Probability or The Story of Google

What are Markov chains? And why are they so useful?
Veritasium

Does a good job of explaining how Google works, which is remarkably simple, all it takes is a bigger computer. If you are just looking at letters, you just need a simple array with room for 26 entries. If you are looking at words, you need an array with a zillion entries, because not only do you are you using all the English words, you're also using all words from all the other languages and all the names and acronyms. And numbers, and punctuation, and symbols. And then, after you have counted all the words and populated your data base, you need to be able to answer a zillion queries simultaneously, which I suspect means you need to make multiple copies of these data bases. No wonder they're building all these data centers in my neighborhood.

And do not forget that all of this is being paid for by advertising. A tenth of a cent times a billion clicks is still $100K, and that probably happens, what? Hourly?

A couple of people mentioned:

Masayoshi Son (1957 - )
Japanese Businessman

Andrey Andreyevich Markov (1856 – 1922)
Russian Mathematician

Pavel Alekseevich Nekrasov (1853–1924)
Russian mathematician

On the downside, he drops in a couple of lines about global warming. I don't know if global warming is a real problem, but I do know that all of the measures western environmentalists have proposed are worse than useless.

It ends with an ad for Brilliant at the 31 minute mark.

No, you can't get there from here

This mechanism shrinks when pulled
Veritasium

Curious stuff. Wikipedia has a page about Braess's Paradox. 

The video has an ad that runs from 12:20 to 14:15.

Via California Bob.

Teflon

How One Company Secretly Poisoned The Planet
Veritasium

What does one part per trillion look like? Well, how may molecules of water in an Olympic sized swimming pool? Google tells us:

An Olympic-sized swimming pool contains approximately 2.5 million liters of water. This translates to roughly 660,000 gallons. Since 1 liter of water contains about 3.3 x 10^27 water molecules, an Olympic-sized pool would contain approximately 8.25 x 10^33 water molecules. 

One trillion is 10^12 (10 to the twelfth power), so one-trillionth of an Olympic size swimming pool would be 0.03 cc of water, or 30 cubic millimeters. Not very friggin' much.

 

The Illusion of Truth

The Illusion of Truth
Veritasium

Advertising 101, also, Propaganda 101. If you don't want the peasants to revolt, you need to master this concept. Master this concept. Master it now. Now, now, now, you grumpy old man.

The reason the recent Presidental election was so close (like less than one zillionth of a percent) is that both parties understand advertising and propaganda. I like to think that Trump won because there are more people with brains than there are brain dead democrats, but maybe not, maybe it was just a matter of  which party did a better job of feeling the pulse of the country and successfully directed their advertising campaign to reach more people. In other words, maybe it was just blind luck that led to Trump winning.

Jump Spider, Jump

What Jumping Spiders Teach Us About Color
Veritasium

The techniques they are using in microbiology these days are out of this world.

Flying Crowbars

We tested the US Military’s secret space weapon
Veritasium
I first came across the idea of using heavy metal rods dropped from space as a weapon in Footfall, a science fiction novel by Larry Niven and Jerry Pournelle. It sounded like a great idea, simple, inexpensive and devastatingly effective. Derek tries to demonstrate it but fails. He might have done better with some kind of guidance system and some steerable fins. However, while there might be cases where it could be useful, he goes on to explain that for any of the proposed uses, it's not going to be all that effective. I think the biggest objection is that pound for pound, nuclear weapons are much more devastating. An ICBM might carry a ten ton payload. That would be enough to launch one big tungsten rod or half a dozen nuclear weapons. And while you aren't going to get any radioactive fallout from a ten ton kinetic weapon, I'm not sure that argument will carry any weight when you are bent on destroying your enemy.

Femtograms

How To Measure The Tiniest Forces In The Universe
Veritasium

How low can you go? Lower than I even imagined.

The Snowflake Mystery

The Snowflake Mystery
Veritasium

Snowflakes are amazing, even after we now have a theory about they get to be snowflakes.

Venom and Anti-Venom

How Horses Save Humans From Snake Bites
Veritasium
Some people are terrified by snakes, some people enjoy killing them, others are enthralled by them. I think they are kind of cool, but not cool enough that I would have one in my house. There are a couple other posts about snakes and venom here.

