Are we looking at the same map? On the one I see, showing western and central Europe, the difference between a great circle and a loxodrome (straight line on a Mercator map) for an intra-European route would be barely visible. And the map is clearly not Mercator — France looks visibly "smashed". Looks like a simple x=longitude, y=latitude projection.
Has the performance of sum on lists of lists in Python been fixed? It used to be pretty abysmal. But I suppose some would say that if you need to consider performance at all, you’re in the wrong language… :)
Python 3.13.5 (main, Jul 15 2026, 20:25:40) [GCC 14.2.0] on linux
>>> x = [[n]*1000 for n in range(1000)]; import timeit, itertools, functools, operator
>>> timeit.timeit("len(list(sum(x, [])))", number=10, globals=globals())
13.009033881127834
>>> timeit.timeit("len(list(list(functools.reduce(operator.add, x, []))))", number=10, globals=globals())
12.941937348805368
>>> timeit.timeit("len(list(itertools.chain.from_iterable(x)))", number=10, globals=globals())
0.0706032607704401
>>> timeit.timeit("out=[]; [out.extend(i) for i in x]; len(out)", number=10, globals=globals())
0.06334403157234192
>>> timeit.timeit("len([i for a in x for i in a])", number=10, globals=globals())
0.1232151910662651
mutable is fastest, itertools is just a bit slower, list comprehension is 2x slower, both "sum(..., [])" and "reduce" are 200 times slower!
Something similar is in place in Sweden. For landline numbers, it is of course easy. A number with, say, a Stockholm area code is not suddenly going to be in Nigeria. For mobiles it is trickier, because a Swedish mobile may very well be in Nigeria. Some additional database look-ups had to be added to the already rubegoldbergesque contraption that handles mobile phone calls.
For those HN readers who are not stationery junkies: The “real” Blackwing pencils went out of production... I don’t know when, but it must be at least 15 years ago, probably longer. (I have only been watching this from the outside, so don’t ask me for details. =) ) Those sold now come from a different production line at a different company, even though the maker is trying to make them as close as possible to the original. Ever since they showed up, pencil aficionados have been debating whether they are better, worse, or about the same. Originals seem to sell for over $20 a piece on eBay (actual "sold" prices, not asking prices).
Thank you! I should have explained more in-depth what I meant. I forget sometimes this is Hacker News and not, everyone has exactly the same interests as me news. I did have quite a few of the originals till I used them and there is such a difference that I had to switch entirely as I just found the new ones weren't that close to allow me to use them in the same way. So I would prefer to completely change method.
If I remember correctly, a recent Gallup in Sweden indicated that about 25 % do not take calls from any unknown number. I don’t know whether this result has been corrected to take itself into account. :)
More advanced slide rules typically have a set of “folded” scales, that can sometimes save a calculation from ending up off scale. In theory, these should be offset by half the scale length, i.e. sqrt(10). However, since the folded scales also offer a convenient way to multiply with the offset factor, most slide rules offset them by π instead, since it’s almost the same as sqrt(10), and multiplication by π is a more useful thing to have around.
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