In January of 2020 researchers published a paper titled “An Adaptive and Wearable Thermal Camouflage Device”  at the University of California, San Diego detailing a wearable device that can hide someone from thermal imaging devices, heat detecting sensors capable of seeing differences in heat at night, such as the kind found in night vision technology.
- Sahngki Hong, Sunmi Shin, Renkun Chen, “An Adaptive and Wearable Thermal Camouflage Device,” Advanced Functional Materials, 2020, Vol 30, Issue 11, 1909788, https://doi.org/10.1002/adfm.201909788
Thermal radiation, also known as heat, is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. If the radiating body and its surface are in thermodynamic equilibrium and the surface has perfect absorptivity at all wavelengths, it is characterized as a “blackbody.” The surface emissivity is a key component for engineering materials to prevent detection using heat sensors. Note that heat is radiated as electromagnetic energy. Emissivity is the measure of an object’s ability to emit infrared energy. Emitted energy indicates the temperature of the object. Emissivity can have a value from 0 (shiny mirror) to 1.0 (blackbody). Most organic, painted, or oxidized surfaces have emissivity values close to 0.95. The mathematical definition of emissivity is e = Me/Mo where Me is the radiant existence of a surface, and Mo is the radiant existence of a black body at the same temperature as the surface. In order to build the right type of material researchers needed to look for a material that works even when the ambient temperature changes. This led to the researchers looking for phase-changing materials whose melting point is at 30 degrees Celsius (approx. 86 degrees F). A phase transition is a thermodynamic property of a material in the sense that this most commonly describes transitions between solid, liquid, and gaseous states of matter, as well as plasma in rare cases. During a phase transition of a given medium, certain properties of the medium change, often discontinuously, as a result of the change of external conditions, such as temperature, pressure, etc. For example, a liquid may become gas upon heating to the boiling point, resulting in an abrupt change in volume. The measurement of the external conditions at which the transformation occurs is termed the phase transition. In the work to create a device with a very low emissivity, researchers looked to phase-changing materials that were similar to wax with more complex properties. The key property of phase transition temperature needed to be at approximately the temperature of human skin, ~34-36.9 degrees C so if the temperature outside of the device got hotter, the material would melt, and if the outside temperature got colder, the material would solidify, essentially behaving as an insulating layer.
The researchers claim the device works even when ambient temperature changes, it cools down or heats up based on the outside temperature. The researchers write that it can go anywhere between 50 and 100.5 degrees Fahrenheit in under a minute. The thermal camouflage strategy utilizes a flexible thermoelectric device (TED) covered with a high-emissivity polymer layer to change and match the surface temperature of the object to the background temperature. This strategy will work for a variety of background temperatures, regardless if it is lower or higher than the object temperature.
The paper  states, the materials are more complex that simple long chain hydrocarbons (wax). This technology contained thermoelectric alloys so the phase transition could be controlled. The device was set up to function on battery power and controlled wirelessly. The researchers claimed that this is the first material that is capable of camouflaging someone from thermal sensors that can adapt to ambient temperature changes. The material consists of a samarium nickel oxide which allows control by electric power how much thermal radiation is emitted. There are many military practical applications for this technology. This technology would essentially allow soldiers to sneak around in the dark without being detected with thermal sensors, this would provide a very valuable tactical advantage. One issue with the low emissivity strategy to shield one’s thermal signature is what is called “infrared reflectance.” Since the camouflage film obviously cannot have infrared transparency, low emissivity inevitably leads to high reflectance. This would cause the reflection of the surrounding nonuniform thermal signatures to an infrared detector and result in a noticeably different thermal pattern compared to the background when there are hot or cold spots in the environment, such as the Sun (≈9900 F) or the sky (≈34 F). Thermal reflection can be captured by an infrared detector when an object moves due to the change of the reflected thermal radiation. The low-e aluminum film used in the demonstration has a reflectance value of 0.96, while the reflectance of the TED was as low as 0.07. This low reflectance of the TED was achieved by the high-emissivity polymeric elastomer material that was used. The low-e film showed the reflected infrared radiation from the human body, which was detectable by the infrared camera. The reflected thermal radiation of the hand showed the exact hand skin temperature (34 °C), suggesting the imperfection of the emissivity manipulation camouflage technique. On the other hand, the camouflage with TED did not reflect the thermal radiation from the warm hand that was placed above the TED. This would prevent a infrared sensor from detecting a moving object that is being shielded.
This technology is fascinating, and there are many practical applications, even nefarious ones, such as those who would use the technology to evade thermal sensors found in home and business security systems. We can imagine the applications for criminal activity, and we can also imagine the benefits of this technology for military applications as well. It will be interesting to watch how this technology develops and is applied as researchers further develop these functional materials!
