Steve : If you want to know why they’re tiny magnets, well, you may as well ask, why are particles charged in the first place? Or why do objects with mass & energy attract each other gravitationally? No one knows. We just know that’s the way the universe works.
Robert : Exactly. & since the 1920s, we’ve known that each individual electron or a proton is basically a tiny magnet, which brings us to the level of atoms. An atom is a bunch of positively charged protons with a bunch of negatively charged electrons whizzing around them. The proton tiny magnets are about 1,000 times weaker than the electron ones, so the nucleus of the atom has almost no effect on the magnetism of the atom as a whole.
Steve : & you might think that since many, though not all, of the electrons are also moving that, like the current in a wire, they should generate magnetic fields due to that motion. & indeed they do. These are called orbital magnetic fields.cylinder magnets
disc magnet modeling on how density, temperature, and pressure interact inside warheads. HELEN can create plasmas of around 106 K, from which opacity and transmission of radiation are measured.
gold plated magnets Neodymium glass solid-state lasers are used in extremely high power (terawatt scale), high energy (megajoules) multiple beam systems for inertial confinement fusion. Nd:glass lasers are usually frequency tripled to the third harmonic at 351 nm in laser fusion devices.
magnetic balls When magnet fishing its not just a case of using any old magnet, you’re going to want to use a magnet that works well in the water, one that doesn’t break straight away and one that is powerful enough to attract what lies beneath to it. It also needs to be powerful enough to keep it attached while reeling in the rope.
magnetic cube Neodymium magnets appear in products such as microphones, professional loudspeakers, in-ear headphones, guitar and bass guitar pick-ups, and computer hard disks where low mass, small volume, or strong magnetic fields are required. Neodymium
magnetic jewelry modeling on how density, temperature, and pressure interact inside warheads. HELEN can create plasmas of around 106 K, from which opacity and transmission of radiation are measured.
neodymium cylinder modeling on how density, temperature, and pressure interact inside warheads. HELEN can create plasmas of around 106 K, from which opacity and transmission of radiation are measured.
neodymium cylinder magnets Some people may suggest a ferrite magnet, and while these cost a lot less they are far more brittle and will not last you as long. Many people who I have spoken to, that have tried ferrite, said the magnet smashed or lost power straight away.
Robert : Except these don’t usually contribute to the magnetic field of an atom. Here’s why. Electrons in atoms are accurately & complicatedly described by quantum mechanics, but the gist of the story is that electrons congregate in shells around the nucleus. The electrons in all filled shell zoom equally in all directions, so the currents they generate cancel out & generate no magnetic field.
These electrons also come in pairs whose tiny magnets point in opposite directions & also cancel. However, in a half-filled shell, all of the electrons are unpaired & their tiny magnets point in the same direction & add up, meaning that it’s the intrinsic magnetism of the electrons in the outer shell that gives an atom the majority of its magnetic field. So atoms near the side of all of the major blocks of the periodic table, which have full or nearly full outer electron shells, aren’t magnetic. & atoms in the middle of the blocks have half-full outer electron shells & are magnetic. For example, nickel, cobalt, iron, manganese, chromium, et cetera.
Steve : Wait, but chromium isn’t magnetic.
Robert : Ah, but just because an atom is magnetic doesn’t mean that a material made up of lots of that atom will be magnetic, which brings us to the level of crystals. When a bunch of magnetic atoms get together to make a solid, they generally have two options. One is for all the atoms to align their magnetic fields with each other, or they can align their magnetic fields in an alternating fashion so they all cancel out. The atoms will do whichever one requires less energy.