Charles Hope and the Luminous Top

Why don't heavier objects fall faster?

The constant acceleration of all objects can be deduced logically.

Consider a stone that falls with a given acceleration.  If heavier objects fell faster than lighter objects, a stone with twice the weight would have to fall with a greater acceleration.  We could construct a double-weight stone by tying two stones together side-by-side and dropping them at once, but it would be equivalent to simply dropping them side by side.  Equally, if the configuration were dropped horizontally, with one stone leading the other, this would only fall faster than a single stone if the leading stone accelerated faster than the trailing stone, but that would contradict the assumption that the two stones are both the same weight.

Why does falling feel like weightlessness?

It's not obvious that one should feel weightless when falling. 

Gravity affects all parts of our body equally.  When we are at rest, this downward force is balanced by an equal and opposite force in resistance, delivered by the ground.  The sensation of weight is the compression between these two forces.

In the absence of gravity, or in freefall, the force of gravity is not opposed by any reaction force, and so we do not feel any compression.

System Equivalents and Computers

There's an equivalence between quantities in mechanics and electrical circuits. Given the similarity between F = −kx = C dx/dt = M d²x/dt² and V = Q/C = R dQ/dt = L d²Q/dt², we can say that Force : Voltage, Springiness : Capacitance, Mass: Inductance, and Damping: Resistance.

Is there any equivalent to the quantities we care about when designing software, such as CPU operations, memory, network bandwidth, and disk speed?