Geochron
2 Globes

 

Code Number: 8A10.80

Demo Title: Analemma

Condition: Good

Principle: Solar Position and Earth's Inclination

Area of Study: Astronomy

Equipment: 

Geochron, Earth Globes.

Procedure:

See also: Geochron 1A10.41 in Mechanics and Geochron/Analemma 1A10.41/8A10.80 in Astronomy.

Although there are methods of plotting solar position verses Earth's position, this usually takes one year for a full cycle.  For practical purposes we use the built in chart on the Geochron or ones on the two Earth globes shown.  Position verses date can be observed there.

NOTE: Not every Earth globe has the Analemma printed on it.  In that sense, these two globes are special and should not be lost, discarded, or removed from Rm. 58 Van.

References:

  • Leslie Atkins Elliot, Amanda Hunter, Carl Krutz, ShaKayla Moran, Elliot Sherrow, "Stop-Motion Animation to Model the Analemma", TPT, Vol. 59, #4, April 2021, p. 230.
  • Alejandro Gangui, Cecilia Lastra, and Fernando Karaseur, "On Times and Shadows: The Observational Analemma", TPT, Vol. 56, #6, Sept. 2018, p. 367.
  • William Baird, Jeffery Secrest, Clifford Padgett, Wayne Johnson, and Claire Hagrelius, "Smartphones and Time Zones", TPT, Vol. 54, #6, Sept. 2016, p. 351.
  • Philip M. Sadler and Christopher Night, "Daytime Celestial Navigation for the Novice", TPT, Vol. 48, #3, Mar. 2010, p. 197.
  • Prabasaj Paul, "Analemma", TPT, Vol. 39, #5, May 2001, p. 265.
  • Dan M. Davis, "An Analemma Experiment", TPT, Vol. 38, #9, Dec. 2000, p. 570.
  • James Brimhall, "The Varying Lengths of Solar Days", TPT, Vol. 34, #6, Sept. 1996, p. 351.
  • R. H. Garstang, "Sunrise and Sunset", TPT, Vol. 34, #5, May 1996, p. 260.
  • Mary Lou West and Jo‐Linda Keith, "Sunrise Surprise", TPT, Vol. 34, #1, Jan. 1996, p. 58.
  • Jennifer Hickman and Robert Mitchell, "Determination of the Subsolar Point or (Where on Earth Is the Sun?)", TPT, Vol. 29, #5, May 1991, p. 318.
  • D. Easton, "On the Sun, Earth, and Clocks", TPT, Vol. 23, #2, Feb. 1985, p. 85.
  • Joseph S. Chalmers, "Ground Trajectories of Geosynchronous Satellites and the Analemma", AJP, Vol. 55, #6, June 1987, p. 548.
  • D. Tattersfield, "5.8, The Analemma", Project & Demonstrations in Astronomy, p. 89.
A very nice time elapsed photo and explanation