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Journal: Economics in Brief (Internet Flotsam)

Journal by lgw

Here's some internet flotsam attributed to a graduation speech by Thomas Sargent (without digging into whether this speech really happened: the content is interesting).

Economics is organized common sense. Here is a short list of valuable lessons that our beautiful subject teaches.

1. Many things that are desirable are not feasible.

2. Individuals and communities face trade-offs.

3. Other people have more information about their abilities, their efforts,
and their preferences than you do.

4. Everyone responds to incentives, including people you want to help. That
is why social safety nets don't always end up working as intended.

5. There are tradeoffs between equality and efficiency.

6. In an equilibrium of a game or an economy, people are satisfied with their
choices. That is why it is difficult for well meaning outsiders to change
things for better or worse.

7. In the future, you too will respond to incentives. That is why there are
some promises that you'd like to make but can't. No one will believe those
promises because they know that later it will not be in your interest to
deliver. The lesson here is this: before you make a promise, think about
whether you will want to keep it if and when your circumstances change.
This is how you earn a reputation.

8. Governments and voters respond to incentives too. That is why governments sometimes default on loans and other promises that they have made.

9. It is feasible for one generation to shift costs to subsequent ones. That is
what national government debts and the U.S. social security system do
(but not the social security system of Singapore).

10. When a government spends, its citizens eventually pay, either today or
tomorrow, either through explicit taxes or implicit ones like inflation.

11. Most people want other people to pay for public goods and government
transfers (especially transfers to themselves).

12. Because market prices aggregate traders' information, it is difficult to forecast stock prices and interest rates and exchange rates.

User Journal

Journal: Geothermal vs Solar Power 1

Journal by lgw

Here are the basic numbers on aailable geothermal vs solar power (since this has come up in discussion more than once).

The surface area of the Earth is about 5.1 x 10^14 m^2. The cross sectional area is about 1.3 x 10^14 m^2 (one quarter of the surface area, of course).

Per this paper found as a cite on wikipedia, the total heat flow out from the Earth's interior is 4.42 x 10^13 W, or 0.0867 W/m^2. Of course, the available power is much less because it's only the subsurface-surface temperature difference that's available.

Total solar irradience is 1361 W/m^2 by NASA's latest estimate (so about 1.7 x 10^17 W across the entire cross section), or about 1000 W/m^2 on the surface at noon on a cloudless day. Averaged over the day-night cycle (surface area vs cross-section, so 250 W/m^2), and taking clouds into account that's about 180 W/m^2 (I can't find a solid source on that yet, but it looks close).

So, total solar power flow is about 4000 times as large as total geothermal flow. I'm not quite sure how to estimate the (ideal) available power as a percentage of the total geothermal power flow, but if we use a WAG of 50%, then the available power from solar is also about 4000 times per square meter more than geothermal - significantly more if we average solar power only across populated latitudes.

Math

Journal: help with math 1

Journal by corbettw

Hopefully somehow out there is better with math than I.

Suppose a giant ball of ice, 130km in diameter (water volume significantly greater than the Great Lakes) were to strike the moon at a speed of 3km/s (just above the moon's escape velocity). If my math is right, most of the water will remain on the moon in the newly formed crater, though I'm sure a significant amount would sublimate away over time.

Any help would be appreciated.

Oh, and this is for a possible scifi story. I just want to make sure the basis for the drama is at least plausible, it doesn't have to be 100% exact.
The question, how much water would end up left behind? I'm not sure if it would rival Lake Superior, Lake Erie, some other lake, or essentially none at all.

User Journal

Journal: Tags? 3

Journal by corbettw

Am I the only one who can't see tags on stores in the new Slashdot 3.0? No matter which story I'm looking at, there are no tags showing up. Which is too bad, because there's usually a lot of meta-humor contained in those things.

If anyone else had this problem and fixed it, please let me know what to do. I'm using the latest Firefox on WinXP SP2.

User Journal

Journal: Games vs sports 2

Journal by DangerFace

I feel that the perennial debate over the difference between games and sports is viewed very, very wrongly by our society. Games are viewed as being childish fripperies, whereas sports are serious tasks that require tactics and dedication. This is utter balderdash. Here is how I would define the difference between a sport and a game:

The activity in question shall be known as X.

if (X.winner(fitMan, skilledMan) == fitMan) {
xIsASport = true;}
else{
xIsASport = false;}

In other words, if a skilled but unfit man can be beaten by an unskilled but very fit man, it is a sport. Examples would be long distance running, football / soccer, or weightlifting. If the converse is true, then the activity is a game. Examples include chess, Call Of Duty MP, WoW PvP, darts, snooker... the list goes on.

I think it is clear from this brief series of examples that games are by far the superior pastime, and yet sports are given a huge amount more time, money, and respect.

Of course, this is somewhat a strawman argument - I am defining common words to mean what I want them to mean so that my argument holds. However, I do feel that this is the most sensible way to delineate the two concepts of game and sport - to establish a continuum with no clear or strict boundary, but which most activities will clearly settle on one side or the other of.

Now that that's off my chest, I'm off to play a game. Or maybe a sport. We shall see...

User Journal

Journal: New Phone, New "Mom", Lifes Good

Journal by Rallias Ubernerd

Two great pieces of news. One is that I have achieved something some geeks don't, I moved out of my moms house, but into my grandmas house. My grandma obtained official legal custody today. I'm happy. I am away from my mom the bitch.
The other good news is I got a new android phone, the tmobile mytouch swipe. Love at first use on this phone. Review comming later.

User Journal

Journal: School Interesting

Journal by Rallias Ubernerd

I write an essay yesterday, making it sound as downplaying to the average person, and I get 20 out of 20. Something is wrong with that. I tell a person that they have no way of join the geek society if they don't join before age 10 and yet she gives me 20 out of 20. Jeez. I mean, it was meant to see how biased her grading scale is, in terms of insults. I gave her the ultimate insult and called the people reading, for a lack of better terminology at the time, STUPID! I sometimes wonder. Does this indicate that the average person is willing to admit that nerds and geeks are better than them? Or is it that she didn't have the ability to find another different English teacher for me for the rest of the year? She is a seemingly average American. Something is wrong with America, if a teacher tells a student good job for calling her stupid. Other than the fact that they force children to go to school.

Firefox

Journal: Just noticed something

Journal by Rallias Ubernerd

Every time I decide to mess off on my school computer in school, I observe the following things. 1. I end up in Firefox Private Browsing. 2. I end up with a full bar (or more) of minnimum-sized tabs. 3. My beautiful girls flash drive becons to me.
Is this normal?

Firefox

Journal: Wow

Journal by Rallias Ubernerd

I just got on a computer, loaded up runescape, used the KVM to hide that i was on Facebook and Slashdot, and found the computer that i didn't re-install had firefox 2.something, 2.5 i think. I am amazed. I mean, i haven't used anything before 3.5 at all this year, and i find firefox 2.5 on a computer

User Journal

Journal: Slashdot in Negative 1

Journal by Rallias Ubernerd

Just a disclaimer: I am using a POS iBook G4. This method is not guaranteed to work for any other computer.
Anyway, Slashdot looks so cool in negative. I got to it by pressing Command, Option, Ctrl, and 8, all at the same time. But it looks cool, especially the apple page.

User Journal

Journal: Some assholes

Journal by Rallias Ubernerd

Today, i find out that some asshole stole the remainder of my fresh gum supply, four pieces. So now, until i can get to the store, i have to survive on pre-chewed gum. At least it is myself who prechewed it.

The secret of success is sincerity. Once you can fake that, you've got it made. -- Jean Giraudoux

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