On 22.00 on Monday 4 August 2014, Ryoji Ikeda turned-on an installation of a vertical light at Westminster,  entitled Spectra, to commemorate the centenary of the entry of Britain into World War I.   The light can be seen from many places elsewhere in central London, appearing to curve over the viewer and ending in a burst of brightness.  The effect is ominous and hauntingly beautiful, particularly in the early hours of the morning when alone on the streets.