A recent publication reported on how bats rely upon the speed of sound as a reference during echolocation.  Echolocation is the location of objects by reflected sound. Bats are not the only animals that use echolocation, dolphins also use echolocation for example. In these animals, there is a physiological process for locating distant objects, such as a moving food source (prey) by means of sound waves reflected back to the emitter. Echolocation is used for orientation, obstacle avoidance, food procurement, and social interactions. Bats, whales, dolphins, a few birds like the nocturnal oilbird and some swiftlets, some shrews and the similar tenrec from Madagascar are all known to echolocate. For dolphins and toothed whales, echolocation enables them to see in muddy waters or dark ocean depths, and for whales, this may also be used to chase squid and other deep-diving species. Echolocation allows bats to fly at night as well as in dark caves. This is a skill that is necessary to locate night-flying insects that birds can’t find in the dark.
- Eran Amichai, Yossi Yovel, “Echolocating bats rely on an innate speed-of-sound reference,” PNAS May 11, 2021 118 (19) e2024352118; https://doi.org/10.1073/pnas.2024352118
The recent research paper  reports how bats use echolocation and have a built in sense of the speed of sound for distance locating. The researchers studied this ability by raising bats in a helium-rich atmosphere. The reason for this was the higher concentration of helium led to a lower density of air and produced an increase in the speed of sound. The speed of sound is sensed by the time delay between vocalization and the return of the echo. This provides a direct “straight line” or “point to point” distance measurement from any object. The researchers studied this phenomenon by changing the density of air and consequently the speed of sound. This caused sound to be faster and provide a sense of objects being closer than they actually were. The species of bat that was used actually changes the sound as it approaches an object, so the researchers were able to track how close a bat thinks it is to an object. The researchers had two groups of bats, some were raised in normal air, and others were raised in a helium rich air mixture. During testing, the bats were switched, so the one’s which grew up in the helium rich environment, when moved to air, would think an object is further away, and the opposite would happen for those raised in air when moved to the helium rich environment. The interesting finding from this experiment was that the bats behaved the same no matter what environment they were moved to. It did not matter what they had learned in the environment they grew up in, the perception of the speed of sound was accurate. This was a surprising finding as this reveals that bats are able to modify their sensing ability to adapt to the changing environments. For example, weather changes and altitude can also affect the speed of sound by up to 5%. In the helium rich environment, it was observed that the bats had trouble flying and landing due to the lower density of air, this however did not modify their perception of the distance. The conclusion of the paper was that though it may be advantageous to be more precise in the measure of distance using echolocation under a variety of conditions, the bats don’t seem to have the ability to adjust their perception. The most likely reason is that the atmospheric changes in density are not significant enough to make a difference. This study does show how bats have the ability to perceive distance relatively accurately without having to relearn due to changes in atmospheric density. This study sheds light on the innate flexibility of the sensory perception of bats and is a testimony to the creative hand of God!
The Spiritual Insight that we receive from this type of research is related to the perception of sin and the differing environments that we live in this world which parallels the scientific research. We note this aspect of man when considering the ways of God. When the prophet Samuel was commanded to anoint Israel’s next king following Saul, the Lord admonished him to not be distracted by the outward appearances of man as it is written according to 1 Samuel 16:7 וַיֹּ֨אמֶר יְהוָ֜ה אֶל־שְׁמוּאֵ֗ל אַל־תַּבֵּ֧ט אֶל־מַרְאֵ֛הוּ וְאֶל־גְּבֹ֥הַּ קוֹמָת֖וֹ כִּ֣י מְאַסְתִּ֑יהוּ כִּ֣י׀ לֹ֗א אֲשֶׁ֤ר יִרְאֶה֙ הָאָדָ֔ם כִּ֤י הָֽאָדָם֙ יִרְאֶ֣ה לַעֵינַ֔יִם וַיהוָ֖ה יִרְאֶ֥ה לַלֵּבָֽב׃ But the LORD said to Samuel, “Do not look at his appearance or at the height of his stature, because I have rejected him; for God does not see as man sees, since man looks at the outward appearance, but the LORD looks at the heart.” (NASB) We note based upon this text God was telling Samuel not to be impressed by looking at one’s outward appearances. The reason being, the Lord God delights to choose the one who has a contrite heart, one of faith and trust in God Almighty and His goodness (1 Samuel 16:12). Because of these things, when we consider the ways of this world and the ways of God, everything is upside down, opposites of a sort, when comparing the principle of spiritual life. This is the principle of “what is on the inside is not on the outside” by appearances. The reason this needed to be told to Samuel, and to us through the pages of Scripture, is due to how easily people may be deceived by mere appearances. We are being warned to look beyond the surface in order to discern the reality that is beneath. These are the things the scientific research is drawing out on bats’ perception of distance in varying atmospheres as the scientists were using differing environments to deceive the bats on their distance perception abilities and echolocation.
