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Showing content with the highest reputation on 10/30/23 in all areas

  1. 1 point
  2. In order to reach LEO, a fully loaded shuttle needs all the fuel in that large external tank, plus two solid fuel boosters. As I pointed out in an earlier post, you need about 2.2 km/sec of delta v to enter a trans-lunar orbit from LEO. Even if the entirety of the cargo capacity of the shuttle was extra fuel, the SSME's wouldn't be capable of getting the shuttle up to this speed. Once at the Moon, your shuttle would be moving ~ 0.8 km/sec slower than the Moon, and would need to do another burn in order to be able match speeds and enter orbit around it. Then to return, another burn is needed to re-enter another trans-lunar orbit in order to get back to Earth. Once back, the shuttle will be moving at ~2.2 km/sec more than LEO orbital speed. The shuttle can't hit the atmosphere at this speed, so it will need to do another burn to shed enough for re-entry. So, this works out to at least 6 km/sec total delta v for the trip. This jumps the fuel requirements to 2.8 times the mass of the empty shuttle. Adding a lander would increase this fuel requirement. (some thing the equivalent of the Apollo LEM, would require ~20% more fuel. A good part of the Shuttle's mass is there for re-entry and landing, and would be dead weight as far as the majority of the trip is concerned, so you'd be burning a lot of fuel to get something to the Moon that is of no use when you get there.
    1 point
  3. I think these equations of Hamas and ordinary Palestinians are typical of political rhetoric where the purpose is to draw attention away from Geneva Convention violations, as in this case the indiscriminate killing of civilians, starvation tactics, and destruction of non military targets like homes. The same rhetoric was used in WW2 to justify Dresden and Hiroshima. Nazis bad, we can kill Germans with impunity. Japanese bad, we can nuke a whole city or two. It's interesting how most people can look back at those events and condemn them, or condemn the US brutal slaughter of indigenous tribal peoples, but somehow Israel gets a special pass and anyone who questions their conduct of war or occupation is pelted with ad hominems like being an antisemite. It doesn't take a moral philosopher to understand two wrongs don't make a right. If someone had stolen my house and plowed the olive groves that five generations of my family had farmed, and did that to thousands of others around me, and drove me into a fetid slum I could not leave and which is subjected to mass murder attacks every decade or so, I might be easy prey to a political party that promised to get tough with my attackers and get my land back, and would probably not really grasp I was voting for a gang full of vicious sociopaths with a very stupid approach to negotiation . So tired of nuance-free discussions around the web where people seem to think Hamas just popped in out of nowhere and announced with a gleeful cackle, "Let's be evil and kill some innocent Jews!" Hamas and PIJ were created by the series of forcings and swindles that started with a letter written by Arthur Balfour. Was Balfour naive or foolishly optimistic or just having a feel-good moment with Britain's Jewish community? Maybe someone more knowledgeable of that history could say.
    1 point
  4. I think so. What other use do you have in mind? In mathematics you have so-called functionals, which are functions of functions. They're referred to with square brackets, e.g.: G[f]
    1 point
  5. An alternate future for fossil gas drilling? The future demand for hydrogen is probably overestimated - the current biggest use is oil refining/desulphurisation and that ought to go down and some projections are for reduced overall demand, which may make fossil hydrogen look more reasonable. But I have serious reservations about Hydrogen outside some hard to decarbonise uses - fertiliser and other chemical feedstock. I would have expected iron and steel but there are other options that avoid the need. If it isn't produced, stored and used on-site the economics are poor and transporting it at large scales is not as easy or cost effective as it sounds . I'm inclined to agree with this -
    1 point
  6. Modal-mu (μ). Lambda-mu (μ). Google and wiki, they got you.
    1 point
  7. “I read it in a calculus book” is not specific enough.
    1 point
  8. Can you give an example of where you encountered this?
    1 point
  9. The idea of fast food parodying healthy food can be the same for many drugs being a victim of their own karma. For example alcoholics might dislike being highly extraverted by overdrinking with others to try and disprove how ethical they were to talk to one another. Humility is very ethical but is easily hijacked by perversion. For example marijuana might make those already prone to spirituality to downplay their spirituality by attributing too much of their insights to drugs when a lot of their thinking might still have been internal. Wiz Khalifa - No Sleep Yet another factor in obesity is that a lot of athletes can be too emphatic without being sexy enough. The dilemma is that many top athletes are able to be sexy if they tried to be but are often unwilling to let slightly less hardworking athletes be viewed as sexy. For example as a teenager I always counterbalanced cardiovascular exercise with weightlifting because no matter how strong and handsome bodybuilders and marathon runners can be they often downplay how nice they are by not being slightly androgynous. As such no matter how superior I try to be at walking I can always mislead others into how egalitarian I can be just to pride myself on walking stamina!
    -1 points
  10. Offering light criticism can often be a backhanded way to downplay just how threatening other people could have been! I feel the entirety of China could be sacrificed in any nuclear exchange just to achieve destruction of critical targets in the west!
    -1 points
  11. I like your style. Nuclear destruction of multiple countries simply isn't very relevant!
    -2 points
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