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    ESA: Technology Readiness Levels for Space...

    ESA: Technology Readiness Levels for Space Applications

    That document then goes into a lot of detail.

    I'm disappointed that no worked examples were provided in either the NASA or the ESA...
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    NASA went into detail: NASA's Technology...

    NASA went into detail:
    NASA's Technology Readiness Level Definitions

    I'm quoting here the definition, the hardware description, and the exit criteria. I'm leaving out the software description,...
  3. Thread: On Deck: 2022

    by lpetrich
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    Here are the QAnon supporters running for...

    Here are the QAnon supporters running for Congress in 2022 | Media Matters for America

    At last count, 33.
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    Another progressive PAC: Catch Fire – Helping...

    Another progressive PAC:
    Catch Fire – Helping progressives catch fire early. | Catch Fire - Catch Fire (@catchfiremvmt) / Twitter

    Some more:
    Randy Friese AZ-02
    Junaid Ahmed IL-08
    Mikayla...
  5. Thread: US Flag Day

    by lpetrich
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    Gore Vidal once expressed disdain for what he...

    Gore Vidal once expressed disdain for what he called the "proto Op Art" appearance of the US flag. I checked on Op art and it is about artwork that features optical illusions. I don't see anything Op...
  6. Thread: US Flag Day

    by lpetrich
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    I've found some sites that feature collections of...

    I've found some sites that feature collections of antique US flags.

    ZFC - Home - the Zaricor Flag Collection

    Lots of goodies in it, like a 13-star flag with hexagram stars in a filled hexagram...
  7. Reserve duty (Israel) The Hamas guys could...

    No, they couldn't. Enough of this false equivalence![/QUOTE]
    Reserve duty (Israel)

    The Hamas guys could point to that as "proof" that the civilians that they attack are not Real Civilians.
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    Finally, the Bussard ramjet. It works by...

    Finally, the Bussard ramjet. It works by collecting interstellar hydrogen with a magnetic field, and then fusing it to power itself and to propel itself.

    That Wikipedia article has none with level...
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    We next go down even further to 2 (technology...

    We next go down even further to 2 (technology concept formulated). They presumably need a lot of work before they would be ready for testing.

    Nuclear pulse propulsion (Project Daedalus), uses...
  10. Thread: US Flag Day

    by lpetrich
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    When Alaska was admitted in 1959, the stars went...

    When Alaska was admitted in 1959, the stars went to 49, with (4,7)(3,7).

    When Hawaii was admitted in 1960, the stars went to 50, with (5,6)(4,5).

    -

    So the various official and semiofficial...
  11. Thread: US Flag Day

    by lpetrich
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    I'll continue. When California was admitted in...

    I'll continue.

    When California was admitted in 1851, the stars went to 31, with 7-5-6-6-7.

    When Minnesota was admitted in 1858, the stars went to 32, with 7-6-6-6-7. It could have been...
  12. Thread: US Flag Day

    by lpetrich
    Replies
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    For a rectangular grid of r rows and c columns,...

    For a rectangular grid of r rows and c columns, there are r*c stars.

    Alternating between r rows of c stars and r of c-1 stars gives a total of r*(2c-1)

    Interleaving (r,c) and (r-1,c-1) gives...
  13. Thread: US Flag Day

    by lpetrich
    Replies
    6
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    82

    US Flag Day

    Flag Day (United States)

    Flag of the United States and List of flags of the United States have depictions of past and present and possible future flags.

    The first flag design was Francis...
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    You'll also need the H-H, O-O, and F-F bond...

    You'll also need the H-H, O-O, and F-F bond energies. Or you can look up heats of formation in the NIST WebBook
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    So far, I have discussed propulsion mechanisms...

    So far, I have discussed propulsion mechanisms that have had some physical manifestation. So I now turn to those that have only been the subject of theoretical studies.

    Here are some that are at 3...
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    Going to 8 (flight qualified), we find resistojet...

    Going to 8 (flight qualified), we find resistojet and arcjet engines. They work by electrically heating a propellant material.

    Next down is solar sails. They are listed as 9 and 6, but I'd place...
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    There are plenty of tradeoffs in design. There...

    There are plenty of tradeoffs in design.

    There are several things that one might want to have:

    High EEV: that means less propellant for some velocity change (delta-v)
    High thrust: that means...
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    Maybe from the perspective of a right-wing...

    Maybe from the perspective of a right-wing dudebro.

    But when it comes to things that right-wingers like, like military and police forces, right-wingers seem to think that money grows on trees for...
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    Charlie J. Johnson on Twitter: "Marjorie Taylor...

    Charlie J. Johnson on Twitter: "Marjorie Taylor Greene says COVID is a bioweapon because God would never create a fatal illness that harms people (link)" / Twitter

    Then
    Alexandria Ocasio-Cortez...
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    The original: Steve Bannon interviewed MTG for...

    The original: Steve Bannon interviewed MTG for "Real America's Voice":
    Marjorie Taylor Greene slams virus research: 'I don't believe in evolution, I believe in God' - YouTube

    Then

    Marjorie...
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    Titled link: The Hybridity of Rural Fascism |...

    Titled link: The Hybridity of Rural Fascism | Society for Cultural Anthropology

    Sort of like the Black Hundreds

    In effect, "I believe in dictatorship, with me the dictator".

    The article on...
  22. Derec, the Hamas guys could make the exact same...

    Derec, the Hamas guys could make the exact same human-shield argument about Israel. They could argue that Israel's leaders are hiding their soldiers among civilians, and that the Israel Defense...
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    How to propel one's spacecraft

    Wikipedia has a rather comprehensive article on that: Spacecraft propulsion

    I looked in Encyclopedia Britannica (that venerable encyclopedia's online site) and Citizendium (a Wikipedia alternative...
  24. Is it really that difficult to search for such a...

    Is it really that difficult to search for such a site?

    Wikipedia is a good place to look, though it should not be treated as a primary source.

    Timeline of Solar System exploration
    List of...
  25. Did they really reach the tops of those mountains?

    Has Anyone Really Summited the World’s 14 Highest Mountains? - The New York Times

    Climb chronicler Eberhard Jurgalski has kept track of high-mountain climbers for some 40 years: 8000ers.com,...
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