solstice pole

[sculptor]

I read that if you have a vertical pole, the shadow at the tip of the pole shadow cast by the sun will trace a line from true west to true east during the solstice.
So, the pole was placed on the deck, and I am occasionally going out and marking the tip of the shadow.

Do you believe that the end result will be a line running due east to due west?

 

[exchemist]

I read that if you have a vertical pole, the shadow at the tip of the pole shadow cast by the sun will trace a line from true west to true east during the solstice.
So, the pole was placed on the deck, and I am occasionally going out and marking the tip of the shadow.

Do you believe that the end result will be a line running due east to due west?

Not unless you are at the equator.

 

[DaveC426913]

I read that if you have a vertical pole, the shadow at the tip of the pole shadow cast by the sun will trace a line from true west to true east during the solstice.
So, the pole was placed on the deck, and I am occasionally going out and marking the tip of the shadow.

Do you believe that the end result will be a line running due east to due west?

Well, it's not going to be a straight line, so it will be pretty tricky to extrapolate to the horizon.

 

[foghorn]

I read that if you have a vertical pole, the shadow at the tip of the pole shadow cast by the sun will trace a line from true west to true east during the solstice.
So, the pole was placed on the deck, and I am occasionally going out and marking the tip of the shadow.

Do you believe that the end result will be a line running due east to due west?

T0day is the Spring Equinox, so do you mean 'Equinox pole'.
This link has a video clip of the shadow of the top of the pole moving along a west to east line.
https://earthsky.org/human-world/equinox-shadows-trace-a-straight-line/

Northern and Southern Hemisphere differences
By the way, there are some major differences between the two hemispheres. On an equinox-day in the Northern Hemisphere, the straight shadow path passes to the north of the gnomon. In the Southern Hemisphere, the straight shadow path passes to the south of the gnomon.

And, at the equator, the shadow path goes neither north nor south of the gnomon. That’s because the noonday sun swings directly over the upright pole on the equinox, casting no midday shadow.

Bottom line: On the day of an equinox, the tip of an upright stick’s shadow follows a straight west-to-east path all day long.

Sculptor, the third from last picture on the link, has a wall mounted pinhole sundial. Have a go at making one if you have the space and a south facing wall, I don't.

 

[foghorn]

Sculptor, the third from last picture on the link, has a wall mounted pinhole sundial. Have a go at making one if you have the space and a south facing wall, I don't.

reply to my own post...
Foghorn, that's not a real all day sundial on the wall, it only records the noon position of the sun throughout the year.

 

[foghorn]

Thank you Foghorn.

 

[gmilam]

I read that if you have a vertical pole, the shadow at the tip of the pole shadow cast by the sun will trace a line from true west to true east during the solstice.
So, the pole was placed on the deck, and I am occasionally going out and marking the tip of the shadow.

Do you believe that the end result will be a line running due east to due west?

Solstice or equinox?

Anyway, I have read that if you mark the end of the shadow of the vertical pole in the morning, and the end of the shadow in the evening. Then draw a straight line between the two points, the point in that line that is closest to the the base of the pole is due north of the pole... in the northern hemisphere. This is supposedly true any day of the year, not just on a solstice or equinox.

 

[exchemist]

T0day is the Spring Equinox, so do you mean 'Equinox pole'.
This link has a video clip of the shadow of the top of the pole moving along a west to east line.
https://earthsky.org/human-world/equinox-shadows-trace-a-straight-line/
View attachment 5342
Sculptor, the third from last picture on the link, has a wall mounted pinhole sundial. Have a go at making one if you have the space and a south facing wall, I don't.

Aha, now I understand. That's interesting.

 

[sculptor]

T0day is the Spring Equinox, so do you mean 'Equinox pole'.
This link has a video clip of the shadow of the top of the pole moving along a west to east line.
https://earthsky.org/human-world/equinox-shadows-trace-a-straight-line/
View attachment 5342
Sculptor, the third from last picture on the link, has a wall mounted pinhole sundial. Have a go at making one if you have the space and a south facing wall, I don't.

Yeh----OOPs---thanx---
I was distracted dealing with slow motion medical personnel---trying to get an appointment to have a possible cancerous(?) tumor examined----
Equinox pole
(actually a 1/2 inch dowel held upright in a vice grip)(but it worked)
and the line was straight---based on about 15 data points
ok
so east and west line is now painted on my deck
(could come in handy(?))

fun anyway

 

[DaveC426913]

Yeh----OOPs---thanx---
I was distracted dealing with slow motion medical personnel---trying to get an appointment to have a possible cancerous(?) tumor examined----
Equinox pole
(actually a 1/2 inch dowel held upright in a vice grip)(but it worked)
and the line was straight---based on about 15 data points
ok
so east and west line is now painted on my deck
(could come in handy(?))

fun anyway

Cool way to do it.

When I landscaped my front yard, I used Google maps to plot the cardinal directions. I made the entire yard into a giant hardscaped 8-point compass rose. All paths, steps and raised flower beds were offset from the property lines by the appropriate 19 degrees. Even the arbor I scratch-built was skewed by 19 degrees.

(Tree belongs to city, so I had to make my whole design around it.)

I went with the compass rose because it is an important component of both sailing and scuba diving.

 

[Neddy Bate]

and the line was straight---based on about 15 data points
ok
so east and west line is now painted on my deck
(could come in handy(?))

fun anyway

One of my neighbors has this painted on the front of their house:

And the sidewalk does run west-to-east, just as their compass shows.

Where I am, just about every street is a straight line that runs east-west or north-south. Traveling east early this morning, I had the sun directly in front of me, blinding me. I'll be traveling west later, around twilight, and expect the same thing for the return trip.

 

[DaveC426913]

Well, after thirty years, the City came today and chopped that tree down and turned it into sawdust*.

*well, the carpenter ants did that. The City just finished the job.

 

[DaveC426913]

One of my neighbors has this painted on the front of their house:

Where I am, just about every street is a straight line that runs east-west or north-south. Traveling east early this morning, I had the sun directly in front of me, blinding me. I'll be traveling west later, around twilight, and expect the same thing for the return trip.

Yeah. I've lived on the West side of my city's downtown for 30 years and occasionally envy the East-enders who have the sun behind them for both the trip in and the trip home.