Some of the extras were actually living and working for months in the decoration of Institute of Physical Problems of Science Academy of USSR, using clothes and things designed to look like 1940's things, or really from that time period, including even cigarettes, matches, money and food. There were even real laboratories where real experiments were done by real scientists.
The movie was originally planned to premiere on the Cannes Film Festival in 2010, but the filming process was much longer than expected.
700 hours of footage in 35 mm, 3000 interview videos, and 28 TB of audio.
For this film the biggest studio decoration was built (depicting Institute of Physical Problems of Science Academy of USSR) on the site of the ex-swimming pool of Dynamo Sports Complex in Kharkiv, Ukraine. With an area of 6 km² (approx. 2 square miles), this location had its own rules - for example no one (not even the crew) could be there if they weren't dressed in 1940's costumes. Modern instruments were usually hidden somewhere, too.
It is the biggest film set in Europe, spanning 12,000 sq meters.