The Universe of Discourse

A message to the aliens, part 12/23 (earth-moon system)

Earlier articles: Introduction Common features Page 1 (numerals) Page 2 (arithmetic) Page 3 (exponents) Page 4 (algebra) Page 5 (geometry) Page 6 (chemistry) Page 7 (mass) Page 8 (time and space) Page 9 (physical units) Page 10 (temperature) Page 11 (solar system)

This is page 12 of the Cosmic Call message. An explanation follows.

The 10 digits are:

0

1

2

3

4

5

6

7

8

9

Page 12, begins a new section of the document, with pages headed with the glyph “Earth”, describing the Earth and its environs. This will help the recipients locate our planet, should they come to visit.

The top of the page has a diagram of the Earth -Moon system and a ruler labeled with the distance between them, !!3844\cdot 10^5!! meters. Since the distance between Earth and Moon varies (the orbit is elliptical) an average value is given.

The glyph used here for distance, , is different from the one defined on page 9 . Neither appears elsewhere in the message, so this is probably a mistake.

The following five lines give the mass and radius of the Moon and the Earth, and also the distance from the Earth to the Sun. The latter would have been better on the previous page, which discussed the solar system, but was omitted from there for some reason.

[Other articles in category /aliens/dd] permanent link