What wavelengths?The article "Icy Heat: Satellites look at heat flow through Antarctica's crust crust Outermost solid part of the Earth, essentially composed of a range of igneous and metamorphic rock types. In continental regions, the crust is made up chiefly of granitic rock, whereas the composition of the ocean floor corresponds mainly to that of basalt and gabbro. " (SN: 6/11/05, p. 373) refers to the Earth's magnetic field Earth's magnetic field (and the surface magnetic field) is approximately a magnetic dipole, with one pole near the north pole (see Magnetic North Pole) and the other near the geographic south pole (see Magnetic South Pole). only at very long wavelengths. In over 70 years' exposure to science, I have never heard of our magnetic field having wavelengths. Please elaborate. KENNETH E. STONE, CHERRYVALE, KAN. Looking at Earth's magnetic field at long wavelengths is analogous analogous /anal·o·gous/ (ah-nal´ah-gus) resembling or similar in some respects, as in function or appearance, but not in origin or development. a·nal·o·gous adj. to looking at a picture in low resolution, says Catherine Fox Maule of the Center for Planetary Science planetary science or planetology, study of planets and planetary systems as a whole. Planetary science applies the theories and methods of traditional disciplines such as astronomy, geology, physics, chemistry, and mathematics to the study of in Copenhagen. Small variations in the field due to local anomalies in the crust disappear, leaving only regional variations, which scientists can interpret as differences in heat flow through the crust. --S. Perkins |
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion