The strength of the Earth's magnetic field is about 30 microtesla. The magnets in an MRI machine clock in at about 3 tesla, and the approximate magnetic field of a white dwarf star is about 100 tesla.
So just think about how powerful this 1,200-tesla magnet created by Shojiro Takeyama and his colleagues at the Institute for Solid State Physics at the University of Tokyo.
To achieve that intensity, Takeyama and his team pump megajoules of energy into a small, precisely engineered electromagnetic coil, the inner lining of which then collapses on itself at Mach 15 — that's more than 3 miles per second (5 kilometers per second). As it collapses, the magnetic field inside gets squeezed into a tighter and tighter space, until its force peaks at a tesla reading unimaginable in conventional magnets. Fragments of a second later, the coil collapses entirely, destroying itself.
The last time Takeyama switched on his super-strong magnet, it blew out the heavy door of the lab that contained the machinery!