The Bicycle Gear Inches calculator computes "gear inches" for your bike from the gear ratio and the tire diameter. 

The Biking Force, Power and Calorie Estimator calculates the approximate forces acting on a bike at a given speed, using various different inputs, and uses these to calculate the power output required from the rider, and an approximate estimate of the calories burned per hour and per mile.  It is very similar to the Energy Consumption During Cycling online calculator, although this one is less sophisticated: both use the same physics to model the problem.  There are three natural forces acting on a bicycle in motion, which are used to calculate the total force and the power: I assume that they are exactly balanced by the propulsive force supplied through the drivetrain by the rider that moves the bike forward.  The forces are: Gravity "drag": the weight experienced pulling a bike either backwards or forwards, due to the grade; Friction: due to the weight of the bike and rider, and the rolling friction coefficient; and Drag: the force due to wind and the motion of the bike through the air. 

The Konecny space station concept envisions a pair of tethered space stations at different orbital distances from the center of the Earth.  Because of the tether, the lower station orbits more slowly ...

This set of algorithms is for people interested in "designing" planets for science fiction settings, or who are simply interested in the science behind the search for exoplanets and extraterrestrial l...