Gav and Dan, The Slow Mo Guys, are interested in visualizing how a liquid on fire spreads on a flat surface. To achieve this, they set a bucket of gasoline on fire, throw the lit gas at a glass windowpane, and film it in slow motion from the other side. You can see the results in the video below!
The law of conservation of energy states that energy cannot be lost or gained but just converted from one form to another. For example, when a pendulum is elevated to a certain height it acquires a potential energy. When the pendulum is released that potential energy is converted to kinetic energy in the downswing and back into potential energy in the upswing. However, unless a source of energy is introduced into the system such as, for example, giving the pendulum a push, the pendulum will not reach a higher elevation than the one from which it was originally released. In the video below, uploaded into You Tube by Johnny Rico, Professor Walter Lewin from the Massachusetts Institute of Technology (MIT) puts his life on the line to illustrate this principle.
Ferrofluids were invented in the 1960s by a NASA engineer. These fluids are made up of very small particles of a magnetic material such as iron oxide mixed with a coating agent that keeps the particles from clumping mixed in a watery or oily liquid. Their distinguishing property is that ferrofluids can be moved by magnets and the fluid aligns itself with the magnetic field forming spikes.
In the video below, Dianna Cowern from the YouTube channel Physics Girl, sets out to take slow motion pictures of drops of ferrofluids splashing on a strong magnet just for the fun of it, and ends up modeling the tidal forces that produce epic black hole death due to spaghettification!
Ferrofluids have been employed by artists to create amazing sculptures, but they are also used in many technological applications such as in rotating shaft motors like computer hard drives to form seals, in loudspeakers to remove heat and dampen vibrations, and as contrast agents in magnetic nuclear imaging. Many other potential applications of ferrofluids are being researched.
In 1993 the astronomers Carolyn and Gene Shoemaker and David Levy discovered the fragments of a comet. The comet, thereafter christened comet Shoemaker-Levy 9, had been torn apart by Jupiter’s gravitational field, and it was calculated that its approximately 21 fragments, the largest of which was half a mile wide, were headed on a collision course with the planet.
In the year 1994, between July 16 and July 22, astronomers pointed every available piece of technology at Jupiter and recorded in awe as multiple titanic explosions, each with the force of hundreds of times the nuclear arsenal of the world, generated colossal fireballs and plumes of smoke that rose nearly two thousand miles over the Jovian clouds and heated the atmosphere to temperatures of tens of thousands of degrees Fahrenheit. The explosions left dark spots on the surface of the planet the size of the Earth which would fade away over several months and provide astronomers with important information about the nature of Jupiter’s atmosphere. The event and its aftermath are described in the video below.
This event and other considerations led to the creation of the Planetary Defense Coordination Office which has as a goal to identify and track potentially hazardous objects that may come close to Earth’s orbit.