an Almost perpetual motion machine.
Perpetual motion is motion that continues indefinitely without any external source of energy. meaning a system in perpetual motion will never stop going, so efficiency is 100% or more - meaning either no energy is ever lost in the system or a surplus “free” energy is generated.
this is theoretically impossible as it violates the first law of thermodynamics (that is the law of conservation of energy that states that energy can neither be created nor destroyed). however, the above set up is one of the closest ever gotten to perpetual energy with an efficiency of 80-99%, an internal combustion engine in a car has around 30% for comparison.
at up to 99%, the rolling ball can continue rolling for years on its own, but will at some point stop. only at 100% efficiency is it perpetual which is not theoretically possible.
Ruby with sapphire core
There are two basic kinds of corundum, basaltic and metamorphic, with the most beautiful stones coming from marble hosted deposits in the Himalayas and its fringes. Localities such as Jegdalek in Afghanistan, Nepal, Mogok and Mong Hsu in Burma and Luc Yen in Vietnam all result from the metamorphosis of Tethyan limestone that were pushed up into mountains and transformed by the pressures accompanying India’s slow motion ongoing collision with Eurasia.
As gems grow, they tend to do so in fits and starts, depositing new layers on pre-existing seed crystals as and when the conditions are appropriate. In this case it involves the concentration of aluminium from the changing limestone, along with minor trace amounts of the impurities that colour corundum. However conditions may change during one of the pauses in crystal growth, and it is not uncommon to find crystals such as this one from Gamesh Himal in Nepal (2.3 x 1.1 x 1.0 cm), where a blue/purple sapphire core has been overgrown by a later generation of ruby.
Blue sapphire is coloured by a complex electronic interchange between iron and titanium in the crystal structure, while ruby gains its fiery hues from chromium. The type of impurity present in the parent medium changed between the two generations of corundum, creating this unusual visual effect. Such stones are commonly heat treated to remove the blue component, particularly the production from Mong Hsu where nearly all the stones exhibit this phenomenon. I also own a sample like this that I bought in Luc Yen in Vietnam some years ago.
Image credit: Joe Budd/Rob Lavinsky/iRocks.com