Comments by "Lawrence D’Oliveiro" (@lawrencedoliveiro9104) on "Scott Manley" channel.

  1. 0:52 Newton’s third law ($F_{action} + F_{reaction} = 0$). The second law says $F = ma$.
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  2. Neat series. Will watch more.
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  3. Lovely stuff. :thumbsup:
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  4. 4:12 900 km/s --- just to give you an idea of how much that is, I think galactic escape velocity is on the order of thousands of km/s.
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  5. 12 parsecs ... too long for the Kessel run, then. ;)
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  6. “Power-sliding off the launch pad” shall be my phrase of the week. ;)
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  7. Greetings from just about the opposite side of the North Island from Mahia Spaceport. ;) How small can you get? Could you have a (figuratively) pocket-sized rocket launch something weighing a few grams into Earth orbit? Or even further, send it to the Moon? Beyond? Seems to me the square-cube law would work in your favour here.
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  8. 1:10 What are you saying??? That Star Wars is FAKE!?!?! Say it ain’t so!
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  9. Haynes Saturn V manual? I can just see some bloke spending his weekend underneath the third stage with a spanner, before uttering that immortal cry to his mate: “Give ’er a kick in the guts, Trev!”
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  10. 3:49 perhaps the wildly different temperatures also had something to do with it.
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  11. Wonderful explanation. ;) Just a note about black holes ripping you apart--that depends on the size of the black holes. Very large ones (like I think the ones at centres of galaxies) have very weak tidal forces, so you could fall in without even realizing it.
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  12. 7:24 Don’t you love the metaphor “smoking gun” applied to the impact of a projectile with a whack bigger than the biggest gun* humans have ever made? ;) *Or bomb, for that matter.
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  13. 1:25 So “re-entry” has become the established term, even though the spacecraft did not originate from the planet it is “re-entering” the atmosphere of?
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  14. 2:33 Presumably they could have used other hydroxides, e.g. Ca(OH)₂. Did they use lithium because it’s the lightest element that will form a suitable hydroxide?
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  15. 15:45 The IBM computer that controlled the Saturn V was a hybrid digital/analog design: the digital part wasn’t fast enough to make corrections to thrust magnitude/direction etc in real time, so that was left to the analog part, while the digital part just computed the direction the rocket needed to go. (I think it could only come up with new numbers once a second, or something of that order.)
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  16. 9:40 Spinning on its short axis? So was Discovery in 2010 . /me adds more confuse-fact-with-fiction fuel to the conspiracy-believers fire...
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  17. Mnjöpe.
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  18. 17:37 What’s that black disk?
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  19. Oh, I see -- planet night side.
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  20. Thought those little lights were stars in a stargate... ... as in “My god! It’s full of stars!”
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  21. 3:29 Cigarette smoke + electronics = euugghh.
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  22. All the controls were designed for that.
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  23. 14:17 “Target object is not grabbed with a grabber” -- have you violated that already?
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  24. I see, those are not requirements, they are status information.
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  25. I thought most of the “hot Jupiters” date from the earlier days of planet-hunting, back when they were concentrating on stars more like our Sun. Then they discovered that lots of dwarf stars have planets, too, and a lot of those are within their Goldilocks zones. So maybe that’s that TESS will look for.
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  26. The old DEC machines (from the same era) had that “page” bit (to select either “same page as current instruction” or “page 0”) but they also had an “indirect” bit, which meant that the word being addressed could hold in its turn a full indirect address. That seems to be missing here.
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  27. Whose idea was it to reuse the MCAS software from the 737 MAX? “Just a little patch or two, it’ll be good,” said the Customer User Experience Delight Optimization Manager ...
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  28. You’ll notice the ISS has a “bottom” side that always faces the Earth, and a “top” side that always faces away. So it rotates once per orbit. This could get complicated if you had a spinning section, due to the potential for gyroscopic effects. You could minimize this by arranging for the plane of rotation to be parallel to the plane of the orbit. I’m not sure if this is always achievable, though. A spacecraft in space would most likely need to be able to change its orientation. You could cancel out the gyroscopic effects by having two counter-rotating sections. But you would still need to deal with sideways forces on the bearings.
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  29. There were quite a variety of word lengths in the days before byte-addressability became the standard. DEC’s first machine, the PDP-1 had an 18-bit word length; their very popular PDP-8 range used 12 bits (awkward to program, but cheap for those days); and their big “mainframe-class” PDP-10 had 36-bit words. I think the CDC 6000-series supercomputers, designed by the legendary Seymour Cray, had a 60-bit word length. The guys at AT&T Bell Labs who invented Unix did their first prototype on an old PDP-7, another of DEC’s 18-bit machines, that they had lying around. That proof of concept allowed them to get the funding for a nice new, 16-bit byte-addressable PDP-11. And the rest, as they say, is history.
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  30.  @jessepollard7132  ECC memory can be done with extra checking bits that are only visible to the hardware, not the software.
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  31. 3:47 Did the workers putting on the asbestos have any idea about the exposure risks?
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  32. 6:15 I think it was basically a power glitch. The SCE got hit by transients that put it into a strange state, and switching power supplies fixed this. Maybe just turning it off and on again would have worked as well ... (Hmmm ... didn’t they do that to something on Apollo 10?)
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  33. 11:15 Not sure what you mean by “pure-electrical”. Do you mean ones using rechargeable batteries?
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  34. 2:38 Maybe they shouldn’t be called “heaters”, they should be called “less-colders”. ;)
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  35.  @211212112  Actually more molecular.
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  36.  @Tod_oMal  Is it something worth fighting for?
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  37. 12:33 Guess what “pintle” means. https://en.wiktionary.org/wiki/pintle
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  38. They wanted a wider choice of landing sites (namely secure ones) in the case of unexpected weather problems, for when they were carrying classified payloads. That capability was never used.
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  39. 5:46 That’s “dissipate”.
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  40. Moral: gravity may be a weakling, but it holds a grudge.
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  41. Have you heard of JP Aerospace? Their aim is to take a craft up to high altitudes, above most of the atmosphere, with a balloon. Then use an ion drive, which as you know is very low-thrust but can run for weeks/months on end, to gradually build up speed in a low-drag environment until it achieves orbital velocity.
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  42. They managed to decide on PowerPC CPUs for the Mars rovers.
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  43. 2:56 Rubber Duckie!
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  44. Or about 27.08 Kessel Runs?
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  45. 13:52 Is that what the Martians did, perhaps? Foreseeing a future when they would lose most of their water and atmosphere? Is that a solution to the Fermi paradox -- that everybody is off in their own virtual worlds, and no longer care about space travel?
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  46. 1:54 That’s automatically arranged by tidal forces, though isn’t it.
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  47. Lighter than the N₂ and O₂?
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  48. 10:50 apparently it was a rogue fleck of paint that was throwing off the laser interferometer. Oh, and the company was Perkin-Elmer. They also made minicomputers.
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  49. 1:45 Elliptical, not parabolic. Parabolic is eccentricity 1.0.
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  50. As I remember it, it was MIT engineering students who did the calculations on Ringworld and discovered it would be unstable to perturbations in the plane of the ring.
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