Magnetism is a class of physical phenomena that includes forces exerted by magnets on other magnets. It has its origin in electric currents and the fundamental magnetic moments of elementary particles. These give rise to a magnetic field that acts on other currents and moments. All materials are influenced to some extent by a magnetic field. The strongest effect is on permanent magnets, which have persistent magnetic moments caused by ferromagnetism. Most materials do not have permanent moments. Some are attracted to a magnetic field (paramagnetism); others are repulsed by a magnetic field (diamagnetism); others have a much more complex relationship with an applied magnetic field (spin glass behavior and antiferromagnetism). Substances that are negligibly affected by magnetic fields are known as non-magnetic substances. They include copper, aluminium, gases, and plastic. Pure oxygen exhibits magnetic properties when cooled to a liquid state.
It saddens me to see NASA having to come out again and explain why the whole ‘Mayan end of the calendar apocalypse’ thing; the US space agency came out with on Saturday in an attempt to debunk these claims and downplay concerns that the world will end in 2012. Mr Don Yeomans from NASA explains [...]
Ever since researchers started studying the Earth’s spin, they noticed that the spin isn’t perfect. Many believe this is a result of the different elements in the Earth’s core, mantle and crust, which have different densities and generate different friction. Most researchers studying this wobble agreed that the mantle would have to respond to the [...]
Graphene is probably the ‘substance of the century’, and it will probably be for us what plastics were in the 1900s. Now, a flower-like defect in the material that can occur during the fabrication process could have a significant effect on graphene’s already impressive mechanical, magnetic, and electrical properties. Amazing graphene Graphene is practically a [...]
I was telling you a while ago about the revolutionary material called graphene. Graphene is a one atom thick layer of carbon packed in a honeycomb lattice. Now, a team led by Professor Andre Geim, recipient of the Nobel Prize for graphene, showed that electric current (which is basically a flow of electrons) can magnetise [...]
Yellowstone is without a doubt one of the most fascinating places on the face of the planet. But it doesn’t only attract families or people who want to relax, but it attracts scientists as well, and among them, geologists and geophysicists hold a top spot. University of Utah researchers made the first large-scale picture of [...]
A huge plasma eruption that took place on the Sun has caused a “solar tsunami” of ionized atoms that are on a course for our planet on Tuesday night. Nothing to be too alarmed here, except for the disruption of some satellites. It will however generate quite a show, a rare and unpredictable one too. [...]
The US-Japan Sukazu observatory reported the finding of some never-before seen embers from the high temperature fireballs that immediately follower the supernovae explosions. Even after thousands of years in which they haven’t been exposed to any heat source, gas within these stellar wrecks is 10.000 hotter than the Sun’s surface. “This is the first evidence [...]