  A new model for space and matter is obtained by joining every pair of point
charges in the observable universe by an ethereal string. Positive
gravitational potential energy in each string gives an attractive gravitational
force due to the action of an energy conservation constraint. Newton's laws of
motion are derived and inertia is explained in accordance with Mach's
principle. The Machian string model gives a surprisingly simple way to
understand the expansion history of the Universe. The decelerating expansion in
the radiation era and the matter era is explained without using General
Relativity and the transition from deceleration to acceleration is explained
without the need to introduce a separate 'dark energy' component. The
interaction between Machian strings gives a physical model for modified
Newtonian dynamics (MOND) and is therefore an alternative to 'dark matter'.
