Oleg Zabluda's blog
Thursday, June 21, 2012
Stanisław Lem (Станислав Лем) predicted it in "Return from the Stars" (1961) ("Возвращение со звезд" (пер.
Stanisław Lem (Станислав Лем) predicted it in "Return from the Stars" (1961) ("Возвращение со звезд"  (пер. 1965)), as well as what happens when inept people use it.


[...] В стене была еще одна дверца, с надписью: "Купальные халаты". Я заглянул внутрь. Никаких халатов, какие-то три металлические фляжки вроде сифонов.[...]  Не только такой халат, но и костюмы, чулки, свитеры, белье - все делалось из выдувного пластика. Понятно, женщинам это должно было нравиться - манипулируя несколькими сифонами, можно было всякий раз создавать себе новый наряд, даже на единственный случай; сифоны выделяли жидкость, которая тут же застывала в виде ткани с гладкой или шершавой фактурой: бархата, меха или упругой с металлическим отливом. [...] Сама процедура одевания с помощью сифонов тоже показалась мне чересчур хлопотной.[...] В конце концов я решился прибегнуть к помощи сифонов [...]  Я ... из любопытства дал себя уговорить заглянуть в салон мод. Меня принял субъект, выглядевший как свободный художник, [...] он сделал мне тут же несколько свитеров. Я стоял, подняв руки, а он вертелся вокруг меня, оперируя сразу четырьмя флаконами. Жидкость, белая, как пена, на воздухе моментально застывала. Таким образом были созданы четыре свитера самых разных цветов, один с полоской на груди, красное на черном; самой трудной, как я заметил, была отделка воротника и манжет. Тут действительно требовалось мастерство.


Lots of wisecracks today about how Apple fanboys think that Apple invented tablets in 2010 (by making a huge...
Lots of wisecracks today about how Apple fanboys think that Apple invented tablets in 2010 (by making a huge friggin' phone [2]), but how Microsoft actually invented tablets in 2002. Then SJMN has a good deeper article how in 1991 Microsoft released "Windows for Pen Computing" add-on to Win 3.1 [1], following other companies' work in "late 1980's"


I don't suffer from amnesia, like so many others, but I came to USA in 1992, so that's the limit of my personal recollections. As always, wikipedia to rescue:


1956 was the first publicly demonstrated system using a tablet and handwriting text recognition. In 1987 Apple Computer started its tablet project, eventually releasing Apple Newton in 1993. That's the first one I actually played with at that time. The earliest I owned (and it is still in good working condition) is Palm III from early 1999.

[1] updated for Win95 in 1995, superseded in 2002 by WinXP Tablet PC Edition, later carried forward in Vista and Win7.
The Surface Pro, running full Windows 8

[2] Note that Microsoft made a small computer instead, running Win8Pro, which will run most software compatible with previous versions of Windows.


"Sunrise, Sunset" from "Fiddler On The Roof" [1] is a staple of our hiking repertoire.
"Sunrise, Sunset" from "Fiddler On The Roof" [1] is a staple of our hiking repertoire.

Let SF denote San Francisco, YO denote Yosemite.

Area of interest:
San Francisco CA to Yosemite National Park CA

Exact coordinates of YO and SF are as indicated by Google Maps (all hail). By an amazing coincidence, the two are almost precisely on the same latitude, 160 mi as crow flies, 200 mi as car drives. [3]

Tomorrow is Jul 9, 2011 [4]. All times are PDT.

SF sunrise is 5:55 am, sunset is 8:34 pm, day length: 14:40
YO sunrise is 5:44 am, sunset is 8:23 pm, day length: 14:40

SF Civil twilight 5:25 am - 9:05 pm Length: 15:40
YO Civil twilight 5:13 am - 8:53 pm Length: 15:40 

As you can see, in Yosemite, the Sun is 11 minutes earlier. so it must be (360/24)*(11/60) = 2.75 degrees to the east.

And indeed it pretty much is. Actually it's 2.85 deg. The difference is (2.85-2.75)*60 = 6 min. The Earth turns that much in 24 sec. 6 min of the great circle is 6 nmi = 6.7 mi. At our latitudes, 6.7*sin(37°)=4.0 mi. Negligible.

A very slight imprecision also comes from the fact that SF is actually 0.03°=1.7min=2 mi to the south of YO. .

Sunrise (actually civil twilight) is when we start hiking. Sunset (actually civil twilight) is when we try to come back. That's why it is called day hike. Tomorrow day is 15h 40min long.

Of course, during sunrise, we could have called back to SF on a cell phone to check on their sunrise 11 minutes later, Then reverse the calculations above (together with our odometer reading) to find out radius of Earth.

[3] When I drive to YO on CA-120 at night during summer, my course is exactly due East, straight to Pegasus/Taurus, and during winter, it's Hercules/Cygnus, so it's easy to navigate. And easy to imagine myself driving a spaceship, except I set my cruise control in mph instead of fractions of c, and odometer is not in ly.

Lyrics by Sheldon Harnick
music by Jerrold Lewis "Jerry" Bock.

[4] This is a repost of my Buzz (RIP) post Jul 8, 2011


In SF (latitude 37.77°N), during summer solstice day (2012-06-20), at solar noon (13:11:25 pm PDT) [1], Sun is...
In SF (latitude 37.77°N), during summer solstice day (2012-06-20), at solar noon (13:11:25 pm PDT) [1], Sun is 37.77-23.44=14.33° from the Zenith. For comparison, at the Equator, at solar noon, during equinoxes, the Sun is 23.44° from Zenith. In your face, Equator! We win sometimes. Now, to really rub it in: cos(14.33°)/cos(23.44°)=1.06. Ha!

Grease - Summer Nights (Summer Lovin) [HD]
Bananarama Cruel Summer Video
Ella Fitzgerald and Louis Armstrong - Summertime

[1] also called local noon or sun crossing meridian. Don't confuse with 12:00:00 pm on your watch.


Summer solstice was yesterday 4:09 pm PDT.
Summer solstice was yesterday 4:09 pm PDT. This is when northern hemisphere is tilted towards the Sun the most. However, Hipparchus discovered around 147-127 BC that Earth's axis precesses with period of ~26,000 years. Does it mean that in ~13,000 years, summer solstice will be around Christmas? That would be terrible!

That would indeed happen if our 12-months calendar year was a sidereal year i.e. the time it takes the Earth to go around the Sun with respect to stars. That would be stupid. Instead, calendar year is Solstice-to-Solstice tropical year, which is 365*24*60/26000~=20 min shorter. So the seasons don't move in across calendar months. All hail Hipparchus.

1 sidereal year = 365.256363004 days (365 d 6 h 9 min 9.76 sec)
1 tropical year = 365.242189 days (365 d 5 h 48 min 45 sec)

Instead, solstices move through constellations. During summer solstice, the Sun was in Gemini 10BC-1989, then passed into Taurus in 1990. In 13,000 years, during summer solstice, it will be exactly on opposite side of the ecliptic. If you know your astrology, it'll pass from Sagittarius into Scorpio. If you don't know your astrology, since the solstice is now, just go out at [astronomic] midnight, and look directly south (at Scorpius). That's the Sun will be.



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