# Illusions

Illusion, Michael. –G.O.B.

(i) Optical illusions are fun. We all have our favorites. There’s one in particular which does not get as much attention as it should. It’s called the McCollough effect and you induce it by alternately staring for five seconds or so at the image below on the left followed by the image below on the right. Repeat this procedure for about a minute or so and then look at the black and white image below the pair.

The fact that the effect can last months following sufficient induction is what makes this one so cool. And a bit scary. Sort of like hiccups that won’t go away. In the back of your mind there is a creeping fear that they may never stop. You might hiccup forty times a minute for several decades or just have the hiccups ruin your life due to an unknown brain stem tumor.

(ii) Infinity is a like a concept, not a number, brah. Yup. ∞ It’s a concept that is notoriously difficult for finite begins such as ourselves to wrap our minds around. To make matters worse (as you are probably aware if you’ve dabbled in the mathematical arts) there are infinities of different size. Now I won’t pretend to have studied or to understand set theory, but it at least makes sense in an abstract way that it would be possible to count forever by whole numbers while also counting forever by half numbers (starting with .5) and there should be more numbers counted in the second case. This next one takes it a step further.

Mathematician Georg Cantor made it his life’s work to outrage his contemporaries and to blow the minds of the rest of us. Again, I won’t pretend to understand most of it, especially in formal terms, but as for one of his more visual proofs regarding infinity, I think I get it.

The basic idea is that there are an infinite amount of points on both a line of infinite extent and a finite line segment. I suppose the numerical comparison would be something like all of the natural numbers versus the all of the real numbers between 1 and 2. Did I mention that I am not a mathematician?

The proof is pretty genius. Cantor draws a perpendicular line segment down from a point on the original segment which intersects a circle between the segment and the line. What it boils down to is the fact that the angle between the diameter of the circle (parallel to the segment) and the segment drawn from the perimeter through the center of the circle, can become infinitesimally small, but as long as there is a positive value, the segment traveling through the center of the circle to the line will intersect the line at some point. So, they both contain an infinite number of points along their length. QED?

I live on the frozen surface of a fireball. –Julian Casablancas

Or, a wet rock.

(iii) If there’s one thing that irrationally bothers me, it’s finding out that a certain factoid I’ve been proudly touting is completely false. In fact, one of the two definitions of factoid, an invented fact believed to be true because it appears in print, seems like a strange indictment of everything I am doing here.

I have dreams of writing a book called Actually… which would debunk factoids. Some examples:

“Hey did you know that window glass in old buildings is thicker on the bottom because the glass flows downward very, very slowly.” Actually… it doesn’t.

“January is named for Janus, cuz he looks back to the old year and forward to the new.” Actually… it’s named after Juno. (That source looks dicey. This one might be a double-actually.)

Proxima Centauri is the closest star to us.” Actually… it’s the sun and that’s a trick question.

Bumblebees shouldn’t actually, be able to fly.” Actually…wait, what?

I swear, I’ve heard this last one too many times and the gist of the confusion is applying (tenuous) knowledge of aerodynamics at the scale of humans and small aircraft to the much smaller world of the bumblebee. The implications of orders of magnitude differences in mass and volume on the fluid mechanics involved in terrestrial flight are profound. Particularly salient for flight are the differences in surface area. Let’s do some calculations:

A standard human length of 1.8 m versus maximal bumble bee length of .04 m = 45 times as long.

We can idealize the human and the bee as right cylinders in order to obtain rough estimates of surface area and volume.

Human: h = 1.8 m r = .25 m; volume = .35 m³; surface area = 3.22 m²

SA:V = 9.2

This Bumblebee: h = .04 m r = .0056 m; volume = .00000394 m³; surface area = .0016 m²

SA:V = 406.1

On a similar note: ever wonder why insects never get hurt when you throw them to the ground or how squirrels are so successful at avoiding death when falling out of trees? Surface area matters as it produces drag, but mass and the effect of atmospheric pressure on terminal velocity also come into play.

Let’s assume the bee and the human are equally dense, that is, made of basically the same stuff.

Human: Mass = 77 kg; [Density (Mass:Volume) = 220 kg/m³]

Bumblebee: Mass = 220*.00000394 = .00087 kg

The drag coefficient of a standing human shaped object is around 1.0.

Here’s a terminal velocity calculator to play around with. I got a human value of approximately 70 m/s whereas the actual value is closer to 53 m/s. The bee is estimate is around 11 m/s.

To sum up, from the perspective of a bee, air is much more substantial than it is from our own perspective. The experience is much more like navigating what we perceive as a dense fluid, such as water in a pool. The terminal velocity comparisons are made clearer through this analogy when imaging the action of gravity (sinking) on objects of distinct shape and mass when thrown into deep water.

