We have to define gnomon - as something perhaps common to all sundials.
It is information reflected off the device. Must a gnomon cast a shadow?
On 8/10/2012 7:41 AM, [email protected] wrote:
Color calibration was the primary function, however these sundials - which
are also on the previous Mars rovers - were in fact designed to also be
used to show time and season. Originally they were meant to be placed on
stationary landers. Since rovers can change direction and latitude, making
permanent lines a problem, the solution was to superimpose time indicator
lines on the images digitally so the dial can be read, as in this photo
from the Spirit rover:
http://www.nasaimages.org/luna/servlet/s/fb8nc5
Here is an article (in PDF) from 2003 describing the design and operation
of the Mars sundials:
http://www.astro.washington.edu/users/woody/MarsDial.Plan_Rept.Jan04.pdf
Don Rogerson
David,
On
http://wtvr.com/2012/08/03/nasa-mars-rover-curiosity-will-land-early-monday/
you can read that de 'sundial' is not used to have information "to
calculate time of day, date, and seasons" but as an appliance to color
balance the photgraphies Curiosity made.
Willy Leenders
Hasselt in Flanders (Belgium)
Visit my website about the sundials in the province of Limburg (Flanders)
with a section 'worth knowing about sundials' (mostly in Dutch):
http://www.wijzerweb.be
Op 10-aug-2012, om 11:03 heeft [email protected] het volgende
geschreven:
Dear Diallists,
I thought you might find this particularly interesting, sent to me by my
USA-based son.
http://mars.jpl.nasa.gov/msl/multimedia/interactives/learncuriosity/index-2.html
then click on the arrow until you get to the description of the 'Back'
Click on the sundial (near the top/middle)
Also:
http://www.pcworld.com/article/260579/mars_rover_curiosity_a_complete_guide_to_tagging_along_online.html
In particular:
https://twitter.com/marscuriosity
https://twitter.com/sarcasticrover (unofficial I'm guessing :)
David Brown
Somerton, Somerset, UK
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
