[ExI] Happy Solstice!
spike66 at comcast.net
Sat Jun 23 17:52:45 UTC 2007
Cool Lee! Since you take into account the latitude and longitude, your next
digit of precision on your yardstick experiment comes from taking into
account the analemma. This website gives a reasonable explanation:
The analemma is the result of the fact that the earth isn't in a circular
orbit around the sun, but rather an ellipse. This time of year when we are
at the aphelion, or farthest point from the sun, the apparent traverse of
the sun across the ecliptic is slightly less than than the usual ~ degree
per day. Mid winter it will traverse slightly more than the average.
By happy coincidence, the aphelion and perihelion almost correspond with the
I am setting up an experiment to mark the pavement on my back patio
corresponding to the shadow of the peak of the house at exactly noon. Of
course most days at noon I would not be home, so it will take years to get
most of the calendar days marked. When I do, I will have a figure 8 shaped
calendar back there. Isaac will love it. Is this cool or what?
> -----Original Message-----
> From: extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-
> bounces at lists.extropy.org] On Behalf Of Lee Corbin
> Sent: Saturday, June 23, 2007 10:32 AM
> To: ExI chat list
> Subject: Re: [ExI] Happy Solstice!
> Happy Solstice to you too, Spike.
> I performed the appropriate ritual in the parking lot at work with the
> help of an assistant. We used a yardstick as plumb line, waited until
> 1pm, and measured the length of the shadow ('twas 9 inches).
> (Oddly, I noted that our shadows didn't seem to point exactly north
> until about 7 minutes after 1pm---1 pm, of course, because of the
> dratted daylight savings time.)
> So the angle generated by the sun and yardstick was arctan of 1/4,
> which is almost exactly 14 degrees. So (drawing a sanity-check
> diagram and) adding to the 23.5 degree axial tilt of the Earth, we
> got 37.5 for our latitude. Very nice for Santa Clara, California,
> no? (Google Earth gave 37.38 or something. Had to be pretty
> lucky given how much the wind was blowing the yardstick around.)
> But it got even better. My assistant pointed out that we were
> somewhere in the middle of the time zone, so substituting +8 hours
> from UCT (GMT in London) was only an approximation. Google
> suggested that the *longitude* of our parking lot is 121.99 W.
> My assistant's idea was
> that if we were, say, a bit to the west of the middle of our time zone,
> then we should have to wait a bit for the sun to get exactly overhead.
> Lo and behold once more! Two degrees (1.99, that is) yields eight
> minutes because the Earth turns one degree every four minutes (an
> hour is 1/24 of 360, or 15 degrees, so 60 minutes = 15 degrees is
> of course four minutes.)
> Delighted was I, since I had noted that we seemed to have to wait
> seven minutes for the sun to get the yardstick's shadow lined up right!
> You can do this any day this summer! See how many minutes before
> or after the hour you have to wait for a shadow to point exactly
> north, and compute your longitude. It makes the Admiralty and
> John Harrison's quest all the more poignant.
> Every time that ritual measurements like this are performed, the claims
> of the flat-Earthers are weakend a little more. :-)
> ----- Original Message -----
> From: "spike" <spike66 at comcast.net>
> To: "'ExI chat list'" <extropy-chat at lists.extropy.org>
> Sent: Friday, June 22, 2007 7:56 AM
> Subject: Re: [ExI] Happy Solstice!
> > Growing seasons would lag behind the solar seasons, which is the most
> > critical schedule to most societies. Those smart Celts, being astronomy
> > minded, would perhaps be more likely ignore the air temperature and note
> > celestial cues.
> > spike
> >> -----Original Message-----
> >> From: extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-
> >> bounces at lists.extropy.org] On Behalf Of Alex Ramonsky
> >> Sent: Friday, June 22, 2007 2:53 AM
> >> To: ExI chat list
> >> Subject: Re: [ExI] Happy Solstice!
> >> Happy Solstice Amara : )
> >> ...Something that I have wondered for many years...Does anyone know why
> >> the Midsummer Solstice/Midwinter Solstice are called so, when (at least
> >> in the UK) they're considered to be the _beginning_ of summer/winter?
> >> The Celts treated them as the middle of the seasons...Is this one of
> >> those eccentric British things or is there genuine worldwide confusion?
> >> Best,
> >> AR
> >> **********
> >> Amara Graps wrote:
> >> >Happy June Solstice  to you Northerners and Southerners
> >> >that is)!! Celebration time!
> >> >
> >> >Midsummer Night 
> >> >by Zinta Aistars
> >> >
> >> >One night each year, that longest night
> >> >be
> >> >
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