The Spiritual Insights that we receive from this type of research is related to an invisibility cloak and our spiritual life according to the Bible. We are told from the beginning, starting with the Torah, how the Lord God Almighty desires to live in our midst. This is the Gospel Message that is laid out from the opening pages of the Torah, the Messiah (Bereshit / Genesis 3:15), the love of God, Sacrifice and redemption (Bereshit / Genesis 3:21). This type of relationship is described as we being the people of God, and the Lord being our God who dwells among us (see Bereshit / Genesis 17:7, Shemot / Exodus 6:7, Ezekiel 34:24, Ezekiel 36:28, Jeremiah 7:23, Jeremiah 30:22, Jeremiah 31:33). The concept of being the people of God was further revealed to us in the Apostolic Writings (NT) in relation to how the Holy Spirit of God would dwell in our hearts, and in our lives, in our body, how God would work in our lives. The Master, Yeshua the Messiah, told us these things, which was further explained by the Apostles and Paul. Paul wrote in Phillipians 2:13 saying, 2:13 for it is God who is at work in you, both to will and to work for His good pleasure. (NASB) This illustrates a promise, a Torah centric principle, of God dwelling in our midst. The Lord God who is at work in you as Paul wrote! The parallel to the scientific research is in the idea of one having woven an invisibility cloak around one’s self such that the God of Creation is hidden. This principle Paul is speaking of God dwelling in our hearts and of his working in our lives for his will, purpose, and good pleasure, is the miracle that God works in our lives daily such that we are able to live our lives for Him, and to love Him with all our heart, strength, and soul (the Shema, Devarim / Deuteronomy 6:4-6). The property of emissivity of the materials directly parallels this concept of the invisibility cloak, and the Lord God living, moving, and performing a work in us for others to see. The idea is some have chosen to keep their faith hidden from their friends, family, and colleagues at work in such a way that is similar to the invisibility cloak, how it works for thermal sensors. What is more disturbing, in relation to “reflected thermal imaging” is the parallel found here int he life of a believer where one can detect movement due to thermal reflections when a cloaked object is moving, the spiritual application is related to such a person who has hidden his faith in Yeshua and the God of Israel such that one’s life, what one believes, how one lives (functions) and behaves, resembles the world and not that of a child of God. This is a serious problem in light of this research as we ask the question:
“Do we live our lives wearing a cloak of invisibility in relation to our faith in Yeshua?”
The root of this question is related to the matter of being ashamed of our faith rather than being bold in our faith! Something also to be aware of is wearing an invisibility cloak is a choice, and due to a particular lifestyle, one could make such choices being unaware of what is happening. This is manifested in the “codependent dynamics” that one may have by identifying with our culture, and agreeing with what society considers good or bad, or politically correctness, or hiding behind one’s career, or even one’s training as a teacher being taught liberal ideologies at university, etc (i.e. most teachers are liberals holding to all sorts of unbiblical ideologies). This is the result of the world we live in which consists of uniformity, standardization, and globalization which runs contrary to the command of God according to Devarim / Deuteronomy 12:1-8.
