesh, but as imagining a different interpretation each associated with those animals. The scientific research which speaks of directing an electron beam at different angles relative to the position of a van der Waals material leads to the ability to more precisely control the release of X-rays for higher resolution measurements. The material behaves as a sort of lens to produce a particular result, where in parallel fashion the hermeneutic or interpretive method, theology, or doctrine we hold on to also acts as a lens for our understanding of truth, righteousness, and holiness in our lives. Here Barnabas interprets at a very early date (110 AD) in such a way as to nullify the command on Kashrut. The danger of nullifying a command, whether one feels kashrut is weighty or not, brings into question what other parts of Scripture may also be effectively nullified by this method of interpretation?

The Allegorical interpretation interpreted the narratives found in the Scriptures as having a second level of interpretation beyond those of the person, place, things, and events which are explicitly mentioned in the text. This method of interpretation is most easily illustrated in what is called typological interpretation. This method of interpretation causes key figures, events, and institutions of the Tanach (OT) as being types and foreshadowing of persons, events, and things in the NT. Because of this method of interpretation (hermeneutical technique) for example, Noah’s ark has been called a type of the Christian church saying this is what God had intended from the beginning. It is easy to interpret a replacement theology which is in direct opposition to what the Scriptures actually state using this method of interpretation.

The fourth type of hermeneutic is the anagogical method. The anagogical method is the mystical interpretation which seeks to explain events in the bible as representing what it will be like in the olam haba (the world to come). The Jewish Kabbalistic interpretation utilizes this approach to biblical interpretation. This leads to the mystical significance of the numerical value of hebrew letters (gematria), etc. Catholicism also uses this approach for interpreting associations with Mary (mother of Yeshua / Jesus, Mariology).  There are obvious dangers to building an opinion on the meaning of the Scriptures through the use of these lenses of interpretation without thinking critically about the Scriptures, and actually knowing the Scriptures (reading our bibles every year). The second most dangerous way to interpret the Scriptures is to let someone create an interpretation for you. This is a natural byproduct of tradition coupled with theology. I have to say all of us have been influenced by tradition and theology of the modern times. This is why it is absolutely imperative for us to know what the Scriptures say! We have to read the bible for ourselves, we cannot rely only upon what is taught once a week at synagogue or church.

The Spiritual Insights that we receive from this research on using the electron beam coupled with van der Waals material to produce X-rays along with the ability to more accurately and precisely control the amount of X-ray radiation which may lead to higher resolution measurements tends to draw these things out in the sense of interpretation. One’s method of interpretation or theology may not necessarily result in a higher resolution understanding of the meaning of the Scriptures, and more specifically, how we are to live our lives before God to bring Glory to His Name. One of Paul’s primary concerns in his letter to the Philippians was that of one conducting his or her self in a manner that is worthy of the gospel of Christ. This is what he is saying to the Philippians according to Philippians 1:27-30.

Philippians 1:27-30

1:27 Only conduct yourselves in a manner worthy of the gospel of Christ, so that whether I come and see you or remain absent, I will hear of you that you are standing firm in one spirit, with one mind striving together for the faith of the gospel; 1:28 in no way alarmed by your opponents which is a sign of destruction for them, but of salvation for you, and that too from God. 1:29 For to you it has been granted for Christ’s sake, not only to believe in Him, but also to suffer for His sake, 1:30 experiencing the same conflict which you saw in me, and now hear to be in me. (NASB)

Paul writes of the importance of conducting ourselves in a manner that is worthy of the gospel. This means that we remain true to God’s Word, we are living out our faith, and that we will be persecuted for standing firm in our faith. Paul is reminding us of our responsibility to walk in a worthy manner. The gospel speaks of the life, death, burial, and resurrection of Yeshua, and of the Lord God dwelling in our midst. Because of these things, we are called to live ethically and moral lives standing for the truth and not a lie.  We have a responsibility to this as the people of God. The Greek and Hebrew translations state the following:

Μόνον ἀξίως τοῦ εὐαγγελίου τοῦ Χριστοῦ πολιτεύεσθε, ἵνα εἴτε ἐλθὼν καὶ ἰδὼν ὑμᾶς εἴτε ἀπὼν ἀκούω τὰ περὶ ὑμῶν, ὅτι στήκετε ἐν ἑνὶ πνεύματι, μιᾷ ψυχῇ συναθλοῦντες τῇ πίστει τοῦ εὐαγγελίου

רַק הִתְנַהֲגוּ כָּרָאוּי לִבְשׂוֹרַת הַמָּשִׁיחַ, לְמַעַן אֶשְׁמַע עֲלֵיכֶם – אִם בְּבוֹאִי לִרְאוֹתְכֶם, אִם בִּהְיוֹתִי רָחוֹק מִכֶּם – כִּי עוֹמְדִים אַתֶּם בְּרוּחַ אַחַת וְנִלְחָמִים בְּלֵב אֶחָד בְּעַד אֱמוּנַת הַבְּשׂוֹרָה

1:27 Only conduct yourselves in a manner worthy of the gospel of Christ, so that whether I come and see you or remain absent, I will hear of you that you are standing firm in one spirit, with one mind striving together for the faith of the gospel;

In the Greek text, the word ἀξίως (Axios, worthy) has the meaning of weightiness in the sense of something having value. In the Hebrew translation we see the use of the word הִתְנַהֲגוּ כָּרָאוּי from the root word נָהַג and רָאָה meaning “to be driven, led, or guided,” and “to see,” respectively. (where the word כָּרָאוּי means “properly”) This suggests how we are led by the Spirit of God in a way that has great value that is consistent with the gospel. Both the Hebrew and Greek texts draw out how the Lord God is moving inside of us, guiding us by His Spirit, and we are to humble our lives submitting to His calling and move. We should walk in a way that demonstrates the extreme value, the extreme worth of the gospel in our lives. The implication by Paul’s exhortation is that some people were not walking worthy. People were being tempted to not live according to God’s Word and possibly even have fallen way, which is the end result. How do we walk in a manner worthy of the gospel? In this text Paul describes what it means to walk worthy of this gospel is to live in a manner that honors Yeshua and his sacrifice for us. The point of Paul’s message is that living worthy of the kingdom is not just a mental exercise (faith) but it is actually living out our faith!