rfr1tz
asked on
How do you read a sundial?
Well, sure look at the shadow, yadda-yadda.
But for better accuracy, since the sun moves north and south with the seasons, is there a better way to read the time from the sundial?
My theory is that the wedge that casts the shadow is somehow curved or something.
But for better accuracy, since the sun moves north and south with the seasons, is there a better way to read the time from the sundial?
My theory is that the wedge that casts the shadow is somehow curved or something.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
......to be abled to read any given subdial you must know what day of the year it was calibrated on.
'sundial' not 'subdial'
Xxavier,
You are a very educated person.
You are a very educated person.
Thank you. :-)
I suggest that if you are from the west you should read from left to right, and from the east, read right to left. I confess I am less edjumacated.
> for better accuracy, since the sun moves north and south with the seasons
You are correct, the sun is not a stationary object in the sky, because like the birds and the fish and the turtles .... it has a different sense of direction than the higher lifeforms.
To improve accuracy, you need to invent the wheel, and then take out a patent for the horse-and-buggy. Hitch up and take your dial down to equator, and bring a bamboo fishing pole. From time to time, place to place, stick th pole into the ground at high noon. When you have succeeded in removing the shadow's persistent attachment to the stick, then you have arrived. If you have found that you have not arrived, then try, try again.
A similar method was employed in ancient history by a famous person who may have been Grecian had he been born in alternative timespace. Often referred to as Alexander, he was very impressed by the scientic capabilities and practices of the eqyptian laborers, and frequently told them how pleased he was about their productivity. In turn the laborers formed a union nominated and elected Alexander for position of boss. OK, maybe he did not precisely follow my directions, but the rest is ;-) so true that his job title was changed from boss to Great.
Xxavier> 'sundial' not 'subdial'
My freudianed friend, this is not the math/science TA, but I still need to know how to tell when I've only ten minutes until curfew
> for better accuracy, since the sun moves north and south with the seasons
You are correct, the sun is not a stationary object in the sky, because like the birds and the fish and the turtles .... it has a different sense of direction than the higher lifeforms.
To improve accuracy, you need to invent the wheel, and then take out a patent for the horse-and-buggy. Hitch up and take your dial down to equator, and bring a bamboo fishing pole. From time to time, place to place, stick th pole into the ground at high noon. When you have succeeded in removing the shadow's persistent attachment to the stick, then you have arrived. If you have found that you have not arrived, then try, try again.
A similar method was employed in ancient history by a famous person who may have been Grecian had he been born in alternative timespace. Often referred to as Alexander, he was very impressed by the scientic capabilities and practices of the eqyptian laborers, and frequently told them how pleased he was about their productivity. In turn the laborers formed a union nominated and elected Alexander for position of boss. OK, maybe he did not precisely follow my directions, but the rest is ;-) so true that his job title was changed from boss to Great.
Xxavier> 'sundial' not 'subdial'
My freudianed friend, this is not the math/science TA, but I still need to know how to tell when I've only ten minutes until curfew
http://www.americanantiquities.com/articles/article14.html
Only a little there about the Macedonian, but among the sundial's history there it has it that the Greeks understood it and with it they began to create/invent sciences such as geometry and trigonometry, but when their inheritors from Rome accumulated their cultural heritage and heirlooms, that like typical descendents the value they placed on the sundial was for ornamental decoration. For religious TA, this can indicate potential frictions when Romans who had troubles counting to five using only their fingers met up with hebrews and christians and other palestinians who could not only read other languages, but actually tell time.
http://www.rnzih.org.nz/pages/sundial1.htm
(relevance to a prior comment)
/quote/
"the Greeks developed the sundial further, and experimented with hemicycles, conical dials, cylindrical dials and flat dials set at various angles. In those days, a system of unequal or temporary hours was in common use, with the available period of daylight divided into 12 parts — resulting in 12 long daylight hours in summertime and 12 short daylight hours in wintertime. Astronomers, however, used 'equal' hours (just as we do today) for charting the moving heavens."
