hydrogen7800

19 ms·

1. 301.▲
   by hydrogen7800 3y ago

   Like the Bill Nye/Ken Ham "debate" some years ago [0]. A bit painful for me to watch. A creationist would come away feeling quite vindicated after that one. [0] https://en.wikipedia.org/wiki/Bill_Nye%E2
2. 302.▲
   by hydrogen7800 3y ago

   Thanks. Like you said, industrial software isn't exactly on the bleeding edge or attracting lots of startup attention. I don't have any specific questions, and I'm not necessarily interested in any single piece of industrial
3. 303.▲
   Ask HN: Who Are the FEA, CAD, etc. SWE's?

   4 points by hydrogen7800 3y ago|2 comments
4. 304.▲
   by hydrogen7800 3y ago

   And isn't most of "matter" not even "stuff", but forces?
5. 305.▲
   by hydrogen7800 3y ago

   Yes! And "Wings of the Red Star" narrated by Peter Ustinov. My friends had posters of Lamborghinis, Ferraris, etc., and I had the SR-71 and space Shuttle on my wall.
6. 306.▲
   by hydrogen7800 4y ago

   I have plex server running on my NAS, but started running Jellyfin and the Gelli app from f-droid to do this. Plexamp seemed like a great option, too, but it's hard to beat foss. Edit: I do love Spotify, however, since I've been a
7. 307.▲
   by hydrogen7800 4y ago

   Boy, this rabbit hole delivers. How about this HDD? https://librascopememories.com/Photos/Pages/Products.html#14
8. 308.▲
   by hydrogen7800 4y ago

   Thanks. I was going to edit my post to include that article. I also found this 1983 video from the librascope company, which mentions the weight and balance computer in the first minute: https://youtu.be/nYeERxT1g38
9. 309.▲
   Mechanical aircraft weight and balance computer using whippletrees(airwaysmuseum.com)

   84 points by hydrogen7800 4y ago|15 comments
10. 310.▲
    by hydrogen7800 4y ago

    This reminds me of a paradox in my understanding of gravity. I often read about the pressure inside the earth resulting from the mass above, but the gravitational force inside a spherical shell is zero [0], and the only force acting at a g
11. 311.▲
    by hydrogen7800 4y ago

    https://www.bogleheads.org for personal finance and investment advice. Both the wiki and forum are excellent.
12. 312.▲
    by hydrogen7800 4y ago

    There are a few pictures with this arrangement. My guess is these are nuclear reactor control rooms, and those representthe control rod arrays.
13. 313.▲
    by hydrogen7800 4y ago

    Egyptian territory on both sides of the Suez canal.
14. 314.▲
    by hydrogen7800 4y ago

    I'm aware of human "computers" but my recollection was that in the case of Prandtl, it was an application FEM. I did not know FEM wasn't developed at that time, as this article shows, so it must have been something else
15. 315.▲
    by hydrogen7800 4y ago

    I once read or heard a similar anecdote about Ludwig Prandtl who set up computation method using a room full of people each doing one step of a calculation. I recall it describing a finite element method, but that would predate the origin o
16. 316.▲
    by hydrogen7800 4y ago

    Yes, big distinction between manned vs unmanned. I don't remember if the situation was the same for the first crew dragon launch. It's just something that stuck with me since watching one of the first broadcasts of high profile
17. 317.▲
    by hydrogen7800 4y ago

    I'm always a bit bothered by the cheering during a SpaceX launch. Maybe I'm just historically attached to the scenes of stoic engineers at JSC mission control, but space fight is always hard and risky, and cheering at every event
18. 318.▲
    by hydrogen7800 4y ago

    Good to know this isn't just my ears or my setup. This was most noticeable to me recently in Dune. So much whispering dialogue, with massive dynamic range and BRAAAM [0]. Using night mode on my receiver and cranking the center channe
19. 319.▲
    by hydrogen7800 4y ago

    And something like 90% of the world population was born during her reign.
20. 320.▲
    by hydrogen7800 4y ago

    And, perhaps equivalent, I've long suspected that all wealth ultimately comes from the earth.
21. 321.▲
    by hydrogen7800 4y ago

    The author was a guest on the Omega Tau podcast back in 2015 [1]. There is a sort of follow-up podcast with a different guest on the same topic [2]. [1] https://omegataupodcast.net/184-societal-complexity-and-coll... [2]
22. 322.▲
    Jemba Inertia Notes System- Automatically generates rally course notes(en.wikipedia.org)

    1 points by hydrogen7800 4y ago|0 comments
23. 323.▲
    by hydrogen7800 4y ago

    I've read about determining the "state vector" on the Apollo missions, and I would imagine it's similar for voyager. The ping delay and Doppler shift should be enough to determine 3D position and velocity with respect t
24. 324.▲
    by hydrogen7800 4y ago

    Love seeing Dream Theater on HN. The first I heard of the term "frisson" was a discussion on the dream theater forums, and I was interested to see that some people don't experience it at all. Another DT song moment that get
25. 325.▲
    by hydrogen7800 4y ago

    Ullage thrusters are used exactly as you described, for tanks that do not have PMDs. For example, the large second or third stage main propellant tanks which need to be lit in zero G. On Saturn V, the ullage motors themselves were solid r
26. 326.▲
    by hydrogen7800 4y ago

    Yeah, the metal deforms. They are single use devices. Imagine a spherical metal tank, with a thin metal hemisphere welded inside. The hemisphere would invert as the propellant is expelled. Hard engineering and manufacturing problems her
27. 327.▲
    by hydrogen7800 4y ago

    Expert here. I'm a longtime lurker on HN, but registered just for this comment. I design aerospace pressure vessels for a living. As showerst alluded to, there are often things called "propellant management devices" or PMD