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November 10, 2013

"The Theory of Interstellar Trade" — by Paul Krugman (1978)

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Yes, it was written by the very same Nobel Prize-winning economist 35 years ago.

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Below, excerpts from a October 26, 2013 article in The Economist about Krugman's paper.


Starships... are a fantastical subject. Yet when engineers design them, they try to be as rigorous as possible. After all, the laws of physics apply to a starship just as much as they apply to bridges or motorbikes.

It is not just scientists who enjoy technically rigorous speculation, though. Economists have investigated interstellar travel as well. One of the best-known papers was written by Paul Krugman, a trade theorist, in 1978, in between his duties as an "oppressed assistant professor." "The Theory of Interstellar Trade" describes itself as "a serious analysis of a ridiculous subject, which is of course the opposite of what is usual in economics."

Dr. Krugman, a science-fiction fan, ponders how trade might work between two widely separated planets, Earth and Trantor. Such trade will be affected by relativity theory, which shows that beings on Earth (or Trantor) will see time pass at a different speed from those who are on board cargo ships moving between the two. This could make it hard to calculate the net present value of a shipment. And the fact that messages can move at best at the speed of light (and cargoes more slowly still) might do odd things to the ability to arbitrage between the economies of the two worlds.

After working through the maths, Dr Krugman came up with two fundamental theorems of interstellar trade. The first is that interest costs on travelling goods should be calculated using clocks on planets, not ships. This is because the opportunity cost of trade — buying a bond on Earth (or Trantor), say — is calculated using planet-bound clocks, regardless of what relativity does to a businessman travelling alongside his cargo.

The second theorem states that, though long travel times mean prices on trading planets will never reach parity, interest rates will. If they differed, then investors could buy bonds on the more attractive planet, driving its rates back to parity with those on its trading partner.


So ladies and gentlemen, start your ion drives and let's light this candle: while you're en route, you'll have plenty of time to read and ponder Krugman's paper, which you can find in its entirety right here.

November 10, 2013 at 08:01 PM | Permalink | Comments (0) | TrackBack

Digital Measuring Cup


From websites:


Quickly and easily measure both solids and liquids with just one tool

The Digital Measuring Cup uses a scale built into the bottom of the handle to quickly and accurately measure weight and volume or weight.

Choose Cups, Ounces, Milliliters, Pounds, or Grams.

Features and Details:

• Cup detaches from handle for easy cleaning and can be used without handle to measure cups, ounces, or milliliters

• Intelligent weight calculation for water, milk, flour, sugar, and oil

• Tare button allows user to weigh multiple ingredients together

• Uses 1 lithium CR 2032 battery (included)

• Measures room temperature in F°/C° 

• Auto-shut-off feature saves power

• Maximum weight capacity: 2.2lbs

• Maximum liquid capacity: 600ml

• Pre-set weight mode

• Blue back-lit display

• 30 minute timer



[via Joe Peach]

November 10, 2013 at 04:01 PM | Permalink | Comments (0) | TrackBack

"Telepathy One headset lets users stream video of what they are seeing"


From yesterday's New York Times story: "...Telepathy One headset [above], which floats a microprojector and camera in front of one eye. The first version is expected this year."

Put me down for one: this is precisely what I want and need to finally bring bookofjoeTV to life: Google Glass has been a nice bridge and proof of concept but I'm ready to lose the sharing and uploading to YouTube and built-in delays and endless technical complications and glitches and go direct to live TV just as soon as the technology makes it possible.

"Real soon now" does not sound like a figure of speech, at long last.

Can't wait!

November 10, 2013 at 12:01 PM | Permalink | Comments (1) | TrackBack

Cleaning Slime — Think outside the nasty keyboard space(s)

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From websites:




The ultimate high-tech reusable cleaning compound that catches dirt and kills germs on keyboards, printers, mobile phones, fax machines, copiers, computer mice, and anything else you can think of.

Features and Details:

• A must for public computers

• Enhances keyboard performance

• Ideal for all devices and surfaces

• Environmentally friendly and 95% biodegradable

• Catches dirt and debris and kills over 80% of germs

• Can be used many times until cleaning compound turns dark

• Soft gum material does not leave residues and keeps your hands clean

• Simply press cleaning slime against surfaces you would like to clean — dust and dirt in gaps will be absorbed by the compound



Yellow, Green, Blue or Red: $15.59.

[via Richard Kashdan]

November 10, 2013 at 08:01 AM | Permalink | Comments (8) | TrackBack

Hot air balloons over Charlottesville — through Google Glass

YouTube caption: "It was 26° outside yesterday around 7:30 a.m. when I ventured onto my patio in scrubs to get an unobstructed view of two hot air balloons in the sky to the northwest. Gray Cat chose to remain indoors atop the toasty cable box: no fool she."

November 10, 2013 at 04:01 AM | Permalink | Comments (2) | TrackBack

What is it?

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Answer here this time tomorrow.

Hint: smaller than a bread box.

Another: will function from within a bread box — although that is not an intended use.

A third: no batteries.

November 10, 2013 at 12:01 AM | Permalink | Comments (5) | TrackBack

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