Allow me to retell, to the best of my ability, an old joke from the comedian Steven Wright:

"I went to a store late at night, and they were closed. Surprisingly, I saw in the window a sign that read 'Open 24 Hours.' The next day I went back, and they were open. I told the owner I stopped by the previous night and they were closed. I then asked why he had the 'Open 24 Hours' sign posted when they were closed. He replied, 'Yes, we are open twenty-four hours, but not in a row!'"

• According to the television program "Book of Secrets," an Arab inventor named Ibn Khalaf al-Muradi developed an elevator in 1000 AD to raise a battering ram for the purpose of destroying a fortress. This makes it one of the oldest elevator concepts created.