In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid is in a turbulent flow regime. The moving fluid creates a space devoid of downstream-flowing fluid on the downstream side of the object. Fluid behind the obstacle flows into the void creating a swirl of fluid on each edge of the obstacle, followed by a short reverse flow of fluid behind the obstacle flowing upstream, toward the back of the obstacle. This phenomenon is naturally observed behind la
Opened on January 15, 1975, Space Mountain is the oldest operating roller coaster in the state of Florida, and is the original version of the iconic attraction that has since been replicated at all of The Walt Disney Company's Magic Kingdom-style theme parks worldwide, except for the Shanghai Disneyland Resort.
NASA had started working on Hubble, the first telescope in the Great Observatories program, in 1977. It was originally supposed to be launched in 1985. But then the space shuttle Challenger exploded in 1986, and flights came to a halt while NASA tried to figure out how to safely resume them.