Quick Lesson In Physics

Which of these two methods of conveyance on the left will be      rendered inoperable under the given circumstances?

Any child knows the answer is the garden hose. Why then do we draw comparisons between fluids and electricity? They're bad analogies.

While the tire is on top of the water hose no fluid will pass the point where the weight of the truck is pinching the hose closed, obviously.

Will the weight of the tire impede the flow of electricity through the extension cord? No it won't, obviously.

Liquid, water in this case will flow through the hose from point a to point b in a single direction.

Electrical current can only flow in a circuit, so it will move in both directions, away from and back to the source. It is not impeded by gravity, it will travel up and down at the same rate.

Mars is grey

In this true color photo from the Mars rover curiosity we see the tailings from two freshly drilled holes on the surface of Mars.

It is clear from the photo that the material beneath the Martian surface is not red, it is greyish.

This clearly demonstrates that the surface of Mars is covered in red dust.

These two holes are about 5/8" diameter.




credit NASA