Devarim / Deuteronomy 12:1-8 אֵ֠לֶּה הַֽחֻקִּ֣ים וְהַמִּשְׁפָּטִים֮ אֲשֶׁ֣ר תִּשְׁמְר֣וּן לַעֲשׂוֹת֒ בָּאָ֕רֶץ אֲשֶׁר֩ נָתַ֨ן יְהוָ֜ה אֱלֹהֵ֧י אֲבֹתֶ֛יךָ לְךָ֖ לְרִשְׁתָּ֑הּ כָּל־הַיָּמִ֔ים אֲשֶׁר־אַתֶּ֥ם חַיִּ֖ים עַל־הָאֲדָמָֽה׃ These are the laws and rules that you must carefully observe in the land that the LORD, God of your fathers, is giving you to possess, as long as you live on earth. אַבֵּ֣ד תְּ֠אַבְּדוּן אֶֽת־כָּל־הַמְּקֹמ֞וֹת אֲשֶׁ֧ר עָֽבְדוּ־שָׁ֣ם הַגּוֹיִ֗ם אֲשֶׁ֥ר אַתֶּ֛ם יֹרְשִׁ֥ים אֹתָ֖ם אֶת־אֱלֹהֵיהֶ֑ם עַל־הֶהָרִ֤ים הָֽרָמִים֙ וְעַל־הַגְּבָע֔וֹת וְתַ֖חַת כָּל־עֵ֥ץ רַעֲנָן׃ You must destroy all the sites at which the nations you are to dispossess worshiped their gods, whether on lofty mountains and on hills or under any luxuriant tree. וְנִתַּצְתֶּ֣ם אֶת־מִזְבּחֹתָ֗ם וְשִׁבַּרְתֶּם֙ אֶת־מַצֵּ֣בֹתָ֔ם וַאֲשֵֽׁרֵיהֶם֙ תִּשְׂרְפ֣וּן בָּאֵ֔שׁ וּפְסִילֵ֥י אֱלֹֽהֵיהֶ֖ם תְּגַדֵּע֑וּן וְאִבַּדְתֶּ֣ם אֶת־שְׁמָ֔ם מִן־הַמָּק֖וֹם הַהֽוּא׃ Tear down their altars, smash their pillars, put their sacred posts to the fire, and cut down the images of their gods, obliterating their name from that site. לֹֽא־תַעֲשׂ֣וּן כֵּ֔ן לַיהוָ֖ה אֱלֹהֵיכֶֽם׃ Do not worship the LORD your God in like manner, כִּ֠י אִֽם־אֶל־הַמָּק֞וֹם אֲשֶׁר־יִבְחַ֨ר יְהוָ֤ה אֱלֹֽהֵיכֶם֙ מִכָּל־שִׁבְטֵיכֶ֔ם לָשׂ֥וּם אֶת־שְׁמ֖וֹ שָׁ֑ם לְשִׁכְנ֥וֹ תִדְרְשׁ֖וּ וּבָ֥אתָ שָֽׁמָּה׃ but look only to the site that the LORD your God will choose amidst all your tribes as His habitation, to establish His name there. There you are to go, וַהֲבֵאתֶ֣ם שָׁ֗מָּה עֹלֹֽתֵיכֶם֙ וְזִבְחֵיכֶ֔ם וְאֵת֙ מַעְשְׂרֹ֣תֵיכֶ֔ם וְאֵ֖ת תְּרוּמַ֣ת יֶדְכֶ֑ם וְנִדְרֵיכֶם֙ וְנִדְבֹ֣תֵיכֶ֔ם וּבְכֹרֹ֥ת בְּקַרְכֶ֖ם וְצֹאנְכֶֽם׃ and there you are to bring your burnt offerings and other sacrifices, your tithes and contributions, your votive and freewill offerings, and the firstlings of your herds and flocks. וַאֲכַלְתֶּם־שָׁ֗ם לִפְנֵי֙ יְהוָ֣ה אֱלֹֽהֵיכֶ֔ם וּשְׂמַחְתֶּ֗ם בְּכֹל֙ מִשְׁלַ֣ח יֶדְכֶ֔ם אַתֶּ֖ם וּבָתֵּיכֶ֑ם אֲשֶׁ֥ר בֵּֽרַכְךָ֖ יְהוָ֥ה אֱלֹהֶֽיךָ׃ Together with your households, you shall feast there before the LORD your God, happy in all the undertakings in which the LORD your God has blessed you. לֹ֣א תַעֲשׂ֔וּן כְּ֠כֹל אֲשֶׁ֨ר אֲנַ֧חְנוּ עֹשִׂ֛ים פֹּ֖ה הַיּ֑וֹם אִ֖ישׁ כָּל־הַיָּשָׁ֥ר בְּעֵינָֽיו׃ You shall not act at all as we now act here, every man as he pleases (Sefaria)
The idea of globalization draws in not just the idea of companies working on a global scale, but also lets down one’s guard against the gods of these nations that is coupled to every man acting, behaving, as he pleases (Note the people of the nations are characterized not as the USA against everyone else, or as Israel against everyone else. This is the language of the Torah that characterizes the differences between the people of God and those who do not know the God of Israel!). This means that as we are commanded to live for the Lord according to His Word. If one has a cloak of invisibility in regards to his or her faith, hiding the fact that the Lord God lives within, to drop the cloak of invisibility means that one must stand out in a way that everyone becomes aware of one’s faith. This isn’t about narcissism or self-centeredness, it is about being humble, being reverent of God and of His commands in the sense that we allow the Lord God to work in our lives for righteousness, holiness, justice, and truth and we are not afraid to let others see this in our lives! In relation to these things, lets think about what the Scriptures have to say concerning things that are “hidden” and “concealed.”