An Explanation for Everything

The Ridiculous Way We Used To Calculate Pi
Veritasium

I'm thinking about how calculating a zillion digits of π is like the intellectual equivalent of peacock feathers (I am sure I am quoting someone here), or as the bald guy (Professor Alex Kontorovich from Rutgers) says:

So this goes way beyond precision for any practical purpose, this is now a matter of flexing your muscles, this is showing off just how much mathematical power you have that you can work out a constant like π to very high precision.

Then it comes to me that what we all want is to be entertained, something that absorbs all of our attention, because when our attention is totally occupied, we don't concern ourselves with boring stuff. We are occupied and we are entertained. And nothing captures our attention better than competition. Trying to beat the other guy is what everyone is striving for. Sometimes it's just a matter of slipping in the right word to stab an opponent with a nasty insult, sometimes it's just an embellishment to your clothing to catch someone's eye, often it's a matter of making more money. Competitions can become heated and result in pushing, escalate into fighting and eventually boil over into war. And when we go to war, there is no end to the complexity of the weapons we build, and when you are building complex weapons you need math, and so you might want the guys who display the intellectual equivalent of peacock feathers helping out on designing weapons.

---

I'm watching this video and I realize that I wrote a program to compute π using several different techniques, one of which was very similar to the method used in the beginning of the video of cutting up a circle into triangles. I thought I had posted it earlier, but I could not find it on my blog. I rooted around on my computer and found it (it's from 2012). I posted it on github.

My program uses floating point numbers to perform the calculations, so it is going to be limited to only a few digits of pi. I should modify it to use the GMP math package so I can get as many digits as Ludolph did.

Distortion

The Illusion You Need To See

Veritasium

You have probably seen this rotating window illusion before, but Derek dives into it (heh heh). He looks at anamorphosis, which is creating distorted images that only look 'right' when they are viewed from a particular vantage points. 

Towards the end he comments on how when people are presented with information, different people can come to wildly different conclusions, which kind of explains the eternal state of human society.

In recent years I have noticed a spate of chalk artists drawing illusions on sidewalks, often of holes in the ground. But the technique has been in use for a long time, as this painting from the 16th century shows.

The Ambassadors (1533) by Hans Holbein the Younger

The blob in lower foreground is a distorted human skull. Derek uses this painting in his video. I can just barely make it recognizable by looking at the screen from a very low angle, so low, the items on the screen almost disappear.

Spinning

The Bizarre Behavior of Rotating Bodies, Explained
Veritasium makes my day, again. When I started working as a carpenter (a half century ago) I remember one of the crew demonstrating that tossing a hammer so that the handle flipped around the head resulted in the face of the hammer head facing the opposite direction. At the time I thought it was a little odd, but it did this every time. As I had no explanation for it, I just filed it away as just one more property of this weird world we live in.

Cod Save the King

How Cod Saved the Vikings
I almost feel guilty about posting Veritasium videos. Almost every one he produces is great, so great that I can't really add much, but I'll give it a shot anyway.

The title on this one is poor. It might be better to call it How Cod Made the Vikings. He ties rickets, vitamin D and cod liver oil together. I remember hearing about rickets and cod liver oil a long time ago, but I never realized there was a connection, probably because rickets was never an issue. I'm taking vitamin D now. My wife recommended it.

Siege of Paris 885 - Jean-Victor Schnetz 1835

The bit about the Vikings laying seige to Paris was new to me, likewise the reason for the failure of the Viking's Greenland colony and

Scurvy

the British experiments to find a cure for scurvy:

However, it was not until 1747 that James Lind formally demonstrated that scurvy could be treated by supplementing the diet with citrus fruit, in one of the first controlled clinical experiments reported in the history of medicine. As a naval surgeon on HMS Salisbury, Lind had compared several suggested scurvy cures: hard cider, vitriol, vinegar, seawater, oranges, lemons, and a mixture of balsam of Peru, garlic, myrrh, mustard seed and radish root. In A Treatise on the Scurvy (1753) Lind explained the details of his clinical trial and concluded "the results of all my experiments was, that oranges and lemons were the most effectual remedies for this distemper at sea.”

I did know that the Brits originated the regimented use of citrus, I just didn't know how that came to pass.

The History of Video

The History of Video
I thought I had a pretty good grasp of how video evolved. I was wrong. I'm better now.

Previous post, a video from S. G. Collins, covers some of the same material.