Six ideas

by Russ Roberts on November 30, 2011

in Beautiful, Education

Some elegant education. Some work better than others but they’re all lovely.


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Invisible Backhand November 30, 2011 at 4:03 pm

This is an awful lot of posts from Russ. He must have gotten a call from someone that he wasn’t meeting his quota.

Invisible Backhand November 30, 2011 at 6:40 pm

If Russ keeps this up, he might post as often as I do!

The difference, of course, is that Russ always has interesting and relevant comments to make, while I engage in nothing but guerilla heckling from the sidelines with pointlessly snide remarks that reveal my ignorance about economics (not to mention history, philosophy, science, and just about everything else worth knowing). I do, however, know the direct telephone numbers and emails of my paymasters at Anonymous and I’ve also read some Marx and a few pages of the introduction to Saul Alinsky’s “Rules for Radicals.”

In other words, I think of myself as an exceptionally well read troll. (I hope you all think of me that way, too.)

SmoledMan November 30, 2011 at 7:22 pm

I’m more worried about his carpal tunnel.

Invisible Backhand November 30, 2011 at 8:17 pm

I tell people that libertarianism attracts aspies and Regards Ken goes and proves it.

Invisible Backhand November 30, 2011 at 8:44 pm

I tell people that libertarianism attracts aspies . . .

And don’t go asking silly questions, everyone, like “What are ‘aspies’”?

CathyC December 5, 2011 at 6:56 pm

My husband is an aspie and is most definitely a CONSERVATVE!!!

Jon Murphy November 30, 2011 at 4:12 pm

Interesting video, Russ. You were right that some worked better than others, but overall I found it clever. I didn’t understand the infinity one (the story about the hotel), though.

vikingvista December 1, 2011 at 12:24 am

It’s just that a countably infinite set must have a one-to-one correspondence with any of its countably infinite subsets. That is, the set of all positive integers has the same size as the set of all positive even integers, where having the same size here means that elements of the sets have a one-to-one correspondence.

It is essentially a mental exercise of one of the implications of abstracting away the observable reality of finiteness–something you need to do for mathematics to have general applicability to problems of unspecified scale.

JohnW November 30, 2011 at 4:44 pm

They really botched the twin paradox clip. The paradox is not that time dilation occurs, as the clip implies. The actual twin paradox is that, relative to the spaceship twin, it looks like the other twin was the one who rushed away and back at near the speed of light. After all, the earth is moving relative to the sun, the sun is moving relative to the galactic core, and the galaxy is moving relative to distant galaxies. It would seem, at first glance, that there is nothing special about the earth twin that allows us to say he did not move but the spaceship twin did move. So why did the spaceship twin end up younger than the other twin? That is the twin paradox.

The resolution has to do with general relativity and the fact the the spaceship twin underwent a great deal of acceleration (i.e., a non-inertial reference frame) when he turned around to come back to earth.

Jon Murphy November 30, 2011 at 4:51 pm

All that stuff goes way over my head. And the cat one, too.

Martin Brock November 30, 2011 at 7:37 pm

“Schroedinger’s Cat” is reductio ad absurdum. Schroedinger never suggested that Quantum Mechanics implies a half-dead cat (or a cat simultaneously living and dead). The point of his cat story is to show that people were misconstruing the theory. He calls the idea of a half-dead cat “ridiculous” when introducing the story.

vikingvista December 1, 2011 at 12:43 am

And I believe both Einstein and Bohr agreed that there was really a problem with reality here.

The fact that not being able know an external event without measuring it must appear the same as the actual measurement determining the event, seems to lead people into strange interpretations of reality (as opposed to interpretations of the limitations of their models of reality).

vikingvista December 1, 2011 at 3:08 pm

no problem, not a problem

Stone Glasgow December 3, 2011 at 3:30 pm

No no, it’s quite obvious that this means information can travel faster than light, and thoughts can change reality!

It’s interesting to see how far out of line people can get in order to support their models instead of stopping to admit that they don’t or can’t know something.

vidyohs November 30, 2011 at 5:59 pm

Actually another botch of that story if you listened carefully is quite common. We were given the supposition of two identical twins……, that would be four people of two sets, each set being identical.

He is a twin. 1 of 2 in the twin set.

They are twins. 2 of 2 in the twin set.

Two twins = 4 people, two sets, identical within set.

I know, picky picky picky. :-)

AR November 30, 2011 at 7:24 pm

Acceleration is the answer, but you do not need general relativity to explain this. General relativity reduces to special relativity in flat space-time, so you only need it when dealing with gravitational effects.

Incidently, the practical application given, GPS, does require general relativity, because clocks in a stronger gravitational field move more slowly, which has to be accounted for because GPS satellites are further away from Earth’s center than receivers.

vikingvista December 1, 2011 at 3:14 pm

Yep. You only need to show a change in inertial reference frames. But in reality, such a change cannot occur without acceleration forces, which in general relativity are the same as gravitational forces.

Martin Brock December 1, 2011 at 6:59 pm

Also right.

Martin Brock November 30, 2011 at 7:32 pm


vidyohs November 30, 2011 at 5:48 pm

Hay-suess Cristo, Prof Roberts! You kinda been saving up a bunch of stuff, huh.

I go to work and come back to find things I looked at this morning are already in the archives!!

Martin Brock November 30, 2011 at 7:51 pm

Since John Searle can imagine replacing every neuron in my brain with a little copy of himself applying rules discovered by neurologists to channel the signals flowing through my brain, I can’t possibly be thoughtful or intelligent.

Gordon Richens December 1, 2011 at 10:17 am

The solution is to do the same to him. Bingo, once again you are thoughtful and/or intelligent.

Stone Glasgow December 3, 2011 at 3:38 pm

Right. Obviously there has to be a ghost in the machine or it’s not intelligent. A common dillusion; the idea that a soul is necessary for consciousness.

Whatever will we do when machines begin passing the touring test.

Fred December 1, 2011 at 7:43 pm

Zombie cats. Funny. I saw a car decorated not with those stick figure family decals, but zombie decals. Down to the pets too. Funny stuff. They even had one of those magnet ribbons on the back that didn’t say “Support our troops” or “I like boobies”.
It said “Support Zombies”.
I’m a guessing they’re fans of The Walking Dead..

emerson December 2, 2011 at 10:13 am

That’s David Mitchell on narration. Allow me to recommend his hilarious show “Peep Show,” available on YouTube.

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