Conscious Choice cover

From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.


“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.


Available everywhere for $3.99 (before discount) at Amazon, Barnes & Noble, and all ebook vendors, or direct from the ebook publisher, ebookit. And if you buy it from ebookit you don't support the big tech companies and I get a bigger cut much sooner.

The Largest Stirling Engine On The Market

An evening pause: It might be engineering but it is also art. For more information about the engineering behind this engine, go here. For some information about the builders themselves, go here.

Hat tip Cotour.


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  • V-Man

    Product page doesn’t give the output power. Can it do useful work besides turning the flywheel?

  • Lee Stevenson

    I’m immediately thinking of the moon, a shadow and sunlight….. Off you go!

  • Jeff Wright

    Cox’s timepiece for the Moon…

  • Lee Stevenson

    @Col Beausabre, who knew that Sweden was a world leader in this tech? I certainly didn’t!

  • Col Beausabre

    Being a “world leader in this tech” is sorta like multiplying by zero – it has very limited practical applications (its been around for two centuries and isn’t a major source of power, so I would conclude it never will be, except in a very limited niche). I’m sure its got its fans, but their enthusiasm seems to be in inverse proportion to its importance, hence my reference to there being a cult around it. And no one seems able to answer V-man’s question – it this is the largest available example, what is its power output. How does that compare with a similarly sized internal combustion engine.

  • A. Nonymous

    Stirling engines should be compared to steam engines, not combustion engines. They are slightly inferior to steam engines in terms of power/weight, and power/volume. That’s why they never caught on, despite being invented at the height of the steam engine’s reign, and like steam, they rapidly became obsolescent upon the development of the piston (and later, gas turbine) engine.

    What Stirling engines *do* provide, and the very thing that Rev. Stirling was attempting to accomplish, is that they completely replace the high-pressure steam used in a steam engine, and all of the dangers that accompany it. They also have the huge potential advantage of being completely fuel-agnostic heat engines. A Stirling engine doesn’t care where the heat comes from, as long as there is a temperature differential between the sink and the source. The heat can come from petroleum products, or a wood fire, or concentrated sunlight, or nuclear decay. It just doesn’t care, and that gives the Stirling engine some real, if uncertain, potential even today. In recent years, there was a company trying to hype up Stirlings with reflectors as superior to photovoltaics, and NASA was looking at them for use with RTGs. I wouldn’t mind having one as a backup generator, if anybody would make one for sale at a reasonable price.

    The closest alternative to what a Stirling can do is probably the Thermoelectric Generator (TEG). Like the Stirling, the TEG is a fuel-agnostic heat engine, producing electricity in a similar manner to PVs rather than shaft horsepower like a Stirling. And, like a Stirling, it can be run in reverse, using electricity to provide refrigeration on one side.

  • Lee Stevenson

    @Col Beausabre, my comment was intended “tongue in cheek”, even though Sweden seems mentioned multiple times in the wiki article, this “tech” has hardly set the world on fire has it?….. On the moon however….

  • Edward

    A. Nonymous noted: “[a Stirling] can be run in reverse, using electricity to provide refrigeration on one side.

    An officemate of mine got into Stirling engines for use in space applications. One was to use solar radiation as the heat source for power generation, but he focused on running the cycle in reverse to produce cryogenic temperatures. A quarter century ago, I was designing a cryocooler, for freezing animal tissue samples aboard the ISS, using his Stirling cycle engines, but NASA decided that, as a partner, Germany should have a project to work on, so they gave them my project.

    That was when I got out of design and into assembly, integration, and test of commercial communication satellites.

  • pawn

    William Beale who invented the free piston Stirling engine was the founder of Sunpower in Athens, Ohio. Sunpower has built and tested many large Stirling engines over the years. Quite a history behind that company and that man, always just on the edge of commercial success.

  • Col Beausabre

    “always just on the edge of commercial success.”

    Which says it all. After two centuries of development. My work is done here.

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