Interesting

Well, to me, anyway. You might think so, too. Certain subjects and activities have engaged my interest for decades, and, in some cases, since childhood. I have always been interested in the military, probably because my father served in the Army, during the Korean War. As a young boy at sleep away camp in New England, I learned to shoot a .22 rifle (earning my marksman’s patch). My interest in shooting deepened after my father retired; he and I would spend time together at the range. I have enjoyed studying science since my days as a curious kid, experimenting (at some personal risk) with one of those metal-cased chemistry sets that were still common in the 1960s.

My purely adult interests include history and literature, geopolitics, economics, philosophy and culture, defense and security (national and personal), as well as technology and religion.

Following are some short write-ups on terms, concepts, ideas, and practical notes, gleaned from my readings, that I find to be both thought provoking and useful. I add more content as the spirit and mood strike me.

5 x 5

Being interested in matters of defense and national security, and also, because I am always looking for useful insights for understanding current affairs, and for investing, I follow a number of military oriented websites and blogs. From these sources, I picked up the term, five by five (that is, 5 x 5,) which is analog radio communications shorthand for the grading of signal quality.

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The phrase, “You’re coming through loud and clear” entered the American vernacular as WWII combat veterans, including radiomen, returned from Europe and the Far East. Similarly, the phrase “five by five,” became slang for “everything’s good.”

Analog signal quality, which is especially important to voice communications, is reported in two numeric scales: one for signal strength, and one for signal clarity, with number “1” being the worst and the number “5” being the best. Signal strength refers to the ability of a radio signal to get through (is the signal weak or strong?) Signal clarity refers to the ability of the signal to convey information as intended (is it garbled, or is it clear?) To say that a signal is “five by five,” or simply, “5 x 5”), means the signal has excellent strength and perfect clarity. “Five-by-five” is analog world tech-speak for “loud and clear.”

When communicating, think about signal quality. Shoot for 5 x 5.

OODA Loop

Developed by the late U.S. Air Force Colonel John Boyd (January 23, 1927 – March 9, 1997), a fighter pilot and influential military theorist, the OODA Loop is a “practical concept designed to be the foundation of rational thinking in confusing or chaotic situations.”1 Boyd first conceived of developed the concept of the OODA Loop to improve the success and survival rate of jet fighter pilots engaged in blink-of-an-eye dogfights with Cold War-era adversaries. An acronym for Observe, Orient, Decide, and Act, the OODA Loop has found application well beyond the military, including business, sports, litigation strategy, self defense and planning.

Boyd was prolific maker of slide presentations, given mostly to military audiences, yet, he authored surprisingly few publications. I’ve read some of his most noteworthy articles, such as “Destruction and Creation.” 2 I have also read several biographies written about Boyd and an an academic treatise on his theories. As often happens with out-of-the-box thinkers, Boyd was somewhat of an outcast within the military establishment, yet his original thinking and influence live on.

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Boyd’s OODA Loop offers a practical mental model for handling dynamic problems in many situations, from life-or-death tactical encounters in war and self defense, to business decisions, litigation strategy and planning.

I highly recommend reading up on the OODA Loop, as the concepts on which it is based apply in many areas of life.

1Here’s a good article about Boyd and OODA Loops.

2Click here for a site dedicated to Boyd’s work, with publications and bibliography.

Cargo Cult Science

Richard Feynman (May 11, 1918 – February 15, 1988) is one of my heroes. Like my late father (another one of my heroes), Feynman was born in the then largely Jewish neighborhood of Far Rockaway, in the New York City borough of Queens. Feynman, one of history’s greatest theoretical physicists, was a genius and an iconoclast. Feynman worked on the Manhattan Project during WWII and shared the 1965 Nobel Prize in Physics for his contributions to the development of quantum electrodynamics. He was famous for his lectures to freshman year physics students at Caltech (his lectures were often attended by other Caltech professors and graduate students and were transcribed and compiled into a series of books and recordings; I own sets of both). Feynman also played the bongos and wrote some very funny books.1

Richard Feyman’s 1974 commencement speech at Caltech.

Feynman first used the term cargo cult science during his 1974 commencement address at Caltech.2 The term refers to anthropologic observations of the behavior of certain primitive South Pacific islanders who witnessed and experienced first hand the arrival and build up of American might during the U.S. military’s island-hopping campaign toward the eventual defeat of Imperial Japan. The islanders observed the construction of runways, radio shacks and control towers and the arrival of cargo-laden military aircraft (C-47s, I would think), bringing all sorts of never before seen wonders. At night, the islanders noticed the lighting of bonfires alongside the runways, which, it turned out, were used to guide pilots to safe landings in the dark.

