Tuesday, April 30, 2013

What If We Never Run Out of Oil?

http://www.theatlantic.com/magazine/archive/2013/05/what-if-we-never-run-out-of-oil/309294/?single_page=true
From the beginning, it was evident that the Kern River field was rich with oil, millions upon millions of barrels. (A barrel, the unit of oil measurement, is 42 gallons; depending on the grade, a ton of oil is six to eight barrels.) Wildcatters poured into the area, throwing up derricks, boring wells, and pulling out what they could. In 1949, after 50 years of drilling, analysts estimated that just 47 million barrels remained in reserves—a rounding error in the oil business. Kern River, it seemed, was nearly played out. Instead, oil companies removed 945 million barrels in the next 40 years. In 1989, analysts again estimated Kern reserves: 697 million barrels. By 2009, Kern had produced more than 1.3 billion additional barrels, and reserves were estimated to be almost 600 million barrels.

Sunday, April 28, 2013

How Long to Suffocate in Space

I previously looked at how long it would take to freeze in space.  In this post, I'm going to look at the other side of the losing life support coin: how long would it take to run out of air in space?

Since the heat being lost is dependent on the temperature, which is changing, we needed a differential equation before (well actually since it's all been worked out before we didn't, but where's the fun in that?).  This time, oxygen use is constant, so the math is much simpler.  On the other hand, there are still plenty of variables to introduce uncertainty.

To begin, if you are sealed in a room with a normal mix of air you will not run out of oxygen.  Rather CO2 will build up to toxic levels, and you will die.  It is possible to scrub CO2 from the air.  In fact, we currently do it on our spaceships.  A major issue Apollo 13 faced was getting circular CO2 filters to work with a square hole.

What this means for us is we need to look at time for CO2 to build up to lethal levels, and for how long it would take to run out of O2 if the CO2 is being removed.

We also need to consider that people consume O2 at different rates, and even at different rates at different times.  VO2 is a measure of what rate a person is consuming O2.  Unfortunately, it is almost always used in the context of measuring peak VO2 during exercise (as a measure of fitness).  It was hard to get good numbers for a resting person, but I settled on about 0.018 cubic meters per hour.  For the active rate, I still couldn't just use typical VO2 numbers because they are for the max consumption rate during bursts of exercise.  A person moving around attempting to repair a ship wouldn't be using as much air as a person sprinting.  I found some good numbers from scuba diving forums and settled on 0.1 cubic meters per hour.

On the subject of the variation of people, different people will be able to tolerate different concentrations of CO2 or levels of O2.  It was hard finding a good number for lethal CO2 concentration.  Most sites were concerned with long term exposure at a work environment (years), or short term accidental exposure (minutes).  I settled on 5% which is probably a bit low.

As for minimum O2 concentration, similar problems apply.  Here I settled on 11%, compared to about 21% normally.  Ships could use slightly higher O2 concentrations to begin with to help with loss of life support situations, but high O2 levels have their own problems.

Additional issues are things like fires or venting atmosphere reducing the time.  Also, the number of people on a ship is harder to estimate.  On larger ships it is probably more constant.  But on small shuttles it could vary quite a bit.

Working in our favor is the fact that the respiration equation:
`"C"_6"H"_12"O"_6 + 6"O"_2 to 6"CO"_2 + 6"H"_2"O"`
Has a one to one mole ratio between O2 and CO2.  Additonaly, a mole of any gas takes up about 24 liters at normal temperature and pressure.  This means we can use the same formula for both O2 consumption and CO2 build up:
`t={V cdot Delta r}/{n cdot R}` Where: V is volume, `Delta r` is the change in the ratio of the gas, n is the number of people, and R is the rate that gas is changed.  As an example:
`t = 36.1 " hours" = {26 "m"^3 cdot 0.05}/{2 cdot 0.018 "m"^3/"hour"}`
This is the formula for a 26 cubic meter shuttle craft, with 2 people.  The change in concentration is 0.05 because CO2 is effectively 0 normally.  0.018 cubic meters/hour is the resting CO2 production rate.

I decided to give a range with worst case and best case scenarios.  The best case is resting, and not worrying about CO2 (because it's being scrubbed).  The worst case is CO2 build up will working to fix the ship.

As you can see there were some cases where heat loss was faster than the best case scenario.  I didn't expect it to even be close.

NameVolume (`"m"^3`)CrewHeat (days)Oxygen, Resting (days)CO2, Doing Work (days)
Death Star II2,144,000,000,000,0002,500,000437,837218,370,37017,866,667
Super Star Destroyer12,645,900,000300,00096710,733878
Borg Cube28,000,000,000130,00025,58554,8434,487
Enterprise-D5,820,9831,2004561,235101
Enterprise211,248430161.0125.110.2
Runabout569311.348.34.0
Type 6 Shuttlecraft26212.83.30.3
TIE Fighter810.72.00.2


Thursday, April 25, 2013

Cat in a Shark Suit Riding a Roomba and Chasing a Duck

http://www.youtube.com/watch?v=OFro7RlKzE8

We might as well close up shop now.  This video is clearly the ultimate culmination of the internet.

Thursday, April 18, 2013

The Geopolitics of the United States, Part 1: The Inevitable Empire

http://www.stratfor.com/analysis/geopolitics-united-states-part-1-inevitable-empire

This is very long, and nothing in it is revolutionary, but I found it an interesting overview of the United States' expansion.

