magnetic field, when measured from Earth, of a large but distant planet such as Jupiter is far smaller than that produced by ordinary household appliances. Western astrology has taken the earth's axial precession (also called precession of the equinoxes) into account since Ptolemy's Almagest, so the "first point of Aries", the start of the astrological year, continually moves against the background of the stars. The tropical zodiac has no connection to the stars, and as long as no claims are made that the constellations themselves are in the associated sign, astrologers avoid the concept that precession seemingly moves the constellations. Charpak and Broch, noting this, referred to astrology based on the tropical zodiac as being "...empty boxes that have nothing to do with anything and are devoid of any consistency or correspondence with the stars." Sole use of the tropical zodiac is inconsistent with references made, by the same astrologers, to the Age of Aquarius, which depends on when the vernal point enters the constellation of Aquarius. Astrologers usually have only a small knowledge of astronomy, and often do not take into account basic principles—such as the precession of the equinoxes, which changes the position of the sun with time. They commented on the example of Élizabeth Teissier, who claimed that, "The sun ends up in the same place in the sky on the same date each year", as the basis for claims that two people with the same birthday, but a number of years apart, should be under the same planetary influence. Charpak and Broch noted that, "There is a difference of about twenty-two thousand miles between Earth's location on any specific date in two successive years", and that thus they should not be under the same influence according to astrology. Over a 40-year period there would be a difference greater than 780,000 miles. Reception in the social sciences The general consensus of astronomers and other natural scientists is that astrology is a pseudoscience which carries no predictive capability, with many philosophers of science considering it a "paradigm or prime example of pseudoscience." Some scholars in the social sciences have cautioned against categorizing astrology, especially ancient astrology, as "just" a pseudoscience or projecting the distinction backwards into the past. Thagard, while demarcating it as a pseudoscience, notes that astrology "should be judged as not pseudoscientific in classical or Renaissance times...Only when the historical and social aspects of science are