/unquote/
The working stiff would complain about long summer hours of labor, and it was not in imagination.
> theory is that the wedge that casts the shadow is somehow
It can be "aligned", to suit a purpose or need. Vertical and horixontal have uses, but the way you phrase it I think you want to account for latitude for current location of servitude:
http://www.rnzih.org.nz/pages/sundial2.htm
"For the majority of sundials, the gnomon (the part which casts the time-telling shadow, pronounced NO-mon with the accent on NO) is placed so that the upper surface is parallel to the axis of rotation of the earth."
"In the Southern Hemisphere this means that the gnomon should be aligned along a true North-South line and be inclined to the horizontal at an angle which is equal to the latitude, with the highest point of the gnomon nearest the South Pole"
Only a little there about the Macedonian, but among the sundial's history there it has it that the Greeks understood it and with it they began to create/invent sciences such as geometry and trigonometry, but when their inheritors from Rome accumulated their cultural heritage and heirlooms, that like typical descendents the value they placed on the sundial was for ornamental decoration. For religious TA, this can indicate potential frictions when Romans who had troubles counting to five using only their fingers met up with hebrews and christians and other palestinians who could not only read other languages, but actually tell time.
http://www.rnzih.org.nz/pages/sundial1.htm
(relevance to a prior comment)
/quote/
"the Greeks developed the sundial further, and experimented with hemicycles, conical dials, cylindrical dials and flat dials set at various angles. In those days, a system of unequal or temporary hours was in common use, with the available period of daylight divided into 12 parts — resulting in 12 long daylight hours in summertime and 12 short daylight hours in wintertime. Astronomers, however, used 'equal' hours (just as we do today) for charting the moving heavens."
/unquote/
The working stiff would complain about long summer hours of labor, and it was not in imagination.
> theory is that the wedge that casts the shadow is somehow
It can be "aligned", to suit a purpose or need. Vertical and horixontal have uses, but the way you phrase it I think you want to account for latitude for current location of servitude:
http://www.rnzih.org.nz/pages/sundial2.htm
"For the majority of sundials, the gnomon (the part which casts the time-telling shadow, pronounced NO-mon with the accent on NO) is placed so that the upper surface is parallel to the axis of rotation of the earth."
"In the Southern Hemisphere this means that the gnomon should be aligned along a true North-South line and be inclined to the horizontal at an angle which is equal to the latitude, with the highest point of the gnomon nearest the South Pole"
>>Xxavier,
>
>You are a very educated person.
Skimming through 'his' comments in Maths&Science he seems so have become more clever since GwenforWeb suspended herself ;)
>
>You are a very educated person.
Skimming through 'his' comments in Maths&Science he seems so have become more clever since GwenforWeb suspended herself ;)
... nice try alder but no cigar, now she has gone my deal with her to stay out of certain areas is null and void unless she returns, and I am having a field day. :)
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
rfr1tz,
Thank you.
I just noticed that the last link in my response was not pasted properly. Here it is, hopefully correct.
http://www.gmat.unsw.edu.au/currentstudents/ug/projects/o'brien/o'brien.htm
Thank you.
I just noticed that the last link in my response was not pasted properly. Here it is, hopefully correct.
http://www.gmat.unsw.edu.au/currentstudents/ug/projects/o'brien/o'brien.htm
yuck,
I guess there's something about the apostrophies that doesn't copy and paste well, as a hot link (or whatever it's called).
The link above is correct, but one needs to cut and paste the whole thing into the address bar.
I guess there's something about the apostrophies that doesn't copy and paste well, as a hot link (or whatever it's called).
The link above is correct, but one needs to cut and paste the whole thing into the address bar.
Hi There - for a nice informative explantion, try going to http://www.planetary.org/mars/earthdial/Time.html , I found this quite informative. Hope this helps!
Kind Regards,
Andy
Kind Regards,
Andy
Look at the shadow.....yadda-yadda.
;)