Changes

Accordingly, in 1984 Humphreys boldly declared:{{cquote|Mercury's decay rate is so rapid that some future probe could detect it fairly soon. In 1990 the planet's magnetic moment should be 1.8 percent smaller than its 1975 value.<ref name=Humphreys/>}}

Accordingly, in 1984 Humphreys boldly declared:{{cquote|Mercury's decay rate is so rapid that some future probe could detect it fairly soon. In 1990 the planet's magnetic moment should be 1.8 percent smaller than its 1975 value.<ref name=Humphreys/>}}

In fact, according to Humphreys' extrapolations of the decay time and half-life of the magnetic field of Mercury, the [[magnetic dipole moment]] in 2008 should be ''four'' percent smaller than that measured in 1975 by Mariner 10. Specifically, this should be (4.5 +/- 0.25) * 10¹⁹ N-m/T.

In fact, according to Humphreys' extrapolations of the decay time and [[half-life]] of the magnetic field of Mercury, the [[magnetic dipole moment]] in 2008 should be ''four'' percent smaller than that measured in 1975 by Mariner 10. Specifically, this should be (4.5 +/- 0.25) * 10¹⁹ N-m/T.

On January 14, 2008, [[MESSENGER]] made rendezvous with Mercury and measured its magnetic field. This rocket probe's measurements are consistent with a magnetic dipole moment of (3.8 +/- 0.7) * 10¹⁹ N-m/T. This represents a significant decline from the Mariner 10 measurement, because the two measurements differ by more than the sum of their respective tolerances. More to the point, the higher tolerance range of the current measurement lies well within the predicted magnetic dipole moment that Mercury should have at present. If, on the other hand, the true measurement is ''less'' than predicted, that would pose an even greater problem for uniformitarian astrophysics, because such a rapid decay would be utterly inconsistent with an age for Mercury of 4.6 billion years. It would present no problem with the Humphreys model, but would suggest that the core conductivity and/or conductive mass of Mercury is less than Humphreys initially supposed.<ref name=Humphreys2/>

On January 14, 2008, [[MESSENGER]] made rendezvous with Mercury and measured its magnetic field. This rocket probe's measurements are consistent with a magnetic dipole moment of (3.8 +/- 0.7) * 10¹⁹ N-m/T. This represents a significant decline from the Mariner 10 measurement, because the two measurements differ by more than the sum of their respective tolerances. More to the point, the higher tolerance range of the current measurement lies well within the predicted magnetic dipole moment that Mercury should have at present. If, on the other hand, the true measurement is ''less'' than predicted, that would pose an even greater problem for uniformitarian astrophysics, because such a rapid decay would be utterly inconsistent with an age for Mercury of 4.6 billion years. It would present no problem with the Humphreys model, but would suggest that the core conductivity and/or conductive mass of Mercury is less than Humphreys initially supposed.<ref name=Humphreys2/>