Cargo cult science: “If you build it, they will come” (except, they won’t).

After the war, American forces abandoned their island airstrips, leaving behind the islanders, now bereft of the wondrous material goods which the wartime aviators and their giant cargo planes had previously brought to the islands in once unimagined abundance. Believing in their innocent ignorance that recreating the wartime appearance of their island would bring the return of the cargo planes and their bounty, the islanders set about rebuilding runways, radio huts and control towers, using nothing but their native materials. Of course, despite their beliefs and best efforts, no cargo planes returned. The unique conditions that existed during wartime were not to exist again, and no amount of primitive belief, wishful thinking, or self deception would change reality.

Feynman used the term cargo cult science as an admonishment to beware the risks of faulty thinking and the dangerous deceptions of pseudoscience. In today’s highly politicized atmosphere, cargo cult science is all too common.

1“Surely You Are Joking, Mr. Feynman” and “What Do You Care What Other People Think?”

2See https://sites.cs.ucsb.edu/~ravenben/cargocult.html and be sure to read the whole thing. Feynman had an unmistakable way with words and ideas.

Triggers and Trigonometry

Pythagoras would have been a good rifleman, because he understood his angles. The Pythagorean Theorem states that, in a right-angled triangle, the square of the hypotenuse (“c”) is equal to the sum of the squares of the two other sides (“a” and “b”), that is, a2 + b2 = c2. The Pythagorean Theorem comes into play when shooting at an angle, i.e., uphill, or downhill, especially at distance. Here’s an interesting phenomenon: When shooting at a distant target, whether shooting uphill or downhill, absent appropriate aiming-point correction (using either an external optic or iron sights), a bullet will tend to hit high. To new shooters, this seems odd. How can it be that, whether shooting uphill or down, the bullet will tend to hit high? Pythagoras has part of the answer. Newton has the other half.

Try this demonstration: Hold one of your arms straight-out in front of you, level (i.e., parallel) to the ground, and pointing straight ahead, with fingers extended. Now, hold your other arm out, but pointed upward, at a 45-degree angle, as if you were aiming a rifle at an uphill target, also, with fingers extended. Now, think of an imaginary plumb line (a string, weighted on one end), descending, from the fingers of your upward-pointed hand, and the finger tips of your other hand (which, of course, is pointed straight ahead). The angle between the plumb line and your level arm would be exactly 90 degree; a right angle. Your upward-pointed arm is the hypotenuse of the triangle formed by your two outstretched arms and the plumb line. Thanks to Pythagoras, we know that the hypotenuse of a right-angled triangle is longer than either of the other two sides of the triangle.

Now, give your arms a rest and imagine yourself holding and aiming a rifle at an upward angle. The untrained shooter, who also happens to intuit a bit of geometry, thinks, “Hmm, if the line of sight between my rifle and my target is the hypotenuse of a triangle, and the hypotenuse is longer than the other sides of the triangle, my bullet will have to travel farther to get to the target versus a bullet shot at a level target, so, I have to aim higher, to account for the longer distance.” However, it turns out that bullets don’t think like Pythagoras. Bullets don’t think at all. Once a bullet exits the muzzle, it just reacts to external factors. Key among those factors, especially in the vertical direction, is the force of gravity, which works at a right angle to the earth’s surface. In other words, all objects, including bullets, fall straight down. A bullet shot at an angle, regardless of whether that angle is upward or downward, falls straight toward the earth’s surface. Thus, at any given point in its flight, a bullet is pulled directly toward the ground, along an imaginary line that is always level–or parallel–to the ground. A bullet does not “care” whether it is aimed at an uphill or downhill target (as if flying along the hypotenuse of triangle). A bullet “cares” about gravity. The problem, here, is that inexperienced shooters who don’t think about trigonometry and the physics of gravity let their eyes deceive them. When shooting uphill, these shooters think they must “aim high” to account for the effect of gravity on a bullet traveling along the hypotenuse of an imaginary triangle, but gravity only effects the bullet along an imaginary line that lies parallel to earth. Yet, from Pythagoras, we know, in a triangle formed by the line of sight to a target located either uphill or downhill from the shooter, a line parallel to the ground, and a third line connecting the other two lines, the line parallel to the ground is shorter than the line of sight to the target.

When shooting at an angle, a knowledge of geometry and physics can improve the shooter’s ability to hit a target accurately. In this illustration, the Line of Site (los) can be thought of as the hypotenuse of a right-angled triangle. As represented above, the True Ballistic Range (tbs), is the line long which the shooter’s bullet is affected by the downward force of gravity. Image source: trapperpredatorcaller.com.

