Subduction Zone

Update. The Blackbird, the vehicle that went directly downwind faster than the wind, has been reconfigured. The propeller was replaced with a rotor that works better as a turbine, the gearing has been changed too so that now the turbine drives the wheels instead of the wheels driving a propeller. It has been turned from a downwind cart to an upwind cart. This last weekend they ran it directly into the wind at a speed nearly twice the speed of the wind. You can read more here: Directly upwind blog.

The vehicle in the video has no problem sailing directly downwind faster than the wind. This has been debated on the internet for years and is one of my favorites. I was a naysayer at first as well, but I found every preconceived notion I had of aerodynamics and sailing seemed to have been wrong. One of the major claims is that if this device goes faster than the wind that would constitute perpetual motion. I can assure you that it does not break any laws of thermodynamics. The cart gets its energy by lowering the speed of the wind relative to the ground. After the air passes through the rotator disc of the propeller its velocity is slower than it was before. Where did that energy go? Into driving the cart of course. There are also videos of small carts running on treadmills. For anyone who is familiar with the relatively simple concept of a Galilean Transformation it is obvious that if the cart can advance up the treadmill it can go faster than the wind. I am nowhere near as expert as the builders of this cart, but I will try to answer any questions about it.

Definitely a geode. If you do take it to a New Age shop don't listen to any of their advice as to properties. But they may actually know what it is. Geodes are commonly found in hollows in limestone or volcanic ash beds. The green coloration of the outside, and darker color, makes me lean to the opinion that this one was from a bed of volcanic ash. It would be richer in metals such as copper than limestone would be.

From what I remember, over 30 years ago, when the Earth was first formed it was fairly hot. It was formed by accretion of material from space. At first it was a fairly homogeneous mixture. This material started out fairly hot from changing gravitational potential energy to heat. It was also more radioactive than current day Earth, it was 4.5 billion years younger after all, This heat built up faster than it could radiate out to space and was enough to melt the iron, nickel, and some other denser materials in the Earth. This migrated to the core, releasing even more heat in the process. That was roughly the theory then, I don't think it has changed much since then.