antiearth

From anti- +‎ earth.

antiearth

1. A hypothetical analog to earth composed entirely of antimatter.
   • 1958, Columbia University Forum - Volumes 2-3, page 29:

     This principle states that, if we could somehow replace every particle on earth with its antiparticle—thus creating a sort of antiearth—no one would be able to tell the difference.

   • 1982, Martin Gardner, The Ambidextrous Universe, page 278:

     Each extends what would be called, on antiearth, a right hand.

   • 1989, Ronald W. Hellings, Relativistic Gravitational Experiments in Space, page 56:

     But actually, CPT only tells you that if you drop an apple to the earth it will fall exactly as if you drop an antiapple to an antiearth.

   • 1998, Meher Antia, Matter, Antimatter, and Why Are We Here:

     Antiapples would still fall to antiearth, radioactive antielements would still decay, and antisugar would taste sweet

2. (historical) A hypothetical twin planet to earth, proposed by the Pythagoreans, which cannot be seen from earth.
   • 1852, Alexander von Humboldt, Cosmos: Sketch of a Physical Description of the Universe:

     The old imaginary antiearth (άγτιχϑωγ) of the Pythagoreans does not belong to the sphere of these conjectures. It and the Earth were supposed to have a parallel concentric movement; it was an idea devised to spare the Earth, which was supposed to perform around the central fire a planetary revolution in 24 hours, from having also to execute a movement of rotation, and, indead, represented no doubt the opposite hemisphere, or the antipodal half of our planet.

   • 1972, Dietrich Schroeer, Physics and its fifth dimension: society, page 63:

     For the later Pythagoreans the world was made up of four elements: earth, water, air, and fire; the universe had a spherical earth traveling around in a circle once every 24 hours (instead of rotating); there was an invisible central fire, with the sun reflecting light from it; and in order to have exactly 10 major bodies in the universe, there was stipulated an antiearth, visible only from the back of the earth.

   • 1992, Alberto Savinio, Alberto Savinio: paintings and drawings, 1925-1952, page 112:

     As for the planet high up to the right in the sky, I have not managed to ascertain whether it is a product of the Pythagorean Antiearth, or of the sentiment laid in my soul by the radiation of Planck's 'Black Body'

   • 1998, Ronald H. Fritze, Travel Legend and Lore: An Encyclopedia, →ISBN, page 17:

     Directly opposite the oikoumene was the "antichthones," or "opposite land," or "antiearth," also called the "periocci." It corresponded to the quarter of the globe North America occupies, and its night and day were the reverse of the oikoumene.

antiearth (not comparable)

1. Facing or moving away from earth.
   • 1984, Edward W. Hones, Magnetic Reconnection in Space and Laboratory Plasmas:

     If particles that originally occupy a box which is 20RE long in the earth-antiearth direction and 10Rf wide perpendicular to the neutral sheet leak out of a slit of 4Rf wide with a speed of 400 km/s, it takes 800s before all the particles are lost.

   • 1985, STAR, an Abstract Journal - Volume 23, Issues 5-8, page 628:

     The Rx antenna has a single hinge line and during launch the reflector dish is restrained against the antiearth panel by two hold-down points.

   • 1995, Free-space Laser Communication Technologies:

     Overview of LUCE The optical part of LUCE (LUCE-O) is installed on the plane of antiearth direction of OICETS for wide visibility of the geo-stationary satellite, ARTEMIS.

2. Opposed to or destructive of the earth and things native to the earth.
   • 1992, Building A Shared Vision For Environmental Education, →ISBN, page 99:

     One thought that much of curricula currently taught, including math and science, could be construed as antiearth, and that students need to feel they are being affected personally in order to be mobilized to action.

   • 1995, Michael E. Salla, Walter Tonetto, Enrique Martínez, Essays on Peace: Paradigms for Global Order, →ISBN, page 80:

     They see these manifestations of a patriarchal biased mentality as antifeminist, antihuman and antiearth.

   • 2008, Camille de Toledo, →ISBN:

     We were at a similar historical point at the turn of this century. The hesitation stage. A passing phase. On the side of the old, the Cassandras of the National Idea. On the new, us! Unreasonable wanderers in an antibody era, antiearth, antiflesh, hiding ourselves out of timidity, joyous because we were desperate, at home with our bodies, but without borders, ironic because unsure, nostalgic not of the past that is no more, but for a future that could be.

• antiheart