Tuesday, April 16, 2013

The Size of Pizza

Pizza is likely the most important substance ever created.  As such, it is crucial that we have adequate information for our various pizza dealings.  In civilized society a pizza is 16 inches in diameter.  However, one must occasionally deal with the barbarians of the pizza word: Fast food pizza, eg, Pizza Hut, Dominoes, Papa John's.

To begin, they have had the audacity to make pizzas in sizes in less than the scientifically proven optimal size.  However, they add insult to injury by calling these smaller sizes "large".  Since pizza size increases as the square of half the diameter, decreasing the diameter doesn't have an intuitive effect on the actual reduction in pizza.

To help illustrate the atrocity being done here, I've compiled this table of various pizza sizes.  I've included the name Pizza Hut (or the others) call them, as well as their name to rational humans.  Next, is the diameter and the area.  The slices equivalent lets you know how many slices of a normal 16" pizza you would be getting at the other sizes; they likely are all cut into 8 slices.  % of a real pizza is exactly what it sounds like.

Pizza Hut NameActual NameDiameter (in)Area (in^2)Slices Equivalent% of a Real Pizza
PersonalJoke628.31.1314%
Small?1078.53.1339%
MedOffensively Small12113.14.5056%
LargeSmall14153.96.1377%
X LargePizza16201.18.00100%
X Large18254.510.13127%
Wonderful20314.212.50156%


Edit:
I've made a calculator to help compare prices across pizza sizes.

Monday, April 15, 2013

Tuesday, April 9, 2013

Leonard v. Pepsico, Inc.

http://en.wikipedia.org/wiki/Leonard_v._Pepsico,_Inc
Leonard v. Pepsico, Inc., 88 F. Supp. 2d 116, (S.D.N.Y. 1999), aff'd 210 F.3d 88 (2d Cir. 2000), more widely known as the Pepsi Points Case, is a contracts case tried in the United States District Court for the Southern District of New York in 1999, in which the plaintiff, John Leonard, sued PepsiCo, Inc. in an effort to enforce an "offer" to redeem 7,000,000 Pepsi Points for an AV-8 Harrier II jump jet, which PepsiCo had shown in a portion of a televised commercial that PepsiCo argued was intended to be humorous. The plaintiff did not collect 7,000,000 Pepsi Points through the purchase of Pepsi products, but instead sent a certified check for $700,008.50 as permitted by the contest rules. Leonard had 15 existing points, paid $0.10 a point for the remaining 6,999,985 points, and a $10 shipping and handling fee.

Among other claims made, Leonard claimed that a federal judge was incapable of deciding on the matter, and that instead the decision had to be made by a jury consisting of members of the "Pepsi Generation" to whom the advertisement would allegedly constitute an offer.

In justifying its conclusion that the commercial was "evidently done in jest" and that "The notion of traveling to school in a Harrier Jet is an exaggerated adolescent fantasy," the court made several observations regarding the nature and content of the commercial. These included (among others) that:
  • "The callow youth featured in the commercial is a highly improbable pilot, one who could barely be trusted with the keys to his parents' car, much less the prize aircraft of the United States Marine Corps."
  • "The teenager's comment that flying a Harrier Jet to school 'sure beats the bus' evinces an improbably insouciant attitude toward the relative difficulty and danger of piloting a fighter plane in a residential area."
  • "No school would provide landing space for a student's fighter jet, or condone the disruption the jet's use would cause."

Sunday, April 7, 2013

So Crates

Two great legal advice threads:

Invoking Socrates to get out of running a red light

Fighting for his "rights"

The Labyrinth of Genre

This uses last.fm genre data to show an endless branching of genres.  Every genre you click shows the 6 closest related ones (not necessarily sub-genres).

Note: It plays a band from the currently selected genre.

http://static.echonest.com/LabyrinthOfGenre/GenreMaze.html

Wednesday, April 3, 2013

The trouble with using police informants in the US

http://www.bbc.co.uk/news/magazine-21939453
Whatever the case, under Florida law Horner now faced a minimum sentence of 25 years, if found guilty.

"My public defender told me, 'They got you dead to rights.' So I thought, 'OK, I guess there's no need taking this to trial.'"

Prosecutors offered a plea bargain of 15 years if Horner accepted a guilty plea.

"I said, 'My youngest daughter will be 25 years old when I get out. I can't do that.'"

That left him with only one option - to become an informant himself.

Under the deal he signed with prosecutors, he agreed to plead guilty. But if he helped make prosecutable cases against five other people on drug-trafficking charges - charges carrying 25-year minimum terms - his own sentence could be reduced from 25 years to 10.

Horner failed to make cases against drug traffickers.

As a result, he was sentenced to the full 25 years in October last year and is now serving his sentence in Liberty Correctional Institution, outside Tallahassee. He will be 72 by the time he is released.

The irony is that if Horner been an experienced drug dealer, he may well now be serving a much shorter term than 25 years.

"What snitching does is it rewards the informed, so the lower you are on the totem pole of criminal activity, the less useful you are to the government," says Natapoff. "The higher up in the hierarchy you are, the more you have to offer."

Court records show that Matt, the person who informed on Horner, had a lengthy record of drug offences. At the point he informed on Horner, he was facing a minimum sentence of 15 years for trafficking. He was ultimately sentenced to just 18 months and is now free.
I believe there's a term for this.