ocfnash

20 ms·

1. 151.▲
   Visualising International Math Olympiad Results(olivernash.org)

   1 points by ocfnash 9y ago|0 comments
2. 152.▲
   by ocfnash 9y ago

   Possibly a good time to plug moissanite again: http://diamondssuck.com
3. 153.▲
   by ocfnash 9y ago

   Indeed. Reading my own words, I sound rather more worked up than I am :) I do think this article is a bit sneaky dressing itself up as entertainment since it is published by a business that profits from people deciding to invest. It does pr
4. 154.▲
   by ocfnash 9y ago

   I think this article is attempting to make a different point. It essentially argues (unconvincingly IMHO) that it is difficult to _distinguish_ a (very contrived type of) "perfect" active investor from a "bad" investor w
5. 155.▲
   by ocfnash 9y ago

   Can the figures for "Real Residential Housing Price Index for Canada" be correct? The quoted index values are: 2010: 36.3 2016: 413.9 I simply cannot believe there was an 11-fold price increase on this index over this period. Goog
6. 156.▲
   by ocfnash 9y ago

   Thanks for these helpful words of clarification! As I commented above, I was rather sloppily using the words "explosion", "detonation" to mean flash and boom. On the two occasions on which I witnessed this event, it was
7. 157.▲
   by ocfnash 9y ago

   I am sure of nothing except that there was a sudden big flash and boom :) From the clarifying comments below it seems likely it was a deflagration but I confess I've been using the words "explosion", "detonation" ra
8. 158.▲
   by ocfnash 9y ago

   Very interesting, thanks! I carried out two rounds of thermite "experiments", both times using oxides of iron, manganese, and copper. I witnessed two "explosions" (I now presume deflagrations) and they occurred with the
9. 159.▲
   by ocfnash 9y ago

   This is a good piece but I have one nit: it is incorrect to say "thermite [...] will not detonate." I was shocked to discover this first hand some years ago: http://olivernash.org/2009/11/12/fun-with
10. 160.▲
    by ocfnash 9y ago

    I don't know; no doubt we could debate the point at length. Nevertheless I stand by my original remark. IMHO the conflation of "Chinese" with "cheap crap" is: * Not relevant * Debatable / Subjective
11. 161.▲
    by ocfnash 9y ago

    I think this comment would be improved by removal of the word "Chinese".
12. 162.▲
    by ocfnash 9y ago

    There are famously-many other axioms that can be added to ZF, and which turn out to be equivalent to Choice. Of the following three equivalent extensions to ZF: * Axiom of Choice * Zorn's Lemma * Well-ordering Principle J
13. 163.▲
    by ocfnash 9y ago

    And it's not just any old radioactive source, it's a positron emission! I believe the way it works is that the injected source emits positrons as it decays (having swiped them from the vacuum), shortly thereafter, these annihilate
14. 164.▲
    by ocfnash 9y ago

    Yes indeed, quite right! 0xA000 is the memory _segment_ and so the linear address is 0xA0000 I think I would have got this right first time ~20 years ago: ftp://ftp.scene.org/mirrors/hornet/code/3d/systems
15. 165.▲
    by ocfnash 9y ago

    Surely this is the point, though? We rearrange the approximation: h = 6.626069934 x 10−34 kg∙m2/s to solve for kg and thus have our definition in terms of h?
16. 166.▲
    by ocfnash 9y ago

    0xA000 is also the address of the memory location that holds the contents of the display in so-called "mode 13h" in the old IBM VGA displays. Mode 13h was an extremely popular graphics mode, used by many PC games in the early 90s
17. 167.▲
    by ocfnash 9y ago

    I am the other commenter! The special icosahedron functions can be expressed in many ways but perhaps the most elementary _explicit_ representation is as particular Gaussian hypergeometric functions. See this repo for example: https:/
18. 168.▲
    by ocfnash 9y ago

    Another lovely aspect to this problem is that the quintic _is_ solvable if you allow yourself to use certain special functions naturally associated to the icosahedron. The genesis of the relationship is that the group of rotations of the ic
19. 169.▲
    by ocfnash 9y ago

    I work at Susquehanna and I believe you may have incorrectly understood this to imply there is a pressure to stay at one's desk over lunch. In my experience, this is not at all the case and I head out over lunch fairly frequently.
20. 170.▲
    by ocfnash 9y ago

    Or she!
21. 171.▲
    by ocfnash 9y ago

    Unfortunately Wakefield's paper that essentially kicked off the "MMR vaccine controversy" was published by the Lancet. They eventually retracted but enormous damage was done (including deaths apparently).
22. 172.▲
    by ocfnash 10y ago

    Great example. It also seems to have been the case that when he became Abbot of his monastery in 1867 he ceased research.
23. 173.▲
    by ocfnash 10y ago

    If we knew that there would only ever be £45m worth in existence then perhaps not but one would expect that this figure is growing.
24. 174.▲
    by ocfnash 10y ago

    Much of the little I know about jet engines was sparked by my reading this wonderful article: https://www.americanscientist.org/issues/pub/each-blade-a-si... (which happily is _not_ paywalled). In particular I lea
25. 175.▲
    by ocfnash 10y ago

    Thanks, this is a good point: we have no idea how accurate they wished to be.
26. 176.▲
    by ocfnash 10y ago

    Thanks for these remarks Stephen. IIUC you're speculating that the relevant constraint they faced was that multiplication was very burdensome. I agree; it seems plausible this was the reason they found this an attractive approach. Also
27. 177.▲
    by ocfnash 10y ago

    I came across this before and found the section "An Algorithm For Logarithms" interesting. As pointed out (in second para. of that section) Feynman's observation about representing a number as product of terms of the form $1
28. 178.▲
    by ocfnash 10y ago

    > A total of 52,734 North Carolina consumers were affected. And also 152,989,508 email addresses were leaked, with sufficient information to derive the password in many cases. I got interested in this at the time and was pretty stunned a
29. 179.▲
    by ocfnash 10y ago

    The emphasis on secrecy is rather overblown IMHO: there's an entire company (not mentioned in the article!) whose sole business is building/maintaining these networks and they make plenty of information public on their website ht
30. 180.▲
    by ocfnash 11y ago

    Brian Hayes wrote a nice article about this a few months ago in American Scientist [1] and also wrote a little JS demo to tinker with linked from here [2]. 1. http://www.americanscientist.org/libraries/documents/20