I learned, 6/24/16 (Brexit edition)

I am a big fan of the idea of the Wisdom of the Crowd – the idea that averaging the desires of a diverse group yields the best answers. Crowds routinely beat experts in the stock market, idea generation, and bookmaking. So should I believe that UK crowd chose correctly in the decision to Brexit?

It’s an emotionally loaded question for me, because I’m a big fan of democracy. Even a populist. But, crap, I can’t help but think that the will of this crowd was horribly, horribly wrong.

So what gives?

There is an idea, supported by recent research, that crowds are great when people make their decisions in isolation from each other, but do a piss-poor job when social influence is present. Social destroys the diversity of the crowd opinions, and thus destroys the multiplicity of thought that bring crowds their wisdom.

Without social coordination, crowds act like a giant computational engine, averaging all of the information taken in by each person’s slightly different perspective. With social coordination, crowds can be persuaded by the loudest narcissist in the room, repeating the same trope as if it wisdom.

With our own election coming up, this does not make me happy.

The good news, I hope, is that the internet sees to be making crowds smaller. With Facebook we all get our own private echo chamber. But maybe in the aggregate our echo chambers are numerous enough and diverse enough that they will average out into something approaching rationality.

I’m an optimist. And at least I can make a case for hope.

I learned, 6/17/16

This edition answers a question that likely bothers no one but me: Why are soda dispensers in restaurants so damn big?

Soda machines are, by volume, mostly ice bins. The soda syrup and carbonated water are either tucked in back or below the counter; the bulk of what you are looking at is a giant hopper for storing and dispensing ice.

So why store all that ice? Why can’t it be made and dispensed in real time?

Being science nerdy, I ran the numbers. The answer is physics, specifically the giant amount of energy that it takes to freeze water. Water is famous for having both a huge heat capacity – a large amount of energy is required to heat or cool it. And it has an even larger “heat of fusion” – the energy that goes into organizing the water molecules into little ice crystals.

If you wanted to make ice “on demand”, you have to supply a *spectacular* amount of power. To fill up a 20 oz cup from “on demand” ice as fast as you can from the hopper would require about 100 kilowatts of energy. That’s big time.

How much is 100 kilowatts? More than your house draws. With that kind of power you could run 100 hair dryers simultaneously. You could charge your iPhone 6 in 200 milliseconds. You could open your own Tesla Supercharger station.

Note that the number is power (“how fast”), not energy (“how much”). It’s another way of saying that the slow step in making ice cubes is not the cubing part. It’s getting the electrons into the ice maker.

In practice, when you pour all of the power from a conventional 120V, 20A circuit into making ice, it will blast out cubes at a maximum rate of about 1 cube every five seconds. Since most machines don’t draw the maximum power avaiable, it’s more like 1 cube every 10-20 seconds. To get around the power issue, restaurants generate ice throughout the day and night, and store it in the giant hopper behind the soda dispenser. Soda machines are big because if you tried to make them smaller, you’d melt all the wiring in the restaurant.

I’m probably alone in this, but I think that’s kind of cool. Something to think about at lunch tomorrow.

I learned, 6/10/17 (vacation edition)

Back from Hawaii and starting to engage the world again, I thought I’d share this crazy tidbit: the upper elevations of Hawaii’s Haleakalā volcano are almost completely barren of plant life, as the arid soil is constantly baked by the sun. Yet in the crevices between the volcanic rock live a range of endemic insects, such as a moth that through evolution has lost its ability to fly. With almost no plants to dine on, it survives during its pupal stage on a diet consisting solely of organic debris blown up from shore by the wind. Damn.

Life is amazing – even under conditions that border on ridiculous, it still manages to find a way.