Those who rely upon the outward appearances will invariably find themselves confounded. This is why the prophet Isaiah stated, Isaiah 6:9, וַיֹּ֕אמֶר לֵ֥ךְ וְאָמַרְתָּ֖ לָעָ֣ם הַזֶּ֑ה שִׁמְע֤וּ שָׁמ֙וֹעַ֙ וְאַל־תָּבִ֔ינוּ וּרְא֥וּ רָא֖וֹ וְאַל־תֵּדָֽעוּ׃ He said, “Go and tell this people: ‘Be ever hearing, but never understanding; be ever seeing, but never perceiving.’” (NIV) and why Yeshua stated many times, מִי שֶׁאָזְנַיִם לוֹ, שֶׁיִּשְׁמַע! The one who has ears to hear, let him hear. (NASB, Mark 4:9) God gave them over to their stubborn hearts, to follow their own devices (Tehillim / Psalms 81:12, Romans 1:24) and they went back and not forward (Jeremiah 7:24). These things reveal to us how one is not to be indifferent to God or His ways, we are either moving forward in our relationship with God or we are going backward by pulling our hearts away and drawing near to this world and sin. (Revelation 3:16, this is the concept of being lukewarm) In the scientific community, we note that modern philosophy denies the existence of sin. Sin is defined through the disobedience of God’s commands. Think about this for a moment, when we ask the question of “What is sin?” when a person seeks the answer to this according to the culture, or the world’s perspective, one is left confused and uncertain. There is a difference between what God calls sin and what the world calls sin. Isaiah 66:3 states, בָּֽחֲרוּ֙ בְּדַרְכֵיהֶ֔ם וּבְשִׁקּוּצֵיהֶ֖ם נַפְשָׁ֥ם חָפֵֽצָה “… They have chosen their own ways, and they delight in their abominations.” Note something from Paul to the Romans, he said “Therefore, just as through one man sin entered into the world, and death through sin, and so death spread to all mankind, because all sinned.” (Romans 5:12) Notice how Paul writes “through one man sin entered into the world…” and how death is through sin. This death led to all dying due to his or her sin. notice it does not say, “through one man sin entered into all men…” but rather “into the world” and consequentially “death by sin.” This reveals to us Paul’s understanding on original sin. The world did not know disobedience or sin until Adam and Eve disobeyed God. This is a significant observation here because the concept of original sin suggests that we inherit Adam’s sinfulness and thus die. The point here is because of Adam’s sin, death entered into the world. The text does not say that sin entered into all men! We also note that we are not condemned because of Adam’s sin, we are condemned because of our own sins. This is why we find so many scriptures which speak to bearing our own iniquity such as in Ezekiel 18:20, הַנֶּ֥פֶשׁ הַחֹטֵ֖את הִ֣יא תָמ֑וּת בֵּ֞ן לֹא־יִשָּׂ֣א׀ בַּעֲוֺ֣ן הָאָ֗ב וְאָב֙ לֹ֤א יִשָּׂא֙ בַּעֲוֺ֣ן הַבֵּ֔ן צִדְקַ֤ת הַצַּדִּיק֙ עָלָ֣יו תִּֽהְיֶ֔ה וְרִשְׁעַ֥ת רָשָׁע עָלָ֥יו תִּֽהְיֶֽה׃ “The soul who sins is the one who will die. A son will not bear the iniquity of his father, and a father will not bear the iniquity of his son. The righteousness of the righteous man will fall upon him, and the wickedness of the wicked man will fall upon him.” and Jeremiah 31:30, כִּ֛י אִם־אִ֥ישׁ בַּעֲוֺנ֖וֹ יָמ֑וּת… “Instead, each will die for his own iniquity …” and most importantly right out of the Torah according to Devarim / Deuteronomy 24:16, לֹֽא־יוּמְת֤וּ אָבוֹת֙ עַל־בָּנִ֔ים וּבָנִ֖ים לֹא־יוּמְת֣וּ עַל־אָב֑וֹת אִ֥ישׁ בְּחֶטְא֖וֹ יוּמָֽתוּ׃ “The fathers shall not be put to death for the children, and the sons shall not be put to death for the fathers; every one shall be put to death for his own sin.” We note the concept of original sin as being judged guilty due to Adam’s sin falls short in light of a few scriptures out of the Bible. The Sin of Adam and Eve led to death entering into the “World” as Paul is writing as all of creation groans as a result. (Romans 8:22) These things parallel the scientific approach the researchers used in regard to studying bat echolocation. The scientists created differing environments in order to deceive the bats and study their response. If we keep ourselves in a strict theological box, the deception can become very great, so much so as superceding what the Bible actually states in truth and righteousness. These things can be understood in light of the modern theologies that produce such movements like NAR (New Apostolic Reformation) movement, or dispensationalism which teaches a form of godliness but denies the power thereof, that is the power of God in our lives (2 Timothy 3:5), or even the so called prophets that are all over YouTube teaching all sorts of strange things. Paul says to avoid such people who teach these things! Consider that Isaiah stated according to Isaiah 29:13 “Wherefore the Lord said, Forasmuch as this people draw near me with their mouth, and with their lips do honor me, but have removed their heart far from me, and their fear toward me is taught by the precept of men.” These are the things the scientific research is drawing out for us today!