One of the Hebrew names of God is El Elyon (אֵל עֶלְיוֹן), which is often translated in the English translations as “God Most High.” This name first appeared in the Torah regarding the mysterious figure of Malkizedek (מַלְכִּי־צֶדֶק). The rabbis speak of this timeless king and priest of Zion who served “bread and wine” to our father Abraham. (see Bereshit / Genesis 14:18) The root word for “Elyon” (עֶלְיוֹן) is derived from the root word עָלָה meaning “to ascend.” This word is found throughout the Torah for example in the “olah korban” (עלָה) the whole burnt offering that ascends towards heaven. We also find this word “aliyah” (עֲלִיָּה) derived from the same root word meaning “to go up” to the land of Israel. Taking these uses of the Hebrew root word עָלָה, the word “Elyon,” then, expresses the idea that the Lord is the One who is raised up, the Resurrected One, who overcame the world, its temptations, its sins, and conquered the powers of hell and utterly destroyed the power death has over man. The way these things are connected (juxtaposed) in the text, to Makizedek, to the sacrifice, to the risen one, this is very suggestive of Yeshua the Messiah! Note something here, in Tehillim / Psalms 91, the author of this psalm is believed to be Moshe, wrote that he dwelled in the secret place (סֵתֶר) of the Most High God. (א ישֵׁב בְּסֵתֶר עֶלְיוֹן בְּצֵל שַׁדַּי יִתְלוֹנָן:) This same word Elyon connects us back to Bereshit / Genesis 14. In addition, we also read according to the Torah, the Lord God spoke out of the midst of the dark cloud (Shemot / Exodus 24:18). As this is a description that is related to concealment, something hidden, or being invisible, like a cloak, the Lord God hides Himself according to Shemot / Exodus in the dark thick clouds. The author of the Psalms states that the one who abides in the secret place of the Most High dwells in an ascended place of rest, a place that is lifted high above the realms of this world. God Himself hides in this world (Isaiah 45:15), and therefore we must humbly seek His face in order to enter into this holy place of concealment. As the Hebrew word “Elyon” (עֶלְיוֹן) speaks of God being above all things (He is Almighty), he dwells high above, and so as the Almighty, he is called Shaddai (שַׁדַּי) the sustainer, creator, provider, and refuge, the one who gives us our daily provisions. We are told in Tehillim / Psalms 91:4 that we are surrounded by his shadow, and that He covers us by his protection. The Scriptures speak of our abiding in the secret place, but this does not mean that we are to hide the work of God in our lives from the world. On the contrary, we are to proclaim the truth and power of God in our lives for the glory of God! This is how we bear His testimonies and bring glory to His Name! King David said shiviti (שִׁוִּיתִי) meaning “I have set the LORD always before me because He is at my right hand, I shall not be shaken” (Tehillim / Psalm 16:8 שִׁוִּ֬יתִי יְהוָ֣ה לְנֶגְדִּ֣י תָמִ֑יד כִּ֥י מִֽ֝ימִינִ֗י בַּל־אֶמּֽוֹט׃ ). The question is how did David “set the LORD before Him?” This is a question of great relevance today in light of the scientific research on the invisibility cloak! The Torah and all of Scripture speaks to our calling to live our lives in the reality of God’s divine presence dwelling in our midst in such a powerful way that others will see and also want that hope that we have in Yeshua the Messiah! This hope enables us to go “Boldly before the Throne of Grace” (Hebrews 4:16) as the author of Hebrews wrote! The world knows nothing of this reality and is enslaved to sin in the appearances and delusions of this realm, the olam hazeh and of the flesh. This is why becoming visible and allowing the Lord God to empower us in our lives for Him in righteousness, holiness, justice, and truth may be dangerous as it sets the world to look at us and judge us, to question us, and even to condemn us for our faith in Yeshua. Yeshua said “To you it has been given to know the secrets of the kingdom of heaven, but to them it has not been given” (Matthew 13:11) and these are the things the scientific research is drawing out for us today. The Spirit of God says “Come, my people, enter your chambers, and shut your doors behind you” (Isaiah 26:20) where Yeshua alluded to the secret place of our heart, the “prayer closet” in a sense, where we appeal to the Hidden Presence of God to be manifest in the midst of every circumstance of our lives. This is what it means to take down that cloak of invisibility and allow everyone to see the glory of God shining through our lives! We are made secure on account of Yeshua the Messiah, who overcame this world, laid his life down for us, and was raised up gloriously ascending over and above the principalities and powers of this present age, and securing our lives by the power of God! Because of Yeshua we have the divine presence of God in our hearts, and we are not to hide this from others. Yeshua is the master over all, he is the King of Kings, and Lord of Lords, who has secured the victory for those who trust in Him! When we consider the scientific research, ideally we are to be characterized as a blackbody in the sense that we have perfect absorptivity at all wavelengths, that we take on the properties that God produces in our lives according to His word, and then we perfectly radiate these things, and God’s love into the world. God is good, He is merciful, He is righteous, He is holy, He is just, and He is true, and all the world needs to know the love that God has for us, if we are willing to accept what He has done and not be ashamed of what we believe according to the Scriptures we will cast off the cloak of invisibility and openly proclaim the Gospel Yeshua to the nations!