The scientists measured the temperature of the rails at 1 degrees, and the length of the rails varied by 1.8 microns per metre. If there is no gap in the rail connection, the rail will be extruded, twisted and arched, so that the whole railway will be deformed.
A zigzag railway is joined by a rail of the same length. Where the rails are joined, there is always a gap for the expansion and elongation of the rail.
