Mike,
It would be fair to tell us which week, so that tourists would know when
to avoid the "aulde countrie" when scheduling visits.
Somehow I've lost the connection to the moving shadow edge. Except
for...
The only vehicular direction that seems to relate to the edge of the
moving shadow is "t
Hi John,
You believe that you are right. The attached sketch (Shadow.jpg) shows this
fairly clearly. At 21 kb it is too big to post on the mailing list unless
there is a strong demand.
Roger Bailey
At 06:45 AM 5/4/99 -0700, you wrote:
>Hello all:
>
>I was just thinking that on a horizontal sun
Hello:
I used what is being called a shadow sharpner in a noon mark made by
drilling a hole in an aluminum plate located at the bottom of a south facing
sky light. To determine the hole size I first tried various holes
in cardboard. A starting point is that a pin hole camera would have
an "f" n
A couple of you asked about where I read of the shadow sharpener.
I have the article, but it is packed away in storage. It would probably
take several hours to find it.
The best I can remember, it was in Sky & Telescope magazine (or possibly
Astronomy magazine) in one of the issues between 1995
At 08:53 PM 5/4/99 -0400, Patrick Powers wrote:
>
>
>It was Sweden some time ago. They changed over at midnight. However, it
>was sensible for them to change; not only was it easier - relatively small
>and sparse population - but previously they drove mostly lefthand drive
>cars on the left !!
Message text written by INTERNET:[EMAIL PROTECTED]
>I've heard of at least one European country that made the switch from
left to right (though I forget which one), the switch took a 10 year plan.
Troy<
It was Sweden some time ago. They changed over at midnight. However, it
was sensible for t
As far as the tounge-in-cheek comment that the more powerful hand should be
availible to hold the wheel--in the days before power steering this may have
been relevant, but the shifter requires more manual dexterity, of course
automatic transmission now makes shifting easier, so whatever you lik
Gordon Uber <[EMAIL PROTECTED]> wrote:
> Roger, thank you for your post. The Shadow Sharpener being a
> pinhole camera, why not replace the gnomon with a pinhole? One then
> could center a circle on the image and determine the time from its
> position.
To form a good solar image the plane of t
We (UK) keep to the left side of the road, so that our
(normally) strongest hand is available to fight an enemy
with a sword - a throwback to the days of King Arthur and
his Knights I suppose.
There was a rumour going round that the governmment were
considering changing us to driving on the right
To all:
As soon as I launched my previous note, re: Shadow Sharpener,
I realized I had failed to attach the GIF image file ...
1627 bytes.
Here it is: (pinhole compound solar telescope)
Bill
Attachment converted: MAC Hard Disk:PIN-HTEL.GIF (GIFf/JVWR) (00015069)
Gordon,
>Roger, thank you for your post. The Shadow Sharpener being a pinhole
camera,
>why not replace the gnomon with a pinhole? One then could center a circle
on
>the image and determine the time from its position.
Some years ago, when thinking about heliochronometers, I realized that the
s
I was just looking at the section on medieval noon marks (illustrated in its
frontispiece) in Waugh's book "Sundials." The one shown had an opaque disk
with a central 1/4" hole supported out from a south-facing wall. He suggests
timing the passage of the two edges of the solar image and averagin
Roger, thank you for your post. The Shadow Sharpener being a pinhole camera,
why not replace the gnomon with a pinhole? One then could center a circle on
the image and determine the time from its position.
My rule of thumb is that the angular resolution of a pinhole is one radian (57
degrees)
Hello all:
I was just thinking that on a horizontal sundial that the true shadow point
would ONLY be at the center of the penumbra at high (apparent) noon. In the
late afternoon or early morning, the sun would be to the side of the style,
causing the shadow to strike the dial face at an angle.
Message text written by INTERNET:[EMAIL PROTECTED]
>As a test, you could make use of a device I read about called a "Shadow
Sharpener", supposedly used by Chinese astronomers centuries ago.
The shadow sharpener is simply a stiff sheet of opaque material with a
clean edged round hole in the middl
At 22:48 3/05/1999 EDT, [EMAIL PROTECTED] wrote:
>It would seem to make more sense to drive on the right side, since the
>handedness of a supermajority of people is right handed, allowing the
>stronger hand in close proximity to the shifter. That and being an American
>that's what I'm used to
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