Killer asteroids. Climate change. Exploding stars. These are terrifying scenarios that threaten life on Earth. But they are also opportunities.
For the first time in history, we have the means to protect our home planet. We can turn these terrifying scenarios into opportunities by using space to discover new threats, develop new methods, and begin colonies to ensure the survival of humanity. We have the technology, brilliant scientists, and brave astronauts. Now we need additional funding for this exploration, research, and development.
A vortex ring, also called a toroidal vortex, is a torus shaped vortex in a fluid; that is, a region where the fluid mostly spins around an imaginary axis line that forms a closed loop. The dominant flow in a vortex ring is said to be toroidal, more precisely poloidal.
Vortex rings are plentiful in turbulent flows of liquids and gases, but are rarely noticed unless the motion of the fluid is revealed by suspended particles—as in the smoke rings which are often produced intentionally or accidentally by smokers. Fiery vortex rings are also a commonly produced trick by fire eaters. Visible vortex rings can also formed by the firing of certain artillery, in mushroom clouds, and in microbursts.
A vortex ring usually tends to move in a direction that is perpendicular to the plane of the ring and such that the inner edge of the ring moves faster forward than the outer edge. Within a stationary body of fluid, a vortex ring can travel for relatively long distance, carrying the spinning fluid with it.