Yesterday I went to say the latest installation in the Grand Palais. Personnes, by Christian Boltanski; in essence a study in negative space. Thousands of garments (strewn into regular squares on the floor and in a large pyramid) testify to their absent owners. The cavernous hall dwarfs these, but numerous recordings of heartbeats complete the piece by filling the space. Worth a visit, good for some inspired wool-gathering, but not especially challenging.
