> did the National Gallery actually close after these incidents, when just one painting was attacked Don't know. Wasn't there. The museums work like a compute

> did the National Gallery actually close after these incidents, when just one painting was attacked Don't know. Wasn't there. The museums work like a computer memory pile. There is an endless stream of people walking in. To keep the system running the same amount must walk out. To keep the system efficient, the flux must have a direction and only one. The tourists must walk the pile until finding the other extreme and walk out. The same door shouldn't be used to enter and exit. If a museum is famous for a particular painting, it is assured that the stream of visitors will be directed towards that room, so nobody miss it. It will be placed most probably on a noble room with a door for entering and another in the opposite side to continue the visit. If this area is blocked, suddenly the incoming flux of people can't go out. The museum needs to find an alternative route ASAP to release that flux pressure before the people start being crushed. Most modern places will have planned that possibility, but architectures don't allow a secondary route everywhere. What I mean is that, as long as the visit is arranged in the traditional way, to close a big museum just by the attack to a single painting is not impossible at all.