[Below I uploaded a cool (related) article on the various implications of size in biology:]

Schmidt-Nielsen-1975-Journal_of_Experimental_Zoology

(iv) But back to the point. I have been going around telling everyone that the surface of the Earth is smoother than a billiard ball. I heard it somewhere and I loved it. “Guess what guys, the Earth is really, really big.” (How big!?) “It’s so big that you wouldn’t even feel the topography if you had really gigantic hands!”

I believed this hours ago. I wanted to demonstrate that it was true. I got as far as the actual smoothness of a billiard ball before I hit a dead end.

Height of Mount Everest: 8,848 m

Depth of Mariana Trench: 10,994 m

Circumference of the Earth: 40,075,000 m

Smoothness (maximum relief/circumference) = 10,994 / 40,075,000 = 0.000274

Circumference of a billiard ball: .1797 m  (diameter: 0.0572 m * π)

How smooth is a billiard ball?

This is where the trail ran cold. After some further searching I found out that someone had already addressed this. They pointed out clearly and intuitively how dumb the idea of a smoothly polished Earth actually is when you really think about it. Oh well.

(v) This one is called Courage.

# Engines

Disclaimer: I know nothing about cars.

(i) My son recently became old enough to play with the toy cars I had when I was a kid. Most of them. I’m keeping the Micro Machines on the shelf until we are fully clear of the choking hazard protocol. Aside from the personal nostalgia of rediscovering material traces of my childhood, what struck me is how old some of my model cars are. Yes, I am also sort of old, too, but these have me beat. Seeing dates from the early 1980s and late 1970s embossed on the metal undercarriages surprised me and prompted mental math, leading to the realization that my son handling these battered Hot Wheels and Matchboxes is comparable to me being given toys from roughly the era of the Second World War. Probably made from lead.

(ii) My favorite car of the group was the yellow one with the hatchback. The rear compartment could be flipped up, revealing a square, plastic engine which gave slightly and bounced back when pushed. Curious to learn more, I turned the car over.

Matchbox. Peugeot 205 Turbo 16. 1984.

It hadn’t occurred to me as a kid that this toy was modeled on an actual car, or if I had entertained that line of thought, it was ultimately a dead-end given that google and wikipedia weren’t around then. Apparently, this car was a big deal. French. Very popular. Won awards. The version that I had was a suped-up racing edition made for rallying. To my mind, the existence of rally car racing is a separate (somewhat absurd) issue in and of itself. I associate it almost completely with sensationally titled compilation videos of cars swerving off of twisty backroads into screaming crowds of panicked onlookers. My personal experience with rallying is limited to being delayed in Lunahuaná for three hours (while suffering the after-effects of foodborne illness) due to a race scheduled along the only road within the valley.

Interestingly enough, the Peugeot 205 T16 is listed as one of the “rallying supercars” unfettered by the sensible restrictions placed on earlier generations of racing vehicles. A series of tragic (fatal) accidents resulted in the restoration of guidelines ensuring that the sport versions would be much closer to the models in general production, ultimately based on the logic that less powerful cars would be easier to control and less likely to be featured in something like People vs Rally Cars | Rally Car Crashes and Saves 2017. (Or, maybe the crashes are expected and the prevalence of “saves” (i.e. narrowly avoiding fatalities) is an acceptable compromise.)

The feature that had drawn my attention as a child, the functional hatchback and its exposed engine, is a key design feature of the vehicle. Mid-engine design places the engine between the front and rear axles allowing for better weight distribution and traction than in cars where the heavy weight of the engine sits at the front. The disadvantage is the fact that the engine is where the back seats should be.

(iii) Engines? I am a not a mechanical engineer, though I have been known to glibly name-check “internal combustion engine” during conversations about the most influential technological advancements in human history, while understanding little about what this technology entails. Are there also external combustion engines? Yup. Steam engines are the most familiar example. The steam, the working fluid, is created by heating water in a mechanism (i.e. a boiler) external to the functional hardware (pistons, turbines, etc.) of the machine where it eventually is used. Internal combustion centralizes this process, as in the familiar case of a conventional automobile engine. Fuel and air mix in the engine (internal) and the combustion process is facilitated by spark ignition. The oxidation of the gasoline produces a hot, pressurized gas that is utilized to work the machine.

Note, though external combustion technology seems a quaint holdover of steampunk lore, this is pretty much how we still generate electricity. Even the most fancy nuclear power plant is essentially a machine that splits atoms in order to boil water.

(iv) Propulsive retro platformer beat:

# Introducing

I’m going to use this space to share some thoughts and some music. They say to write what you know, but I prefer to write about the things I don’t actually know, aside from my most recent wikipedia binge. The music, as always, is a work in progress.

DnB loop