Nice article, but I couldn&#x27;t pass up a chance to correct Elon Musk&#x27;s math:<p><i>It is important to note that the amount of energy needed to achieve a given velocity increases with the square, so going from 1000 km&#x2F;h to 2000 km&#x2F;h takes four times as much energy as going from 0 km&#x2F;h to 1000 km&#x2F;h, not twice as much.</i><p>Three times, not four--you already spent a quarter of the energy getting to 1000 km&#x2F;h.  Getting the rest of the way to 2000 km&#x2F;h takes the remaining three quarters.