MRI body scanners use a large coil of niobium-titanium wire cooled down to superconducting temperatures with liquid helium (-269°C). A huge current in the coil produces an electromagnet with a field strength of around 3 Tesla.
The first video is a superb demonstration of Lenz's law. The aluminium block is first toppled in the Earth's magnetic field (about 40 microtesla). It falls normally. Then it is toppled in the intense magnetic field of the scanner. As the metal moves through the field a current is induced within it, which in turn produces a magnetic field opposing that of the scanner. The fall is dramatically slowed due to this eddy current braking.
Lightning is an absolutely fascinating natural phenomenon, the second video shows the slow motion formation of negative stepped leaders.
Coal Dust Explosions have been the cause of many mine disasters. Typically, a pocket of methane gas in a mine tunnel gets accidentally ignited, the resultant conflagration stirs up coal dust, which then in turn ignites. A coal dust fireball can be seen in the open air in the third video, when the blasting at an open cast pit throws up and accidentally ignites the pulverised coal. As can be imagined, this happening inside a mine would be catastrophic.
X-Rays are explained in the next video by William D. Coolidge, the inventor of high vacuum hot cathode X-ray tubes. Note that the initial drama section is completely naff, with Röntgen shown as the bemused owner of a retort, and a half-wit being X-rayed by totally inadequate equipment (the Wimshurst machine shown being far too small to drive a cold cathode tube).
The following film is of a particularly gruesome and disturbing nature. It concerns Soviet experimentation upon dogs, circa 1940. A poor animal is kept alive after having it's body amputated, another is resuscitated after being dead for 10 mins. One can only hope that the unfortunate canines involved helped the development of present day life-saving heart/lung machines. Narrated by Professor J.B.S. Haldane.
Haldane wasn't squeamish about animal experimentation, nor of experimentation upon himself; he suffered crushed vertebrae during an oxygen-enrichment induced fit, and also perforated eardrums in his decompression chamber, quote:- "The drum generally heals up; and if a hole remains in it, although one is somewhat deaf, one can blow tobacco smoke out of the ear in question, which is a social accomplishment."Bullets in ultra slow motion. Some of the projectiles are traveling at around mach 2, the million frame per second camera allows us to see the axial rotation imparted by the barrel rifling and the fluid like behavior of the metal upon impact.
Accelerating from shit at over 180000g. These spores explode from the herbivore-crap based fungi using osmotic pressure. Filmed at 250000 frames per second, they can reach 25 ms-1 and travel up to 2.5 meters from the turd.
Volcanic eruptions 1959 & 1960. Excellent footage of spectacular Hawaiian fire fountains and lava flows.
Mining for uranium, an open university presentation from the '70s.
Glacial time. Astonishing time-lapse footage from the bottom of a river of ice near Mt. Blanc.
Lichtenberg figures in acrylic. This video shows the manufacturing process using 5 MeV electrons produced by a linear accelerator.
Meteors. Shooting stars are produced by lumps of interplanetary matter which enter the Earth's atmosphere at high speed and cause the air to become incandescent. The intrinsic velocity of the meteor can be up to 26 miles per second. The Earth's velocity through space is 18 miles per second, so some meteors can enter the atmosphere at 44 miles per second. They become visible at altitudes of 40 to 75 miles.