Scientists at the U.S. Army Research Laboratory were enlisted in the $12 million restoration of Alexander Calder's giant sculpture Mountains and Clouds.

The work, which sits in the Hart Senate Office Building in Washington D.C., includes a set of 51-foot steel triangular mountains and originally had black aluminum clouds floating above it but they were taken down after an earthquake in 2011.

New carbon-fiber clouds, paid for by collectors Kim and Jon Shirley, have replaced them and are the same shade of the artist's now-discontinued Calder Black paint after Maryland senator Angela Alsobrooks asked the scientists to recreate it.

But despite all that, Calder's grandson Sandy Rower said the work will not be fully authentic until a new motor is installed in November and the clouds move as originally intended.

He told the New York Times: "In order for it to be a Calder, the clouds have to be there and they have to move."

Yoko Ono's slice of Apple Corps' profits last year as renewed interest in The Beatles boosted the business.

The painting that inspired a teenage Lars von Trier is at the heart of a new exhibition curated by the now-70-year-old film director.

Von Trier was 19 when he travelled to Stockholm just to see Vilhelm Hammershoi’s 1901 work Five Portraits at the Thiel Gallery.

It is one of several works including pieces by Caspar David Friedrich, Paul Gauguin and Edvard Munch - as well as one of his own paintings - that he describes as the artistic "family" that influenced his career.

The exhibition opens on October 10 and runs to January 24.

Amsterdam's Rijksmuseum and the Prado in Madrid are teaming up for a research project on women in art.

The Dutch museum will also host a 2029 exhibition on female leaders in the Netherlands in the 16th century with works loaned from Spain.

Both museums previously pledged to increase the number of works by female artists in their permanent collections with the Rijksmuseum acquiring pieces by Gesina ter Borch, Maria van Oosterwijck and Marlow Moss among others.

1 - Joost van der Hoeven has been appointed head of the new research department at the Van Gogh Museum in Amsterdam. He joined the museum in 2015 and has worked as an assistant curator and helped develop its online catalog of work by the painters' contemporaries.

2 - Works by Francis Bacon, Somaya Critchlow, Judy Chicago and Marina Abramovic are on show in a new exhibition about falling in and out of love. Ecstasy and the Aftermath, curated by Huma Kabakci, opens in November at the Sainsbury Centre in Norwich, southern England.

3 - Chinese ceramics feature alongside art from the Himalayas, India and Japan in a sale at Christie's in London on November 6. The Fine Asian Art sale follows a public view from October 31 to November 5.

4 - Julie Mehretu’s 17-foot-long print Epigraph, Damascus goes on show at the Saint Louis Art Museum in a free exhibition from November 6. The Ethiopian-born artist worked with a print studio in Copenhagen to make the work which was acquired by the Missouri museum in 2017.