Again, why does a bullet aimed either uphill or downhill tend to hit “high?” Because the inexperienced shooter is thinking about the distance to the target along the line of sight, whereas the bullet is “thinking” about the distance along a shorter, imaginary line that is parallel to the ground.

Satcoms

I own shares in an Israeli company, called Gilat Satellite Networks (Nasdaq: GILT). Gilat (pronounced “ghee-lot”) specializes in technology, products and services for satellite communications (satcoms).

Gilat is a provider of end-to-end satcom solutions for governments, militaries, commercial customers and private users that require broadband connectivity, wherever conventional telecommunications infrastructure is unavailable, due to locational, technical, economic or other considerations.

I first became aware of Gilat when I was reading something online and came across the term “satellite backhaul.” With a quick online search, I learned  that backhaul is the part of a telecommunications network that connects the core network, or backbone, to the smaller subnetworks at the edge of a network.  In particular, satellite backhaul is the part of the network that connects the backbone to a satellite orbiting the earth.

Satellites can be classified by the distance of their location (orbit altitude) above the earth’s surface. Geosynchronus (GEO) satellites orbit at a distance approximately 22,300 miles above the earth. GEOs are geo (earth) synchronous (time) because they remain stationary over a particular point on the earth’s surface at all times, providing a fixed field of signal coverage across a huge swath of terrestrial real estate.  The physical reason that GEOs are geosynchronous is that they travel at the same angular velocity around the earth as the earth’s rotational velocity (are you feeling smarter, yet?)

GEO, MEO and LEO satellites operate at distance from about 1,200 miles to about 22,300 miles above the earth’s surface. The greater the distance, the GEOs are larger and heavier than LEOs. The lower launch cost and lower signal latency of LEOs versus satellites operating at higher orbits will facilitate expansion of the satcom market as a whole, with more competitors able to launch more satellites and a broader range of services for customers back on earth.

Along with GEOs, we have low earth orbit satellites (LEOs) and medium earth orbit satellites (MEOs). LEOs orbit at a distance about 1,200 miles above the earth’s surface (for reference, the International Space Station orbits at about 248 miles above the earth). MEOs orbit at distances above LEOs and below GEOs.

What makes LEOs a hot topic today is their lower cost, relative to satellites operating at higher orbits. LEOs are smaller than GEOs and can be launched in multiples on a single flight, making them ideal for building constellations of satellites, with each LEO satellite functioning as a node in an expansive network–allowing for the proliferation of satellite services across the globe. Recognizing the business potential for LEOs, Elon Musk’s satcom company, Starlink, as of early 2021, is able to launch 60 LEOs into space on a single SpaceX rocket. Starlink intends to build a constellation comprised of thousands of LEOs (see illustration, below). This is really cool stuff.

Starlink satellite constellation map.

Back to Gilat. Their products include VSATS (very small aperture terminals), which are defined as two-way ground stations with a dish antenna smaller than 3.8 meters. Most VSATs are considerably smaller–similar in size to the familiar rooftop satellite dish. Some VSATs are small enough to be disassemped or collapsed and contained within a backpack, for ease of portability by a single person, such as a soldier or emergency services worker operating in a location that may be remote or physically damaged, as in the aftermath of an attack on infrastructure or a natural disaster. Gilat also makes satellite modems, and block up converters (BUCs), which convert lower band frequencies to higher band frequencies for transmission of signals to satellites.

All this neat gear enables installation of satcom systems on the ground (including roofs and towers), on aircraft (military, commercial, corporate, private), ground vehicles (on- and off-road vehicles, trains) , on boats and ships, and in man-portable applications. Increasingly, satcoms are also being set up to provide rapid or lower cost connectivity in so-called “edge” communities, on the outskirts of urban areas, and for densification of urban networks. 

The holy grail of satcom performance is low latency. Because satellites orbit in space, far above the earth surface, a satellite signal (which is two-way; “up” to the satellite, and “down” to a base station), takes time to reach its intended destination. Latency is the delay between sending and receiving a signal.  One important advantage of low earth orbit satellites is reduced latency. It’s simple physics. An LEO signal makes a round trip of about 2,400 miles, whereas a GEO signal must make a round trip of about 44,600 miles. Shorter distance means lower latency.

Satcom economics are driven by capacity cost, measured in dollars per gigabits (or megabits) of data per month. The smaller size, lower launch cost, lower maintenance cost and lower replacement cost of LEOs versus GEOs is driving down the cost of satellite communications. Coupled with ever greater demand for connectivity around the world, for both existing, new and still yet to be conceived services and applications, increasing demand for satcom technologies, products and services should be good news for investors in Gilat.

As a Gilat investor, I’m in for the long haul – and the backhaul.