Comments on economics, mystery fiction, drama, and art.

Tuesday, December 29, 2015

Is Inter-Stellar Trade Even Possible?

Many science-fiction books and movies have as a central plot convention the existence of very large, multi-star-system confederations that are linked both politically and economically.  Unfortunately, unless some method of by-passing what is currently believed to be the limit to the speed at which interstellar travel can occur can be found, such systems are impossible.  And that limit is the speed of light, about 186,000 miles per second.
The closest solar system that apparently might have habitable planets is the Alpha Centauri system. Which is approximately 4.25 light-years away.[1]  What about this makes, in particular, economic links between stellar systems impossible?
The terrestrial calendar year has 31,536,000 seconds.  The speed of light is about 186,000 miles per second.  So the distance light travels in one year (one light year, or 1 LY) is 5.8657x1012 miles.  And suppose we want to ship some physical object from Earth to a (hypothetical) inhabited planet located 1 LY away.  How much will that cost, and what are the implications of such a cost?
I own a car (1997 Honda Accord) which weighs approximately 3,000 pounds,[2] and can carry about 1,000 pounds of load (passengers plus baggage), for a  total of 2 tons.  My cost per mile of operating the car, excluding any capital costs or depreciation, and ignoring the value of the time of the driver, is approximately $0.10 per mile, or approximately $0.05 per ton-mile.  But since we’re talking about moving cargo, let’s suppose we manage to develop extremely cost efficient interstellar transports that travel at very nearly the speed of light.[3]  What do I mean by “extremely efficient,” and what would that entail?  By “extremely efficient,” I mean a cost of moving 1 ton 1 mile of one one millionth of a cent [($0.01)/(1,000,000)]. 
What could we move?  The space shuttle had a gross vehicle weight of about 2,000 tons, and could carry a payload of about 24 tons.[4]  So to move the shuttle 1 mile, fully loaded, at a cost of $0.00000001, would cost $0.000002024.  Now we have to move that 1 LY…which would cost approximately $119 million.  And that’s a cost of $5 million per ton of cargo, to travel 1 LY.  Alpha Centauri is 4.23 times as far, so to get something to or from there would be nearly $21 million per ton of cargo…around $500 million for the flight.
That does not include any costs attributable to staffing the transports.  But that is almost irrelevant.  Consider a cargo that is valuable enough that we are willing to pay $21 million (or more, for longer distances—the next closest is Tau Ceti, 11.9 LY away—and wait at least 4+ years to get it.
I would argue, incidentally, that the cost per ton mile is unlikely to be as low as I have suggested here.  The cost of propelling a large spacecraft at a high rate of speed is likely to be considerably greater than $0.00000001 per ton-mile.[5] 
If all this is even anything close to accurate, then the possibility of interstellar trade is remote.  Overcoming that sort of cost issue requires that the cost per ton mile be reduced to an almost unimaginably low level.  And free energy is not yet on the horizon.

[1]List of nearest terrestrial exoplanet candidates,” Wikipedia, August 2015,
[3] Charles Stross makes the case for the great expense and difficulty of interstellar exploration/colonization at
[5] One source projects a cost per pound from launch to earth orbit of $10,000 for the ship’s payload…about $20  million per ton just to get it into orbit, let alone to Alpha Centauri.

Tuesday, December 01, 2015

Dangerous Ideas/Safe Places

You may have seen, or heard, about this elsewhere:…/university-president-blasts-students…

This is the comment I posted there:
I've argued for more than 40 years that one function of colleges/universities if to provide a *safe* place in which people can explore difficult and challenging and "dangerous" ideas. The safe part is important--we have to be able to delve into, discuss, and even espouse unpopular ideas without becoming the target of anger and, yes, hate. The difficult, challenging, and dangerous ideas part is also important, because if our thinking is not challenged, we are unlikely to grow intellectually (and, if it matters, morally). I remember the struggles we had, back when, with university administrations that actively opposed the kind of open intellectual ferment I'm talking about.

What I am afraid is happening now is that university administrations will use what some see as the rise of student agitation for the restriction of some ideas as a justification for going back to a world in which only established ideas are allowed.

I would ask that you be aware that at the University of Missouri, and at a number of other campuses, it's not unpopular, or challenging, or dangerous IDEAS that students are reacting to, it is the openly racist atmosphere that exists as in Missouri, for example), the assault on the ability to explore difficult, challenging, and dangerous ideas in a SAFE environment--not safe from challenge, but safe from physical (n some cases) or psychological (in other cases) danger. I know a lot of people will see my inclusion of psychological danger as a cop-out. But imagine trying to think creatively in an environment in which your presence is deemed by many people to be an intrusion, in which you are deemed to be unworthy of being there. I have never had to deal with that, but I have had students--even at a university campus with one of the most "diverse" student populations in the country--who felt as if they were being treated (by other students, by some of the faculty...) as not deserving to be there.

I will say it again: Colleges and universities should be places in which students (and faculty) can explore difficult, challenging, dangerous (unpopular) ideas safely. If they cease to be that, they might as well be simply vocational schools, where there is one right was to do things, one right way to think, one right way to BE.

I have ranted long enough. Thank you, and good night.