In Hebrew there are approximately eight words which describe sin, רַ֖ע (evil, Bereshit / Genesis 38:7); רָשָׁ֔ע (wickedness, Shemot / Exodus 2:13); אֲשָׁמ֨וֹ, (guilt, Vayikra / Leviticus 5:15 ); חַטָּאתוֹ֩ (sin, Vayikra / Leviticus 4:3); עֲוֺ֣ן (iniquity, 1 Samuel 3:13); שָׁג֔וּ (stagger, error, Isaiah 28:7); תָע֗וּ, (wander, error, Ezekiel 48:11); פִּשְׁעֵיהֶ֖ם / pesha (crime, offense, rebel, 1 Kings 8:50). The way these words are used in the Tanakh leads to certain conclusions, (i) sin is fundamentally disobedience to God’s commands, and (ii) disobedience involved the willful commission of violating God’s commands, and (iii) sin takes many forms which are defined in different ways, as wandering away from God’s ways, and committing an offense before God.
The perception of sin and the differing environments that we live in this world parallels the scientific research on the way these bats were studied, reminding us about how easy it is to be desensitized to iniquity in this world. The Lord God Almighty has called us to holiness (Vayikra / Leviticus 19:2). This means we are not to be desensitized to sin. In today’s world it is very easy to do just that. We watch movies, listen to music, watch television series all filled with profanity, sex, and violence. It is possible to see so much of these things that we become tolerant of them. If we spend too much time watching television or movies it’s possible to make these things become a normal part of one’s life. These things rather than being appalling become something that is simply ignored or even desired. After enough time of exposure one might not even realize anything is wrong and assume that one may join with these things making them an acceptable way of life. As God’s people, the Lord calls us to be holy and set apart from the rest of the world. A good question is if we want to make a difference for the Lord in this world, how do we do that if our lives or even our thought life isn’t any different from the world? The point is our relationship with God isn’t a game, it is to be taken very seriously. So often believers try to see how close they can get to sin without actually sinning. Instead of seeing how close one can get to sin, we should be seeing how close we can get the to Lord God Almighty our Father in heaven in His Son Yeshua the Messiah.
So the question is have we failed to do what we should be doing? Does the term sins of omission apply to us? Remember how Yeshua spoke saying there are those who have left undone the things they ought to have done (Matthew 23:23, Luke 11:42). James speaks of something similar saying “Therefore to him that knoweth to do good, and doeth it not, to him it is sin” (James 4:17). Sinning is not just limited to the breaking of the command, or doing and saying things that are wrong. Sin also extends to our failure to do what God expects of us. Because of this we miss the mark and fall short of the honor and glory of the Almighty God. Because of all of these things, because of our failures to keep all of the mitzvot (commands), khukim (statutes), and mishpatim (judgments) this is why our Father in heaven sent His Son Yeshua the Messiah to die for our sins. He did this because the environment we grew up in actually can affect our perception of sin. Our culture, this world, skews morality and redefines ethics. For this reason we need a standard by which we can have the kind of principles God wants for our lives. These principles can be found in scripture, the Torah, Prophets, Writings, and the Apostolic Writings. It is only by the power of God and His Spirit that we are able to take His word and apply it to our lives so that we are able to know the difference between good and evil, right and wrong. And this is the power of God who dwells in the hearts of men, to help us overcome this world just as Yeshua overcame the world!