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Cake day: June 18th, 2023

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  • mkwttopicsOfficial NASA photo
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    15 hours ago

    I believe two of these are naval aviators, and they would take exception with the “army” characterization.

    But you’re generally correct. It’s very common that astronauts will not only have a military background, they frequently are active duty military officers on a long term detail to NASA.

    The army is not well represented in the astronaut corps, because the US army only flies helicopters under an inter-branch coordination agreement.


  • mkwttopicsOfficial NASA photo
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    15 hours ago

    Toilet drains into two different containers for each type of waste. The urine holding tank periodically vents overboard. The feces canisters are stored and returned to earth.

    The ongoing problem is that the urine holding tank is not venting into space very well when they open the valve. The toilet drains both waste types into their containers ok. But since the urine holding tank is about the size of an office trash can, it can fill up very fast.





  • If you’re training right it never gets any easier, but you do get faster.

    Having said that, most people when they first start can’t run slow enough to maintain a stable aerobic heart rate. The solution is alternating run / walk, building up to progressively more running between walk breaks.

    As an example, right now I can maintain 11:00 mi / mile at, my threshold heart rate, where I can maintain a conversation, and feel like I can keep going indefinitely. So I run 80% of my runs at that speed, and the rest at faster speeds over shorter distances. Great.

    But 2 years ago when I restarted running after a break, my aerobic pace was more than 13:00 / mile. That’s a problem because at that speed I can’t physically maintain the running mechanic. It breaks down. So the only options are to run faster than optimal, which means you’re not getting aerobic training (instead it’s anaerobic training); or to slow down into the walking mechanic.

    Research suggests that slow running in the aerobic zone is the key to improving aerobic pace and endurance. And if that aerobic pace is not possible because of mechanics, then alternating run / walk is a good way to average out the heart rate.


  • mkwttoLemmy ShitpostWasted potential.
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    2 days ago

    “Red dirt” specifically refers to a region straddling the Red River, including parts of Oklahoma and Texas. The soil in the region is actually red. But the musical area is much larger than the geological area.


  • By the time you reached GEO, the horizontal velocity you started with on the ground would be enough to keep you “weightless”.

    That assumes that you’re climbing something like a space elevator that rotates with the earth. If you built a machine that hypothetically lets you climb by pushing reaction mass down in inertial space (employing a stairmaster-style motion), then you won’t get the centrifugal effect.

    But then when you do reach the moon’s orbit, it smashes into you at several kilometers per second.

    If you do the space elevator, then you actually start down-climbing immediately above the GEO level. Because the centrifugal force is stronger than earth gravity, and it pulls you farther out.

    A cable that linked the earth and the moon would have to not be attached to the earth’s surface. Otherwise it would wind up around the earth as the earth’s faster rotation drags the earth end of the cable around.




  • This is for the pre-millennial dispensationalists. For the pre-millennials, the rapture will occur at the start of the 1000 year tribulation (as depicted in Left Behind). So it’s exciting if there’s a sign it might happen soon.

    (Let’s just ignore the gospel passage about “ye shall know not the hour…” Etc etc.)

    For the post-millenials, the rapture will occur after the 1000 years of tribulation, not before. So it’s less exciting, because you’ll probably die before then, so you won’t be eligible for rapture.

    And of course the amillennials don’t necessarily think the 1000 years is a literal 1000 years, and they have various opinions about how figurative John of Patmos was, or just how many balls he was tripping.





  • mkwttoMicroblog MemesThe speed of light
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    8 days ago

    There’s a convention in theoretical physics to adopt so-called “natural” units. In the natural system of units, measures of length, time, and mass are chosen so as to make the speed of light and the gravitational constant 1. Or sometimes it’s the speed of light and Planck’s constant.

    Anyhow, this makes the resulting measures of length, time, and mass completely nonsensical to any human scale problem. But it makes physics equations much shorter to write down, because you can drop all of the c’s, G’s, and h-bars and whatnot.

    For example, the famous E = m c^2 becomes E = m. Energy is mass. Voila.


  • These planes are modified airliners with a giant spinning radar thingy stuck on. One of them can provide radar coverage over an entire region and tell all of our other planes where to go and what to do. That is too say, these planes are extremely important to modern air warfare, even if they don’t carry their own offensive armaments.

    These planes also have a very custom, very unique design, and that makes them very expensive. You can’t just go buy more at the store, even if you have unlimited money. For starters, there aren’t many working Boeing 707s lying around any more to convert.

    The US started this war with a fleet of 16 total airplanes. We now have 14, with one that appears to be a total hull loss, and another one confirmed to be damaged.

    As an American, I am unhappy about this. This puts us in a significantly worse position if this shit escalates into the world war that some are saying has already started.



  • mkwttoScience Memes@mander.xyzafter you pi
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    13 days ago

    The proof is not that ancient. Pi was proven to be irrational in 1761, and proven to be transcendental in 1882.

    For a long time the problem was known as “squaring the circle”: Given a circle in a plane, construct a square with the same area using a compass and straightedge. This was a famous unsolved problem in mathematics from antiquity all the way through the renaissance.


  • IMAX film is twice as wide as standard film. 70 mm instead of 35 mm. The IMAX film platters are physically ginormous. All that extra film gives you a bunch of extra resolution compared to regular film.

    The first catch is that “IMAX standard” may not be real IMAX. I don’t know exactly what that means. Perhaps it could even be digital projection that aims to be comparable to IMAX in some ways?

    Second catch is that a lot of films that are shown in IMAX theaters were not actually shot on IMAX originally. If a film was shot on 35mm, say, and then printed onto IMAX, you don’t get all of the resolution benefits, and you may also get letter boxes or pan-and-scan because the aspect ratio isn’t the same. IMAX cameras are massively more expensive and logistically difficult than regular film cameras.


  • Just to be clear: with a marginal tax rate, if your income is $10,000,001, you pay $0.70 tax for the $1, and the rest of the $10,000,000 is taxed according to the lower tax brackets.

    The first $50,000 of that $10 million is taxed just like the guy that only made $50,000.

    The US tax system is slightly more complicated than this, but there’s no situation where you can get stuck with a huge additional bill because you edged slightly into the next higher tax bracket.