Transits of Mercury are relatively rare. Monday's leisurely 7.5 hour long event was only the 2nd of 14 Mercury transits in the 21st century. If you're willing to travel, transits of the International Space Station can be more frequent though, and much quicker.
This image shows the ISS, moving from upper right to lower left, as it crossed the Sun's disk in 0.6 seconds. Mercury too is included as the small, round, almost stationary silhouette just below center. In apparent size, the International Space Station looms larger from low Earth orbit, about 450 kilometers from Philadelphia. Mercury was about 84 million kilometers away.
Watch:http://www.astrophoto.fr/mercury-transit-2016.html
Image & Info via APODhttp://apod.nasa.gov/apod/astropix.html
Image Credit & Copyright: Thierry Legault
You may have noticed when baking that fluids don’t always behave as expected when you agitate them. If you put a spinning rod into a fluid, we’d expect the rod to fling fluid away, creating a little vortex that stirs everything around. And for a typical Newtonian fluid, this is what we see. The fluid’s viscosity tries to resist deforming the fluid, but the momentum imparted by the rod wins out.
With a viscoelastic fluid, on the other hand, the story is much different. As before, the spinning of the rod deforms the fluid. But the viscoelastic fluid contains long chains of polymers. As those polymers get stretched by the deformation, they generate their own forces, including forces parallel to the rod. Instead of being flung outward, the viscoelastic fluid starts climbing up the rod, with the stretchy elasticity of the polymers helping pull more fluid up and up.
Video source:https://www.youtube.com/watch?v=P8hFf7e4sa4
References:http://wwwhome.lorentz.leidenuniv.nl/~saarloos/Papers/rodclimbing.pdf
http://www.rheosense.com/applications/viscosity/newtonian-non-newtonian
Experiment:http://web.mit.edu/nnf/research/phenomena/rodclimbing.html
